Advanced Search

Journal Navigation

Journal Home

Subscriptions

Archive

Contact Us

Table of Contents

Sign In to gain access to subscriptions and/or personal tools.
Food Science and Technology International
This Article
Right arrow Abstract Freely available
Right arrow Free Full Text (Free PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to Saved Citations
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Request Reprints
Right arrow Add to My Marked Citations
Citing Articles
Right arrow Citing Articles via Web of Science (9)
Right arrow Citing Articles via Google Scholar
Right arrow Citing Articles via Scopus
Google Scholar
Right arrow Articles by Askari, G. R.
Right arrow Articles by Mousavi, S. M.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Effects of Combined Coating and Microwave Assisted Hot-air Drying on the Texture, Microstructure and Rehydration Characteristics of Apple Slices

G. R. Askari

Transfer Properties Lab (TPL), Department of Food Science and Technology, Agricultural Engineering Faculty, University of Tehran, Iran

Z. Emam-Djomeh

Transfer Properties Lab (TPL), Department of Food Science and Technology, Agricultural Engineering Faculty, University of Tehran, Iran; emamj{at}ut.ac.ir

S. M. Mousavi

Transfer Properties Lab (TPL), Department of Food Science and Technology, Agricultural Engineering Faculty, University of Tehran, Iran

The effect of coating, hot-air and microwave drying on the texture, microstructure and rehydration characteristics of Golden Deliciousapple slices (22mm diameter, 4mm thickness) was investigated. Blanching was carried out in hot water (80°C, 1 min) to prevent undesirable enzymatic reactions. To induce a porous structure during microwave treatment, coating with a starch (suspension), pectin and carboxymethylcellulose (CMC) solution (20 g/L) with and without CaCl2 (10 g/L) was carried out. A puncture test and a scanning electron microscopy (SEM) technique were used to analyse the effects of these processes on texture and microstructure. Rehydration in distilled water was also studied. Coating, air-drying (70°C, 1.5 m/s) and microwave treatment (300W, 10s) resulted in the production of puffed and porous products. Microstructure of samples coated by starch and pectin with CaCl2 improved. Coating had a beneficial effect on the microstructure of samples after microwave treatment. In addition, microstructural studies showed that coating with pectin had a significant effect on the thickness of the cell wall whereas those treated with starch or CMC did not exhibit such an effect. Adding CaCl2 to the coating solution improved the microstructural properties and prevented central heating phenomena.

