THERMAL DECOMPOSITION OF SUNFLOWER OIL DURING DEEP FAT FRYING OF POTATO CHIPS AND EFFECTS OF USING RICE HULLS AND RICE STRAW AS NATURAL ADSORBENTS

Barbary, O. M.; Osman, H. M.; Zeitoun, M. A.; Basha, M. A.

doi:10.21608/jfds.2004.240339

THERMAL DECOMPOSITION OF SUNFLOWER OIL DURING DEEP FAT FRYING OF POTATO CHIPS AND EFFECTS OF USING RICE HULLS AND RICE STRAW AS NATURAL ADSORBENTS

Document Type : Original Article

Authors

Food Science Department, Faculty of Agriculture (Saba.Bacha). Alexandria University, P.O. Box 21531- Bolkley, Alexandria, EGYPT

10.21608/jfds.2004.240339

Abstract

Deep-fat fried foods have exquisite taste. good flavour. excellent mouthful,
and a characteristic texture. The primary function of oils during frying is to serve as a
heat-transfer medium. Chemical and physical changes took place during frying
leading to the odorous, flavours. and textures associated with fried foods. A myriad of
less desirable products also are formed. which in tum affect heat -transfer efficiency
and also the nutritional value of the incorporated oil. The objedive of this work was to
obtain a better understanding of using lice hulls (RHB) and rice straw (RSB) (10 % of
oil weight)" with citric acid (CA) (0.5 % w/w), carboxy methyl cellulose (CMC) (10 %
w/w) and silica gel (SG) (10 % w/w). as inexpensive by-products as adsorbents for the
heated oil used during deep-fat frying of potato chips at 180·C for 36h continousely.
The degradation products that formed due to the heat treatments were investigated
using the GC/MS. The degradative products included short chain free fatty acids. butyl
esters. oxygenated compounds and hydroxylated products suggesting that the main
mechanism involved was the thermooxidation mechanism. The concentrations of
these products. however. were not quantitatively determined. The RHB and RSB were
found to be more effective during the first 24h of heating and their effectiveness were
reduced during the following heating hours up to 36h.