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pasteurized using a continuous plate heat exchanger for 30 min at 85C or 10 min at 95 C.These heat treatments,which are much more severe than fluid milk pasteurization,are necessary to acheive the following: produce a relatively sterile and condusive environment for the starter culture denature and coagulate whey proteins to enhance the viscosity and texture The mix is then ho oge mized using high pre ssures of 2000-2500 psi.Beside thoroughly r cers and ation als preven creaming and ng the ngoff during incub tion a consistency an d to ar optimu th t e yogurt sta added A ratio of 11 ST to lb inoculation is added to the iacketed fermentation tank a erature of 43c is maintained for 4-6 h under au escent (no agitation)conditions This temperature is a compromise between the optimums for the two micoorganisms (ST39 C:LB 45 C).The titratable acidity is carefully monitored until the TA is 0.85 to 0.90%.At this time the jacket is replaced with cool water and agitation begins, both of which stop the fermentation.The coagulated product is cooled to 5-22C. depending on the product.Fruit and flavour may be incorporated at this time,then packaged.The product is now cooled and stored at refrigeration temperatures(5 C) to slow down the physical.chemical and microbiological degradation. 3.How can raw milk be homogenized ?(p.52) Milk is an oil-in-water emuulsion,with the fat globules dispersed in a continuous skimmilk phase.If raw milk were left to stand,however,the fat would rise and form a cream layer.Homogenization is a mechanical treatment of the fat globules in milk brought about by passing milk under high pressure through a tiny orifice,which results in a decrease in the average diameter and an increase in number and surface area,of the fat globules.The net result,from a practical view,is a much reduce ency for creaming of fat globules.Three factors contribute to this enhance stability of homogenized milk:a decre ase in the mean diameter of the globules (a facto aw), s (caus I rise to be for the g0 they dont ing the to the heat the cryo-gl comp hich ends to cluster fat globules causing them to rise 4.What's the Membrane Processing and how can it be used in dairy industry? Membrane processing is a technique that permits concentration and separation without the use of heat.Particles are separated on the basis of their molecular size and of pressure and specially designed semi-permeal e mem ranes. ere are some I e w developments in terms of commercial reality and is gaining readily in its applicationspasteurized using a continuous plate heat exchanger for 30 min at 85° C or 10 min at 95° C. These heat treatments, which are much more severe than fluid milk pasteurization, are necessary to acheive the following: • produce a relatively sterile and condusive environment for the starter culture • denature and coagulate whey proteins to enhance the viscosity and texture The mix is then homogenized using high pressures of 2000-2500 psi. Besides thoroughly mixing the stabilizers and other ingredients, homogenization also prevents creaming and wheying off during incubation and storage. Stability, consistency and body are enhanced by homogenization. Once the homogenized mix has cooled to an optimum growth temperature, the yogurt starter culture is added. A ratio of 1:1, ST to LB, inoculation is added to the jacketed fermentation tank. A temperature of 43° C is maintained for 4-6 h under quiescent (no agitation) conditions. This temperature is a compromise between the optimums for the two micoorganisms (ST 39° C; LB 45° C). The titratable acidity is carefully monitored until the TA is 0.85 to 0.90%. At this time the jacket is replaced with cool water and agitation begins, both of which stop the fermentation. The coagulated product is cooled to 5-22° C, depending on the product. Fruit and flavour may be incorporated at this time, then packaged. The product is now cooled and stored at refrigeration temperatures (5° C) to slow down the physical, chemical and microbiological degradation. 3. How can raw milk be homogenized ?(p.52) Milk is an oil-in-water emulsion, with the fat globules dispersed in a continuous skimmilk phase. If raw milk were left to stand, however, the fat would rise and form a cream layer. Homogenization is a mechanical treatment of the fat globules in milk brought about by passing milk under high pressure through a tiny orifice, which results in a decrease in the average diameter and an increase in number and surface area, of the fat globules. The net result, from a practical view, is a much reduced tendency for creaming of fat globules. Three factors contribute to this enhanced stability of homogenized milk: a decrease in the mean diameter of the fat globules (a factor in Stokes Law), a decrease in the size distribution of the fat globules (causing the speed of rise to be similar for the majority of globules such that they don't tend to cluster during creaming), and an increase in density of the globules (bringing them closer to the continuous phase) oweing to the adsorption of a protein membrane. In addition, heat pasteurization breaks down the cryo-globulin complex, which tends to cluster fat globules causing them to rise. 4. What’s the Membrane Processing and how can it be used in dairy industry? Membrane processing is a technique that permits concentration and separation without the use of heat. Particles are separated on the basis of their molecular size and shape with the use of pressure and specially designed semi-permeable membranes. There are some fairly new developments in terms of commercial reality and is gaining readily in its applications:
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