Microprocessor controlled low-temperature corn drying system
Abstract Hardware, software and control criteria of microcomputer control of low-temperature corn drying are discussed. The ambient temperature and relative humidity were monitored by the microcomputer as a measure of the input conditions. A model of the low-temperature drying process stored in the memory enabled the microcomputer to calculate the grain moisture contents at assigned locations in the bin. Control decisions were then based on predicted moisture levels and on predicted or measured grain temperatures. Simulation results showed that the proposed system can save energy from 5 to 31% compared with high-temperature drying, depending upon the weather conditions.
A THIN-LAYER DRYING MODEL FOR PADDY DRYER
Precision control of drying conditions is very important in conducting thin-layer drying experiment on agricultural products. For control of drying it is necessary to determine drying kinetics, and obtain the moisture change during the drying process. In order to carry out the experiments a generalpurpose fully automated thin-layer dryer was designed and tested. Experiments on the drying kinetics of paddy (Fajr variety) were conducted at five drying air temperatures, ranging from 30 to 70 C o , in four air velocities, ranging from 0.25 to 1.0 m/s. During the drying the mass loss of samples measured continuously with a digital balance. Drying curves obtained from the experimental data were fitted to nine thin layer models. Results showed that two-term model predicts moisture change in drying with higher accuracy than other models.
The status of FAO and codex alimentarius developments on vegetable proteins
The FAO is interested in increasing world protein supplies both by advising and assisting developing countries to increase their production of staple foods and by encouraging the development of technology to produce protein concentrates both from vegetable and animal sources to supplement diets which are low in protein content. Recent revisions of the amount of protein required in the diet in relation to total per capita energy requirements and the difficulties encountered in introducing novel foods into established dietary patterns has led FAO to concentrate on increased agricultural productions in developing countries as the primary means of combatting malnutrition. In the meantime, in North America and Europe, advances in the technology of processing vegetable proteins has given highly acceptable products simulating meats which are being used as meat extenders and meat analogues. The consequent increase in vegetable protein production has revealed a need for international, agreement on standardization, and it has been agreed that this will be undertaken by the Joint FAO/WHO Food Standards’ Programme. The program operates chiefly through the Codex Alimentarius, Commission, an international governmental body, the purpose of which is to protect consumers against health hazard in food and against fraud. The Commission, which has 116 member governments, controls an intensive program of work covering the composition, labeling, additives, contaminants, pesticide residues, hygiene, sampling and analysis aspects of foods and has established a procedure which allows member governments ample opportunity to reach agreement on food standards and to accept them for incorporation into national legislation. The Codex Commission, at its 12th session, decided to establish a Committee on Vegetable Proteins with the following terms of references: “to elaborate definitions and world-wide standards for vegetable protein products deriving from soybeams, cottonseed, groundnuts, cereals and from other vegetable sources as they come into use for human consumption, and to elaborate guidelines on utilization of such vegetable protein products in the food supply system, on nutritional requirements and safety on labeling and on other aspects as may seem appropriate.” The question of which country will host the Committee is still under discussion.