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Title:Effects of oil types and beta-carotene in repeated deep-fat frying of French fries
Author(s):Meng, Jingyi
Advisor(s):Engeseth, Nicki Jene
Department / Program:Food Science & Human Nutrition
Discipline:Food Science & Human Nutrition
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Deep-fat frying
oil performances
French fries
Abstract:Deep-fat fried food is popular for its unique and desirable characteristics. In this study, the effects of deep-fat frying on oil deterioration were analyzed for soybean oil, palm olein and palm stearin. Frying performances were studied through 100 cycles of intermittent frying of French fries without replenishment of oils. Color changes were noticeable with increased frying time. Peroxide value was unstable and fluctuated over time. The p-Anisidine value increased fastest for soybean oil, with a final value of 190.84 at 100 cycles. With respect to the content of total polar compounds, the stability of the oils decreased in the order of palm stearin > soybean oil = palm olein at 100 cycles. Heated control oils showed much lower content of free fatty acids than fried oils with French fries. Palm stearin showed highest oxidative stability in p-Anisidine value and total polar compounds, however, the solidification of oils on the food surface during cooling make it unsuitable for practical use. Oil type was observed to have a significant effect on the changes of principal physicochemical parameters during repeated deep-fat frying. One of the characteristic features of palm oil is its high content of carotenoids. This prompted the study of the effect of β-carotene as an antioxidant in deep-fat frying. β-carotene was added to palm olein at a concentration equivalent to the total carotenoids in crude palm oil. With respect to p-Anisidine value, the antioxidant contribution of carotenoids was negligible under high temperature, as no significant difference was observed between palm olein containing β-carotene and the one without. Palm olein containing β-carotene developed higher total polar compounds and free fatty acids inversely, indicating a probable pro-oxidant effect of β-carotene at a concentration of ~0.07%.
Issue Date:2019-07-17
Rights Information:Copyright 2019 Jingyi Meng
Date Available in IDEALS:2019-11-26
Date Deposited:2019-08

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