Food Science and Technology International recent issues

Review. Freeze Concentration in the Fruit Juices Industry

Sanchez, J., Ruiz, Y., Auleda, J.M., Hernandez, E., Raventos, M. — Wed, 04 Nov 2009 09:16:38 PST

In conventional processes, such as evaporation, higher levels of concentration can be reached compared with freeze concentration or membrane techniques. However, the advantage of the freeze concentration technique is based on the quality of the product obtained due to the low temperatures used in the process, which makes it a very suitable technology for the processing of fruit juices. There are two basic methods for concentrating solutions by freezing: suspension and film freeze concentration. Suspension freeze concentration systems (FCS) already have operating equipment in the food industry, while film FCSs, also called layer crystallization, is still at an experimental stage. This review summarizes the most important studies relating to the suspension and film freeze concentration in fruit juices and sugar solutions, illustrating the different possibilities that freeze concentration has in the fruit juices industry; it also presents trends and suggests improvements for the future development of this technology. It is noted that most recent publications refer to the film FCS. The technology used to design, build and maintain layer crystallization equipment is simple and it can be available to any operator in the food industry, layer systems will be used in the future if their results can be improved in terms of ice purity and degree of fluid concentration.

Inulin Addition in Starch-based Dairy Desserts: Instrumental Texture and Sensory Aspects

Lobato, L.P., Grossmann, M.V.E., Benassi, M.T. — Wed, 04 Nov 2009 09:16:38 PST

Interactions between ingredients have a wide application in the food industry. The objective of this work was to investigate the combined effect of milk, starch, and inulin on textural properties (firmness, gumminess, cohesiveness, and adhesiveness), syneresis, and sensory characteristics of pudding (by free-choice profile (FCP) and acceptability test), applying the experimental design for mixtures. Milk and starch were significant for all the studied texture parameters. Milk, inulin, and the interaction of the inulin with starch were significant for syneresis. It was possible to formulate pudding with the maximum inulin concentration (3.9%) with good textural characteristics. The judges were capable of distinguishing attribute differences and similarities, mainly in relation to texture, by applying the FCP. In the acceptance test, the judges concluded that there are no differences (p < 0.05) among the tested formulations. The different proportions among ingredients in the system can affect the characteristics of the final product. Inulin inclusion in pudding, as a functional ingredient, was successful.

Effect of Raisin Juice Addition on Bread Produced from Different Wheat Cultivars

Sabanis, D., Soukoulis, C., Tzia, C. — Wed, 04 Nov 2009 09:16:38 PST

Concentrated and two types of dried raisin juice were added to bread and durum wheat flour dough at 50% level of sucrose substitution to prepare different bread samples. Baking (specific volume, color, crumb moisture, sensory evaluation), textural properties, and dough rheological properties were determined in breads. Results suggested that Greek durum wheat flour was appropriate for breadmaking and contributed to the baking, sensory, and textural properties of the final product. Addition of concentrated raisin juice in dough products both as a sucrose substitute and natural colorant gave breads with a higher loaf volume, fruity flavor, and an appealing brown color. Breads containing dried raisin juice were sensory rated lower than those with sucrose, however, they improved loaf volume and increased preservation time. This study also examined statistically the relationship between sensory responses and instrumental measurements, which is of major importance in the food industry for various applications.

Nutritional Effects of Mechanically Deboned Chicken Meat and Soybean Proteins Cross-linking by Microbial Transglutaminase

Wed, 04 Nov 2009 09:16:38 PST

This work studied the nutritional effects of protein cross-linking as mediated by microbial transglutaminase (TGase) using rats as biological models. Rats were divided into six groups that received diets containing casein (standard protein diet), cross-linked meat protein (CMP), meat protein (MP), cross-linked soy protein, or soy protein (SP) as the protein sources of their diets, which were compared against an aproteic diet (basal diet). The cross-linking process showed a significant (p < 0.05) impact on the true digestibility (TD) of meat and SPs, decreasing it for the first and increasing it for the second. As a consequence, the TD of modified SP became similar to that observed for CMP, although, the biological value, net protein utilization, net protein ratio, and protein retention efficiency values of meat and SPs were not affected in the process. These results suggest that the use of TGase for the reticulation of isolated SP can improve its nutritional quality.

The Effect of Cooking in a Steam-convection Oven and Storage in Vacuum on the Quality of Turkey Meat

Wed, 04 Nov 2009 09:16:38 PST

The effect of cooking on the quality of turkey meat heated by steam at different temperatures and saturation levels, and then vacuum stored at 3 °C for 28 days, was studied. The smallest cooking loss was observed in meat cooked at 220 °C and when the highest air steam saturation was applied. The rate of lipid oxidation as a result of cooking and storage was the lowest in sample cooked at 180 °C and in meat heated by 20% steam, and additionally during storage in sample treated with 0% steam. The higher cooking temperature was applied, the more intensive hydrolytic process took place in fat. Heating at 180 °C and in hot air with 0%, 70%, and 90% steam resulted in a more intensive hydrolytic process in meat during storage than other cooking parameters. The oxidation rate of -SH groups was higher in sample heated by 90% steam than the ones by 20%, 50%, and 70% steam. The use of steam saturation over 20% caused a decrease in mono-unsaturated fatty acids and an increase in saturated fatty acids content. Meat cooked at 220 °C and treated with 0% or 90% steam was characterized by better sensory attributes than other samples.

Effect of Sweeteners on Radical Formation in Starch Studied by Electron Paramagnetic Resonance Spectroscopy

Wed, 04 Nov 2009 09:16:38 PST

The process of radical generation occurring upon thermal treatment of potato and corn starch containing sweeteners: saccharose, acesulfam K, aspartame, and sorbitol was investigated by electron paramagnetic resonance spectroscopy, using Cu²⁺ ions as a paramagnetic probe. It was found that the influence of acesulfam K and sorbitol on radical formation is stronger than that of other additives. Acesulfam K increased the amount of radicals in the starch compared to native starch, whereas sorbitol significantly decreased their concentration. The influence of sweeteners on radical processes in the starch is because of differences in their molecular structures and presence or absence of OH groups.

Influence of Semicontinuous Processing on the Rheology and Droplet Size Distribution of Mayonnaise-like Emulsions

Bengoechea, C., Lopez, M.L., Cordobes, F., Guerrero, A. — Wed, 04 Nov 2009 09:16:38 PST

Oil-in-water (o/w) emulsions stabilized by egg yolk, with a composition similar to those found in commercial mayonnaises or salad dressings, were processed in a semicontinuous device. This specially designed emulsification device consists of, basically, a vessel provided with an anchor impeller, where the continuous phase was initially placed; a pumping system that controls the addition of the oily phase; a rotor-stator unit, where the major breaking of the oily droplets takes place, and a recirculation system. The design allowed the introduction of a rotational rheometer to obtain viscosity data along the emulsification process. The most important advantages of this in-line emulsification device, when compared to discontinuous emulsification equipment, are the possibilities of recording viscosity data along the process and the higher values for the storage, G', and loss moduli, G'', of the resulting emulsions. The influence of egg yolk concentration, agitation speed, and flow rate over the rheological properties (G', G'') as well as droplet size distribution were investigated. Higher protein concentration, agitation speed and flow rate generally produce emulsions with higher G' and G'' values.

