Nutritional quality of different grades of adult male chinese mitten crab, Eriocheir sinensis

Abstract

This study mainly investigated the composition of adult male Chinese mitten crab () from four grades/sizes (Grade I: 200-249 g; Grade II: 175-199 g; Grade III: 150-174 g; Grade IV: ≤ 150 g). The results showed that the grade III crabs had the largest gonadsomatic index (GSI), which was significantly higher than the grade I and grade II crabs, no significant difference was found with the grade IV crab. Significant differences in moisture and total lipid contents were observed among various edible parts from different grades of male . In particular, grade II crabs had the highest total lipid and dry matter content for hepatopancreas. A balanced amino acids composition and a high essential amino acids score (EAAS) were found in the muscle and gonads of grade III crabs. The levels of poly-unsaturated fatty acids (PUFA), n-3 PUFA, n-6 PUFA and docosahexaenoic acid (DHA) in the hepatopancreas, as well as the contents of PUFA, highly-unsaturated fatty acids (HUFA), n-3 PUFA, arachidonic acid (ARA), and eicosapentaenoic acid (EPA) in the gonads were significantly increased in the grade II crabs. Taken together, it can generally be concluded that adult male of 150-200 g (Grade II-III) weight have the highest nutritional quality even though they are not the largest crabs.

Nutritional qualities of normal and precocious adult male Chinese mitten crabs (Eriocheir sinensis)

“…This may be attributed to the higher protein content of precocious crabs, which has been showed in table . Gly and Ala contribute sweet flavours, whereas Glu acid contributes a strong umami taste (Wang et al, ). Hence, the higher contents of these in precocious crabs may enhance the flavour of precocious crabs.…”

“…Moreover, the levels of various functional dietary substances have been determined (Sun et al, ; Wu et al, ), including highly unsaturated fatty acid, phospholipids, and Cu contents, and the comparisons were previously made between other species of crabs and between those from different places of origin (Jiang et al, ; Wang et al, ). Whereas the nutritional qualities of different grades of adult male Chinese mitten crab were determined in a recent study (Wang et al, ), studies of precocious crabs are mainly focused on factors that lead to precocity. To date, the precocity of Chinese mitten crabs has been linked to the genetic (Li, Hou, & Wei, ; Li, Kang, Zhao, Wen, & Han, ) and nutritional (Cheng & Wang, ; He, Yin, & Zhu, ) factors, to cultivation conditions such as high temperature (Xu, Zhang, & Shen, ; Zhang & Xu, ), and to imbalances of dietary lipids (Lu et al, ; Wu et al, ).…”

Effects of dietary replacement of fish oil by vegetable oil on proximate composition and odor profile of hepatopancreas and gonad of Chinese mitten crab (Eriocheir sinensis)

“…Although there was no significant difference in HSI between female and male crabs, the GSI of female crabs was higher than male crabs, it could explain that gonad of female E. sinensis reached sexual maturity on November and needed to take enough energy (Wang et al, ; Ying, Yang, & Zhang, ). HSI of female crabs in D4 was the highest, and at the same significant level with D3 and D5.…”

“…Therefore, we can conclude that the dietary replacement of FO/VO had predominant influence on the aroma profiles of gonad, followed by hepatopancreas. In addition, the results showed that the effects of dietary replacement on female crabs was greater than male crabs, this may be due to the fast ovarian maturation of female crabs in the late of fattening period (Chang et al, ; Wang et al, ).…”

“…Therefore, it may be assumed that feeds containing only fish oil or vegetable oil could not reach the best effect of weight increment. However, the growth of E. sinensis could be improved with suitable replacement of FO/VO.Although there was no significant difference in HSI between female and male crabs, the GSI of female crabs was higher than male crabs, it could explain that gonad of female E. sinensis reached sexual maturity on November and needed to take enough energy(Wang et al, 2018;Ying, Yang, & Zhang, 2006). HSI of female crabs in D4 was the highest, and at the same significant level with D3 and D5.For male crab, HSI in D4 were higher than D1 and D3, but showed no significant difference.…”