ABSTRACT
BACKGROUND: Asiatic hard clam (Meretrix meretrix) is an underutilized bivalve resource. This study discusses dried clam powders prepared from this resource to enhance its utilization and improve nutritional security in protein-deficient populations. Dried clam powder was prepared from Asiatic hard clam and the effects of different pre-cooking methods (boil-dried clam powder, BDCP; steam-dried clam powder, SDCP; and microwave-dried clam powder, MDCP) on nutritional (proximate composition, amino acid profiling, mineral profiling, fatty acid profiling) and physicochemical qualities were investigated. RESULTS: Different pre-cooking methods significantly influenced the characteristics of the clam powder. The MDCP sample showed the highest concentration of amino acids, polyunsaturated fatty acids, Na, K, Ca and Mg content compared to BDCP and SDCP. The boiling process led to a loss of nutritional quality in terms of amino acids and macrominerals. The MDCP displayed the highest solubility in water (30.10%) but its oil and water absorption characteristics were the lowest among all the samples. Boil-cooked clam powder displayed the highest oil binding (2.03 mL g-1 protein) capacity. Boiling and steaming processes resulted in malondialdehyde generation compared to microwaving. Different pre-cooking processes did not influence the colour attributes significantly, but the control sample prepared without pre-cooking (CCP) had a significantly lower L* value (32.34), resulting in a darker product. In vitro digestibility of the clam powder varied in the order MDCP > SDCP > BDCP > CCP. CONCLUSION: The study demonstrated that nutritionally rich protein powder can be prepared from Asiatic hard clam. Based on the results, microwave pre-cooking is considered the best pre-cooking method to preserve the nutritional qualities of clam powder. © 2024 Society of Chemical Industry.
Subject(s)
Amino Acids , Bivalvia , Cooking , Fatty Acids , Nutritive Value , Powders , Animals , Bivalvia/chemistry , Amino Acids/analysis , Amino Acids/chemistry , Fatty Acids/chemistry , Fatty Acids/analysis , Powders/chemistry , Shellfish/analysis , Food Handling/methods , Desiccation/methodsABSTRACT
Shrimp allergen, tropomyosin is a highly heat stable allergen a common causative of shrimp allergy in sensitive individuals. Effect of house hold pressure cooking on immunogenicity of shrimp allergen, topomyosin from Metapenaeus dobsoni was investigated in both shrimp extract and peeled shrimp by extending the time of pressure cooking to 5, 10 and 20 min. Soaked shrimps in salt, baking soda, papain and acetic acid along with pressure cooking was also investigated. In the case of extracts, IgE activity was significantly (p < 0.05) decreased and the tropomyosin band was absent in the immunoblott using pooled sera of shrimp sensitive individuals. While in the case of whole peeled shrimp, IgE activity was significantly (p < 0.05) increased and the tropomyosin band was retained in the immunoblott analysis which indicates the retention of allerginicity in the peeled shrimp. Although pressure cooked shrimp after soaking in acetic acid didn't show significant (p > 0.05) difference to that of without soaking, the tropomyosin band was observed to be very faint or absent in SDS PAGE and immunoblott analysis which indicated the effective reduction in allegenicity of whole peeled shrimp.
ABSTRACT
Shrimp allergy, a common form of food allergy is an adverse immunological response to shrimp proteins. BALB/c mice was sensitized by an adjuvant free oral administration of purified tropomyosin, from Metpenaeus dobsonii to characterize intestinal histological responses and immunological protein recognition pattern as it is unpractical in human subjects. Sensitized mice with higher dose of tropomyosin expressed symptoms of anaphylaxis including puffiness around eyes and snout, no activity, tremor and convulsion after challenge. The responses of high level of sera IgE, tropomyosin specific IgE and histamine in the treatment groups indicated the increased allergic reaction by ELISA. Sera IgE of sensitized mice exhibited a comparable recognition pattern to tropomyosin by immunoblotting similar to human subjects. Histological changes were comparatively highly affected in the intestinal area of duodenum in the sensitized mice. Hence BALB/c mice can be used as a suitable adjuvant free shrimp allergy model for immunotherapy tools.
