枯草芽孢杆菌通过液体发酵豆乳可大量富集纳豆激酶,但随之产生的特有不良风味严重影响其产业推广。为探明其特有风味的来源,通过电子鼻和气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)对BSNK-5发酵豆乳不同时间点的挥发性成分进行了跟踪鉴定,并采用理化方法分析了其蛋白质的代谢变化规律。电子鼻感官分析表明,随发酵时间的延长,样品风味呈现一定的变化趋势;GC-MS共检测出60种挥发性成分,包括烷烃类、醇类、醛类、酮类、有机酸酯类、杂环化合物。整个发酵过程中,只有以吡嗪类为主的杂环化合物含量显著增加,其中2,5-二甲基吡嗪、2,3,5-三甲基吡嗪在杂环化合物中占比分别为76.65%和16.00%,因此,推测2,5-二甲基吡嗪是发酵豆乳特有风味物质。理化分析表明,蛋白质的降解加速了氨基酸的生成,氨基酸的分解代谢可能促成了2,5-二甲基吡嗪的合成,引起了发酵豆乳的风味劣变。该研究有望为功能性发酵豆乳的风味改良和产业发展奠定理论基础。
高雅鑫
,
倪楠
,
许斌
,
范海茹
,
张蒙冉
,
卢聪
,
张娜娜
,
范蓓
,
王凤忠
,
李淑英
. 枯草芽孢杆菌BSNK-5发酵豆乳特有风味物质研究[J]. 食品与发酵工业, 2020
, 46(15)
: 258
-264
.
DOI: 10.13995/j.cnki.11-1802/ts.023635
Nattokinase can be enriched in Bacillus subtilis fermented soymilk,but the resulting off flavor has seriously affected its industrial promotion. In order to ascertain the source of peculiar flavor in fermented soymilk,this study traced and identified volatile components of fermented soymilk at different times by electronic nose and gas chromatography mass spectrometry (GC-MS),and analyzed the metabolic changes of protein in fermented soymilk by physicochemical methods. The results of electronic nose reflected the trend of sample's flavor over time. GC3MS detected a total of 60 volatile components during the entire fermentation process,including alkanes,alcohols,aldehydes,ketones,organic acid esters,heterocycles. However,only the heterocyclic compounds dominated by pyrazines showed an increasing trend while the proportions of 2,5-dimethylpyrazine and 2,3,5-trimethylpyrazine in heterocyclic compounds were 76.65% and 16.00%,respectively. Therefore,2,5-dimethylpyrazine is presumed to be a flavor characteristic of fermented soymilk. Moreover,physicochemical analysis showed that the degradation of protein accelerated the production of amino acids,and the catabolism of amino acids might promote the synthesis of 2,5-dimethylpyrazine,which caused the flavor deterioration of fermented soymilk. This study will be expected to provide a base for the flavor improvement and industrial promotion of functional fermented soymilk.
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