Effect of pressure cooking alone and in combination with other treatments on shrimp allergic protein, tropomyosin

Effects of different cooking methods on the proximate composition and physical properties of Brown shrimp (Metapenaeus dobsonii) during cooking and freezing cycle

Present study aimed to evaluate the changes in proximate composition and physical attributes in brown shrimp (Metapenaeus dobsonii) exposed to different methods of cooking followed by freezing. For this, three different grades (100/200, 200/300, and 300/500 numbers per kg) of brown shrimp were cooked at 90 °C till the core temperature of the product reaches 85 °C using hot water, steam, and microwave (400 W) techniques. The changes in yield, cooking loss, proximate composition, textural, and colour profile were assessed for cooked shrimps. The cooking loss was higher for larger grades of shrimp, whereas shrimp cooked using hot water exhibited the highest cooking loss. Lowest cooking loss was observed for microwave-cooked shrimp. Moisture content decreased after cooking whereas protein, fat, ash, and calorie content increased. After cooking, different grades of shrimp showed an increase in their lightness (L*), redness (a*), and yellowness (b*) values. The smaller grade shrimp exhibited lower value for cohesiveness, hardness, chewiness, and gumminess. Different cooking techniques yielded cooked shrimp of varying hardness values.

Covalent conjugation with polyphenol reduced the sensitization of walnut and ameliorated allergy by enhancing intestinal epithelial barrier in mice

In order to reduce the sensitization of walnut protein (WP), the effects of the interaction between WP and (-)-Epigallocatechin gallate (EGCG), quercetin, trans-ferulic acid, and resveratrol were investigated. Covalent and non-covalent conjugations were compared. The results suggested that covalent conjugation reduced the free amino acid content, sulfhydryl content, and surface hydrophobicity. When compared to non-covalent conjugation, covalent modification showed a lower IgE binding capacity, accompanied by changes in protein conformation. Moreover, animal experiments revealed that there were up-regulation of transforming growth factor-β, T-box expressed in t cells, and forkhead transcription factor Foxp3 mRNA expression, and down-regulation of IL-4, IL-17, GATA binding protein 3 and retinoid-related orphan nuclear receptor γt mRNA expression in the conjugate groups. These results suggested that covalent conjugation of polyphenols, especially EGCG, likely ameliorated allergy by promoting Th1/Th2 and Treg/Th17 balance and alleviating allergy-induced intestinal barrier damage, which might be a support in reducing the allergenicity of WP.

Effects of dielectric barrier discharge cold plasma on structure, surface hydrophobicity and allergenic properties of shrimp tropomyosin

Effects of dielectric barrier discharge (DBD) cold plasma (CP) on structure, surface hydrophobicity and allergenic properties of tropomyosin (TM) in shrimp were investigated in this study. Results showed that the molecular weight of TM increased and the protein concentration decreased with CP treatment time increased. The content of free amino acids was increased by 74.7 % and the distribution of aromatic amino acids was altered. The content of α-helix was decreased by 69 % and the surface hydrophobicity increased by 57.8 % after 20 min treatment. Allergenicity analysis showed that the IgE binding capacity decreased by 96 % after 20 min treatment, and the degranulation indexes of KU812 cells like the β-HEX release rate, the intracellular calcium ion intensity, the release of histamine and inflammatory cytokines (IL-4, TNF-α) were decreased by 32.5 %, 31.0 %, 37.3 %, 51.7 %, and 70.2 %, respectively. The current study confirmed that DBD CP could reduce the TM allergenicity through structural changes.

Crustacean shellfish allergens: influence of food processing and their detection strategies

Despite the increasing popularity of crustacean shellfish among consumers due to their rich nutrients, they can induce a serious allergic response, sometimes even life-threatening. In the past decades, a variety of crustacean allergens have been identified to facilitate the diagnosis and management of crustacean allergies. Although food processing techniques can ease the risk of crustacean shellfish allergy, no available processing methods to tackle crustacean allergies thoroughly. Strict dietary avoidance of crustacean shellfish and its component is the best option for the protection of sensitized individuals, which should rely on the compliance of food labeling and, as such, on their verification by sensitive, reliable, and accurate detection techniques. In this present review, the physiochemical properties, structure aspects, and immunological characteristics of the major crustacean allergens have been described and discussed. Subsequently, the current research progresses on how various processing techniques cause the alterations and modifications in crustacean allergens to produce hypoallergenic crustacean food products were summarized and discussed. Particularly, various analytical methodologies employed in crustacean shellfish allergen detection, and the effect of food processing and matrix on these techniques, are also herein emphasized for the appropriate selection of analytical detection tools to safeguard consumers safety.