沙棘添加对乳酸菌发酵牛乳风味和消费者接受度的影响

本研究目的是探究添加沙棘（5%，v/v）对发酵乳风味和消费者接受度的影响。选取本实验室前期从新疆老酸奶、西藏开菲尔颗粒等样品中筛选到的8株乳酸菌进行原味发酵乳和沙棘发酵乳的制备。通过电子鼻（Electronic-nose，E-nose）和电子舌（Electronic-tongue，E-tongue）技术，采用模糊数学综合评定法对不同发酵乳的消费者接受度作出评价，进一步利用顶空固相微萃取气质联用技术（Head space-solid phase microextraction-gas chromatography/mass，HS-SPME-GC/MS）对原味发酵乳和沙棘发酵乳中的风味物质组成进行分析。结果显示添加沙棘（5%，v/v）可以对发酵乳的风味产生显著影响，主要体现为香气的增加和不良气味的减弱，在滋味上表现为苦味、鲜味和丰富度的减少。GC/MS结果表明沙棘发酵乳中含有更高浓度的酯类和醇类化合物，是其中水果香气、发酵香气和浓郁花香的主要贡献者；在所选取的8株乳酸菌中，来源于泡菜的戊糖乳杆菌Z-14（Lactobacillus pentosus Z-14），其沙棘发酵乳的综合评定结果最优，且具有最高的消费者接受度。

Study on the Effect of Sea Buckthorn on the Flavor and Consumer Acceptance of Lactobacillus Fermented Milk

The aim of this study was to evaluate the influence of 5% (v/v) sea buckthorn on the flavor and consumer acceptance of probiotic yogurts. Eight strains of lactic acid bacteria (LAB) were screened from pickled cowpea, pickles, Tibetan kefir, kurut, Xinjiang condensed yogurt previously and then applied in the fermentation of plain yogurt and sea buckthorn yogurt. Firstly E-nose, E-tongue and fuzzy comprehensive evaluation method were used to evaluate the consumer acceptance of the plain yogurt and sea buckthorn yogurt fermented by different LAB. Then head space-solid phase microextraction-gas chromatography/mass (HS-SPME-GC/MS) method was used to analyze the flavor composition of plain yogurt and sea buckthorn yogurt. The results showed that addition of 5% (v/v) sea buckthorn could significantly affect the flavor of yogurt, including the increase of aroma and the decrease of unpleasant odor, as well as the decrease of bitterness, umami and richness. The results of GC/MS showed that the addition of sea buckthorn could provide more esters and alcohols to yogurt, which were well-known to present fruity, fermentative and floral aroma in many fruits. The results of sensory evaluation showed that among 8 strains of selected LAB, sea buckthorn yogurt fermented by Lactobacillus pentosus Z-14 screened from pickles had the highest score and was best accepted by consumers.