ABSTRACT
Tropomyosin (TM) is the main allergen in shrimp (Litopenaeus vannamei). In this study, the effects of allergenicity and structure of TM by glycosylation (GOS-TM), phosphate treatment (SP-TM), and glycosylation combined with phosphate treatment (GOS-SP-TM) were investigated. Compared to GOS-TM and SP-TM, the IgG/IgE binding capacity of GOS-SP-TM was significantly decreased with 63.9 ± 2.0 and 49.7 ± 2.7%, respectively. Meanwhile, the α-helix content reduced, surface hydrophobicity increased, and 10 specific amino acids (K30, K38, S39, K48, K66, K74, K128, K161, S210, and K251) were modified by glycosylation on six IgE linear epitopes of GOS-SP-TM. In the BALB/c mice allergy model, GOS-SP-TM could significantly reduce the levels of specific IgE, IgG1, and CD4+IL-4+, while the levels of IgG2a, CD4+CD25+Foxp3+, and CD4+IFN-γ+ were increased, which equilibrated Th1 and Th2 cells, thus alleviating allergic symptoms. These results indicated that glycosylation combined with phosphate treatment can provide a new insight into developing hypoallergenic shrimp food.
Subject(s)
Allergens , Immunoglobulin E , Penaeidae , Phosphates , Tropomyosin , Animals , Female , Humans , Mice , Allergens/immunology , Allergens/chemistry , Arthropod Proteins/immunology , Arthropod Proteins/chemistry , Food Hypersensitivity/immunology , Glycosylation , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Immunoglobulin G/chemistry , Mice, Inbred BALB C , Penaeidae/immunology , Penaeidae/chemistry , Phosphates/chemistry , Shellfish/analysis , Shellfish Hypersensitivity/immunology , Th2 Cells/immunology , Th2 Cells/drug effects , Tropomyosin/immunology , Tropomyosin/chemistryABSTRACT
Lycium barbarum seed meal contains a variety of bioactive compounds, but the use of L. barbarum seed meal in the food industry is rare. This study aimed to evaluate the effect of reducing sugars on the structural and flavor properties of the Maillard reaction products (MRPs) of the Lycium barbarum seed meal hydrolysate (LSH). The results showed that the flavors and tastes of the MRPs were affected by reducing sugars. In comparison to oligosaccharides, monosaccharides were more suitable for the development of MRPs with good sensory qualities. The structural characteristics of L. barbarum seed meal precursor MRPs were also affected by reducing sugars. The MRPs produced with the participation of monosaccharides had higher ultraviolet absorption and browning than the MRPs produced with oligosaccharides. The molecular weights of the MRPs were found to be 128-500 Da and 500-1000 Da. Compared to the MRPs made from other sugars, xylose-meridian products (X-MRPs) had a stronger meaty flavor. The mellowness and continuity of the MRPs made from monosaccharides were superior to those made from oligosaccharides. The MRPs formed by L. barbarum seed meal exhibited the characteristics of umami and meat flavor. MRPs with better flavors may be used to develop new types of seasoning salts.