Sensory Profile and Acceptability of Juices from Mandarin Varieties and Hybrids

Carbonell, L., Bayarri, S., Navarro, J.L., Carbonell, I., Izquierdo, L. — Wed, 04 Nov 2009 09:16:38 PST

Fresh juices from mandarin varieties, from hybrids, and from blends of these raw materials were evaluated by 100 consumers to determine acceptability, and by 10 trained panelists to quantify sensory attributes. Trained panelists found the juice from Clemenules richer in both mandarin and fresh flavor (odor and taste) whereas Nova juice presented minimum scores for these attributes. These aspects obviously affected the evaluation of acceptability by consumers, who preferred the juice from Clemenules (a Clementine variety) either alone or blended in major proportions with less preferred varieties such as Marisol, Hernandina (Clementines), Ortanique or Nova (hybrids). Nova juice was rejected by most consumers, but accepted by a small group of them. These results are of great importance for the European citrus industry since Clemenules is the most abundant variety and will constitute the main source of raw material for processing plants.

Chromatic Changes in Broccoli (Brassica oleracea italica) under Modified Atmospheres in Perforated Film Packages

Rai, D.R., Jha, S.N., Wanjari, O.D., Patil, R.T. — Wed, 04 Nov 2009 09:16:38 PST

Broccoli was stored under modified atmosphere packaging (MAP) at 20 °C in perforated and unsealed polypropylene film packages for a storage period of 10 days to evaluate the effect of modified atmospheres on the chromatic changes. At the end of storage, MAP resulted in differential changes in the original green color of broccoli under different packaging treatments. Instead of conventional CIELAB color space system utilizing only L*, a* and b* values, the chromatic changes were analyzed as per L*C*h* color space system using lightness, chroma, and hue angle values to evaluate the final hue (color) along with its associated attributes. On 10th day of storage, broccoli samples kept under different modified atmospheres were observed to be yellow-green only for 4 holes, but between yellow-green and yellow for 8, 12, and 16 hole treatments, respectively. Further, the saturation of final hue attained under different packaging treatments kept on increasing in the order of 4, 8, 12, and 16 holes. On the other hand, broccoli kept in air in unsealed packages turned orange-yellow with higher saturation as compared with MAP samples. The direction of color difference for different treatments with respect to fresh broccoli samples was observed as light and the degree of color difference indicated that 4 and 8 hole treatments were only slight and medium light, respectively. The 4 hole treatment had best color retention as it had slightly saturated yellow-green hue, which was only slightly lighter than the fresh broccoli. Also, the results of sensory and visual analysis confirmed the results obtained from L*C*h* color space diagram and indicated that the modified atmosphere (6.1% O₂ and 9% CO₂) generated inside the perforated film packages having 4 macro-holes was the most suitable in maintaining the chromatic quality of the broccoli heads.

Intermittent Microwave-convective Air Drying of Oregano

Soysal, Y., Arslan, M., Keskin, M. — Wed, 04 Nov 2009 09:16:38 PST

Effectiveness of intermittent microwave-convective air drying (IMWC) was investigated and compared to continuous microwave-convective air drying (CMWC) and convective air drying for oregano. Both CMWC and IMWC increased the drying rate of oregano compared to convective drying. The CMWC and IMWC were 12.7-14.0 and 4.7-11.2 times more energy efficient in drying than convective drying, respectively. The highest essential oil contents were obtained from convective drying at 40 °C and 45 °C. However, these treatments had the longest drying time and the highest energy consumption. The CMWC yielded the lowest essential oil content and resulted in an extreme change in the essential oil composition. The IMWC, except with the pulse ratio of 3.0, resulted in similar essential oil content compared to convective drying at 50 °C and shade drying. No identical result was found among the prevailing compounds of essential oil of oregano obtained from shade drying, convective drying and IMWC. Both CMWC and IMWC did not yield acceptable results of product color. However, in terms of essential oil content and quality, the IMWC at 25 °C room temperature with the pulse ratio of 5.0 was judged as the most suitable drying method for oregano due to its rational drying time and energy consumption compared to CMWC drying, convective air dying, and shade drying.

Microcapsules of a Casein Hydrolysate: Production, Characterization, and Application in Protein Bars

Rocha, G.A., Trindade, M.A., Netto, F.M., Favaro-Trindade, C.S. — Wed, 04 Nov 2009 09:16:38 PST

The aim of this work was to encapsulate a casein hydrolysate by spray drying using maltodextrins (DE 10 and 20) as wall materials and to evaluate the efficiency of the microencapsulation in attenuating the bitter taste of the hydrolysate using protein bars as the model system. Microcapsules were evaluated for morphology (SEM), particle size, hygroscopicity, solubility, thermal behavior (DSC), and bitter taste with a trained sensory panel by a paired comparison test (nonencapsulated samples vs. encapsulated samples). Bars were prepared with the addition of 3% casein hydrolysate at free or both encapsulated forms, and were then evaluated for their moisture, water activity (a_w) and for their bitter taste by a ranking test. Microcapsules were of the matrix type, having continuous surfaces with no apparent porosity for both coatings. Both encapsulated casein hydrolysates had similar hygroscopicity, and lower values than free encapsulated hydrolysates. The degree of hydrolysis of the maltodextrin influenced only the particle size and T_g. The sensory panel considered the protein bars produced with both encapsulated materials less bitter (p < 0.05) than those produced with the free casein hydrolysates. Microencapsulation by spray drying with maltodextrin DE 10 and 20 was successful to attenuate the bitter taste and the hygroscopicity of casein hydrolysates.

Antigenotoxic and Antioxidant Activities of Fruit Extracts from (Tunisian) Pistacia Lentiscus

Wed, 23 Sep 2009 02:20:26 PDT

Genotoxic and antigenotoxic activities against direct acting mutagen nifuroxazide, and indirect acting genotoxin aflatoxine B1 (AFB1) of extracts prepared from fruits of Pistacia lentiscus, were studied using the SOS chromotest with Escherichia coli PQ 37 as a tester organism. It was found that different extracts showed no genotoxicity when tested with E. coli PQ 37 strain either with or without microsomal extract. On the other hand, our results showed that ethyl acetate fraction and total oligomers flavonoids (TOF) extract obtained from P. lentiscus significantly decreased the genotoxicicity induced by AFB1 (10 µg/assay) and nifuroxazide (20 µg/assay). In addition to antigenotoxic activity, these extracts showed an important free radical scavenging activity towards the 2,2-diphenyl-2-picrylhydrazyl (DPPH) free radical and an important antioxidant activity using xanthine/xanthine oxidase system.