Key Words: microwave • microstructure • coating • rehydration capacity • texture

References

  • Al-Duri B. and McIntyre S. (1992). Comparisons of drying kinetics of food using a fan assisted convection oven and a combined microwave/convection oven . Journal of Food Engineering 15: 139–155 .
  • AOAC (1995). Official Methods of Analysis, 16th edn. Washington, DC: Association of Official Analytical Chemists .
  • Araszkiewicz M., Koziol A., Oskwarek A. and Lupinski M. (2004). Microwave drying of porous materials . Drying Technology 22: 2331 – 2341 .[CrossRef]
  • Ayappa K.G. (1997). Modeling transport processes during microwave heating: a review . Reviews in Chemical Engineering 13(2): 1–68 .
  • Bazhal M.I., Ngadi M.O. and Rahgavan V.G.S. (2002). Textural change in apple tissue during combined pressure and pulsed electric field treatment . In: Proceedings AIC2002 Meeting CSAE/SCGR Program Saskatoon. Saskatchewan, Canada.
  • Bobic S., Bauman E. and Tripalo B. (1988). Fluidized bed drying of fruit and vegetable particle with different pretreatments . In: Rouguse M.A and Mujumdar A.S. (eds), Proceedings Sixth Internatioanl Drying Symposium, Vol. 2. Versailles, France: Hemisphere, pp. 47–51 .
  • Chardonnet C., Charron C., Sams C. and Conway W. (2002). Chemical changes in the cortical tissue and cell walls of calcium-infiltrated ‘Golden Delicious’ apple during storage . Postharvest Biology and Technology 28: 97–111 .[CrossRef]
  • Contrad N., Guilbert S. and Cuq J.L. (1992) Edible wheat gluten films: influence of the main process variables on film properties using response methodology . Journal of Food Science 57(1): 190–195 .
  • del Valle J., Aranguiz V. and Leon H. (1998). Effect of blanching and calcium infiltration on PPO activity, texture, microstructure and kinetics of osmotic dehydration of apple tissue . Food Research International 8: 557–569 .[CrossRef]
  • Feng H. and Tang J. (1998). Microwave finish drying of diced apples in a spouted bed . Journal of Food Science 4(63): 679–683 .
  • Funebo T., Kidman S. and Langton M. (2000). Microwave heat treatment of apple before air dehydration effects on physical properties and microstructure , Journal of Food Engineering 46: 173–182 .
  • Jen J.J., Mudahar G.S. and Toledo R.T. (1989). Chemistry and processing of high-quality dehydrated vegetables products. In: Jen J.J. (ed.), Quality Factors of Fruits and Vegetables. Chemistry and Technology. ACS Symposium series 405. New York: American Chemical Society , pp. 204–249.
  • Kaensup W. and Wongwises S. (2004). Combined microwave/fluidized bed drying of fresh peppercorns . Drying Technology 22: 779–794 .[CrossRef]
  • Karathanos V.T. and Saravacos G.D. (1993). Porosity and pore size distribution of starch materials . Journal of Food Engineering 18: 259–280 .[CrossRef]
  • Karel M. (1991). Physical structure and quality of dehydrated foods . Drying Technology 25: 47–60 .
  • Khraisheh M.A.M., Cooper T.J.R. and Magee T.R.A. (1997). Shrinkage characteristics of potatoes dehydrated under combined microwave and convective air condition . Drying Technology International 15: 1003–1022 .
  • Langton M. and Hermansson A.M. (1996). Image analysis of particulate whey protein gels . Food Hydrocolloids 10: 179–191 .
  • Lehne M., Barton G.W. and Langrish T.A.G. (1999). Comparison of experimental and modeling studies for the microwave drying of ironbark timber . Drying Technology 17(10): 2219–2235 .
  • Lenart A. and Dabrowska R. (1997). Osmotic dehydration of apples with polysaccharide coating . Polish Journal of Food and Nutrition Sciences 6/47: 103–112 .
  • Lewicki P.P. (1998). Some remarks on rehydration of dried foods . Journal of Food Engineering 36: 81–87 .
  • Lewicki P.P. and Michaluk E. (2004). Drying of tomato pretreated with calcium . Drying Technology 22: 1813–1827 .[CrossRef]
  • Lewicki P.P., Lenart A. and Pakula W. (1984). Influence of artifical semi-permeable membranes on the process of osmotic dehydration of apples. Ann. Warsaw Agricult. Univ.-SGGW-AR . Food Technology and Nutrition 16: 17–24 .
  • Lozano J.E., Rotestein E. and Urbican M.J. (1980). Total porosity and open-pore porosity in the drying of fruits , Journal of Food Science 45: 1403–1407 .
  • Lozano J.E., Rotestein E. and Urbican M.J. (1983). Shrinkage, porosity and bulk density of foodstuff at changing moisture content . Journal of Food Science 48: 1497–1502 .
  • Maskan M. (2001. Drying, shrinkage and rehydration characteristics of kiwifruits during hot- air and microwave drying . Journal of Food Engineering 48: 177–182 .[CrossRef]
  • Mujumdar A.S. (2000). Drying technology in agricultural and food science. Plymouth, UK: Science Publishers, Inc. , pp. 61–98, 253–286.
  • Prabhanjan D.G., Rammaswamy H.S. and Raghavan G.S.V. (1995). Microwave-assisted convective hot-air drying of thin layer carrots . Journal of Food Engineering 25: 283–290 .[CrossRef]
  • Saltiel C. and Datta A.S. (1999). Heat and mass transfer in microwave processing . Advances in Heat and Mass Transfer 33: 1–94 .
  • Stern C.H. (1998). A transient heat transfer model for selective microwave heating of multilayer material systems . International Microwave Power Institute 33: 207–215 .
  • Thompson R.L., Fleming H.P., Hamann D.D. and Monroe R.J. (1982). Method for determination of firmness of cucumber slices . Journal of Texture Studies 13: 311–324 .
  • Torreggiani D., Toledo R.T. and Bertolo G. (1995). Optimization of vapor induced puffing in apple dehydration . Journal of Food Science 60: 181–186 .
  • Torringa E., Esveld E., Scheewe I., Van den Berg R. and Bartels P. (2001). Osmotic dehydration as a pretreatment before combined microwave-hot-air drying of mushrooms . Journal of Food Engineering 49: 185–191 .[CrossRef]
  • Ulrich E. and Helmar S. (2001). Combined osmotic and microwave-vacuum dehydration of apples and strawberries . Journal of Food Engineering 49: 193–199 .[CrossRef]
  • Ventakesh M.S. and Raghavan G.S.V. (2004). An overview of microwave processing and dielectric properties of agri-food materials . Biosystems Engineering 88 (1): 1–18 .[CrossRef]
  • Wong W.S., Tillin S., Hudson J.S. and Pavlath E. (1994). Gas exchange in cut apples with bilayer coatings . Journal Agricultural Food Chemistry 42: 2278–2285 .[CrossRef]
  • Zogzas N.P., Maroulis Z.B. and Marinos-kouris D. (1994). Densities, shrinkages and porosity of some vegetables during hot-air drying , Drying Technology 12: 1653–1666 .

Food Science and Technology International, Vol. 12, No. 1, 39-46 (2006)
DOI: 10.1177/1082013206062480
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



This Article
Right arrow Abstract Freely available
Right arrow Free Full Text (Free PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to Saved Citations
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Request Reprints
Right arrow Add to My Marked Citations
Citing Articles
Right arrow Citing Articles via Web of Science (9)
Right arrow Citing Articles via Google Scholar
Right arrow Citing Articles via Scopus
Google Scholar
Right arrow Articles by Askari, G. R.
Right arrow Articles by Mousavi, S. M.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?