Cultured And Acidified Milk Products PDF

Milk Products Cultured and Acidified Milk Products - fermented milks products: milk products that produced through fermentation by specific M.O’ cultured buttermilk acidophilus milk yogurt Kefir: from goat, sheep and cows using yeast Koumiss: from mare’s milk using yeast Ymer Acid...

Milk Products Cultured and Acidified Milk Products - fermented milks products: milk products that produced through fermentation by specific M.O’ cultured buttermilk acidophilus milk yogurt Kefir: from goat, sheep and cows using yeast Koumiss: from mare’s milk using yeast Ymer Acidophilus Milk - steps of production of cultured product, (1) starter culture preparation (2) treatment of milk, skim milk, cream, or other product (e.g., pasteurization and homogenization) (3) Inoculation (4) incubation (5) Cooling (6) packaging.  Additional steps fluid for drinking, the curd must be broken and agitated to produce a smooth homogenous body. Cooling to 7°C or below is essential to stop acid development and to assure safety addition of stabilizers to thicken and to prevent separation of whey from the coagulated mass. Supplementing milk: - vitamins - casein (why) - minerals  Cultures - starter cultures: controlled bacterial population that is added to milk or milk products to produce acid and/or flavorful substances that characterize cultured milk products. - Lactococcus diacetilactis: more acid and more diacetyl - Diacetyl is a major component of flavor and aroma in cultured products. - nutlike flavor - Diacetyl is a degradation product of citric acid, hence Le. cremoris and - Lc. diacetilactis are referred to as citrate fermenters.  Cultures may be frozen concentrate or in the lyophilized Frozen concentrates have become popular ( easily retained and propagates) mixed strain starter cultures. (what and why) Think: if you have risk of bacteriophage contamination and don’t have mixed culture what to do? Yogurt Yogurt (or yoghurt, yahourt, yaourt, leben, madzoon, naja, dahi, dudh, dadiah, and zabadi) Fermented by Lactobacillus bulgaricus and S. thermophilus in all countries. except Turkey: yeast that ferments lactose. Yogurt contains large quantities of protein, lactose, calcium, and B-vitamins and hihighly digestible.  Dehydrated yogurt (yogurt powder or nonfat yogurt powder) has found many applications as a flavoring for soups, dips, chocolate brownies, snack bars, and other foods. cultured to a pH near 5.0 is dried yielding a protein content of 33 to 36% and a lactic acid content of about 6%. Cultured dairy solids: in addition to cultured nonfat milk, one or more of the following ingredients: cultured whey, cultured whey protein concentrate, nonfat dry milk, dry whey, lactic acid, natural and artificial flavorings, and silicon dioxide as an anti-caking agent. Probiotic yogurts: add probiotic bacterial strains to yogurt (those with proven health- promoting benefits, in addition to ST and LB as (Lactobacillus spp,, Bifidobacterium spp, and streptococcus thermophiles fruit-flavored yogurt: Yogurt Production made from homogenized milk, lowfat milk, or skim milk with added nonfat dry milk. Firmness of yogurt is increased by increase the milk soilds variables affecting yogurt composition include: 1. plain or flavored (stirred or set style) 2. fat content 3. sweetened with natural or artificial sweet 4. Fruit-on-the-bottom set style  ch-ch of used milk: 1. Low bacteria count 2. Free from: (a) antibiotics, (b) sanitizing chemicals, (c) mastitis milk, (d) colostrum, and (e) rancidity 3. No contamination by bacteriophages 4. Milk Non-fat-solid should be at least 8.25%, often 12.0%  Starter Culture A symbiotic blend of Streptococcus thermophilus (ST) and Lactobacillus delbrueckii subsp. bulgaricus (LB) ST can grow at 43-44 C (optimum 39) LB grows at 44 C, cause post-processing acid development due to its ability to grow at refrigeration temp. proteolytic activity of LB produces peptides and amino acids and give the flavor. The streptococci are responsible for the initial pH drop of the yogurt mix to approximately 5.0. The lactobacilli are responsible for a further decrease to pH 4.5. The common final acidity is 0.90% lactic acid Yogurt Manufacturing Method The milk is clarified and separated into cream and skim milk, then standardized with other dairy ingredients to achieve the desired fat and milk solids-not-fat content. The various ingredients are then blended together in a mix tank equipped with a powder funnel (if dry milk is added) and an agitation system The mixture is then pasteurized at 85 C for 30 min or at 95 C for 10 min. The mix is then homogenized using high pressures of 2000-2500 psi. Fermentation process A ratio of 1:1, ST to LB, inoculation is added to the fermentation tank A temperature of 43° C is maintained for 2-2.5 h under no agitation This temperature is a compromise between the optimums for the culture At temp. less than 43, ST dominates thus low flavor At temp. more than 43, LB dominates thus high flavor At end of fermentation, yogurt is cooled down to 5 C. Yogurt Production Greek Yogurt Concentrated form of yogurt by: 1- filtration.: after coagulation of casein, whey is removed from the product 2- fortification; adding of milk proteins or a mixture of milk protein and whey protein 3- ultrafiltration of milk. 4- extra heating  Kefir is an acidic and alcoholic fermented milk characterized by aerated foaminess and a sour flavor. contains up to 1.1% lactic acid, 0.3 to 1.0% ethyl alcohol, and carbon dioxide (CO2) Traditionally: making kefir involves direct addition of kefir grains (2 to 10%) to raw milk with occasional agitation during incubation. After fermentation for about 24 hr, ideally at (20 to 25°C), grains are removed by sieving and are reserved as starter for another batch. commercially, milk is heated to a high temperature (commonly 95°C for 5 min), which denatures protein and increases viscosity of the finished product. A mixed culture of bacteria and yeast forms “grains” comprised of proteins, lipids, lactose, and microorganisms within the milk. Ymer Ymer is a creamed, high-moisture skim milk curd that is homogenized to a smooth and silky texture. This dairy food is similar to yogurt but has a higher content of diacetyl, less acetaldehyde, manufacturing process involove (1) a different culture mixture is used—Lc.lactis ssp. cremoris, Lc. lactis ssp. lactis biovar. diacetylactis, and Le. mesenteroides ssp. cremoris—to assure strong gas production (2) whey is removed, leaving 50% of the original volume; (3) cream is mixed with the broken curd (4) the mixture is homogenized. Acidophilus milk Acidophilus milk is a traditional milk fermented with LA Skim or whole milk may be used. The milk is heated to high temperature, e.g., 95°C for 1 hour, to reduce the microbial load and favor the slow growing LA culture. coagulated. Milk is inoculated at a level of 2-5% and incubated at 37°C until Acidity as high as 1% lactic acid, but for therapeutic purposes 0.6-0.7% is more common. The number of viable organisms is an important prerequisite for premium acidophilus milk (5X108)/ml at the end of incubation but decrease rapidly during storage at (5°C). Best time of consumption ?? Other Fermented Milks Scandanivia—Filmjölk (cow milk) Japan—Yakult (yacult) from skimmed milk Middle East—Zabady (buffalo milk) and gariss (camel milk) Central Asia—Koumiss (kumys) from mare’s milk India—Dahi (cow or buffalo milk) Indonesia—Dadih (buffalo milk) Mongolia—Airag (horse milk) and tarag (goat milk)