Nitric Oxide Reduced Chlorophyll Degradation in Broccoli (Brassica oleracea L. var. italica) Florets During Senescence

Hyang Lan Eum, , Dae Keun Hwang, , Seung Koo Lee, — Wed, 23 Sep 2009 02:20:26 PDT

Nitric oxide (NO) was applied to broccoli (Brassica oleracea L. var. italica) florets and analyzed its effect on chlorophyll degradation during postharvest senescence. Florets were treated with 1000 µL/L of NO for 5 h and placed in darkness at 20°C. During storage, the NO treatment delayed yellowing and retarded the onset of chlorophyll degradation. The activity of lipoxygenase was not related to the development of yellowing during storage. However, the accumulation of malondialdehyde, which could be used as an index of lipid peroxidation, was higher in the control than observed in the NO treatment. In untreated broccoli florets during storage, lipid peroxidation influenced the yellowing of broccoli florets while NO-treated florets maintained chlorophyll levels and decreased lipid peroxidation.

Effects of Chemical Dehulling of Sesame on Color and Microstructure

Wed, 23 Sep 2009 02:20:26 PDT

Sesame seeds must be dehulled before processing for the food industry because the husk provides undesirable darker color and bitter taste. Currently, sesame seeds are mechanically peeled but this procedure requires high volume of water, which is a scarce resource in most of the countries where sesame is consumed by humans. In this study, several chemicals have been used in order to facilitate the peeling process and reduce the water requirement. The feasibility of using chemicals was evaluated by studying the color (instrumental and sensory) and the microstructure of seeds. Addition of both NaClO and H₂O₂ before the mechanical dehulling of sesame seeds will be the recommended treatments for combining the dehulling and whitening steps of the sesame processing. This recommendation is supported by the high values of the L* and dehulling percentage and the low values of the color coordinates a* and b*. Besides, the scanning electron microscopy proved that the NaClO treatment was able to remove the hulls without causing damage to the cotyledons.

Simulation of Phenolic Compounds Transformations and Interactions in an In Vitro Model of the Human Alimentary Tract

Tarko, T., Duda-Chodak, A., Tuszynski, T. — Wed, 23 Sep 2009 02:20:26 PDT

Phenolic compounds play an important role in the defense system of the human organism against reactive oxygen species. They are present mainly in fruit and vegetables, but their bioavailability is the key factor determining their concentration in blood and tissues. The aim of this article was to study the transformations that apple polyphenols undergo during digestion. An in vitro model with dialysate membranes simulating the human alimentary tract was used for evaluating the composition and antioxidant properties of fresh apples and products of their digestion in dialysates. Epicatechin, chlorogenic acid, and procyanidins were the main antioxidant compounds in the whole fruits and flesh of the two varieties of apples analyzed. In the apple peel additionally quercetin glycosides were present. As a result of in vitro digestion both polyphenolic compounds concentration and the antioxidant activity of the dialysates increased as compared to the raw materials (from 35% to 95% and from 50% to 236%, respectively). In the simulated alimentary tract, it was proved that procyanidins disintegrate to (+)catechin, which is well absorbed from the small intestine, while chlorogenic acid and quercetin glycosides were characterized by a low bioavailability.

Oil Characteristics and Nutritional Composition of the Ridge Gourd (Luffa acutangula Roxb.) Seeds Grown in Bangladesh

Ali, M.A., Azad, M.A.K., Yeasmin, Mst. S., Khan, A.M., Sayeed, M. A. — Wed, 23 Sep 2009 02:20:26 PDT

The aim of the work was a comparative study of oil characteristics and nutritional composition of seeds of two local varieties of ridge gourd collected from different districts of Bangladesh: Prince ridge gourd (PRG) and Hercules ridge gourd (HRG). Most of the physicochemical characteristics reported herein, of the seed oils of both varieties were significantly (p < 0.05) affected by sampling locations. Acylglycerol classes were estimated to be monoacylglycerols (1.6-1.9% in PRG and 1.4-1.6% in HRG), diacylglycerols (4.0-4.6% in PRG and 2.6-3.0% in HRG) and triacylglycerols (84.6-86.7% in PRG and 86.7-88.3% in HRG) whereas lipid classes to be neutral lipids (92.5-94.2% in PRG and 91.7-94.9% in HRG), glycolipids (2.8-3.2% in PRG and 2.5-3.9% in HRG) and phospholipids (1.9-2.4% in PRG and 1.2-2.6% in HRG). Glyceride and lipid compositions of PRG seed oil did not show any significant difference (p < 0.05) between the two samples of Rajshahi and Dinajpur districts. HRG samples had similar values for diacylglycerol contents. GLC analysis showed the presence of only four fatty acids from series C_16:0 to C_18:2. Linoleic acid was the major ranging from 49.5% to 51.0% in PRG and 48.6% to 49.2% in HRG. Both varieties contained considerable amounts of lipid (26.8-28.2% in PRG and 23.2-25.4% in HRG), protein (20.8-23.1% in PRG and 25.9-26.8% in HRG) and other essential nutrients. Most of the nutrient contents in PRG samples differed significantly (p < 0.05) than those found in HRG samples. Nutrient information reported herein illustrates the benefits to public health for those, who consume this plant fruit.

Descriptive Sensory Analysis and Acceptance of Stingless Bee Honey

Ferreira, E.L., Lencioni, C., Benassi, M.T., Barth, M.O., Bastos, D.H.M. — Wed, 23 Sep 2009 02:20:26 PDT

Stingless bee honey samples were evaluated by sensory descriptive analysis using free choice profile methodology. Appearance, flavor, and aroma were described and the data were treated with Generalized Procrustes Analysis. Individual descriptive terms ranged from 8 to 20. Plotting the samples in a bidimensional plan indicated that appearance attributes (color and viscosity) and sweet, sour and acid flavor were strongly correlated with x axis (Dimension 1) while coconut, wood, acid, sour, and sweet flavor aroma attributes were correlated with y axis (Dimension 2). The affective test was also performed and with the exception of the Melipona scutellaris honey, all the other samples showed good acceptance. Honeys that were described as sweeter and less acid were preferred by nontrained assessors, indicating that the regular consumer recognizes honey produced by Apis mellifera bee as a standard.

Influence of Cultivar and Growth Stage on Pigments and Processing Factors on Betacyanins in Red Amaranth (Amaranthus tricolor L.)

