Lipids in foods are sensitive to various environmental conditions. Under light or high temperatures, free radicals could be formed due to lipid oxidation, leading to the formation of unstable food system. Proteins are sensitive to free radicals, which could cause protein oxidation and aggregation. Protein aggregation significantly affects protein physicochemical characteristics and biological functions, such as digestibility, foaming characteristics, and bioavailability, further reducing the edible and storage quality of food. This review provided an overview of lipid oxidation in foods; its implications on protein oxidation; and the assessment methods of lipid oxidation, protein oxidation, and protein aggregation. Protein functions before and after aggregation in foods were compared, and a discussion for future research on lipid or protein oxidation in foods was presented.

Peanut, an important oil crop worldwide, is highly susceptible to oxidative damage during storage due to its high level of fats and unsaturated fatty acids which will affects its nutritional value and agricultural importance. Therefore, it is significantly important to research the physicochemical properties changes of peanuts during storage. Peanuts belong to two varieties were stored at various temperatures (15°C, 25°C, and 35°C) for 320 days. Peroxide value (PV), carbonyl value (CV), and malondialdehyde (MDA) content of oil extracted from peanuts were determined every 80 days to evaluate lipid oxidation degree. Proximate composition (fat, protein, total sugar, moisture, and ash), fatty acid, and amino acid compositions were also assessed. All samples exhibited increased CV and MDA contents during storage. The PV of peanuts increased continuously when stored at 15°C and 25°C, but the PV increased firstly and then decreased sharply when stored at 35°C. Storage significantly affected the contents of lipids, proteins, total sugars, and moisture in peanuts but did not influence the ash content. In general, the fatty acid and amino acid compositions changed significantly during storage at different temperatures. High temperatures lead to a high degree of lipid oxidation and nutrient loss. The results above of this study can provide a theoretical basis for the actual storage and preservation of peanuts.