Yoghurt – Lets hear from the gut

Most of you might have heard that “Pathway to ones heart go through your gut”. This article will dive readers into one of the most preferred and healthy food that people consume i.e., Yoghurt.

Yoghurt is a fermented, milk based product. It is one of the nutritious food which helps in improving our gut health. It comes under the category of probiotic food.

Almost everyone have heard about curd. Yoghurt as well as curd have similar appearance, taste and also similar health benefits. So how does one differentiates between yoghurt and curd. The following differences might help one to differentiate between yoghurt and curd:

• Curd utilizes cow or buffalo milk; while yoghurt utilizes cow milk.
• We add previously made curd in the fresh milk to make curd; while we add culture in milk for preparing yoghurt.
• Microorganisms responsible for making curd are Streptococcus lactis, Streptococcus diacetylactis or Streptococcus cremoris singly or in combination with Leuconostic species; while yoghurt culture contains Streptococcus thermophilus and Lactobacillus bulgaricus.

How to process yoghurt?

It’s processing involves various unit operation and these are:

1. Initial treatment: This important step in processing aims at clarifying the milk from the physical impurities and stabilizing the milk with the application of pre heat treatment. This ensures to inhibit vegetative cells and enzymes in the milk.
2. Standardization: This involves standardizing the fat and SNF % in the milk so that consistency in the different production batches can be obtained depending on consumer preferences and company’s product depth.
3. Homogenization: This process involves passing the milk through a homogenizer to mix the milk fat thoroughly into the milk and make it a stable oil-in-water emulsion. Homogenization stabilizes the milk fat globules and prevents separation of fat globules from milk.
4. Pasteurization: The milk should undergo pasteurization. The main aim of this processing step is to hinder all the growth of the vegetative cells in the milk. The milk is pasteurized using HTST or LTLT method.
5. Cooling & Inoculation: After pasteurization, temperature of the milk is lowered. Ideally the temperature is around 45 degree C. Yoghurt culture, also known as inoculum, is added into milk. A continuous stirrer mixes the inoculum thoroughly in milk.
6. Filling: After completion of inoculation, dispensing of milk in the sterile cups takes place. Aseptic sealing machine seals these cups. It ensures that there is no cross contamination.
7. Incubation: Incubation is a process in which the sealed sterile cups are sent in a temperature maintained room. Generally the temperature of the incubation room is 40 degree C and the duration is 4 hours.
8. Cooling: This is the last step. After incubation, yoghurt is sent to cooling room. The temperature of a cooling room is 4 degree C. This ensures that there is no overgrowth of culture in milk.

Changes during yoghurt processing

Do you know that milk undergo various changes during processing into yoghurt? In this segment we’ll be going through various physical, chemical and biological changes that occur during this process.

Firstly, the most important, biological changes. The yoghurt culture multiplies into the milk, also known as probiotic. Probiotic in a yoghurt should be at least 100 million per gram.

Secondly, there are various chemical changes. As these microorganisms (probiotic) are LAB (Lactic acid bacteria), they are responsible for the conversion of milk sugar (lactose) convert into lactic acid during the fermentation of milk. This results in reduction of the pH. It generally varies between 4.0 to 4.6. There are various compounds which are developed during processing. These account for the delicious flavor of the yoghurt. These include acetaldehyde, diacetyl, acetoin, acetone, and 2-butaone

Lastly, there are also physical changes. There is a desirable textural change that occurs during the process which makes the it more appealing to consume it.

Health benefits of yoghurt

There are various health benefits of consuming yoghurt. Due to its various health benefits, its consumption is very high among the people.

1. It is a great source of calcium.
2. Lactose intolerance people consume it without having any discomfort. At the same time, they can enjoy all the goodness of milk.
3. It balances the intestinal microflora. There is an adequate increase in Lactobacilli and Bifidobacteria.
4. It provide therapeutic effects such as diarrhea, prevention of osteoporosis, prevention of hypercholesterolemia, etc.