Mechanisms and Combined Technologies for Reduction of Allergenic Potential in Peanuts and Tree Nuts

Abstract Nuts are nutrient-dense foods, along with being a source of healthy fats. It has been observed that nut allergies have been increasing substantially, which can lead to severe allergic reactions such as rashes, shortness of breath and life-threatening anaphylaxis. Hence, identifying and eliminating nut allergens are important and critical food safety concerns. Food processing techniques may have a significant effect on allergenic protein, which may also affect allergenicity. This article reviews the effect of different food processing methods on allergens and allergenicity of nuts. It delves into the mechanism of thermal, chemical, biological and novel technologies leading to a reduction in allergens. The article also mentions different allergens present in the nuts and how some types of allergens are more susceptible to specific treatments. To improve the reduction, combination treatments and the effect on protein should be considered. The nut allergens are classified into various superfamilies and subfamilies. For instance, processing conditions cause denaturation, insolubility, unfolding and aggregation of allergenic proteins, leading to a reduction in allergenicity, immunoglobulin E (IgE) binding and immunoreactivity in nuts. The effect on reduction of allergenic potential and protein varied depending on the processing conditions. Alcalase enzyme treatment shows 99.8–100% degradation of the Ara h 3 and Ara h 1. Fermentation for 48 h and chemical treatment with sodium sulphite at 37 ℃ can reduce approximately 90% and 65% IgE activity, respectively. Additionally, on average, cold plasma and high-pressure processing (HPP) can reduce 54.6% from fat free peanut flour and 72% Ara h 1 allergen at 600 MPA for 20 min, respectively, attributing to reactive oxygen and nitrogen species production during cold plasma and protein denaturation due to very high pressure. This paper concludes that combining novel technologies can significantly reduce allergens, ensure food safety and maintain nutritional quality.