Improved protein extraction from thermally processed shrimp (Litopenaeus vannamei) for reliable immunodetection via a synergistic effect of buffer additives

Understanding the Mechanism of Increased IgG/IgE Reactivity but Decreased Immunodetection Recovery in Thermally Induced Shrimp (Litopenaeus vannamei) Tropomyosin via Multispectroscopic and Molecular Dynamics Simulation Techniques

“…Similarly, our recent findings also confirmed that the major allergen TM could retain its extractability and IgG/IgE immunoreactivity after various cooking treatments. , Additionally, both heat-treated nTM and rTM showed higher IgG/IgE binding capacity than the control (25 °C), and autoclaved TM displayed the highest IgG/IgE binding value according to IgG/IgE immunoblotting and indirect ELISA analysis. Similarly, our recent findings demonstrated that the TM from different cooked shrimp (Litopenaeus vannamei) extracts showed significantly increased IgG/IgE binding capacity. , The increased IgE reactivity from TM also was found in the investigation of cooked extracts of blue swimmer crab (Portunus pelagicus) and other crustacean extracts, including shrimps (Penaeus sp), American lobster (Homarus sp), and spiny lobster (Palinurus sp), which might be attributed to the alteration of epitopes, thus promoting the antigen–antibody interaction. , Significantly, the rTM showed higher IgG binding capacity and lower IgE binding capacity, which might be due to their structural difference. Furthermore, the in vitro digestibility of both heat-treated nTM and rTM was significantly improved compared to the control, and the digested fraction from autoclaved TM could be detected within 1 min of SGF and SIF digestion.…”

“…Tropomyosin (TM), a major allergen identified in various crustaceans, is highly heat-stable due to its characteristic α-helical coiled coil, which is responsible for 72–98% of shrimp-allergic patients, exhibiting a positive IgE-mediated allergic reaction. ,, Consequently, TM is always considered the main target for the immunodetection of crustacean residues to meet food labeling regulations. However, our recent study confirmed that thermal processing can pose a considerably negative influence on crustacean residue detection . Lin et al also observed that the recoveries of TM in steamed shrimp (3 min) extracts varied from 54.5 to 90.1% in different shrimps using a TM-based sELISA test in contrast with raw shrimp extracts, despite the fact that TM with highly stable structural characteristics.…”

“…Lin et al also observed that the recoveries of TM in steamed shrimp (3 min) extracts varied from 54.5 to 90.1% in different shrimps using a TM-based sELISA test in contrast with raw shrimp extracts, despite the fact that TM with highly stable structural characteristics. Similarly, significant poor immunodetection recoveries in processed foods also were found in numerous other allergen analyses, including soybean allergen, milk allergen, and peanut allergen, by the sELISA test, but the molecular basis for such an effect has not been elucidated yet. ,, Significantly, earlier studies indicated that TM maintained its IgG reactivity under common thermal treatments, even displaying stronger IgG/IgE reactivity. − As one of the most important and widely used techniques in the household and food industries, thermal processing can alter protein structure and decrease the extraction efficiency of allergenic proteins, therefore altering the antigenicity of food allergens. , Meanwhile, any alterations in the target protein can influence the antibody’s recognition and may adversely affect the results of the detection. , A better understanding of how thermal processing affects the target protein structure and its immunodetection, which are vital to fabricating an appropriate and reliable allergen control protocol as well as mitigating hazards for allergic consumers.…”

A sensitive sandwich enzyme‐linked immunosorbent assay (sELISA) targeted multiple wheat protein fractions for the detection of several cereal grains in processed foods

“…Whereas for the autoclaved wheat flours and baked wheat flours at higher temperatures (160, 200, and 240 • C), the severe processing conditions cause large aggregation and loss of protein fractions with significant underestimation in wheat protein level (p > 0.05) (Figure 2b,c). Interactions with other proteins, fat, and carbohydrates in the food matrix can bring about significant structural modification during processing (Tiwari et al, 2010;Zhao et al, 2022). Similarly, earlier research has shown that the formation of colored compounds due to the Maillard reaction does not dramatically alter up to 120 • C, but has increased rapidly at 150 • C in the wet gluten-glucose model system (Fogliano et al, 1999), indicating that higher temperature condition (≥150 • C) could induce lots of complex modification to the wheat proteins causing wheat protein unextractable.…”

“…Similar underestimation also was found in processed whole egg powder (Fu et al, 2010) and laboratory-prepared peanut flours (Fu & Maks, 2013) using commercial ELISA test kits from Veratox (Neogen Corp. Lansing, MI, USA), Biokits (Tepnel Biosystems, Ltd, Deeside, UK) and Morinaga kit (Morinaga Institute of Biological Science, Inc., Yokohama, Japan). In our previous study, thermal treatments resulted in a 39.27−71.15% reduction in the yield of tropomysion when shrimps were subjected to varied thermal treatments, such as boiling, baking, autoclaving, steaming, frying, and microwaving (Zhao et al, 2022). To construct the antibody-antigen-antibody complex, immunodetection requires at least two or more binding sites in the target allergen.…”