Sains Malaysiana 37(1): 65-69 (2008)

Coating Gelatinization During Initial Frying Period

As Affected By Temperature

(Pengelatinan salutan semasa tahap awal

Penggorengan oleh pengaruh suhu)

Salma Mohamad Yusop, Mohamad Yusof Maskat,

Wan Aida Wan Mustapha & Aminah Abullah

Food Science Program

School of Chemical Sciences and Food Technology

Faculty of Science and Technology, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E., Malaysia

Received: March 2007 / Accepted: 1 June 2007

ABSTRAK

Sifat pengelatinan salutan semasa peringkat awal penggorengan pada beberapa suhu yang berbeza telah dikaji. Nuget ayam, sebagai substrat, dicelup ke dalam cecair penyalut dan kemudiannya digoreng pada 150, 165 dan 180^oC selama 0, 6, 18 dan 30s. Selepas penggorengan,  bahagian salutan dan substrat dianalisis secara berasingan untuk kandungan lembapan. Bahagian salutan juga dianalisis untuk suhu permulaan (T_o), puncak (T_p) dan akhir (T_e) serta entalpi pengelatinan. Keputusan menunjukkan tiada kesan ketara oleh suhu penggorengan terhadap kandungan lembapan kedua-dua bahagian salutan dan substrat. Tetapi, terdapat pola pengurangan kandungan lembapan dengan peningkatan masa penggorengan sehingga 30s untuk setiap suhu yang dikaji. Tiada kesan ketara oleh suhu penggorengan terhadap T_o, T_p dan T_e. Tetapi, penggorengan pada 180 ^oC menghasilkan darjah pengelatinan yang lebih tinggi selepas 6s. Peningkatan kadar pengelatinan apabila digoreng pada suhu yang lebih tinggi boleh disebabkan oleh peningkatan kadar perpindahan haba semasa penggorengan.

Kata kunci:  Salutan; penggorengan; pengelatinan; suhu, tepung gandum

ABSTRACT

The gelatinization properties of coating during initial frying period at different temperatures was studied. Chicken nuggets, as substrate, were immersed in batter and then fried at temperatures of 150, 165 and 180^oC for 0, 6, 18 and 30 s. After frying, the coating and substrate were analyzed separately for moisture content. The coating layer was also analyzed for onset (T_o), peak (T_p) and end (T_e) temperatures and gelatinization enthalpy. Results showed no significant effect of frying temperature on the moisture content of both coating and substrate. However, a decreasing trend in moisture content can be noticed with increasing frying period up to 30s for all temperature studied. There were no significant effect of frying temperature on the T_o, T_p and T_e. However, frying at 180 ^oC produced a higher degree of gelatinization after 6s. The increase in gelatinization rate when fried at a higher temperature may be attributed to the increase in heat transfer rate during frying.

Keywords:  Coating; frying; gelatinization, temperature; wheat flour

RUJUKAN/REFERENCES 

A.O.A.C. 1990. Official Method of analysis. 15^th edition. Washington D.C: Association of Official Analytical Chemists,.

Aguilera, J. M., Cadoche, L., Lopez, C. & Gutierrez, G. 2001. Microstructural changes of potato cells and starch granules heated in oil. Food Research International 34: 939-947.

Alberto, D., Gilles, T., Olivier, V., Dominique, D. & Anne-Lucie, R.W. 1999. Kinetics of moisture loss and fat absorption during frying for different varieties of plantains. Journal of the Science of Food and Agriculture 79: 291-299.

Ateba, P. & Mittal, G.S. 1994. Modelling the deep-fat frying of beef meat balls. Int. J. Food Sci. and Tech. 29: 429-440.

Bryant, C.M. & Hamaker, B.R. 1997. Effect of lime on gelatinization of corn flour and starch. Carbohydrates 74(2): 171-175.

Chungcharoen, A. & Lund, D.B. 1987. Influence of solutes and water on rice starch gelatinization. Cereal Chemistry  64(4): 240-243.

Farkas, B.E., Singh, R.P. & Rumsey, T.R. 1996. Modeling heat and mass transfer in immersion frying. I, Model development. Journal of Food Engineering 29: 211-226.

Fennema, O.R. (1985). Water and ice. In, Food Chemistry, Fennema, O.R. Ed. pp. 23-68. New York: Marcel Dekker Inc.

Hug-Iten, S., Handschin, S. Conde-Petit, B. & Escher, F. 1999. Changes in starch microstructure on baking and staling of wheat bread. Lebensmittel-Wissenchaft-und-.Technologie  5: 255-260.

Jenkins, P.J. & Donald, A.M. 1998. Gelatinization of starch: a combined SAXS/WAXS/DSC and SANS study. Carbohydrate Research 308: 133–147.

Kawas, M.L. & Moreira, R.G. 2001. Characterization of product quality attributes of tortilla chips during the frying process. Journal of Food Engineering  47: 97-107.

Kimber, M.P. & Holding, S. 1987. Some technological aspects of batter. In Savoury Coatings Fuller, D.B., Parry, R.T. Eds. pp. 85-89. New York: Elsevier Applied Science.

Lin, S., Hsieh, F. & Huff, H.E. 1997. Effects of lipids and processing conditions on degree of starch gelatinization of extruded dry pet food. Lebensmittel-Wissenchaft-und-.Technologi. 30: 754-761.

Loewe, R. 1990. Ingredient selection for batter systems. In Batter and breadings in food processing, Kulp, K., Loewe, R. (Eds.), pp. 11-28. Minnesota: American Association of Cereal Chemists, Inc.,

Loewe, R. 1993. Role of ingredients in batter systems. Cereal Foods World  38(9):  673–677.

Mallikarjunan, P., Chinnan, M.S., Balasubramaniam, V.M. & Philips, R.D. 1997. Edible coating for deep-fat frying of starchy products. Lebensmittal-Wissenschaft und.-Technologie 30: 709-714.

Pedreschi, F. & Moyano, P. 2005. Oil uptake and texture development in fried potato slices. Journal of Food Engineering 70:  557-563.

Primo-Martin, C., Nieuwenhuijzen, N.H., Hamer, R.J. & Vliet, T. 2007. Crystallinity changes in wheat starch during the bread-making process: Starch crystallinity in the bread crust. Journal of Cereal Science  45(2): 219-226.

SAS. 1996. User's Guide. SAS Institute Inc., Cary, North Carolina.

Sakonidou, E.P., Karapantsios, T.D. & Raphaelides, S.N. 2003. Mass transfer limitations during starch gelatinization. Carbohydrate Polymers1-9.

Sasaki, T., Yasui, T. & Matsuki, J. 2000. Effect of amylose content on gelatinization, retrogradation and pasting properties of starches from waxy and non-waxy wheat and their F1 seeds. Cereal Chemistry 77:  58–63.

Varela, G. 1988. Current facts about the frying of food. In, Frying of Food: Principles, Changes and New Approaches, Varela, G., Bender, A.E., Morton, I.D. Eds. pp. 2-25. Chichester, U.K: Ellis Horwood.

Vasanthan, T. & Hoover, R. 1992. Effect of defatting on starch structure and gelatinization properties. Food Chemistry 45: 337-347.

Zanoni, B., Peri, C. & Bruno, D. 1995. Modelling of starch gelatinization kinetics of bread crumb during baking. Lebensmittel-Wissenchaft-und-.Technologi. 28: 314-318.