基于辅助发酵剂制备传统奶豆腐的风味特性研究

Flavor characteristics of traditional Hurood based on auxiliary starter

以奶豆腐中分离的乳酸菌为研究对象,筛选出产酸能力强、风味良好、发酵时间短的乳酸菌,并对其发酵酸度、发酵终点时间和质构特性进行测定,确定传统奶豆腐辅助发酵剂菌株的配比组合。再通过辅助发酵剂的单因素和正交试验,确定传统奶豆腐的最优生产工艺,分析成品风味特性的研究。研究筛选出产酸能力强、风味良好、发酵时间短的乳酸菌4株,菌株D655、686、NDF9-3和MN1-7。经16S rDNA序列检测分析,上述菌株分别被鉴定为泡菜乳球菌(Lactococcus kimchii)、植物乳杆菌(Lactiplantibacillus plantarum)、乳酸片球菌(Pediococcus acidilactici)和粪肠球菌(Enterococcus faecium)。2种最优组合的3株菌配比发酵试验结果表明,最佳组合为D655∶686∶NDF9-3=5∶2∶3。将该组合作为辅助发酵剂,并以产品弹性、酸度与感官评分为指标进行工艺优化,最佳辅助发酵剂的添加量3%、发酵温度25℃、排乳清温度65℃,此时的奶豆腐弹性(0.92±0.05)g、酸度(70±1.2)°T、感官评分为(83±0.2)分。试验组的风味物质均高于对照组,酸类物质在风味中占主体地位,其次为醇类、脂类、烷烃类、醛类以及其他。综上所述,试验组风味较好,具有浓郁的奶香味,呈现传统乳制品特色。

Taking lactic acid bacteria isolated from Hurood as the research object,the lactic acid bacteria with strong acid producing ability,good flavor,and short fermentation time were screened,then the fermentation acidity,fermentation end time,and texture characteristics were determined to confirm the matching combination of traditional Hurood assisted starter strains.The optimal production technology of traditional Hurood was selected by single factor and orthogonal experiment of auxiliary starter.The results showed that there were four strains of lactic acid bacteria with strong acid producing ability,good flavor,and short fermentation time.After 16S rDNA sequence analysis,strains D655,686,NDF9-3,and MN1-7 were identified as Lactococcus kimchii,Lactiplantibacillus plantarum,Pediococcus acidilactici,and Enterococcus faecium respectively.The results of the fermentation experiment showed that the optimal combination was D655∶686∶NDF9-3=5∶2∶3,which was used as the auxiliary fermentation agent.The product elasticity,acidity and sensory score were used as the indexes to optimize the process.The optimal supplemental amount of auxiliary starter was 3%,fermentation temperature was 25℃,and whey temperature was 65℃,while the Hurood elasticity was(0.92±0.05)g,acidity was(70±1.2)°T,and sensory score was(83±0.2).The flavor substances in the experimental group were higher than those in the control group,while acids were the main flavor substances,followed by alcohols,lipids,alkanes,aldehydes,and others.In summary,the experimental group had better flavor with strong milk flavor as the traditional dairy products.