Khandaker, L., Ali, Md. B., Oba, S. — Wed, 23 Sep 2009 02:20:26 PDT

Seven cultivars of red amaranth (Amaranthus tricolor L.) with different leaf color were evaluated for their betacyanin and chlorophyll content at two stages of development. The effects of food processing factors such as thermal treatment, light, H₂O₂, and prolonged storage on betacyanin extracts were also examined. Betacyanin concentrations were highly correlated with the leaf color index and the cultivars (Rocto joba, BARI-1, and Altopati) with better color index tended to be associated with high betacyanin. Within a shoot canopy, the apical leaves accumulated higher betacyanin than those of middle and basal leaves. While the highest concentrations of chlorophyll were found in BARI-1, however Red queen had the lowest concentrations. Color index of leaves and betacyanin concentrations were increased and chlorophyll concentrations were decreased with the plant age, which indicate that change of these colorant pigment concentrations with plant age enhance the red leaf formation in red amaranth. Low temperature, darkness, and free or low oxidants maintained the stability of betacyanin concentrations of red amaranth; prolonged storage degraded the betacyanin. Variable factors such as the cultivar of red amaranth, its degree of maturity, and the food processing factors have been shown to have a quantitatively important influence on betacyanin yields and preservation.

Genotoxicity of Aqueous Extract From Heated Cooking Oils and its Suppression by Lactobacilli

Isidori, M., Parrella, A. — Wed, 23 Sep 2009 02:20:26 PDT

In the present study the mutagenic and genotoxic effects of aqueous extracts from six cooking oils (extra vergine olive, peanut, sunflower, soybean, corn, and various seeds oils) heated to the respective smoke point were investigated. The Ames test and the SOS Chromotest were carried out for this evaluation. The same oils were also tested after their re-frying, simulating domestic reuse process. Furthermore, the ability of different lactobacilli to reduce the potential genotoxic activity of the fried and re-fried oils was determined applying SOS Chromotest after co-incubation of samples with lactobacilli. The results showed that all the fried oils did not produce mutagenic effects while they induced a SOS response with the highest induction factor for the corn oil. Double heat-treatment caused an increase of the genotoxic activity until two times the first heating. The most susceptible oil to the re-frying procedure was the sunflower oil. The antigenotoxicity results were expressed as percent of genotoxicity inhibition. All the tested strains of lactobacilli exhibited antigenotoxic properties on the fried oils.

Effect of Pulsed Electric Fields on Physical, Chemical, and Microbiological Properties of Formulated Carrot Juice

Akin, E., Evrendilek, G.A. — Wed, 23 Sep 2009 02:20:26 PDT

The objective of this study was to process a developed carrot juice-based beverage by pulsed electric fields (PEF) and determination of its physical, chemical, and microbiological properties before and after PEF processing. Results revealed that PEF processing did not cause any significant change in pH, titratable acidity (TA), ^°Brix, conductivity, color (L*, a*, and b*), nonenzymatic browning index (NBI), metal ion, and vitamin C concentration (p > 0.05). There was a significant reduction on the total aerobic mesophilic bacteria, total mold and yeast, total enterobactericeae and Escherichia coli O157:H7 counts resulting with 4.30 ± 0.26, 3.4 2 ± 0.40, 4.46 ± 0.36, and 3.57 ± 0.32 log cfu/mL, respectively (p ≤ 0.01). PEF processing could be successfully used to process a carrot juice based beverage with significant amount of microbial reduction.

Quality of Fish Muscle Infested with Anisakis simplex

Vidacek, S., de las Heras, C., Tejada, M. — Wed, 23 Sep 2009 02:20:26 PDT

Marine fish species infested with Anisakidae larvae are reported in many fishing grounds. Besides the problems related to consumer’s health when the live larvae are ingested (anisakidosis) or to allergic problems caused by the larvae, the products excreted/secreted or released by the larvae are recognized as proteases, protease inhibitors or antioxidants, which can cause changes in fish muscle during storage. To study this problem, live larvae or a homogenate of larvae in water were added in controlled conditions to gelatin agar gels and minced fish muscle and stored at 20 or 5 °C for 7 days. A high activity in the gelatin agar gels was observed, whereas the inclusion of larvae or larvae homogenates in the muscle did not produce detrimental changes in texture, viscosity, color, or oxidation of fish muscle. The electrophoretic pattern of the extracted natural actomyosin presented fewer changes during storage in the larvae and larvae homogenate added lots than in the control lots. Nevertheless in naturally infested fish different parasite-host mechanisms might be involved. Parasitized fish has to be processed with treatments which kill the larvae to avoid consumers’ anisakidosis. However, as some of the Anisakis allergens are very stable to heat, patients allergic to Anisakis sp. have to be informed before ingesting parasitized fish or fish products.

Antioxidant Activity of Melanoidins from Different Sugar/Amino Acid Model Systems: Influence of the Enantiomer Type

Kim, J.-S., Lee, Y.-S. — Wed, 23 Sep 2009 02:20:26 PDT

The effect of amino acid enantiomers on the antioxidant activity of melanoidins was examined. For this purpose, antioxidant activities were evaluated on the basis of ferric reducing/antioxidant power (FRAP) and free radical scavenging activity including 1, 1-diphenyl-2-picryl-hydrazil (DPPH) and 2, 2'-azinobis (3-ethylbenothiazoline-6-sulfonic acid), diammonium salt (ABTS) and ferrous ion chelating activity. Ethylene diamine tetraacetate and trolox, a water-soluble analog of tocopherol, were used as the reference antioxidant compounds. Melanoidins formed from D-isomers were found to be effective antioxidants in different in vitro assays with regard to the ferrous ion chelating activity, ABTS and DPPH radical scavenging activities, and FRAP. In particular, the antioxidant activities of melanoidins formed from fructose systems were higher than those of melanoidins formed from glucose systems. In addition, the results showed that melanoidins formed from D-isomers had antioxidant activities, similar to those of melanoidins formed from L-isomers.

Influence of Extraction Time and Different Sage Varieties on Sensory Characteristics of a Novel Functional Beverage by RSM

Ozcelik, B., Karadag, A., Cinbas, T., Yolci, P. — Mon, 29 Jun 2009 06:17:23 PDT

An optimized formulation was developed for the preparation of an `ice-sage tea' which might be considered to be a new healthy functional product and designed as an alternative to other cold-served drinks in the market. A central composite design was used for modeling of the experiment with two independent variables (extraction time and blending ratios of two different sage varieties: Salvia officinalis (SO) and Salvia sclarea (SC)). Flavor profile of this novel product was developed using descriptive sensory analysis techniques; consumer acceptability of the product was also tested. Blending SO with SC was expected to increase the positive health effects of this novel product, while there was a limit for its concentration at increased extraction times. According to the evaluation of experienced panelists, blending common sage SO with SC did not reduce the overall likeability of this novel product at low extraction times. Statistically, just two models for astringency and overall impression were found to be acceptable by taking into consideration their regression coefficient and probability values. On the other hand, consumer test results showed that the samples prepared by blending SO with SC up to 25% might increase the likeability scores of the product when compared to the product without SC.

