Doctoral Dissertations

Date of Award

12-1999

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Food Science and Technology

Major Professor

Sharon L. Melton

Committee Members

J. L. Collins, M. P. Penfield, A. M. Saxton

Abstract

To increase stability of sunflower oil (SFO) during frying and of potato chips during storage, 20 and 40% palm oil olein (POO) were added to SFO and compared to cottonseed oil (CSO). The oils/blends were sampled fresh, after break-in heating and at 2 5- and 5-hr frying. Oils were analyzed for of fatty acid composition, C18:2/C16:0 ratio, total polar compounds (TPO), free fatty acids (FFA), conjugated dienoic acids (ODA), and color. Moisture and fat levels and Agtron color of fresh chips were determined. Potato chips from each oil/blend were stored for 0 wk and 3 or 6 wk in dark or light and analyzed for peroxide values (PV), headspace flavor volatiles and sensory attributes. SFO contained 65.8% C18.2 compared to 51.7, 54 6 and 43 3% in CSO, and 20:80 and 40:60 POO:SFO, respectively. Levels of all fatty acids and C18:2/C16:0 ratio remained unchanged during frying, except for C18:1, which increased. Levels of TPO, FFA and ODA differed among oils/blends and increased during frying but TPO increased at the fastest rate in SFO. Addition of POO to SFO retarded oil degradation rate during frying to that of CSO. Fresh chips had 1.96% moisture, 39.2% fat, and an Agtron color of 60.5. During dark storage, PV increased only In SFO-fried chips at 6 wk and were lower than in chips stored in light. Addition of 40% POO to SFO increased chip stability to that of CSO-fried chips during dark storage and greater than that of same chips during light storage. Of 10 volatiles identified in chips, only hexanal increased progressively during storage in dark and light, the desirable fried flavor volatile (t,t-2,4-decadienal) level did not change. After 6 wk in light, only CSO-fried chips had increased intensities (p<0.05) of oxidative rancidity and off-flavors (OF), while chips fried in 20% POO:SFO had a lower intensity of OF than SFO-fried chips. Characteristic potato chip flavor was similar (p>0 05) in intensity among frying oils/blends and did not change during chip storage. Addition of POO to SFO improved the stability of SFO-fried chips without sacrificing characteristic potato chip flavor.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS