枸杞酸奶的制备及质构品质和风味物质分析

Preparation, Texture Quality and Flavor Substance Analysis of Goji Berry Yoghurt

摘要:

该研究以枸杞浆、纯牛奶为主要原料，采用单因素试验和正交试验优化枸杞酸奶的配方和发酵条件，同时采用物性测定仪测定其质构参数，并采用顶空固相微萃取-气相色谱质谱联用仪测定其挥发性风味物质组成和含量。结果表明，最佳枸杞酸奶配方为：以纯牛奶为基准（质量分数），枸杞浆添加量5%，奶粉添加量3%，蔗糖添加量10%，发酵剂添加量0.1%，42 ℃条件下发酵8 h，其感官评分为85.2分，硬度28.32 g，稠度379.31 g·sec，粘聚性-18.35 g，粘度指数-16.98 g·sec，酸度值100.20 0T。相关性分析表明，枸杞酸奶的硬度与色泽和组织状态呈极显著负相关（P<0.001），稠度与口感呈极显著正相关（P<0.01），色泽和组织状态呈极显著正相关（P<0.001），组织状态和风味呈显著正相关（P<0.05），以及风味与口感呈极显著正相关（P<0.001）。枸杞酸奶含有32种挥发性风味物质，含量为1417.09 μg·kg-1。枸杞浆中的醛类等是枸杞酸奶中枸杞风味主要来源。研发的枸杞酸奶色泽柔和，质地均匀，稠度适中，口感细腻，酸甜适宜，兼顾营养和风味。

Abstract:

Goji berry puree and pure milk were chosen as the main raw materials, and the fermentation conditions of goji berry yogurt were optimized based on single factor and orthogonal experiments. Texture parameters were assessed by texture analyzer, meanwhile, flavor substances of goji berry yogurts were analyzed by headspace-solid phase microextraction-gas chromatography-mass spectrometry. The results showed that, the optimized formula for goji berry yogurt was as follows: based on the pure milk (mass fraction), goji berry puree 5%, milk powder 3%, sucrose 10%, lactic acid bacteria 0.1%, fermentation temperature 42 ℃, and fermentation 8 h. The sensory score for the optimized goji berry yogurt was 85.2. The texture parameters for the optimized goji berry yogurt were like that, the firmness was 28.32 g, the consistency was 379.31 g·sec, the cohesiveness was -18.35 g, the index of viscosity was -16.98 g·sec, and the acidity was 100.20 0T. The correlation analysis showed that the firmness of goji berry yoghurt was significantly negatively correlated with the color score and tissue status score (P<0.001), and the consistency was positively correlated with the taste score (P<0.01), the color score was significantly positively correlated with the tissue status score (P<0.001), the tissue status score was significantly positively correlated with the flavor score (P<0.05), and the flavor score was significantly positively correlated with the taste score (P<0.001). The goji berry yogurt contained 32 volatiles, and the content was 1417.09 μg·kg-1. Aldehydes in goji berry were conducive to the flavor characteristic formation of goji berry yogurt. Goji berry yoghurt has a gentle color, uniform texture, moderate consistency, delicate taste, suitable acidity and sweetness, with high nutrition and rich flavor.