Why is milk white but cheese yellow?
Cheese has long been associated with human civilization, and there are now thousands of species. It is said that while an ancient Arabian merchant traveled with milk in a leather pocket made of sheep’s stomach, an enzyme called “Rennet” that remained in the pocket acted on the milk and cheese was made.
Milk solidifies by adding acid or rennet, an enzyme that hardens milk. In the process, it is separated into lumps consisting of whey, protein, and fat, and cheese is processed and aged.
Cheese is largely divided into natural cheese and processed cheese. Natural cheese is made by fermenting and maturing crude oil and has its own taste and flavor, but the retention period is short. Processed cheese is made by heating and melting natural cheese and then adding various kinds of pigments or emulsifiers, which have the advantage of preserving it for a long time.
Both types of cheese should be thoroughly managed to prevent contamination of food poisoning bacteria during the processing process, and should be used within the specified range when adding preservatives.
Cheese is classified into soft cheese and hard cheese according to the amount of moisture. Moisturized super soft cheese includes cream cheese that you can spread on it and mozzarella cheese that stretches. Ultra-hard cheese with low moisture has powdery parmesan cheese, Gorgonzola cheese is divided into semi-hard cheese, and yellow cheddar cheese is divided into hard cheese. Soft cheese with a lot of moisture has a short shelf life, and once opened, it is better to consume it as soon as possible because there is a possibility of microbial growth.
There is also a unique appearance of cheese. Breeze made with white mold looks like white snow on the outside. Gorgonzola cheese using blue mold is characterized by a random blue pattern in the middle of the yellowish cheese.
There is also cheese with holes that are often seen in cartoon movies and advertisements, which is Emmental Cheese. The hypothesis of holes in emmental cheese has been around for the past 100 years, and in recent studies, various lactic acid bacteria from hay components in milk gather to generate carbon dioxide, which naturally creates holes.
There is a reason why milk is white and cheese is yellow. It’s because of beta-carotene. Beta-carotene, a yellow component, is contained in various organisms such as grass and flowers and is a precursor to vitamin A.
When cows consume plants containing beta-carotene, beta-carotene is stored in fat tissue in the body, and beta-carotene from fat tissue around the breast comes out with milk fat during the milking process. Milk appears white despite the presence of beta-carotene due to the thin film surrounding milk fat, but when the film is destroyed during milk processing, the yellow color of beta-carotene is visible. However, goat oil converts beta-carotene into vitamin A and stores it in the process of metabolism in the body, so it does not turn yellow even when processed.
The Ministry of Food and Drug Safety is also doing its best to manage food safety such as HACCP and collection inspection for cheese producers. The more you know, the more fun and delicious cheese you eat with confidence. 안전놀이터