益生菌发酵苹果浆工艺优化及发酵前后挥发性风味成分分析  

Process Optimization for Production of Fermented Apple Pulp with Probiotics and Analysis of Volatile Flavor Components before and after Fermentation

作　　者：任婷婷 岳田利[1] 魏欣 王璇 袁亚宏[1] REN Tingting;YUE Tianli;WEI Xin;WANG Xuan;YUAN Yahong(College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China)

机构地区：[1]西北农林科技大学食品科学与工程学院,陕西杨凌712100

出　　处：《食品科学》2019年第8期87-93,共7页Food Science

基　　金："十三五"国家重点研发计划重点专项(2017YFD0400105-04)

摘　　要：以苹果浆为原料,研究益生菌混菌发酵苹果浆工艺条件及发酵前后挥发性风味成分的变化。选取Lactobacillus plantarum 21805、Lactobacillus acidophilus 20250混合发酵苹果浆,以活菌数和感官评分为评价指标,研究乳酸菌接种量、发酵温度、发酵时间、菌种比例、灭菌条件、苹果浆料液比对发酵苹果浆品质的影响,在单因素试验基础上采用正交试验对发酵工艺进行优化,并采用顶空固相微萃取和气相色谱-质谱联用方法分析苹果浆发酵前后挥发性风味成分的变化。结果表明,益生菌发酵苹果浆最佳工艺条件为发酵温度32℃、发酵时间36 h、接种量2%、菌种比例4∶1、苹果浆料液比2∶1(g/m L),灭菌条件为100℃、15 min,在此条件下,发酵苹果浆风味良好,活菌数达到8.93(lg(CFU/mL))。苹果浆经益生菌发酵后共检出27种挥发性风味物质,其中醇类6种、酯类10种、酮类5种、醛类2种等。与发酵前相比,苹果浆发酵后新产生15种挥发性风味物质。发酵后酯类、醇类和酮类挥发性风味物质相对含量呈增加趋势,而醛类挥发性风味物质呈降低趋势。经聚类分析,苹果浆经乳酸菌发酵后其挥发性风味物质改变显著。The fermentation conditions for the production of fermented apple pulp with a probiotic mixture were optimized and the change of volatile flavor components was investigated before and after fermentation. Lactobacillus plantarum 21805 and Lactobacillus acidophilus 20250 were selected for use as mixed starter culture. The effects of inoculum composition and amount, fermentation temperature, fermentation time, sterilization conditions, and apple pulp-to-water ratio on the quality of fermented apple pulp as evaluated by viable bacterial count and sensory score were studied. One-factor-at-a-time and orthogonal array design methods were used to optimize the fermentation conditions. Head-space solid phase micro-extraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile flavor components. The results showed that the optimum fermentation conditions were determined as follows: fermentation temperature 32 ℃, fermentation time 36 h, inoculum amount 2%, L. plantarum 21805 to L. acidophilus 20250 ratio 4:1, apple pulp to water ratio 2:1 (g/mL), and sterilization at 100 ℃ for 15 min. The flavor of the fermented apple pulp produced under the optimized was good, and the viable bacterial count reached 8.93 (lg (CFU/mL)). A total of 27 volatile flavors were detected in the fermented apple pulp, including 6 alcohols, 10 esters, 5 ketones, and 2 aldehydes. Apple pulp produced 15 new volatile flavors after fermentation. The relative contents of esters, alcohols and ketones increased after fermentation, while aldehydes showed a decreasing trend. Hierarchical cluster analysis (HCA) indicated that the volatile flavor composition of apple pulp was significantly changed after fermentation.

关 键 词：益生菌 苹果浆 发酵 风味 顶空固相微萃取 气相色谱-质谱联用 

分 类 号：TS255.4[轻工技术与工程—农产品加工及贮藏工程]