直投式发酵剂的优化及其对火腿风味的影响

Preparation of Direct Vat Starter and Its Effect on Flavor Quality of Fermented Ham

摘要:

本文以木糖葡糖球菌（Staphylococcus xylosus，SX）和植物乳杆菌（Lactobacillus plantarum，LP）为研究对象，考察不同发酵剂（SX；SX+LP）对火腿风味的影响。通过单因素和响应面试验优化了木糖葡萄球菌（脱脂乳8.05%、蔗糖8.83%、山梨糖醇7.78%）和植物乳杆菌（脱脂乳6.43%、蔗糖7.91%、山梨糖醇4.28%）的冻干保护剂配方，并制备SX和LP直投式发酵剂用于火腿发酵。将SX和SX+LP接种于发酵火腿中，研究不同发酵剂对其风味品质的影响。应用HS-SPEM-GC-MS（head space-solid phase microextraction-gas chromatography-mass spectrometry）技术，从SX+LP、SX和对照样品中分别检出53、52和31种挥发性风味物质。在接种发酵样品中，阈值较低的醛类物质含量大幅增加，而阈值较高的烃类物质含量下降。SX+LP样品的主体风味物质最多，其次为SX和对照样品。同时，PCA双图显示11种主体风味物质在可在PC1上判别SX+LP样品，4种主体风味物质在可在PC2上区分SX样品，而对照样品仅有1种特征风味物质。以上结果表明木糖葡糖球菌和植物乳杆菌均能改善发酵火腿的风味品质，且复合发酵剂效果优于单菌种发酵剂。

Abstract:

Staphylococcus xylosus (SX) and Lactobacillus plantarum (LP) were used as research objects to investigate the effects of different starter cultures (SX; SX+LP) on ham flavor. The cryoprotectant formula of SX (8.05% skim milk, 8.83% sucrose, 7.78% sorbitol) and LP (6.43% for skim milk, 7.91% for sucrose, 4.28% for sorbitol) were optimized by single-factor and response surface tests. Direct vat starter of SX and LP was prepared for ham fermentation. SX and SX+LP were inoculated into fermented ham to study the effect of different starter cultures on the flavor quality of fermented ham. The HS-SPEM-GC-MS technique was used to detect the type and content of volatile flavor compounds in SX+LP, SX and control sample, 53, 52 and 31 volatile flavor substances were detected, respectively. In samples with starter culture, the content of aldehydes with lower odor thresholds increased, while the content of hydrocarbons with higher odor thresholds decreased. The amount of the main flavor substance in the SX+LP sample was the most, followed by the SX and the control sample. At the same time, the PCA biplot showed that SX+LP sample can be discriminated by 11 main flavor substances on PC1, SX sample can be distinguished on PC2 by four main flavor substances, and only one characteristic flavor substance can be used to identify control sample. This result indicated that both SX and LP can improve the flavor quality of fermented ham, and the mixture culture starter is better than the single culture starter.