Effect of lactic acid bacteria and yeasts on the structure and fermentation properties of Tibetan kefir grains was written by Chen, Zhina;Liu, Tian;Ye, Tao;Yang, Xijuan;Xue, Yongzhen;Shen, Yeqiao;Zhang, Qing;Zheng, Xiaomei. And the article was included in International Dairy Journal in 2021.Reference of 659-70-1 This article mentions the following:
To better understand the effects of lactic acid bacteria (LAB) and yeasts on the structure and fermentation properties of Tibetan kefir grains (TKGs), we treated TKGs for 1 mo with high doses of mycillin and cycloheximide to inhibit LAB and yeasts, resp. The results showed that in each group of TKGs, Lactobacillus kefiranofaciens was the only dominant and stable bacterial species, and it exhibited two distinct morphologies in TKGs, short rods in the LAB-inhibited group, and long rods in the yeast-inhibited and control groups, which might directly result in the inability of the grains in the LAB-inhibited group to grow further. Compared with bacteria, the relative abundance of yeasts in TKGs was very low. However, even though yeast had no effect on the structure and growth characteristics of TKGs, they had a great influence on the fermentation characteristics of Tibetan kefir, such as acid production and aroma. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1Reference of 659-70-1).
Isopentyl 3-methylbutanoate (cas: 659-70-1) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Reference of 659-70-1
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics