核桃燕麦发酵酸奶工艺条件研究

Optimization of processing conditions of fermented yogurt with walnut and oat

以核桃和燕麦作为主要原料,以七种乳酸菌为发酵剂筛选最优菌种,基于单因素试验考察原料料液比、菌种添加量、稳定剂添加量、发酵温度和发酵时间对酸奶品质的影响,并结合响应面试验优化产品工艺参数。结果表明,核桃燕麦酸奶发酵最优菌种为科汉森Mild 1.0,感官评分为85.06±0.60分,具有核桃及燕麦独特风味,口感最佳;核桃仁、燕麦、水以料液比1∶0.8∶4混合打浆,添加0.05‰菌种、0.96%稳定剂,在42.34℃下发酵8.15 h,此工艺条件下感官评分达89.46±1.16分,产品酸度为84.83±1.04°T,蛋白质含量为5.11±0.67(g/100 g),乳酸菌数为2.36×10^(8)(CFU/g),大肠杆菌及致病菌未检出,符合相关标准要求,是一款口感细腻、酸甜协调、质地均匀、风味优良,产品质量较佳的纯植物基酸奶产品。本研究可为植物基酸奶研发提供一定理论数据,同时为核桃及燕麦精深加工提供参考。

Walnut and oat were used as the main raw materials,and seven lactic acid bacteria were used as starters to screen the optimal strains. Based on single factor tests,the effects of solid-liquid ratio of raw materials to water,the dosages of bacteria and stabilizer,fermentation temperature and time on the quality of yogurt were studied,and the product processing parameters were optimized by the response surface test. The results showed that the best strain was Chr.Hansen Mild 1.0,with a sensory score of 85.06±0.60. It had the unique flavor of walnut and oat and the best taste. The optimized processing condition were :walnut kernel,oats and water were mixed and pulped at a ratio of 1∶0.8∶4,strain inoculation 0.05‰,stabilizer 0.96%,fermentation at 42.34 ℃ for 8.15 h. Under the above technological conditions,the sensory score was 89.46±1.16,the product acidity was 84.83±1.04 °T,the protein content was 5.11±0.67(g/100 g),and the number of lactic acid bacteria was 2.36×10^(8)(CFU/g),Escherichia coli and pathogenic bacteria were not detected and the product met the requirements of relevant standards. It was a pure vegetable based yogurt,had a harmonious sweet and sour flavor and uniform texture,good flavor and better quality. This study provides theoretical data for future research and development of plant based yogurt and provides reference for walnut and oat deep processing.