Changes in Lipid Profile by Vegetable Oil Blends Rich in Polyunsaturated Fatty Acids in Rats with Hypercholesterolemia

Mon, 29 Jun 2009 06:17:23 PDT

The objective of this study was to investigate the effect of different blended vegetable oils having different levels and profiles of polyunsaturated fatty acids (PUFA) on hypercholesterolemia by analyzing the changes in lipid profile in high-cholesterol diet fed rats. Three vegetable oils (soy oil, sunflower oil, and the nonconventional flaxseed oil) were blended to obtain blends rich in PUFA. Thirty albino rats were used over the 2-month period. The animals were divided into five groups, wherein group 5 represents negative control, where rats were fed basal diet, while rats in group 4 received high cholesterol diet and served as positive controls. The other three groups were fed hypercholesterolemic diet (1% cholesterol + 0.25% colic acid) supplemented with blended oils. Generally, rats fed blended oils showed significantly lower levels of total cholesterol (TC), triacylglycerol (TG), and low-density lipoprotein (LDL) cholesterol as well as higher levels of high-density lipoprotein (HDL) cholesterol, in comparison with animals fed high-cholesterol diet and cholesterol-free diet. Thus, oil blends under study may be useful formulations for the treatment of hypercholesterolemia. In addition to improving the lipid profile by lowering TC, total TG, and total LDL and increasing HDL, blending of vegetable oils can result in an economic advantage of lower prices.

Qualitative and Textural Changes in Fresh Okra Pods (Hibiscus esculentus L.) under Modified Atmosphere Packaging in Perforated Film Packages

Rai, D.R., Balasubramanian, S. — Mon, 29 Jun 2009 06:17:23 PDT

Improper post-harvest handling and storage under room temperature lead to high loss of moisture resulting in loss of strength and development of flaccidity in okra tissues, apart from the loss of its characteristic green color. In this study, different weights of freshly harvested okra pods (Hibiscus esculentus L.) were stored at 15°C and 75% relative humidity packaged under modified atmosphere (MAP) in 35 µm thick polypropylene film packages to assess the effect of different in-pack gaseous compositions of O₂ and CO₂ on the properties of okra. During storage, the normal freshness indicators of okra namely, the bright green color and ease of snapping at the tip served as the prominent qualitative and textural parameters, indicative of the acceptability of okra. Results indicated that an in-pack gaseous range for O₂ (6.3-8.4%) and CO₂ (10.7-11.8%) under MAP resulted in maintenance of green color and β-carotene in the pericarp, and ascorbic acid in the seeds as well as other qualitative parameters. Further, the texture analysis of okra at the pre-determined snapping point at the tip and also along the longitudinal portion showed that MAP stored okra were snapping easily at the tips and had a very slight increase in the other mechanical properties which were considered to be within acceptable limits.

Anisakis Simplex Antigens in Fresh and Frozen-thawed Muscle of Anchovies in Vinegar

Mon, 29 Jun 2009 06:17:23 PDT

Marinated fish treatment using low pH to enlarge the storage life of fish as in anchovies in vinegar, does not kill Anisakis simplex larvae infesting fish muscle. To kill the larvae it is compulsory in many countries to freeze fish intended to be marinated raw, which prevents the consumer to be infested with the live larvae. However, it is not known if A. simplex antigens are released to the media after freezing and vinegar processing, which may cause allergic reaction to A. simplex sensitized consumers. Anchovy fillets were artificially infested with A. simplex L3, treated with a vinegar solution and chilled stored for 10 days. Infested frozen-thawed fillets were treated and stored in the same conditions. Viability of the larvae, SEM, immunoblotting and immunohistochemistry were performed on the treated fillets before and after pepsin treatment. Viability of the larvae was detected only in the chilled fillets; however, A. simplex antigens were detected in the chilled and in the frozen-thawed fillets even after pepsin treatment. This suggests that the consumption of anchovies in vinegar may be a potential hazard when ingested by sensitized consumers, even if freezing kills the larvae.

Improvement of Water Barrier Property of Rice Starch-chitosan Composite Film Incorporated with Lipids

Bourtoom, T., Chinnan, M.S. — Mon, 29 Jun 2009 06:17:23 PDT

This study investigated the effect of lipid types (oleic acid, palm oil, and margarine) and their concentrations (0, 10, 20, 30, 40, and 50wt%) on the water vapor permeability (WVP), tensile strength (TS), percentage of elongation at break (%E), and structure of emulsified rice starch-chitosan composite film. The influence of rice starch-chitosan composite film incorporated with lipids in controlling the moisture transfer in moisture-sensitive products was determined by wrapping a low a_w-type cracker product in rice starch-chitosan composite film. TS and WVP of rice starch-chitosan composite film decreased with the addition of lipids, whereas %E increased in these films. Addition of lipids significantly raised film yellowness for composite films. The results showed that films added with oleic acid gave higher L*, b*, and chroma values but lower a* value than margarine and palm oil, respectively. The lower transparency of the films was noticed when a greater amount of lipid was incorporated (p < 0.05). Oleic acid-incorporated films provided the films with smoother surface and higher values of TS and %E but lower WVP than margarine and palm oil, respectively. Wrapping cracker samples in the rice starch-chitosan composite film incorporated with oleic acid could maintain the hardness and provide longer shelf life and lower moisture content than synthetic polyvinyl chloride film (PVC) and unwrapped (reference) crackers, respectively.

Oxygen Absorption Kinetics of Sheets and Films Containing a Commercial Iron-based Oxygen Scavenger

Galotto, M.J., Anfossi, S.A., Guarda, A. — Mon, 29 Jun 2009 06:17:23 PDT

Absorption kinetics of three different forms of the same iron-based oxygen scavenger were studied. Oxygen scavengers were used as pellet, sheet, and film materials. Two scavenger concentrations were used for sheet and film forms. Scavenger samples were analyzed at 75 or 100% relative humidities and stored at 5, 15, and 25°C. Oxygen concentration in the headspace was measured as a function of time. Absorption kinetics was best described by the Chapman-Richards empirical growth model rather than by a first-order reaction. Arrhenius behavior was observed for variations in the final absorption rate with temperature. Absorption capacities, final absorption rates, and activation energies were evaluated and discussed. Scavenger concentration, relative humidity, and temperature effects on kinetic parameters were studied for each experimental condition. Temperature was the most important factor that affected kinetic parameters. At the relative humidity levels studied, any important effect on kinetic parameters was not observed, except on absorption capacities.

Note. Sugar, Moisture Contents, and Color of Chestnuts during Different Storage Regimes

Chenlo, F., Moreira, R., Chaguri, L., Torres, M.D. — Mon, 29 Jun 2009 06:17:23 PDT

Color, moisture and sucrose, glucose and fructose contents of chestnuts (Castanea sativa Mill.) at several initial states (whole and undried; whole, peeled, and partially air-dried, with or without prior sucrose treatment; peeled, broken, and undried or partially air-dried) were monitored for 11 months during storage under various conditions (unpacked, packed in plastic bags at ambient pressure, or vacuum packed) and temperature (at room temperature, 3°C or -18°C). Moisture content decreased considerably in all cases except in those of packed whole peeled chestnuts without sucrose treatment and stored at room temperature or 3°C. Chestnuts stored for 2 months in contact with the atmosphere had moisture contents of only ~4% of their dry weight. After 4 months storage, sucrose content had fallen (in some cases to zero) in all samples except in broken chestnuts dried to a 2% moisture content and conventionally stored whole unpeeled chestnuts (in which sucrose content rose slightly). Glucose and fructose contents generally peaked after 1-2 months of storage, and by month 4 returned to initial or lower levels. Sugar content was hardly affected by initial moisture or sugar contents except when moisture content had been reduced to 2%. Color changes were least during storage in air or at 3°C.

