Abstract: Taking the eutectic point as the final freezing temperature, the differences of flavor substances of in hand grab mutton (HGM) frozen at three rates of 0.26 cm/h (-18℃), 0.56 cm/h (-40℃) and 2.00 cm/h (-80℃) were determined and analyzed. The results showed that the flavor of HGM decreased significantly after freezing. With the increase of freezing rate, the contents of aldehydes, alcohols, ketones, acids, esters, others, free amino acids and 5′-nucleotides were higher, and the content of specific substances was also generally increased. All samples from unfrozen and frozen HGM could be divided into four groups using an electronic nose based on different flavor characteristics. Seven common key aroma components were determined by relative odor activity value (ROAV), including hexanal, heptanal, octanal, nonanal, (E)-2-octenal, (E, E)-2,4-decadienal and 1-octen-3-ol. The higher the freezing rate, the greater the ROAVs. Taste activity values calculated by all taste substances were far less than 1, and the direct contribution of the substances to the taste of HGM was not significant. The equivalent umami concentration of HGM frozen at -80℃ was the highest. These findings indicated that higher freezing rate was more conducive to the retention of flavor substances in HGM, and the flavor fidelity effect of freezing at -80℃ was particularly remarkable.

摘要：以共晶点为最终冷冻温度，分别以 0.26 cm/h（-18℃）、0.56 cm/h（-40℃）和 0.56 cm/h（-40℃）三种速率冷冻手抓羊肉（HGM）风味物质的差异。测定和分析2.00 cm/h (-80℃)。结果表明，HGM冷冻后风味明显下降。随着冷冻速度的增加，醛类、醇类、酮类、酸类、酯类等、游离氨基酸和5'-核苷酸的含量较高，特定物质的含量也普遍增加。来自未冷冻和冷冻的 HGM 的所有样品可以根据不同的风味特征使用电子鼻分为四组。通过相对气味活性值 (ROAV) 确定了七种常见的关键香气成分，包括己醛、庚醛、辛醛、壬醛、(E)-2-辛醛、(E, E)-2、4-癸烯醛和 1-octen-3-ol。冻结率越高，ROAV 越大。所有味觉物质计算的味觉活性值远小于1，物质对HGM味觉的直接贡献不显着。-80℃冷冻HGM的当量鲜味浓度最高。这些发现表明，较高的冷冻速率更有利于HGM中风味物质的保留，其中-80℃冷冻的风味保真效果尤为显着。