Impact of frying practices and frying conditions on the quality and safety of frying oils used by street vendors and restaurants in Nairobi, Kenya

Karimi, Solomon; Wawire, Michael; Mathooko, Francis M.

doi:10.1016/j.jfca.2017.07.004

Cited by 51 publications

(34 citation statements)

References 28 publications

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“…Also, there was a weak correlation between p-AV and the other parameters because p-AV targets secondary oxidation products, while F I G U R E 3 Rancidity measurements of the discarded frying oil samples from fast food restaurants. (a) Total polar compound; (b) peroxide value; (c) panisidine value; and (d) free fatty acid the rest of the parameters are more sensitive to both the primary oxidation and the hydrolysis stages of frying oil breakdown (Karimi, Wawire, & Mathooko, 2017;Sebastian et al, 2014).…”

Section: Variables Resultsmentioning

confidence: 99%

Evaluating the rancidity and quality of discarded oils in fast food restaurants

Esfarjani

Khoshtinat

Zargaraan

et al. 2019

Food Science & Nutrition

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This cross‐sectional study attempts to determine the rancidity and quality of discarded oils in fast food restaurants. Samples of the discarded frying oils were collected randomly from 50 fast food restaurants in Tehran, Iran. Their physicochemical properties were assessed and compared to the standard values. The means (± SD ) of the physicochemical indicators of the rancidity in the discarded oils were as follows: peroxide value, 3.06 (0.51) (mEq/kg); free fatty acids content, 1.52 (2.26) (%); p ‐anisidine value, 57.63 (4.02) (mEq/kg); total oxidation value, 64.53 (4.15); total polar compounds (TPC), 20.19 (1.02) (%); viscosity, 107.87 (2.35) (cp); and red color, 9.64 (0.84). Positive correlations were found between the TPC, viscosity, and red color ( p ≤ 0.01) of the oil samples. The majority of discarded oil from fast food restaurants were overdegraded containing hazardous secondary oxidative products, and also, the consumption of nonstandard frying oil has increased in fast food restaurants. Policymakers should develop guidelines to determine whether and when frying oils should be discarded and consider the consumption of overdegraded oils as a public health hazard.

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Section: Variables Resultsmentioning

confidence: 99%

Evaluating the rancidity and quality of discarded oils in fast food restaurants

Esfarjani

Khoshtinat

Zargaraan

et al. 2019

Food Science & Nutrition

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“…The safety of deep‐fried foods largely depends on the quality of the frying oil . Although deep frying makes food taste good, many chemical reactions – including oxidation, hydrolysis, fission, and polymerization – also occur during deep frying, because the oil is exposed to oxygen and moisture from the food at high temperatures. These reactions continue to occur as the oils are used repeatedly.…”

Section: Introductionmentioning

confidence: 99%

A Novel Evaluation Index for Predicting the Degradation Rate of Frying Oils Based on Their Fatty Acid Composition

Liu

Hoshino

Wang

et al. 2018

Euro J Lipid Sci & Tech

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The changes in the fatty acid composition of eleven edible oils (soybean, rapeseed, natural and refined sesame, corn, safflower, olive, rice bran, natural and refined perilla, coconut) are investigated during deep frying. French fries are intermittently fried for 5 h each day for 6 consecutive days at 180 °C in these oils. The results suggested that all of the oils contained large amounts of unsaturated fatty acids (83.49–95.28%) before deep frying, except for coconut oil (7.13%). With the extension of frying time, the content of unsaturated fatty acids in the oils decreased linearly (Y = −AT + 100, R2 = 0.955–0.990) except in the coconut oil. The equation (A = 0.113X + 0.203, R = 0.836) can be used to determine the decomposition rate of unsaturated fatty acids (A) in a variety of unsaturated fatty acid‐based oils. The ratio of palmitic acid to oleic acid in the oils before deep frying (X) has an important impact on the degradation of a variety of unsaturated fatty acid‐based oils, and can be used as an evaluation index for predicting the degradation rate of such oils before deep frying. Practical Applications: Changes to the unsaturated fatty acid content of a variety of unsaturated fatty acid‐based oils during deep frying can be predicted using this novel evaluation index. A clear understanding of the deterioration process of frying oils can be obtained when the index is combined with other indicators of deterioration. The index can facilitate timely judgments to prevent the over‐use of frying oils according to the waste oil standards of individual countries. This would maximize the utilization of oil while reducing the production of substances that are harmful to the human body. With the extension of frying time, the content of unsaturated fatty acids in the oils decreased linearly (Y = −AT + 100). The equation (A = 0.113X + 0.203) can be use to determine the decomposition rate of unsaturated fatty acids in a variety of unsaturated fatty acid‐based oils. X is the ratio of palmitic acid to oleic acid in the oils before deep frying, and can be use as an evaluation index for predicting the degradation rate of a variety of unsaturated fatty acid‐based oils before deep frying.

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“…Meanwhile, the above results also indicate the leaching of FFA into the frying oil from clam tissues. FFA is more susceptible to oxidation, which may increase the oxidation level of frying oil (Frega et al, ; Karimi et al, ).…”

Section: Resultsmentioning

confidence: 99%

Impact of Frying on Changes in Clam (Ruditapes philippinarum) Lipids and Frying Oils: Compositional Changes and Oxidative Deterioration

Liu

Zhou

Rakariyatham

et al. 2019

J Americ Oil Chem Soc

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The current study shows the compositional changes and oxidation development of clam (Ruditapes philippinarum, R. philippinarum) lipids and frying oils when subjected to different processing conditions. Parameters measured include acid value, peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), total oxidation (TOTOX), lipid classes, fatty acid composition, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) contents together with major glycerophospholipid (GP) molecular species. Deep-fat frying increased triacylglycerol (TAG) content and decreased the contents of PC, PE, and GP molecular species in clam in a timedependent manner. Meanwhile, minor amounts of free fatty acids, diacylglycerols, monoacylglycerols, and polar lipids were detected in frying oils, indicating lipid migration between the clam and frying oils. The time-dependent increase of POV, TBARS, and TOTOX in fried clams and frying oils with concurrent reduction of docosahexenoic acid and eicosapentaenoic acid indicates extensive oxidative degradation of clam lipids. Moreover, the moisturerich clam aggravated the deterioration of frying oils. Consequently, deep-fat frying significantly altered the lipid profile and decreased the nutritional value of clams.

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Impact of frying practices and frying conditions on the quality and safety of frying oils used by street vendors and restaurants in Nairobi, Kenya

Cited by 51 publications

References 28 publications

Evaluating the rancidity and quality of discarded oils in fast food restaurants

Evaluating the rancidity and quality of discarded oils in fast food restaurants

A Novel Evaluation Index for Predicting the Degradation Rate of Frying Oils Based on Their Fatty Acid Composition

Impact of Frying on Changes in Clam (Ruditapes philippinarum) Lipids and Frying Oils: Compositional Changes and Oxidative Deterioration

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