Analysis of Domains in Selected Plant and Animal Food Proteins - Precursors of Biologically Active Peptides - In Silico Approach

Iwaniak, A., Dziuba, J. — Mon, 29 Jun 2009 06:17:23 PDT

In silico methods are useful tool in protein structure-functional relationships analysis. BIOPEP and InterPro databases were applied to analyze the presence of bioactive fragments in the domains occurring in the sequences representing the major groups of proteins. Domains found in the proteins analyzed had mostly transporting (bovine β-lactoglobulin), immunoglobulin-like (chicken connectin), alpha-amylase inhibitor (a/β-wheat gliadin), calcium binding (chicken myosin) functions, or allowed straightly to assign the protein to an appropriate superfamily (bovine casein). It confirmed the thesis about the existence of the functional relations between the structure (sequence) and the domains with identified conformation. Amongst the domains present in the protein sequences we revealed the presence of fragments with the activities: antihypertensive, opioid, dipeptidylpeptidase IV inhibitors, immunomodulating, and neuropeptides. In the chicken connectin within the immunoglobulin-like domain we found immunomodulating fragments. InterPro analysis did not reveal the existence of any domains in a soybean globulin. It can be explained by the lack of the key structure information helpful in the defining the structure-function relationships. As the number of information in the applied databases will continue to increase we can expect to find stronger relationships between bioactivity of fragments encrypted in proteins and the functionality of domains. This might allow in the future to find evolutionary similarity between different origin food proteins - sources of bioactive peptides.

Improvement of Quality of Gluten-free Layer Cakes

Ronda, F., Gomez, M., Caballero, P.A., Oliete, B., Blanco, C.A. — Mon, 29 Jun 2009 06:17:23 PDT

The development and study of new gluten-free foods of high quality that are suitable for people with celiac disease is necessary since there is increasing frequency of people who have been found to be allergic to proteins in wheat flour. Rice is one of the most used cereals in these special foods elaborations. However, replacement of wheat flour by rice flour usually leads to a noticeable decrease in the quality of the products discussed in this study. This work studied the individual and combined influence of xanthan gum (XAN), emulsifier, pregelatinizated starch, and transglutaminase on quality of rice yellow layer cake (YLC) by means of a systematic study based on a two-level half-fractional factorial experimental design. Size and shape, texture, color, crumb grain profile and sensory acceptance were evaluated in YLC. XAN, white egg proteins, and emulsifier showed significant positive effects on volume, texture and crumb grain characteristics. The feasibility of rice YLC reaching acceptable levels of customer satisfaction was demonstrated.

Acceptability of Milk and Soymilk Vanilla Beverages: Demographics Consumption Frequency and Sensory Aspects

Villegas, B., Carbonell, I., Costell, E. — Mon, 29 Jun 2009 06:17:23 PDT

Acceptance of food is basically the result of the interaction between food and humans, and it depends not only on the product characteristics but also on those of each consumer. The main objective of this study is to analyze how the acceptability of milk and soymilk vanilla beverages is influenced by demographic characteristics, consumer habits and individual preferences, and the sensorial properties of both products. Six commercial samples, comprising three milk beverages and three soymilk beverages of different brands and characteristics, were sensorially evaluated. Overall acceptability was tested by 142 consumers using a 9-point hedonic scale, and 36 assessors ranked the samples from the least to the most intense according to their yellow color, brightness, vanilla flavor intensity, sweetness, and thickness. The milk samples were significantly (P<0.05) more acceptable than the soymilk ones and were perceived as being stronger yellow and less light in color, with a more intense sweetness, stronger vanilla flavor, and thicker consistency. The results obtained led us to the conclusion that the difference in acceptability between milk and soymilk beverages is more closely related to their sensorial attributes than to other characteristics (demographic, consumer habits, and individual preferences) of the consumer population surveyed.

Sterol, Triterpenic Dialcohol, and Triacylglycerol Compounds of Extra Virgin Olive Oils from Some Tunisian Varieties Grown in the Region of Tataouine

Fri, 22 May 2009 06:25:49 PDT

The aim of this work was to study some of the chemical characteristics of virgin olive oils produced by three varieties grown in Tataouine (south of Tunisia). The oil samples studied were characterized by high levels of oleic acid (470%) and relatively low percentages of linoleic and palmitic acids (≤13% and ≤10%, respectively). They were also characterized by three primary triacylglycerols: OOO, POO, and OOL, and three secondary triacylglycerols POL + SLL, SOO, and PPO. The sterol and triterpenic dialcohol compositions of all the samples lay within the established regulatory limits. The main sterols found were b-sitosterol, 5-avenasterol, and campesterol. The amount of minor sterols present (24-methylenecholesterol, cholesterol, 7-avenasterol, and 7-stigmastenol) varied widely according to the varieties. The levels of erythrodiol + uvaol were below the upper legal limit of 4.5% in all analyzed samples. The results obtained showed that the great variability in oil composition among the varieties studied are influenced exclusively by the genetic factor.

Health Benefits of Using Red Palm Oil in Deep-frying Potatoes: Low Acrolein Emissions and High Intake of Carotenoids

Fri, 22 May 2009 06:25:49 PDT

Palm oil is the second largest vegetable oil in terms of world production. Besides, red palm oil (RPO) is nonhydrogenated, has a high oxidative stability and contains high levels of natural antioxidants, such as carotenoids. The main objectives of this study were to study acrolein emissions during deep-frying operations, as an indicator of potentially toxic volatile compounds, and to evaluate the importance of French fries (fried with red palm oil) as an extra source of carotenoids in the diet. The acrolein emission rates from mono-unsaturated oils, such as red palm and olive oils, were much lower than that of poly-unsaturated oils, sunflower. The total carotenoid content of red palm oil, 480 mg/L, makes this oil perfect for developing functional foods round the world and gives the oil a high oxidative stability and long shelf life. Sensory tests proved that RPO French fries were scored positively by regular consumers. Their color was initially considered unusual and got low scores; however, when the flavor was evaluated RPO fries got higher scores than olive or sunflower fries. RPO proved to generate low amounts of potentially toxic volatiles, acrolein, and be an excellent source carotenoids.

