Comparative study on the fillet quality of triploid Oncorhynchus mykiss with different sizes
Triploid rainbow trout has been the main upmarket cold-water fish because of its fresh meat,rich nutrition,red fillet color and marbling score.There is still a lack of systematic research on the variation of fish quality among different sizes of triploid rainbow trout.We selected nine triploid rainbow trout of small[(2.10±0.04)kg],medium[(2.93±0.02)kg]and large[(4.01±0.01)kg]from the same commercial cage to ex-plore the quality differences of triploid rainbow trout with different sizes.Meanwhile,the differences of fillet ap-parent quality,texture,nutrients and taste substances were analyzed.The results showed that in terms of ap-parent obvious quality,body length,body height,fillet length,and fillet thickness gradually increased with the increase in fish sizes,and no significant difference in fillet color was observed.Regarding fillet texture,medium and large-sized fish had higher hardness,elasticity and chewiness value and lower juice loss rate.In terms of nutritional composition,large-sized fish had a higher protein content(20.41％)and a lower fat content(13.50％),and sized fish had a higher total essential amino acid content(7.18 g/100 g).The medium-sized fish had a higher content of eicosapentaenoic acid(1.14 mg/g),docosahexaenoic acid(4.55 mg/g)and poly-unsaturated fatty acid(26.8 mg/g).In terms of taste,inosine acid(IMP)was the primary source of the umami taste of rainbow trout fillets(TAV ranges from 21.23 to 27.39),and the medium-sized fish had a high total umami activity value(28.64).Small-sized fish had a higher total sweet activity value(1.37),and large-sized fish had a lower free histidine content,so they had a lower total bitter activity value(5.57).In summary,the results of this study showed that the three-sized rainbow trout fish had similar fillet color.Small-sized triploid rainbow trout was rich in essential amino acids and sweet substances,while medium-sized triploid rainbow trout was rich in high-quality fatty acids and umami substances.rainbow trout had a firmer texture,higher protein content,and lower bitterness.Furthermore,the results of this study can provide data support for the variation pattern of rainbow trout quality and rainbow trout quality evaluation and grading.
万方数据
维普
