发酵时间对干盐腌制臭鳜鱼品质及蛋白构象的影响

Effects of Fermentation Time on the Quality and Protein Conformation of Dry Salted Stinky Mandarin Fish

臭鳜鱼是我国安徽黄山地区的特色发酵鱼制品。臭鳜鱼的腌制发酵是一个持续的演化过程,发酵时间是影响臭鳜鱼品质的重要因素。文章探讨在干盐腌制(加盐量6%,12℃)条件下,发酵时间(0~9 d)对臭鳜鱼肉质的影响。结果发现:在9 d时间内,臭鳜鱼的pH值从6.95逐步降低至6.75,水分含量从78.1%降低至65.8%,蒸煮损失从32.34%下降至11.14%,总体而言保水性提高;从水分的分布来看,不易流动水占比明显上升、自由水比例明显下降,与保水性结果一致;臭鳜鱼的硬度随发酵时间呈上升趋势,从2177 g上升至3397 g;臭鳜鱼的风味强度逐步增强,特别是芳香族化合物和醇类化合物成分明显增加,二者是臭鳜鱼的主要气味成分;蛋白质二级结构向解螺旋结构转化,α-螺旋结构从60%降低至44%,β-折叠、β-转角、无规则卷曲都有一定的增长。臭鳜鱼蛋白的二级结构与品质指标之间存在明显的相关性,因此通过拉曼光谱测定蛋白质的二级结构可以用于快速判定臭鳜鱼的品质。

Stinky mandarin fish(Siniperca chuatsi)is a local characteristic fermented fish product in Huangshan area of Anhui province.The fermentation of stinky mandarin fish is a continuous evolution process,so the fermentation time is an important factor that affect the quality of stinky mandarin fish.The effect of fermentation time(0~9 days)on the meat quality of stinky mandarin fish under the condition of dry curing(salt 6%,12℃)were investigated.The results showed that the pH of stinky mandarin fish gradually decreased from 6.95 to 6.75 within 9 days.The moisture content dropped from 78.1%to 65.8%;The cooking loss decreased from 32.34%to 11.14%,and the water-holding capacity was generally improved.From the perspective of water distribution,the proportion of immobilized water increased significantly,while the proportion of free water decreased significantly,which was consistent with the result of cooking loss.The hardness of mandarin fish increased with fermentation time,from 2177 g to 3397 g.The intensity of flavor increased gradually,especially aromatic compounds and alcohol compounds,which were the main odor components of stinky mandarin fish.The secondary structure of protein was transformed into nonhelical structure,theα-helix structure was reduced from 60%to 44%,and theβ-fold,β-turn and random coil were all increased.There was an obvious correlation between the secondary structure of the protein and the quality attributes,so the determination of the secondary structure by Raman spectroscopy can be used to quick determination,The secondary structure of protein can be used as an indicator of the quality change of mandarin fish to quickly determine the quality of mandarin fish.