几种海水和淡水贝类的大宗营养成分比较研究

Comparison of macronutrient components of several marine and freshwater shellfish

摘要:

分别对3种淡水贝和3种海水贝的大宗营养成分进行了较为系统的研究。总体而言，这6种贝的水分含量相差不大，但粗蛋白、粗脂肪和灰分含量却相差明显。其中，波纹巴非蛤和长竹蛏属于高蛋白贝类，其蛋白占干物质的75%，而其脂肪和灰分含量中等，分别占8%和14%左右；近江牡蛎和河蚌属于多脂肪贝类，其脂肪含量在所测贝类中最高,约占干物质的14%，而蛋白和灰分则相对较少，分别为14%和6%；螺蛳和中华圆田螺属于高灰分贝类，其灰分含量高达27%，蛋白居中（60%），而脂肪最低（3%）。在蛋白质量方面，这几种贝类的氨基酸评分总体略低于全鸡蛋蛋白，但其赖氨酸评分优于全鸡蛋蛋白，在与粮谷类的搭配上具有更明显的蛋白质增效作用。在脂肪质量方面，海水贝的多不饱和脂肪酸特别是EPA和DHA明显比淡水贝高，如属于海水贝的长竹蛏、波纹巴非蛤、近江牡蛎的EPA和DHA的含量总和分别为14.19%、25.51%和34.29%，而属于淡水贝的中华圆田螺完全不含EPA或DHA，海水贝在脂肪营养方面明显优于淡水贝。在矿物质营养方面，淡水螺表现出非常明显的优势，有开发成补充多种矿物质之天然膳食补充剂的潜力。本研究对指导人们按各自的营养需求选择不同的贝类品种具有非常重要的意义。

Abstract:

This paper reported and compared macronutrient components of six species of marine and freshwater shellfish in China. Marine shellfish species included 〖Crassostrea ariakensis (the Jinjiang or Asian oyster), Solen strictus (razor clam), and Paphia undulata (shortnecked clam or undulated surf clam). Freshwater species were Anodonta woodiana (Chinese pond mussel, the Eastern Asiatic freshwater clam or swanmussel), Cipangopaludina cathayensis (river snail), and Bellamya purificata (mud snail). No significant differences were found in water content of edible portions among all species except the Chinese pond mussel. However, remarkable differences were detected in contents of crude protein, lipid, and ash. Razor and shortnecked clam was classified as shellfish with high protein, containing approximately 75% protein, 8% lipid, and 14% ash (at dry mass), respectively. Chinese pond mussel and the Jinjiang oyster belonged to shellfish species rich in lipid (14% lipid, 50% protein, and 6% ash). River and mud snails were grouped as shellfish with high ash (30% ash, 60% protein, and 3% lipid). Based on amino acid scores, protein quality of these shellfish was slightly lower than whole egg protein in general. However, score of lysine was higher than that of whole egg protein, indicating that shellfish meat can exert better complementary effects of proteins if combining with food stuffs in lack of lysine especially grains and cereals. Regarding lipid quality, marine shellfish showed more advantages than freshwater species since the former contained higher polyunsaturated fatty acids especially eicosapentaenoic acid (EPA) and docosahaenoic acid (DHA) than the latter. The total amount of EPA and DHA in razor and shortnecked clams, and the Jinjiang oyster was 14.19%, 25.51% and 34.29%, respectively. However, no EPA or DHA was detected in river snail. In mineral nutrients, two species of snails possessed promising potential and might be applied in development of natural dietary supplements for minerals. This study provided useful information for consumers during decision on shellfish selection according to their nutritional requirements (fit for purpose).