该研究采用分子量截留法将猪骨素分为3个组分，并以感官分析法对猪骨素组分增鲜及增鼻后香气能力进行评价，进一步对猪骨素中蛋白组分的分子量分布、疏水性情况进行评价分析，探讨其蛋白质组分疏水性聚集与其增鲜、增香能力间关系。结果表明，变性剂处理后，猪骨素中>30 ku组分可由36.07%降至2.95%，说明其蛋白存在聚集现象；将3个组分分离冻干后感官分析发现，PBE（10~30 ku）组分在以NaCl为基底的溶液中评分分别为咸味7.6、浓厚度8.6、连续性7.6、口感丰富度8.0，高于另两种组分的感官评分，而其香气鼻后感受评分为7.5，也高于另两种组分。对3个组分进行分析发现，PBE（10~30 ku）的鲜味及甜味氨基酸含量分别为14.7%及44.19%，与PBE（>30 ku）差异不具显著性，但其增鲜效果显著高于该组分，而分析疏水性后发现，PBE（10~30 ku）组分的疏水性指数为60.00±1.33，与另两种组分差异存在显著性，据此推测呈味氨基酸（鲜味、甜味）含量高对PBE（10~30 ku）组分的增鲜增香效果起到一定提升作用，但只有蛋白质或肽的整体疏水性在一定范围内时，其鲜味及香气增强作用才最佳。最后，疏水性与增鲜、增鼻后香气感受方面关系由40及70 ℃加热处理实验所证明。

In this study, the molecular weight cut-off method was used to divide pork bone essence (PBE) into three fractions, and sensory analysis was performed to evaluate the enhancing effect of the constituents in PBE on umami and retronasal aroma. The molecular weight distribution and hydrophobicity of the peptide fractions from PBE were further analyzed to elucidate the relationship between hydrophobic aggregation of the peptide components and their umami-/aroma-enhancing abilities. The results showed that after the treatment with a denaturant, the content of the fraction >30 ku of PBE dropped from from 36.07% to 2.95%, indicating that there was aggregation of proteins in this PBE fraction. After the three fractions were freeze dried, sensory evaluation was performed. It was found that the PBE (10~30 ku) fraction in a NaCl-based solution had a score of 7.6 for saltiness, 8.6 for thickness, 7.6 for continuity and 8.0 for mouthfulness, which were all higher than those of the other two fractions. In addition, the intensity of retronasally perceived aroma of the PBE (10~30 ku) fraction scored 7.5, which was also higher than those of the other two fractions. Analyses of the three fractions revealed that the contents of umami and sweet amino acids of the PBE (10~30 ku) fraction were 14.7% and 44.19% respectively, which were insignificantly different from those of PBE (>30 ku), and the kokumi effect of the PBE (10~30 ku) fraction was significantly greater than that of PBE (>30 ku). After the hydrophobicity was analyzed, it was found that the hydrophobicity index of the PBE (10~30 ku) fraction was 60.00±1.33, which differed significantly from those of the other two fractions. It could be speculated that the high content of taste-active amino acids (umami and sweet) could increase the intensities of the umami taste and retronasally perceived aroma to some extents, but only when the overall hydrophobicity of proteins or peptides was within a certain range, the enhancement of the umami taste and retronasal aroma was the greatest. Finally, the relationship between hydrophobicity and the enhancement of umami taste and retronasally perceived aroma were confirmed by the heat treatment experiments at 40 ℃ and 70 ℃.

国家自然科学基金青年项目（32001684）；云南省地方本科高校基础研究联合专项资金面上项目（2018FH001-037）；云南省科技厅应用基础研究计划青年项目（2017FD086）