Effects of quercetin on emissions of aldehydes from heated docosahexaenoic acid (DHA)-fortified soybean oil

 J. Hazard. Mat. 442, 130134, 2023

Home cooking has been considered as an indoor pollution problem since cooking oil fumes contain various toxic chemicals such as aldehydes. Fortifying edible oils with docosahexaenoic acid (DHA) has been applied to enhance the nutritional value of oils. This study designed a frying simulation system and examined the effect of oil type, DHA fortification, heating time, and addition of natural antioxidant on the emissions of aldehydes from heated oils. Results showed that linseed oil had the highest total aldehyde emissions, followed by soybean oil, peanut oil, and palm oil. Fortifying soybean oil with DHA increased the toxic aldehydes emitted. Quercetin, a flavonoid, significantly reduced aldehydes emitted from DHA-fortified soybean oil (by up to 39.80%) to levels similar to those of normal soybean oil. Further analysis showed that DHA-fortified soybean oil with quercetin had a significantly higher DHA and unsaturated fatty acids (UFAs) content than the control oil at each heating time point. The result indicated that quercetin inhibited emissions of aldehydes, at least in part, by protecting UFAs from oxidation. Collectively, quercetin could be used as a natural additive in DHA-fortified and normal cooking oils to reduce aldehyde emissions, indoor air pollution, and preserve functional DHA and other UFAs.

Antioxidant ability of potato (Solanum tuberosum) peel extracts to inhibit soybean oil oxidation

Eur. J. Lipid Sci. Technol. (2016)

doi:10.1002/ejlt.201500419

Potato peels are an agro industrial waste of one of the major crops worldwide. However, the potential of potato peels as source of antioxidants in the food industry is not yet sufficiently known. In this work, the antioxidant effect of potato peel extract (PPE) on oxidative stability of soybean oil was evaluated. We found that the addition of low PPE concentrations to soybean oil at four different levels, expressed as chlorogenic acid concentrations (14.01, 20.37, and 31.94 ppm), affected lipid oxidation indices (peroxide, anisidine, and conjugated dienes values), fatty acid composition, and volatile compounds. Antioxidant effect increased with increasing dose extract. Inhibition percentages of hexanal production increased with the PPE concentration. In addition, low concentrations of PPE showed higher oxidation stability than control untreated samples. Overall, our study shows that low concentrations of PPE exhibited promising antioxidant activity to be applied over a wider range of products in the food industry.

Practical applications: The prevention of lipid oxidation during processing and storage of food products is of great concern in order to obtain products of high quality and health. Together with the fact that synthetic antioxidants may constitute a potential health hazard for consumers, interest in natural antioxidants and search on naturally occurring compounds with antioxidant activity has increased dramatically. The study of the antioxidant capacity of potato peel extracts to inhibit soybean oil oxidation provides information about an alternative antioxidant further are by-products of agro-industries and their use could represent a significant step toward maintaining an environmental balance.