Quality of Red Sweet Pepper Fruit Treated with 1-MCP during a Simulated Post-harvest Handling Chain

Fernandez-Trujillo, J.P., Serrano, J.M., Martinez, J.A. — Fri, 22 May 2009 06:25:49 PDT

Red pepper fruit (Capsicum annuum L. cv Setubal) were treated with air (control) or 900 ppb 1-methylcyclopropene (1-MCP) for 24 h at 20°C. The fruit were packed in perforated polypropylene and stored for 4.5 days at 8°C (storage), 3 days at 20°C (simulated retail display), and 4.5 days in domestic refrigerator at 5.6°C. Fruit stored continuously at 20°C served as reference of respiration rate and ethylene production. The fruit quality, storage disorders, and physiological behavior in this simplified post-harvest handling chain and the possible effects of the CO₂ accumulated during 1-MCP treatments were particularly studied. The critical points of the simulated post-harvest chain as regards fruit quality were the retail display stage at 20°C, the inhibition of ethylene as a side effect of 1-MCP, and, to a lesser extent the domestic refrigeration phase. Simulated retail display exacerbated shriveling and weight loss, and negatively affected aroma, finger texture and, to a lesser extent, fruit taste, and mouth texture. The 3% increase in the CO₂ accumulated in both treatments resulted in a transient increase in the respiration rate, flesh and juice hue angle, glutamic and ascorbic acids; an increase in succinic acid (higher in 1-MCP treated fruit), and a transient decrease in citric acid, juice lightness and chroma. Compared with the control, the 1-MCP prevented the increase in skin chroma during the storage phase, the upsurge of ethylene production during the retail display phase, and doubled the fumaric acid levels in the refrigerator phase. 1-MCP may have increased the fruit susceptibility to shriveling and weight loss and, to a greater extent, pitting and gray mold rot in the domestic refrigerator. In brief, 1-MCP cannot be recommended for extending non-climacteric pepper shelf-life.

Relationship between Acoustic Firmness and Magness Taylor Firmness in Royal Gala and Golden Smoothee Apples

Molina-Delgado, D., Alegre, S., Puy, J., Recasens, I. — Fri, 22 May 2009 06:25:49 PDT

This study aimed to evaluate apple firmness measured using both the penetrometer and acoustic methods. The methodologies were applied to Royal Gaya and Golden Smoothee apples (Malus domestica. Borkh) harvested from 12 different orchards in Catalonia (Spain), on six different dates, and over three seasons. The relationship between firmness and physicochemical quality parameters was analyzed at harvest and post-harvest. The results obtained showed a noticeable correlation between Magness Taylor firmness and acoustic measurements in Royal Gala, but no correlation was found for Golden Smoothee. Fruit variety and storage had a clear influence on correlations between the two measurements. Measurements of Magnes Taylor and acoustic firmness seemed to correspond to different physical properties. Acoustic measurements seemed to be a good tool for evaluating changes in tissue firmness during long-term storage, especially for Golden Smoothee apples. The maturity of the fruit seemed to play a more important role in the measurement of Magnes Taylor firmness than in the measurement of acoustic firmness for the Royal Gaya variety.

Changes in Polyphenols Distribution and Antioxidant Activity during Fermentation of Some Underutilized Legumes

Oboh, G., Ademiluyi, A.O., Akindahunsi, A.A. — Fri, 22 May 2009 06:25:49 PDT

The effect of fermentation on the polyphenol distribution and antioxidant activity of four underutilized legumes [Cajanus cajan L. Millsp (Pigeon pea), Vigna subterranea L. Verdc (Bambara groundnut), Sphenostylis stenocarpa Harms (African yam bean), and Phaseolus vulgaris L. (Kidney bean)] were investigated. The beans were cooked (12 h), soaked in boiled water (12 h), dehulled, and then cooked again (2 h). The cotyledons were drained, wrapped in jute sacks and left to ferment at 37°C (4 days) to produce condiments. The distribution of free and bound phenolic compounds in the fermented and unfermented beans was determined; thereafter the free radical scavenging ability, reducing power, and the ability of the free and bound phenolic compounds of the fermented and unfermented beans to inhibit lipid peroxidation were determined. The results of the study revealed that fermentation caused a significant increase (p<0.05) in the free soluble phenol content of the legumes, while there was a significant decrease (p<0.05) in the bound phenol content of the legumes. Free soluble phenol from both the fermented and unfermented legumes had a significantly (p<0.05) higher reducing power (except C. cajan), free radical scavenging ability (except C. cajan) and inhibition of lipid peroxidation than bound phenolic extract. However, free soluble phenolic compounds from the fermented beans had a significantly higher (p<0.05) reducing power, free radical scavenging ability, and inhibition of lipid peroxidation than free soluble phenols from unfermented beans. Hence, it was concluded that, fermentation could increase the free soluble phenolic content of the underutilized legumes tested and consequently enhance the antioxidant activities of the legumes; fermented V. subterranea was found to be the most promising condiment with antioxidant activity.

Characterization of Spanish Tomatoes using Aroma Composition and Discriminant Analysis

Fri, 22 May 2009 06:25:49 PDT

Nowadays, tomato breeders are trying to associate high fruit firmness, long shelf life, high disease resistance, and good flavor; however, breeding for sensory quality has been severely restricted up to date. In this study, a system specifically designed for the analysis of low amounts of material has been set up and tested to quantify the volatile aroma constituents of tomatoes. Ten volatile compounds with a major contribution to tomato aroma have been quantitatively determined in two traditional tomato types (Muchamiel and De la Pera) and one hybrid type (Odissea). Both traditional types presented higher intensities of tomato odor and aroma according to a trained panel and they were more accepted by a consumer panel than the hybrid tomatoes. The traditional tomatoes showed significantly higher contents of most of the volatiles studied. Significant differences among traditional and hybrid types were found and a mathematical model that successfully discriminated among tomato types was developed using only the concentrations of six volatile compounds: 3-methylbutanal, 1-penten-3-one, hexanal, trans-2-hexenal, 1-hexanol, and 2-isobutylthiazole. This mathematical model could help in using volatile determination as a possible tool in tomato breeding programs and in maintaining and improving traditional Spanish tomato cultivars.

Determination of Vitamin E in Coffee Beans by HPLC Using a Micro-extraction Method

Alves, R.C., Casal, S., Oliveira, M.B.P.P. — Fri, 22 May 2009 06:25:49 PDT

This work reports a solid—liquid micro-extraction method for vitamin E quantification in coffee beans (before and after roasting) with normal-phase HPLC/diode-array/fluorescence detection. The compounds were extracted after protein precipitation and overnight maceration (4°C) in n-hexane, in the presence of butylated hydroxytoluene, using tocol as internal standard. The extraction method precision was inferior to 5% with mean recoveries near 100%. Chromatographic resolution from co-eluting interferences was achieved within 8 min with a 75 x 3.0 mm (3 µm) silica column by using an isocratic elution with n-hexane/ 1,4-dioxane (98 : 2), at a flow rate of 0.7 mL/min. The diode-array detector was a valuable tool in the detection of co-eluting interferences and quantification was based on the fluorescence measurements. Only two vitamers, a- and b-tocopherol, were confirmed and quantified, being the latter generally the major compound in both arabica and robusta coffees. The present analytical method proved to be simple, sensitive, reproducible, accurate, allowing a fast quantification with low organic solvent consumption.

