Fermented Milk Products

Yoghurt involves the symbiotic action of *Streptococcus thermophilus* and *Lactobacillus delbrueckii subsp. bulgaricus*. These bacteria work together, with one creating an environment favorable for the other, leading to efficient fermentation of milk. This process results in the formation of yoghurt with its characteristic flavor, texture, and probiotic benefits, aiding in digestion and gut health.

Cheese cancer, a defect in Swiss and similar cheeses, is caused by Oospora crustacea. This microorganism affects the internal texture of cheese, leading to structural breakdown and unappealing quality. Proper fermentation and control of microbial activity during cheese production are crucial to avoid this defect.

Kumiss, a traditional fermented dairy product, contains both lactic acid and ethanol. The high acid and high alcohol variant has approximately 1.0% lactic acid and 1.7–2.5% ethanol, resulting from a dual fermentation process involving lactic acid bacteria and yeasts. This composition gives kumiss its distinct tangy and slightly alcoholic flavor.

Bifighurt is a probiotic yoghurt product that uses a combination of Streptococcus thermophilus(A), Lactobacillus delbrueckii ssp. bulgaricus(B), and Bifidobacterium bifidum(C). These bacteria work symbiotically to enhance probiotic benefits, improve gut health, and provide a balanced taste and texture. Lactobacillus acidophilus(D) is not typically used in Bifighurt.

In yoghurt production, the optimal ratio of cocci (e.g., Streptococcus thermophilus) to rod-shaped bacteria (e.g., Lactobacillus delbrueckii subsp. bulgaricus) is 1:1. This balance is crucial for proper acidification, texture development, and flavour formation during fermentation. Deviating from this ratio may impact the sensory and functional properties of the yoghurt.