Comparative analysis of quality characteristics of muscles in different grades of two tunas
Tuna is esteemed as one of the world's three most nutritious fish species,exhibiting considerable economic values.Variability in tuna quality is significantly influenced by factors such as species,anatomical location,and capture season.In response to market demands for differentiated consumption based on quality,this study examined the abdominal muscles of yellowfin tuna(Thunnus albacares)and bigeye tuna(Thunnus obesus),which are prominent in domestic markets.Samples were categorized into two market grades based on sensory experience(grade A and grade D)and analyzed for parameters including freshness,nutritional content,color variation,and textural properties.The findings indicated that grade A tuna exhibited significantly lower levels of total volatile basic nitrogen(TVB-N)compared to grade D(P＜0.05),suggesting superior freshness.Moisture and crude protein contents displayed no significant variance in muscle grades(P＞0.05),with moisture content ranging from 74.56％to 76.22％and crude protein from 22.33％to 23.70％.Amino acid profiling identified 17 amino acids,with essential amino acids comprising over 38％of the total amino acid content,spanning from 12.14 g·100g-1 to 14.44 g·100g-1.Glutamic acid was the most prevalent amino acid(14.93％-15.11％),followed by aspartic acid,histidine,and leucine.Both amino acid score(AAS)and chemical score(CS)exceeded international standards,with tryptophan and methionine identified as the first and second limiting amino acids,respectively.No significant difference in amino acid composition was observed between different grades of two tunas(P＞0.05).The crude fat content in grade A was significantly higher than that in grade D(P＜0.05),with grade A T.albacares exhibiting a crude fat percentage of 0.98％,which was 8.91 times that of grade D.Additionally,the crude fat content in grade A T.albacares was significantly greater than that in T.obesus,by a factor of 2.39.Analysis of color differences demonstrated significant variations between grade A and grade D(A E values of 3.75 and 3.26,respectively;P＜0.05),with grade A presenting a more pronounced red hue.Textural analysis revealed no significant differences in hardness and cohesiveness between two grades.However,the elasticity and chewiness of grade A T.obesus muscles were the highest,whereas the viscosity and shear force of grade A T.albacares muscles were significantly superior to those of other grades(P＜0.05).This study offers a robust scientific basis for the accurate classification of tuna quality grades and furnishes guidelines for the specialized processing and utilization of tunas,aligning with contemporary market segmentation strategies.
Thunnus albacaresThunnus obesusTVB-Nnutritional color differencechromatismtexture characteristics
万方数据
维普
