ABSTRACT
Food ingredients plants utilize agricultural and natural raw materials to separate and recover valuable food components, such as wheat flour, sugar, edible oils, pectin, protein, and salt, which are used in the manufacture of several food products. Wheat flour and other cereal flours can be considered as food ingredients, which are used in large quantities in the baking and other food industries. Various other food ingredients, used in smaller quantities, are produced by the Chemical Process Industries, e.g., flavors and gums, coloring materials, sweeteners, antioxidants, preservatives, vitamins, nutritive minerals, and special food chemicals. The raw materials of the natural food ingredients are bulk agricultural products of relatively low cost, such as cereal grains (wheat, corn), sugar beets or sugar cane, and soybeans. Some food ingredients are produced from byproducts of food preservation or food manufacturing plants, e.g., pectin from citrus or apple peels, and protein from cheese whey. The design and economics of food ingredient plants is based on conventional Chemical Engineering technology. The plants are optimized, instrumented and controlled, and the plant effluents are treated to meet the environmental requirements. Microbial spoilage and chemical or biochemical deterioration of food ingredients during processing are very limited, and hygienic and food safety requirements in such plants are less severe than in conventional food preservation and food manufacturing plants. Food ingredients plants produce higher value-added products, compared to the food preservation and food manufacturing plants. The raw materials are subjected to extensive processing in order to separate and purify the desired
ingredient. As a result, the cost of processing is increased and the cost of raw materials becomes less important. Table 9.1 lists various food ingredients plants of importance to food manufacturing. Food flours (mainly wheat) are produced in large milling plants, using mechanical reduction (mills) and separation (sieving) equipment, operated continuously. A number of flour fractions are produced, used in bakeries and other food manufacturing plants. Flour mills are located near ports and large population centers. Bulk storage and transportation of flours are used extensively. Starch and sugar plants are generally large chemical engineering installations producing large quantities of food ingredients from agricultural raw materials. The food ingredients are separated, recovered and, if needed, modified by a series of mechanical, physical, and chemical processes. The plants use large amounts of energy (steam, fuel, electricity) and process water, and they produce significant amounts of wastes, which should be treated. Food biopolymer plants utilize agricultural raw materials and food plant wastes to produce pectin, gelatin, whey protein, etc., which are used in the manufacture of several food products. Food proteins are especially important because they provide the required high nutritive value to various foods. Vegetable oil plants produce large quantities of edible oils from oil seeds, olives, and corn, using mechanical expression, mechanical separation, and solvent extraction. These plants produce large amounts of by-products, which can be utilized in the production of proteins and other useful food ingredients (Shahidi, 2005). The liquid, solid, and gaseous wastes of these plants must often be treated to comply with the environmental pollution laws. Plant extracts are produced by water or solvent extraction of useful ingredients from vegetable plant materials, such as flavor compounds, gums, or phytonutrients (flavonoids, carotenoids, etc.). These ingredients are produced in relatively small quantities in specialized chemical processing plants. A large number of food chemicals and biochemicals are produced in specialized chemical plants, e.g., vitamins, food preservatives, and food enzymes. These ingredients are produced in relatively small quantities, often batch operated, using complex processes and specialized equipment, and hence they are relatively expensive materials.
