Quantitative profiling and comparison of biochemical, mineral, and nutritional compositions of common and stone oysters from Weizhou Island in Beibu Gulf

Oysters are ectothermic and euryhaline bivalve mollusks. The Beibu Gulf is a key mollusk aquaculture area in the northwest South China Sea. Parahyotissa numisma ( P. numisma ) and Parahyotissa sinensis ( P. sinensis ), two wild oyster species belonging to the family Gryphaeidae, are found locally on Weizhou Island and known as "stone oysters". However, limited research exists on them. Therefore, this investigation determined proximate composition, metal content, as well as nutritional and flavour-related compositions, and analysed by principal component analysis and partial mantel tests of pairwise comparisons to compared them with two commonly cultured oysters, namely Crassostrea sikamea ( C. sikamea ) and Crassostrea gigas ( C. gigas ), to quantitatively profile their quality and nutritional values. The results showed that P. sinensis had a relatively lower content of crude fat (7.1 %) but higher protein content (41.06 %), as well as the highest ash content (7.38 %). Additionally, free amino acid and free fatty acid profiles comprehensive anlaysis results indicated that P. sinensis had better nutritional value and taste. P. numisma was a suitable choice as a source of polyunsaturated fatty acids (DHA, EPA, and ARA). Therefore, stone oysters, especially P. sinensis , represent a potential seafood resource to explore for functional or flavorful ingredients for food industry applications. • P. sinensis is lean, rich in protein and ash content. • P. sinensis has better nutritional value and tastes for free amino acid and fatty acid profiles. • P. numisma is rich in polyunsaturated fatty acids (DHA, EPA, and ARA). • Stone oysters ( P. sinensis ) are promising food sources.