According to the Oxford English Dictionary to spoil is to 'deprive of good or effective qualities'. When a food is spoiled its characteristics are changed so that it is no longer acceptable. Such changes may not always be microbiological in origin; a product may become unacceptable as a result of insect damage, drying out, discolouration, staling or rancidity for instance, [...]
The heat sensitivity of various micro-organisms is illustrated by Table 4.3 which shows their D values. Generally psychrotrophs are less heat resistant than mesophiles, which are less heat resistant than thermophiles; and Gram-positives are more heat resistant than Gram-negatives. Most vegetative cells are killed almost instantaneously at 100 °C and their D values are measured and expressed at temperatures appropriate [...]
The following article highlights the four radiation techniques for preservation of food: The techniques are:- 1. Irradiation 2. Microwave Radiation 3. UV Radiation 4. Ionizing Radiation Radiation Technique # 1. Irradiation: Electromagnetic (e.m.) radiation is a way in which energy can be propagated through space. It is characterized in terms of its wavelength A, or its frequency v, and the [...]