Yogurt Bacteria
Yogurt is a dairy product made by bacterial fermentation of lactose in milk. This produces lactic acid and gives yogurt its distinct taste. Yogurt bacteria are also called cultures and probiotics.
The most common cultures used in making of yogurt are Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus and Streptococcus salivarius subsp. Thermophilus. Yeast can act as a probiotic too.
You will find variations in yogurt taste and texture in different parts of the world due to various techniques and bacteria used. Other yogurt bacteria / cultures that are used in different types of yogurt that work in any type of milk- cow’s, soy, almond, nut or coconut include:
- Acetobacter orientalis
- Bifidobacterium longum
- Lactobacillus acidophilus
- Leuconostoc mesenteroides
- S. taette
- S. lactis var. Bollandicus
- Leuconostoc mesenteroides subsp. cremoris
- Lactococcus lactis subsp. cremoris
The history of yogurt goes back to roughly 3000 BC in ancient Middle East. It is quite interesting to see that the bacterium Bulgaricus has evolved over time, eliminating those genes that are not needed anymore: Those responsible for the metabolic process of plant sugars as L. Bulgaricus is originally a type of bacterium that went from the plant surfaces or grass to dairy.
Yogurt typically has a sour taste and the level of sourness is determined by the type of live yogurt cultures used in the acidification of milk while being fermented. Approximate pH level of 4 is the normal acidity level of yogurt. And the number of live bacteria required in a gram of yogurt is at least 100 million, so that they can survive the digestive process.
The process and the types of bacteria are different with fruit and low- fat yogurts. Although I am not so sure if the friendly bacteria would do well with lots of sugar found in typical fruit yogurts. So you are better off buying normal plain yogurt and adding fruits or a little jam in it or buying those that contain no sugar or artificial sweeteners but only fruits.
There is a great range of firmness and textures in yogurt. The culture used, the length and temperature of culturing, and the type of milk used will all play a part in the consistency of yogurt.
Greek yogurt is the thickest type of yogurt with the highest protein content , less sodium and the lowest carbohydrates and Piima is probably the thinnest. Texture is also partly because of the type and the temperature of the yogurt bacteria used.
Your tummy is already filled with so many different types of friendly bacteria, mainly to help with digestion and to fight off harmful bacteria. Bad bacteria can cause a variety of infections, diarrhea, tooth decay and bad breath.
You need to maintain a very good balance of these good and bad bacteria to keep a strong immune system. You also need to replace those friendly bacteria killed by antibiotics that you take when you are ill. Yogurt is always great for that.
Also for those lactose intolerant people that can not drink milk, yogurt is a great way to get friendly bacteria, calcium, riboflavin, vitamin D, protein and potassium as well as other nutrients. Low fat yogurt can help you lose weight by improving your body’s ability to burn fat.
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