雪莲菌发酵提高枸杞原浆甜菜碱含量的工艺优化及品质分析

Process Optimization and Quality Analysis to Increase the Betaine Content of Wolfberry Pulp Through Fermentation

摘要:

该研究以混合菌种雪莲菌为发酵菌种，枸杞原浆中甜菜碱含量为指标，通过单因素试验和正交试验对雪莲菌发酵枸杞原浆进行工艺优化，并对发酵后的枸杞原浆进行品质分析。结果表明，最佳发酵工艺条件为雪莲菌接种量5%（m/V），发酵时间48 h，发酵温度25 ℃，此条件下甜菜碱含量为18.95 mg/mL，比未发酵枸杞原浆甜菜碱含量增加2.54倍，总酚含量为2.03 mg/mL、黄酮含量为0.68 mg/mL、总糖含量为11.92 mg/mL。雪莲菌发酵后枸杞原浆中共检测出65种挥发性成分，包括21种醇类、27种酯类、1种醛类、1种酮类、8种酸类、3种烷类、2种酚类和2种烯类，与发酵前相比新增24种，且醇类、酯类和酸类物质较发酵前显著性增加，挥发性成分总含量由8.94 mg/mL增加至39.76 mg/mL，为制备高品质枸杞原浆提供理论依据，为枸杞产业化深加工提供指导。

Abstract:

Kefir grains comprising mixed strains were used as a fermentation inoculum, and the content of betaine in wolfberry pulp was measured and adopted as an analysis index. The single factor test and orthogonal test were used to optimize the wolfberry pulp fermentation process and to analyze the quality of wolfberry pulp fermented using kefir grains. The results show that the optimal fermentation conditions are: 5% (m/V) kefir grain inoculation, followed by fermentation at 25 ℃ for 48 h. Under these conditions, the betaine content reached 18.95 mg/mL, which was 2.54 times higher than that in unfermented wolfberry pulp. Furthermore, the total phenol, flavonoid, and total sugar content was 2.03, 0.68, and 11.92 mg/mL, respectively. A total of 65 volatile components were detected in the wolfberry pulp fermented using kefir grains, including 21 alcohols, 27 esters, 1 aldehyde, 1 ketone, 8 acids, 3 alkanes, 2 phenols, and 2 alkenes. Twenty-four new species were detected after fermentation. In addition, the alcohols, esters, and acids increased significantly after fermentation, and the total volatile component content increased from 8.94–39.76 mg/mL. This research provides a theoretical basis for preparing high-quality wolfberry pulps and guidance for the deep processing and industrialization of wolfberry production.