Food Science and Technology

What are the causes of product colour fading? This is one of the most frequent problems, and sources of the complaint, that beverage manufacturers encounter. It is a problem that may have several possible causes the most likely of which is exposure of the product to excessive amounts of light. It is also noteworthy that fading is normally associated with the use of added colours, either natural or artificial, rather than the intrinsic colour of a pure fruit juice. Products should be shelf tested in both south-facing and north-facing light to represent both direct sunlight exposure and the more normal daylight to assess their overall susceptibility to light. For products that are light-sensitive, use of protective films can be of value as can wrap-round labels. Another approach is to shrink wrap bulk packs in the protective film. Other likely causes are the presence of ingredients such as sulphur dioxide and ascorbic acid and the initial (or subsequent) level of oxygen...

Ethylene. To trigger the fruit within a ripening room to ripen uniformly and predictably, an external source of ethylene is required for most fruits. Ethylene is a natural plant hormone that affects the growth, development, ripening, and senescence (aging) of all plants. Ethylene has been found not harmful or toxic to humans in the concentrations found in ripening rooms (typically less than 250 ppm). In fact, ethylene was used medically as a anesthetic in concentrations significantly greater than that found in a ripening room.  For more information on ethylene, please see our Resources page. Ethylene is explosive at 27,000 ppm; however, all that is required to ripen fruit is 100 - 150 ppm.  There are several sources of ethylene application systems available; the safest form is ethylene generators and concentrate .  In fact, the United Kingdom's HSE has stated in a document that "the use of cylinders of pure ethylene should be vigorously discouraged." Ripening r...

42 cau hoi de thi PGTP.doc Học phần cung cấp những kiến thức về Các loại chất phụ gia được phép sử dụng trong chế biến nông sản thực phẩm. Các phương pháp sử dụng các chất phụ gia trong quá trình chế biến, bảo quản và lưu thông các sản phẩm thực phẩm trên thị trường. Khả năng gây độc hại của chất phụ gia thực phẩm . Các chất trợ giúp thường được sử dụng trong quá trình chế biến thực phẩm