Many kinds of processed foods are produced with salt as an important ingredient. Ham and sausage are pickled with salt. The role of salt is preservation of the products with lowering water activity. Salt is also playing an important role in processing of fishes. Many kinds of salted fish are produced in Japan. Bread and noodles are produced from wheat flour. By mixing with salt, wheat flour produced gluten from gliadin and glutenin whose elastic property is characteristic in bread and noodles. Pickles are produced from many kinds of vegetables with salt. High osmotic pressure of salt solution softens the vegetables. Fermented seasonings such as Miso (fermented soybean-paste) and Shoyu (fermented soybean-sauce) have high concentration of salt. Kamaboko is a typical Japanese fish product. Fish meat is mashed with salt followed by steam heating. Fish protein, Myosin, produce high elastic property named as “Ashi” in the process.
Salt is a versatile seasoning in the cooking. For example, the addition of salt to the cooking water of rice make the water absorption of rice grains suppress. The salt is necessary for making the noodle because it can enhance the elasticity of the dough. The softening of vegetables and beans are promoted by the salt added to the cooking water. The browning of such fruits as an apple is restricted by the salt solution. The aggregation of egg is accelerated by the salt, while the strength of the soybean curd is weakened by the salt added to the cooking water. Thus the salt has various influences on appearance, taste, texture of foods during cooking. Some effects of salt on the textural changes of foods have concentration dependence. We need to control the concentration of salt for the desirable use to obtain the optimum cooked state. The mechanism of various changes by the salt is not always enough. For better understanding of the role of salt in the cooking, the mechanism of such changes as texture by the salt needed to be investigated.
Japanese pickling vegetables “Tsukemono” are a main componet of Japanese cuisine. Pickles were first produced as a means of preserving food. Pickles with various salt concentration are produced in Japan. Pickles are preserved by osmotic pressure of salt and glucose, sugar and other materials. Lactic acid bacteria of fermented vegetables are either Gram positive aerobic or facultatively anaerobic organisms and are salt resistant. The growth of spherical lactic acid bacteria constantly regardless of fermentation temperature, but at higher temperatures, the growth of lactobacilli (rod) occurred along with the sporadic growth of lactic enterococci and pediococci (sphere). Salt was the most important limiting factor, because fermented vegetables cannnot be made without salt. The optimum concentration og salt for the growth of lactic acid bacteria was found be in the range 2-4%. Fermeted vegetables are produced at various area of the world. Kimuchi (Korea), Sauerkraut (Europe) and Paozai (China) are well-known fermented vegetables.
The kind of salt in Japanese market was increased rapidly because of shift to a free trade. A lot of users are confused to select a suitable salt. This paper tries to review on food salt in market for aid of selection. It is included as 1) classification by manufacturing process and raw material, 2) characteristics of vacuum salt, solar salt, rock salt and spray dry, 4) an effect of difference of raw material, area and depth of sea, and concentration process, 5) processing, 6) Additives. The main point of this review is that the characteristics of salt will be determined mainly by crystallizing process, not area and depth of sea, or concentration process.