Antioxidant and Nutritional Properties of Date Fruit from Elche Grove as Affected by Maturation and Phenotypic Variability of Date Palm

Fri, 22 May 2009 06:25:49 PDT

Some parameters related to nutritive and functional properties were evaluated in date fruit from seven date palms from the Elche grove along the maturation process, in order to obtain information about differences due to phenotypic variability. Results showed that sugar and organic acid concentration were different depending on date palm, the highest levels being reached at 100% Rutab stage, with glucose and fructose as the predominant sugars and malic acid as the major organic acid. Hydrophilic total antioxidant activity (HTAA) was high and correlated to phenolic content, with maxima levels being found at early, medium or late Khalal stages, depending on date palm. In addition, significant differences were found in both, phenolic concentration and HTAA among date palm and maturation stages, while lipophilic total antioxidant activity (LTAA) was very low, without changes along maturation and not correlated to HTAA. Then, date fruit from Elche grove could serve as a good source of natural antioxidant and it would be advisable to consume them at medium or late Khalal stages, in order to achieve the maxima nutritional (high concentration of sugars and organic acids), organoleptic (appropriated firmness levels, yellow or red color and low astringency) and functional properties with benefits to human health.

Development and Characterization of Spaghetti with High Resistant Starch Content Supplemented with Banana Starch

Fri, 22 May 2009 06:25:49 PDT

Spaghetti developed by substituting semolina with 5, 10, 15, and 20% (w/w) banana starch were evaluated by specific physical and chemical parameters such as chemical composition, resistant starch (RS) content, diameter, bulk density, color, cooked weight, cooking loss, and firmness. They were also evaluated by their sensory attributes. In general, the addition of banana starch promoted a dilution effect on protein, lipid, and ash content, while moisture content was not affected. On the other hand, the content of RS significantly increased ( p50.05) with an increase of banana starch in the spaghetti. Spaghetti containing 5 and 10% of banana starch had similar diameter than the control spaghetti, but the diameter of spaghetti with 15 and 20% banana starch were significantly lower ( p50.05). The bulk density values of spaghetti with banana starch were all similar and not different from the control spaghetti. The values of L* indicated that the color of spaghetti containing banana starch was darker than the control at all levels of substitution, while the values of C* indicated that only spaghetti containing banana starch in the range of 10—20% was less saturated than the control. The evaluation of cooking quality demonstrated that the cooked weight of spaghetti containing banana starch was similar to the control, but their cooking loss was significantly higher and their firmness significantly lower ( p50.05) than the control. However, the values of cooking loss and firmness were in the acceptable range for good quality pasta. Sensory evaluation of the product showed that the addition of banana starch improved the acceptability of the spaghetti. The overall result of this study shows that spaghetti with up to 15% of banana starch addition could have great potential for commercial acceptability as a functional food with high levels of healthy RS.

Breadmaking Performance and Keeping Behavior of Cocoa-soluble Fiber-enriched Wheat Breads

Collar, C., Rosell, C.M., Muguerza, B., Moulay, L. — Fri, 22 May 2009 06:25:49 PDT

The effects of increasing amounts (from 0 up to 8%) of soluble dietary fiber preparations from cocoa shell samples obtained at different pH, on fresh and stored wheat bread performance were investigated, and results were compared with those provided by addition of a `hidden' fiber inulin. Flour addition with dietary fibers from cocoa shell — natural (ACSF) and alkalinized treatment (BCSF) — significantly modify visual properties, specific volume, and sensory perception of breads thereof as well as textural profile and staling kinetics during storage of fiber-supplemented breads. At 6% of addition, an increase in specific volume with respect to control samples was achieved by breads with ACSF (+5%), whereas BCSFcontaining loaves showed reduced specific volume (-5%). None of the cocoa shell fiber-supplemented breads scored higher than control without fibers and/or inulin-enriched breads but were sensory acceptable at all dosages used except for those at 8% of addition in terms of overall acceptability and taste. ACSF-supplemented breads were as acceptable as the control breads concerning appearance and aroma when added up to 4%, had taste and overall acceptability up to 2%, and texture up to 8%. BCSF-enriched breads deserved the same scores as ACSF at the same/lower percentage of incorporation into doughs. On increased dosage of addition cocoa-soluble fibers provided an initial softening effect. Dietary fibers from cocoa shell added up to 6% can be used to design technologically feasible, sensory acceptable, and long-term stored innovative fiber-enriched wheat bread formulations.

Reducing Sugar Production in Sweet Potatoes Heated by Electromagnetic Radiation

Sawai, J., Nakai, T., Shimizu, M. — Fri, 22 May 2009 06:25:49 PDT

The apparent reaction rate constant needed to generate reducing sugar was determined by heating a thin slice of sweet potato using thermal conductive heating. This value was used to predict reducing sugar production in sweet potatoes cooked by electromagnetic irradiation. The generation of reducing sugar in the thin slice was not observed at temperatures <65°C or >85°C, but it increased linearly during the early stage of heating. The Arrhenius plot had a peak of approximately 83°C, allowing determination of the values for activation energy and frequency factor. Then, using the values obtained for apparent reaction rate constant, the yields of reducing sugar in sweet potatoes cooked by infrared (IR) and microwave (MW) heating were calculated and compared with experimental data. Although the calculated values exceeded the experimental values in the early stages of electromagnetic irradiative heating, the calculated amounts of reducing sugar generally agreed with the experimental values. Moreover, when the time needed to heat the sweet potato from 65°C to 85 °C was longer than approximately 8 min, the yield of reducing sugar was maximized for both MW and IR heating. These results indicated that the yield of reducing sugar did not depend on the heat transfer mechanism and that the amount of reducing sugar produced in heat-treated sweet potatoes could be predicted.

Acyl Transferase Domains of Putative Polyketide Synthase (PKS) Genes in Aspergillus and Penicillium Producers of Ochratoxin A and the Evaluation of PCR Primers to Amplify PKS Sequences in Black Aspergillus Species

Martinez Culebras, P.V., Crespo-Sempere, A., Gil, J.V., Ramon, D. — Fri, 22 May 2009 06:25:49 PDT

Fungal polyketide synthases (PKS) are responsible for the biosynthesis of several mycotoxins and other secondary metabolites. PKS genes in ochratoxin producing species from Aspergillus and Penicillum genera have been identified using a degenerate primer pair developed for the acyl transferase (AT) domain of fungal PKSs. Sequences of AT domains were aligned and analyzed using phylogenetic methods. The AT domain sequences appeared to be specific for a particular type of fungal PKSs and were related to PKSs involved in different mycotoxin biosynthesis pathways, including ochratoxin A. We have also developed primers suitable for amplifying AT domain sequences in strains belonging to the A. niger aggregate. DNA from most of the black Aspergillus species currently recognized was tested. Primers showed general applicability and other Aspergillus species belonging to section Nigri were successfully amplified.