tailieunhanh - Giáo trình Tiếng Anh chuyên ngành công nghệ thực phẩm - The language of techno-food processing in English: Phần 2

Trong cuốn sách này các tác giả đã dịch các bài khóa ra tiếng Việt và chuyển thành song ngữ để hỗ trợ cho sinh viên và đồng nghiệp tự học, tự đọc hiệu quả nhất. Các tác giả đã chọn 40 bài khóa gồm các kiến thức tổng hợp nhất, có kết cấu khoa học, thường gặp với nội dung chính của ngành Chế biến Thực phẩm. Mời các bạn tham khảo phần 2 cuốn sách. | Unit 17. POST-HARVEST SYSTEM BLO S QC Hệ thống công nghệ và thiết bị trong bảo quản và chế biến sau thu hoạch This section outlines the steps involved in traditional processing of cereals. It is vital that project planners and managers consider the traditional technologies in their particular socio- economic context when introducing any technical improvements or adaptations. The following main components of the post-harvest food system are discussed. Harvesting threshing winnowing drying and storage primary processing methods. Post harvest grain losses are a major concern in the traditional system. This section describes some improved technologies which have been developed to further reduce losses and increase productivity in cereal processing together with essential relevant technical background. Most of the cereals discussed are processed in much the same way but where relevant differences in processing techniques are mentioned. Harvesting There is an optimum time for harvesting which depends upon the maturity of the crop and climatic conditions FAO 1970 and has a significant effect on the subsequent quality of grain during storage. Harvesting often begins before the grain is fully ripe and extends until mould and insect damages are prevalent. Grajn not fully ripened contains a higher proportion of moisture and will deteriorate more quickly than mature grains because the enzyme systems are still active. If the grain remains in the field after maturity repeated wetting from rain and dew at night along with drying by the hot sun by day may cause grain to crack particularly long-grain paddy . Advice is therefore frequently necessary on the correct harvesting time. Cereal crops are traditionally harvested manually requiring high labor demand and therefore in many situations providing an important means of work to landless laborers. Threshing and Winnowing Threshing is the removal of the grains from the rest of the plant. In the case of maize the removal of the grain