Behind the "white fine beauty" of grain is unnecessary loss and nutrient loss.

Behind the "white fine beauty" of grain is unnecessary loss and loss of nutrition
waste shameful savings proud
now finely processed food products are favored by many consumers. But it seems that behind the "white fine" grain, there is the problem of food loss caused by over-processing.
, Aug. 27 (Xinhua) -- China loses more than 15 billion pounds of grain per year due to over-processing, according to a notice issued by the former Ministry of Agriculture in 2014 on strengthening the work of grain processing and impairment.
, why are some companies now over-processing food? To what extent should grain be processed to satisfy the taste, but also to ensure nutrition, but also to reduce losses? With these questions, Science and Technology Daily reporter interviewed industry experts.
up to 15 per cent of food losses due to over-processing
."The so-called over-processing refers to the high consumption of raw materials in order to over-pursue processing accuracy, low product yield of grain processing methods." Tao Peijun, a professor at Hebei Agricultural University and head of the national key research and development plan "Food Production and Efficiency Science and Technology Innovation" special "Wheat-Corn Postpartum Impairment, Technology Diffusion and Comprehensive Evaluation" in Hebei Hydrothermal Resources Limitation Zone, said.
" overprocessing results in food losses of about 3 to 10 per cent, with the high likely to be around 15 per cent. The loss of quantity is mainly due to the processing process, will affect the appearance of grain, taste or processing characteristics of the skin, paste powder layer by grinding, polishing and other processes removed, resulting in the resulting edible food weight reduction. Li Regui, a professor at the School of Food Science and Nutritional Engineering at China Agricultural University, said.
To wheat as an example, "modern wheat flouring process generally uses grade powder production technology, usually including leather grinding, heart grinding, slag grinding, tail grinding composed of grinding system process and screening system process." In order to achieve the high accuracy and high rate of wheat flour, enterprises using powder machine graded purification, can be finely from the endosperm center to the outer week gradually take powder, and then according to the accuracy of high or low or end-use to be made into different specifications or uses of wheat flour. This process is characterized by the removal of the cortical layer, paste layer, embryo as far as possible, and therefore will lead to higher wheat processing losses. Li Huijing, a professor at Hebei Agricultural University and the backbone of the "Wheat-Corn Postpartum Impairment, Technology Diffusion and Comprehensive Evaluation" task force in Hebei Hydrothermal Resource Limitation Zone, said.
reported that in the 1980s and 1990s, the average powder rate in China's wheat processing industry was about 85%, which is now down to about 73%. According to the State Food and Material Reserve Bureau, the country's wheat flour production in 2018 reached 73.035 million tons, if the current average yield compared with more than 20 years ago, the consumption of more than a year of wheat can reach more than 14 million tons.
one-sided pursuit of fine will lead to the loss of nutrients
experts admitted that the current domestic food processing industry is prevalent in the one-sided pursuit of precision phenomenon, products more and more white, more and more fine production. "The root cause of over-processing in the wheat processing industry is the consumer's preference for white and thin wheat flour. In order to meet market demand, grain processing enterprises have good raw products, good taste of wheat flour, which reflects the processing accuracy of pink bran star and ash and other indicators are much higher than national standards. Tao Peijun said.
In Li's view, some enterprises to over-finishing grain, mainly because of the refined grain appearance, taste and processing characteristics are better, can be sold at a higher price. For example, the appearance of white rice white, taste is also better;
, over-processing not only results in the loss of food quantities, but also the loss of nutrients.
, the grain structure of wheat can be divided into four parts: cortical layer, paste layer, embryo and endosperm. Nutrients are unevenly distributed in wheat grains. The cortical layer, paste layer and embryo mainly contain cellulose, protein, fat, vitamins, minerals and phenols, etc. Over-processing will try to remove the cortical layer, paste layer, embryo, the endosperm grinding fine into powder, so this process more retains the wheat grain starch and protein, and cellulose, fat, vitamins and minerals and other nutrients lost a lot, and the higher the accuracy of wheat flour processing, the more serious the loss of nutrients.
Li said that whether rice or wheat, its paste layer is rich in protein, fat, dietary fiber, minerals and vitamins, especially dietary fiber, minerals and vitamins and other consumers are prone to inadequate intake of nutrients, in the paste layer is much higher than endosperm, that is, rice and wheat is now commonly consumed parts.
scientific means to reduce the loss of nutrition taste
How to reduce the loss of food during processing, while taking into account nutrition and taste?
there is a gradual correspondence between "food taste, appearance improvement and loss of food nutrition and quantity." After grain processing to a certain precision, its taste and appearance improvement is not obvious enough, but the loss of nutrition and quantity will still increase proportionally, so there is a moderate processing concept. Moderate processing is the pursuit of nutrition, appearance and taste balance, to prevent the one-sided pursuit of appearance and taste and excessive improvement of processing accuracy. Li said that scientific means will play a role in it. For example, when wheat flour is processed, the flour appearance, processing characteristics, nutrition and taste can be coordinated by increasing the powder yield and appropriately increasing the content of bran and paste layer in flour. The dietary fiber content of wheat bran is high, if not treated directly after crushing to produce whole wheat flour, crushing particles when larger easily affect the taste, which requires the use of scientific means, dietary fiber as much as possible crushed. The microbial content of bran is high, the fat of wheat germ is easy to oxidize and decay, and needs to be sterilized and enzyme-destroyed in order to extend the shelf life of whole wheat flour and its products, and improve the market and consumer acceptance of whole wheat flour and products. For rice, according to different rice varieties, choose the appropriate polishing process and polishing pressure, retain the germ and other nutrient-rich parts, so that it will not obviously affect the quality of consumption, but also can improve the rice yield. Of course, the rice that retains the germ and part of the paste layer is prone to oxidation leading to a decrease in quality, so storage and circulation conditions are more demanding. All these need to be guaranteed by supporting technical means.
Li Huijing added that it is necessary to adjust and improve the wheat flour processing process, appropriately reduce the use of powdering machine and light roller grinder, to a greater extent to retain vitamins, minerals and other nutrients; The loss of wheat processing is reduced by the moderate processing of wheat and the comprehensive utilization of by-products.
addition, Tao Peijun pointed out that to improve consumer health awareness, let them realize that wheat flour is not the whiter nutrition better, do not pursue the high precision of wheat flour one-sided. Through market demand to force processing enterprises to moderate processing. "National wheat flour standards will also be revised and enforced. The national wheat flour standard should not only have the minimum requirements of processing accuracy, but also have the highest requirements of processing accuracy, and also consider the type and content of essential nutrients in the human body. Through the enforcement of national standards to promote the moderate processing of enterprises. Tao Peijun said.
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