Tyrosinase/caffeic acid cross-linking alleviated shrimp (Metapenaeus ensis) tropomyosin-induced allergic responses by modulating the Th1/Th2 immunobalance

Enzymatic crosslinking and food allergenicity: A comprehensive review

“…Enzymatic treatments can further improve the digestibility of TM and dramatically reduce the recognitions of IgG/IgE of the digested crosslinked TM samples. The secretions of cytokines and mediators from KU812 and RBL-2H3 cells could be significantly inhibited upon stimulation with crosslinked TM, thereby revealing the abridged stimulation abilities upon enzymatic crosslinking (Ahmed et al, 2020(Ahmed et al, , 2021.…”

“…Enzyme to substrate ratio and reaction conditions such as temperature, time, and pH are imperative factors in obtaining maximum polymerization of allergenic proteins. The addition of small phenolic mediators in combination with oxidative enzymes has shown higher efficacy to improve the crosslinking ability of enzymes by providing additional functional groups and reactive sites (Ahmed et al, 2021;Heck et al, 2013;Isaschar-Ovdat & Fishman, 2018). Figure 2 presents the proposed underlying mechanism of crosslinking of food allergens catalyzed by crosslinking enzymes in the presence and absence of phenolic mediators.…”

“…Enzymatic crosslinking helps in the improvement and protection of the life quality of shellfish-sensitized/allergic individuals by developing hypoallergenic shellfish products. TYR, LAC, TG, and HRP can alter the biochemical structure of shellfish allergen via crosslinking and aggregation, which subsequently reduce the immunological properties (Ahmed et al, 2018(Ahmed et al, , 2021Liu et al, 2017;Yuan et al, 2017). A number of recent studies on the influence of enzymatic treatment on the allergenicity of shellfish allergens are listed in Table 2.…”

“…Enzymatic crosslinking inhibited the degranulation of RBL-2H3 cells and reduced the allergenic potency in a mouse model. Enzymatic crosslinking has shown high potential to downregulate Th2 related cytokines and upregulate the Th1 and Tregs in the splenocytes, along with the reduction in the serum IgG1, IgE, mMCP-1, histamine, and tryptase levels (Ahmed et al, 2021;Liu et al, 2017). Yuan et al (2017) studied the influence of TG-catalyzed glycosylation on the allergenic potential of shrimp TM.…”

“…Oxidative enzymes such as tyrosinase (TYR) and laccase (LAC) have shown promise as novel crosslinking agents in processing food. TYR can catalyze orthohydroxylation of monophenols to o-diphenols, which subsequently converted to o-quinones upon oxidation, and these quinones further react non-enzymatically with tyrosines, sulfhydryls, amides, amines, and/or with each other to form inter-and/or intramolecular crosslinks (Ahmed et al, 2018(Ahmed et al, , 2021Tian et al, 2019). Whereas, LAC is capable of forming free radicals by catalyzing the oxidation of wide-ranging compounds by a singleelectron removal mechanism that subsequently undergoes further polymerization reactions non-enzymatically with other free aromatic groups or phenolic radicals from the coupling of reactive radical intermediates (Isaschar-Ovdat & Fishman, 2017;Stanic et al, 2010).…”