Question

The effectiveness of heat for sterilization is a function o.. Time Temperature Both a and b None of the above 4 Flash pasteurization holds the liquid at heat and time that eliminates all pathogens. 71 C for 15 Seconds 71 C for 15 minutes 140 C for 3 seconds 140 C for 15 seconds

Answer 1

Ans -( c) both a and b

Heating is one of the most common—and oldest—forms of microbial control. It is used in simple techniques like cooking and canning. Heat can kill microbes by altering their membranes and denaturing proteins. The thermal death point (TDP) of a microorganism is the lowest temperature at which all microbes are killed in a 10-minute exposure. Different microorganisms will respond differently to high temperatures, with some (e.g., endospore-formers such as C. botulinum) being more heat tolerant.

Ans-4 ( a) 71 C for 15 sec

In flash pasteurization, the product is held at a higher temperature, but for a shorter time, so that there is less development of a cooked flavour.
Pasteurization of milk destroys all pathogens, and although it will sour within a day or two, this is not a source of disease. It is achieved either by heating to 63–66 °C for 30 minutes (holder method), followed by immediate cooling, or (the high‐temperature short‐time process) heating to 71 °C for 15 seconds.

Pasteurization, partial sterilization of liquids such as milk, orange juice, wine, and beer, as well as cheese, to destroy disease-causing and other undesirable organisms. The process is named for the French scientist Louis Pasteur, who discovered in the 1860s that undesired fermentation could be prevented in wine and beer by heating it to 135°F (57°C) for a few minutes. Milk is pasteurized by heating it to about 145°F (63°C) for 30 min or by the "flash" method of heating to 160°F (71°C) for 15 sec, followed by rapid cooling to below 50°F (10°C), at which temperature it is stored. The harmless lactic acid bacteria survive the process, but if the milk is not kept cold, they multiply rapidly and cause it to turn sour.