方法与结果
使用响应面法研究发酵温度、接种物和成分浓度与响应变量之间的关系（在冷藏储存4周后，当发酵时间在发酵终点pH 4.5时，用模拟胃肠道酶液处理的南瓜饮料中的马里乳杆菌 K8的存活率、α-葡萄糖苷酶抑制活性以及感官均为总体接受性好）。在大约40％南瓜泥浓度、8 Log CFU / mL接种物和35℃下获得最佳制剂。该最佳配方的产品在28.34±0.10小时后达到发酵终点，并研究了4周储存期间的质量变化。经过模拟胃液和肠液处理后，该产品的L. mali存活率达到了88.56±0.67％。该产品在贮存4周后显示出95.89±0.30％α-葡萄糖苷酶抑制活性，并且其感官总体可接受性评分为6.99±0.40。
这些发现说明该模型在改善益生菌存活率和α-葡萄糖苷酶的抑制活性方面是有效的，并具有极好的感官可接受性，因此可以为高血糖的治疗提供饮食手段。
文章摘要
ABSTRACT
Optimization of a fermented pumpkin-based beverage to improve Lactobacillus mali survival and α-glucosidase inhibitory activity: A response surface methodology approach
W.Y. Koh a，U. Uthumporn a,?，A. Rosmab，A.R. Irfan c，Y.H. Park c
aFood Technology Division, School of IndustrialTechnology, Universiti Sains Malaysia, Minden 11800, Penang, Malaysia
bBioprocess Division, School of Industrial Technology,Universiti Sains Malaysia, Minden 11800, Penang, Malaysia
cDepartment of Applied Microbiology and Biotechnology,Yeungnam University, Gyeongsan, South Korea
Received 11 May 2017; received in revisedform 30 October 2017; accepted 1 November 2017
Available online 26 November 2017
The aim of this research was to develop an optimum fermentation and composition model for a new fermentedpumpkin-based beverage with high probiotic survival and α-glucosidase inhibitory activity. Relationship between fermentation temperature, inoculum and ingredient concentration with response variables (fermentation time at the fermentation endpoint pH 4.5, survival rate of Lactobacillus mali K8 in pumpkin-based beverage treated with simulated gastrointestinal tract enzyme fluids, α-glucosidase inhibitory activity and sensory overall acceptability after 4 weeks of refrigerated storage) was investigated using response surface methodology. Optimalformulation was obtained at an approximation of 40% pumpkin puree concentration, 8 Log CFU/mL inoculum and at 35 ?C.The product derived from this optimum formula reached the fermentation endpoint after 28.34±0.10h and the quality change during 4 weeks storage was studied. The product achieved 88.56±0.67% of L. mali survival after treatment with simulated gastric and intestinal juices; demonstrated 95.89±0.30% α-glucosidase inhibitory activity, as well as scored 6.99±0.40 on sensory overall acceptability after 4 weeks of storage. These findings illustrated that the model is effective in improving probiotic survival and α-glucosidase inhibitory activity with excellent sensory acceptability, thus may offer a dietary means for the management of hyperglycaemia.
