全脂乳粉乳味不足物质基础及机制解析

Analysis of the Material Basis and Mechanism of Milk Flavour Deficiency in Whole Milk Powder

摘要:

为探究全脂乳粉乳味不足的原因，采用顶空固相微萃取-气相色谱-质谱联用技术（Headspace Solid-phase Microextraction-gas Chromatography-mass Spectrometry, HS-SPME-GC-MS）对多种全脂乳粉样品中的挥发性香气成分进行测定，并结合相对气味活度值（Relative Odor Activity Value, ROAV）进行分析。研究结果表明六份样品中，共检出酸、酮、醛、醇、酯、芳香族化合物等87种挥发性成分。正常样品R中酮类物质含量为9.65%，乳味不足样品R1-R5中酮类物质有所增加，分别增加了1.11%、0.85%、2.97%、0.18%、8.95%；同时，酯类物质含量显著下降：样品R中酯类物质的含量为15.56%，乳味不足样品R1-R5中酯类物质的含量分别下降了12.09%、9.35%、7.14%、6.70%、6.20%，由于大多数酯类物质具有花果香气，对提升乳粉风味具有积极作用，因此酯类物质含量的降低，更易导致乳味不足的情况出现。其中乳味正常样品R独有的香气成分是香兰素，含量为7.30%，提供了浓郁的奶香味且风味贡献突出，同时ROAV值表明香兰素和4-羟基-2,5-二甲基-3(2H)-呋喃酮对乳粉风味具有重要贡献，该结果为今后进一步探究乳粉乳味不足的原因提供了物质基础及机制解析。

Abstract:

In order to investigate the reasons for the lack of milky flavor in whole milk powder, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used for the determination of volatile aroma components in a variety of whole milk powder. The volatile aroma components in the samples were determined in combination with Relative Odor Activity Value (ROAV). The results showed that a total of 87 volatile components including acids, ketones, aldehydes, alcohols, esters and aromatic compounds were detected in the six samples. The content of ketones was 9.65% in the normal sample R, and increased in R1-R5 samples with insufficient milky flavor (increased by 1.11%, 0.85%, 2.97%, 0.18%, and 8.95%, respectively); Meanwhile, the content of esters decreased significantly: the content of esters in sample R was 15.56%, and the content of esters in the R1-R5 samples with insufficient milky flavor decreased by 12.09%, 9.35%, 7.14%, 6.70% and 6.20%, respectively. Since most of the esters have floral and fruity aromas, which has a positive effect on the enhancement of milk powder’s flavour. Therefore, a decrease in the ester content would more likely lead to insufficient milky flavour. Among them, the unique aroma component of the R sample with normal milky flavour was vanillin (its content: 7.30%), which provided a strong milky aroma and an outstanding flavor contribution. Meanwhile, the ROAV value indicated that vanillin and 4-hydroxy-2,5-dimethyl-3(2H)-furanone made important contributions to the flavour of the milk powder. These results provide a material basis and mechanistic explanation for further investigation on the causes of the lack of milky flavour in milk powders in the future.