Fermented milk products

Fermented milk products

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  Fermented milk products -ByTahura Mariyam Ansari
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  Introduction • Milk isa whitish liquid containing proteins (2.5%), lactose (5%), fats (3.6%),water (87.5%) and various minerals and vitamins (0.7%) produced by the mammary glands of all mature female mammals. • The milk produced by cows, goats and other animals is used for human consumption. • Milk is extremely perishable and various methods are employed to preserve it, the most prominent being fermentation.
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  What is fermentation? •Fermentation is a metabolic process in which an organism (such as bacteria or yeast) converts a carbohydrate (like starch and sugar) into alcohol or organic acids under anaerobic conditions.
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  Fermented milk products CheeseYogurt Cultured milk Acidophilus milk Kefir
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  Cheese • Cheese isconcentrated form of 2 major milk components - milk protein (casein) and milk fat. • Besides milk, it contains a selected strain of bacteria, a milk clotting agent and sodium chloride. • Use of additional ingredients and different environmental conditions surrounding the manufacture and subsequent ripening of cheese have given rise to various varieties of cheese.
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  Types of cheese(examples) 1. Soft cheese (camembert, feta, etc.) 2. Semi soft cheese (gouda, port soft, etc.) 3. Hard cheese (mimolette, pelorina etc.) 4. Semi hard cheese (cheddar, cantal etc.) 5. Fresh cheese (cottage cheese, mozzarella etc.) 6. Blue cheese (roquefort, stilton etc.) 7. Processed cheese
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  Types of organismused for cheese production Streptococcus cremoris Brevibacterium linensLactococcus lactis Penicillium roqueforti Lactobacillus casei Lactobacillus plantarum ( For Soft cheese & Semi hard cheese) ( For Semi soft cheese & Blue cheese) ( For Semi soft cheese) (For Blue cheese) (For Hard cheese & Semi hard cheese) (For Hard cheese )
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  Yogurt • Yogurt isproduced by the controlled fermentation of milk by 2 species of bacteria Lactobacillus bulgaricus and Lactococcus thermophilus (Streptococcus thermophilus). • The lactose is fermented to lactic acid and it is the one which cause the characteristic curd to form. • Streptococcus thermophilus brings the pH of the milk down to 5.5. • Lactobacillus bulgaricus converts lactose to lactic acid. • Proteolytic enzymes from L. bulgaricus break down milk protein into peptides. • These peptides stimulate the growth of L. thermophilus which in turn produces formic acid and carbon dioxide. • These are the growth stimulants for L. bulgaricus.
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  Types of yogurt Concentrated/Greek yogurt Set yogurt Stirred yogurt Drinking yogurt Flavored yogurt Frozen yogurt
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  Cultured buttermilk • Culturedbuttermilk is the fluid remaining after ripened or sour cream is churned into butter using mesophylic starters. • Different products are produced by using different stains of lactic acid bacteria as starter cultures and different fractions of whole milk as the starting substrate. • Cream is starting substrate, butter is normally made by churning cream that has been soured by lactic acid bacteria. • Sour cream uses Streptococcus cremoris or S. lactis for producing lactic acid and Leuconostoc cremoris for characteristic flavor. • Ripened cream uses Streptococcus cremoris or S. lactis to produce lactic acid rapidly and Leuconostoc citrovorum produce the necessary flavor.
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  Acidophilus milk • Wholeor skimmed milk is fermented with Lactobacillus acidophilus which is said to have therapeutic benefits in the gastrointestinal tract. • It has an overall beneficial effect on people especially those suffering from frequent diarrhoea and intestinal gas. • It has a very harsh acid taste and thus faces rejection by consumers. • To overcome this, sweet acidophilus milk was developed. • In this, the bacteria are grown separately and added to pasteurized milk and the inoculated milk is kept at 4°C. • When this milk is consumed, the beneficial bacteria are activated in the warm stomach and intestinal tract. Lactobacillus acidophilus L. Acidophilus in a soya medium
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  Kefir • Kefir isa beverage produced by the action of lactic acid bacteria, yeast and acetic acid bacteria on milk, which produces a distinctive fermented milk product with unique properties. • It is produced by adding a starter culture called "kefir grains" directly to milk. The kefir grains are a mass of several different bacteria and yeasts embedded in a complex matrix of protein and carbohydrate. • Traditionally prepared kefir contained 1-2% alcohol, due to the complex fermentative process of kefir grains. But new and improved production methods have resulted in much lower levels. • The mouth feel of kefir is described to be 'prickly' and 'sparkly'. Kefir grains Flavored Kefir
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  Uses of fermentedmilk products • The fermentation process makes the fermented milk product easier to digest, especially for people who have milk allergies or are lactose- intolerant. • Some evidences suggests that drinking fermented milk product containing lactobacillus GG for about 5 days reduces the duration of diarrhea caused by rotavirus. • Cheese is most widely used in various food products and also used for preventing cavity, cancer etc. • Yogurt is used for treating high cholesterol, diabetes, prevent urinary tract infection etc. • Cultured buttermilk is used to maintain health and as a treatment against diseases. • Whole or skimmed milk is fermented with Lactobacillus acidophilus which is said to have therapeutic benefits in the gastrointestinal tract. • Acidophilus milk has an overall beneficial effect on people especially those suffering from frequent diarrhoea and intestinal gas. • People use kefir for indigestion, upset stomach, lactose intolerance etc.
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  Thank you for listening