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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Functional Foods Research » Research » Publications at this Location » Publication #369562

Research Project: Improving Quality, Stability, and Functionality of Oils and Bioactive Lipids

Location: Functional Foods Research

Title: Amino acids as natural antioxidants for frying: Feasibility for practical application and factors affecting the activity

item Hwang, Hong-Sik
item Moser, Jill
item Liu, Sean

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2020
Publication Date: 7/15/2020
Citation: Hwang, H., Moser, J.K., Liu, S.X. 2020. Amino acids as natural antioxidants for frying: Feasibility for practical application and factors affecting the activity. Meeting Abstract. IFT Annual Meeting & Food Expo 2020. July 12-15, 2020, Chicago, IL.

Interpretive Summary:

Technical Abstract: Although there are several reports on antioxidant activity of amino acids, they are not used in the food industry. Our research group reported that some amino acids were very effective in preventing oxidation of frying oil. For practical application of amino acids as natural antioxidants for frying, the properties of amino acids were further investigated. Amino acids that showed strong antioxidant activity typically contained an extra amine group, a thioether, or a thiol group indicating that these functional groups play an important role in the activity. It was also found that the synergistic effect with tocopherols is an important mechanism for the activity amino acid. Amino acids with greater lipophilicity generally had higher antioxidant activity. Although amino acids are known to chelate metals to reduce oxidation of oil, it was not confirmed in this study that the chelation of metal was a factor for the activity in soybean oil heated at 180 ºC. Formation of peptide bonds between amino acids negatively affected the activity so that protein hydrolysates and dipeptides were not as effective as single amino acids. Methionine also had strong antioxidant activity in sunflower, peanut, corn, canola, high oleic soybean, and olive oils. Activity of methionine and lysine was even stronger than that of the leading commercial natural antioxidant, rosemary extract. This presentation will also provide information on the concentration effect and interactions with currently used antioxidants such as tocopherols, rosemary extract, green tea extract, and ascorbic acid.