The purpose of this study was to evaluate the effect of different cooking methods on the allergenicity of cockle and to identify proteins most frequently bound by IgE antibodies using a proteomics approach. Raw, boiled, fried and roasted extracts of the cockle were prepared. The protein profiles of the extracts were obtained by separation using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and 2-dimensional gel electrophoresis (2-DE). IgE-immunoblotting was then performed with the use of individual sera from patients with cockle allergy and the major IgE-binding proteins were analyzed by mass-spectrometry. SDS-PAGE of raw extract showed 13 protein bands. Smaller numbers of protein bands were detected in the boiled, fried and roasted extracts. The 2-DE gel profile of the raw extract further separated the protein bands to ~50 protein spots with molecular masses between 13 to 180 kDa and isoelectric point (pI) values ranging from 3 to 10. Immunoblotting of raw extract exhibited 11 IgE-binding proteins with two proteins of 36 and 40 kDa as the major IgE-binding proteins, while the boiled extract revealed 3 IgE-binding proteins. Fried and roasted extracts only showed a single IgE-binding protein at 36 kDa. 2-DE immunoblotting of raw extract demonstrated 5 to 20 IgE reactive spots. Mass spectrometry analysis led to identification of 2 important allergens, tropomyosin (36 kDa) and arginine kinase (40 kDa). Heated extracts showed a reduction in the number of IgE-reactive bands compared with raw extract, which suggest that thermal treatment can be used as a tool in attempting to reduce cockle allergenicity. The degree of allergenicity of cockle was demonstrated in the order raw > boiled > fried ≈ roasted. Two important allergens reacting with more than 50% of patients' sera identified using mass spectrometric approaches were tropomyosin and arginine kinase. Thus, allergens found in this study would help in component based diagnosis, management of cockle allergic patients and to the standardisation of allergenic test products as tools in molecular allergology.
The lagoon of Setiu Wetlands has high biodiversity of bivalve’s species. The majority of villagers are fisherman and bivalves are one of their income-generating activities. Studies on parasites of bivalves are important to our knowledge for maintenance of natural resources. This study investigated the parasite prevalence among four commercially exploited shellfish species from Setiu Wetland, Malaysia. A total of 120 samples were collected during the low tide time for four shellfish species which were Polymesoda expansa, Meretrix meretrix, Anadara sp. and Crassostrea iredalei. The bivalve specimens were measured on its length with and without shell, width, height, weight and microscopically examined on the presence of parasites focused at gills, muscle and digestive tract. The discovered macroparasite were fixed into 70% ethanol solution for preservation. In this study, Anadara sp. was highest infestation of parasites, while Polymesoda expansa has the least infestation of parasites. There were occurrence of copepod and Nematopsis sp. in Anadara sp., M. meretrix and C. iredalei. Apart from that, there were other parasites observed in four bivalve species such as metacercaria, cestode larvae, Panopeus sp., Pinnotheres sp., Balanus sp. and unidentified ciliates. Ecological factors, feeding activity, season and abundance of definitive host were known to be elements that altered the prevalence of parasites in host. Upon the observation, a high prevalence of Nematopsis sp. were observed in three species of bivalves except P. expansa. Whereas for other parasites were occurred in low prevalence and intensity, without causing significant damage towards host.
Molluscan shells are attracting research interest due to the diverse application properties possessed. As shells are very similar to bones, this study was conducted to analyze the mineral and physiochemical composition of Cockle (Anadara granosa) shell and three other types of molluscan shell, namely Strombus canarium, Oliva sayana and Terebra dislocata as potential biomaterial for bone tissue engineering applications. Approximately 200 g of shells from each species were processed and powdered for the purpose of this study. Carbon was analyzed using the carbon analyzer while minerals and heavy metals through ICP-MS. The phase purity and crystallographic structures of the powders were identified using X-Ray Diffractometer (XRD) while the chemical functionality was determined using the Fourier transform infrared (FTIR) spectrophotometer. The analysis showed that Cockle shells contained higher content of calcium and carbon including varying amount of other minor elements comparatively. However, all four types of shell powders were found to contain below detectable levels of toxic elements. Physiochemical analysis on phase purity and crystallographic structures showed similar characteristics of carbonate group present in all four shell types. A predominantly aragonite form of calcium carbonate was detected in both XRD diffractogram and FTIR spectra for all samples. Our findings demonstrated that different types of molluscan shells have almost similar mineral and physiochemical characteristics and a predominantly aragonite form of calcium carbonate that provides a strong basis for their use as a potential bone tissues engineering material.