Which enzyme that was traditionally taken from calves' stomachs is now mostly produced from vegetarian sources?

Rennet is the correct enzyme associated with this transition from traditionally animal-based sources to vegetarian alternatives. Originally, rennet was derived from the stomach linings of calves, where it plays a crucial role in the coagulation of milk, aiding in cheese production. However, due to dietary preferences and an increase in vegetarianism and veganism, as well as ethical considerations around animal welfare, rennet is now mostly produced from microbial or plant sources. These alternatives can effectively mimic the coagulating properties of animal-derived rennet, allowing for the production of cheese without the use of animal products.

In contrast, pepsin, trypsin, and amylase do not share this transition in sourcing. Pepsin is primarily obtained from the stomachs of animals, particularly pigs, and is not typically produced from vegetarian sources. Trypsin is a digestive enzyme produced in animals, specifically in the pancreas, and is also not sourced from plant-based materials. Amylase, while it can be derived from various sources including plants and microbes, is used in different contexts mainly for carbohydrate breakdown, rather than in dairy applications like rennet. Thus, rennet stands out as the enzyme that has successfully transitioned to predominantly vegetarian sources while maintaining its functionality in food production