Packaging of the hottest cereals and other seeds

2022-08-13
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Packaging of cereals and other seeds

types and organizational characteristics of rice

rice is the staple food of people in Southeast Asia. China, India, Java, Vietnam, Thailand, Japan, Korea, the Philippines, Malaysia, Bosnia and Herzegovina, Sinan, Soviet Russia, Turkey, etc. rice production accounts for 95.7% of the total rice in the world, followed by 1.69% in Europe, 1.51% in the Americas, and only 1.10% in Africa

(1) types of rice

rice can be divided into rice and upland rice because of the difference in water content during planting. It is also classified according to the essential differences of rice grains: among them, the most important one is the fundamental differences in the quality of stems and glutinous rice, so there are differences in utilization

(2) composition of rice

endosperm accounts for 92% of the whole rice grain, embryonic tooth 3%, outer skin (bran layer) 5%, vitamin B is distributed in endosperm 5%, embryonic tooth 66%, outer skin 29%. White rice only accounts for the endosperm in the reserved rice. 1. The symptoms of unstable rate of the hydraulic universal experimental machine are mostly the parts with high or low pressure. The dermis, stroma and embryonic teeth have fallen off, so there is very little vitamin B in white rice. The general nutritional components of rice are sugar (mainly starch), accounting for 74.21% - 79.4%, protein 6.54%, 7.95%, fat 0.3%, 3.07%, crude fiber 0.2% - 1.22%, ash 0.4% - 2.07%, moisture 13.28% - 14.86%. Their components vary from place to place

(3) the nature of meters

① physical properties

rigidity: the crushing endurance of meters is called rigidity, that is, the hardness and softness of meters. The rigidity of rice varies with variety, climate, soil quality and dryness, and the content of protein is directly proportional to the rigidity. Generally, the new rice is fully dry, the rice grains are rich in fat, protein, rigidity and good quality

weight: brown rice with dry grain weight of more than 28g is the largest grain, 26-28g is the large grain, 22-26g is the medium grain, 20-26g is the medium grain, 20-22g is the small grain, and below 20g is the smallest grain+

proportion: it varies with rice producing area, cultivation land (water and land rice) and drying method. Generally, the proportion of good quality is significant

bulk density: expressed in the weight of one liter of rice, it varies with the variety of rice and the place of origin. Those with good quality have large capacity. The bulk density of white rice and brown rice is the largest when the water content is 5-6%, and the bulk density of rice is smaller than that of upland rice

expansibility: that is, the increased volume of rice cooked into rice is called this expansibility. Usually, 1L white rice can cook 2-4.5l. Generally speaking, Lai rice is more expansive than Penglai rice, and glutinous rice is the least expansive. Thai rice is more bulky than Chinese rice. Those with high bulkiness have loose quality and little protein, because there is air between starch. 0 = SCW

the longer the rice is stored, the drier it is, and the greater its expansibility is. Experiments have proved the relationship between bloating and rice taste. It is found that the greater the bloating, the worse the rice taste

② chemical properties

the phosphorus compounds in white rice range from 0.2% to 0.3% (more than 2% in sugar) are mainly calcium and magnesium phytate, so the rice is acidic, and the pH value is 4 G and 6 G. Color reaction to iodine: the adsorption capacity of Japonica Rice to iodine is large. It is usually blue, and glutinous rice starch has less absorption of iodine, and it is purple, which is due to the phenomenon of cell body adsorption. Due to the different sizes of starch cell body, the blue starch grain is coarse, and it is blue; If the dispersion is fine, it is purple brown

japonica rice has a faster coagulation effect than starch cytosol in the presence of acid and salt. Rice contains liquefaction enzymes and saccharifying enzymes. The former mainly liquefies starch, while the latter mainly keeps out starch

miscellaneous grain varieties and their tissues and characteristics

(1) maize

is native to tropical climate, with short growth period and strong adaptability to the climate. Some varieties can also be cultivated in the northern temperate zone

there are many varieties of maize. According to the shape of seeds, it can be divided into about 7 species, namely lemma species, popping species, tunneling species, horsetooth species, soft species, sweet species, soft sweet species, etc

the colors of the particles are white, yellow, yellow red, red, reddish brown, dark purple, purple, etc., and there are all kinds of striped colors

maize has a wide range of uses. The fruit is generally directly used as feed, and can also be directly supplied for consumption. It can be eaten raw, cooked or processed. In the processing industry, it can also be used as raw materials for glucose, dextrin, starch, alcohol, etc. Its germ contains a lot of fat, which can be extracted from edible oil, and can also be roasted and eaten as a whole, which is called popcorn. Others, such as cooking and drinking, flour making, candy making, bread making, etc., can be used as raw materials

its general composition is about as follows:

① the average content of protein is about 10%, most of which are corn protein, which is about 5%, soluble in dilute alcohol, and other proteins dissolved in potassium carbonate are more about 31.5%. How to effectively maintain the compression testing machine? The rest are water-soluble protein, globulin dissolved in salt water, maysm, hemp protein, etc

② grease, content about 4% - 10%. (for whole grains). Most of them exist in the germ. The fresh oil is light yellow or golden yellow with special fragrance

③ enamel: accounting for about 70%, most of which are starch, accounting for about 84.6% of the total sugar, and other sugars such as five carbon sugar, glucose, fiber, etc. account for a small part

④ ash: accounting for about 2% of anhydrous matter, most of it exists in phosphates, mainly in organic form in the germ, and others, such as ferrosilicon

⑤ vitamins: almost no white species a, more yellow species. Vitamins B and E are also contained. Ro

maize disease:

this disease is caused by the long-term consumption of Maize in South America, Italy, and subtropical countries. The disease was caused by the lack of protein and Nordic acid (anti fatigue element). In 1830, there were 12000 patients in the United States, and 7000 people died. These patients ate only rice, beans, molasses and a small amount of bacon except corn. If normal people only eat these foods, they can develop skin fatigue disease in about half a year, so the disease is most likely to occur in people with poor economic conditions. People with this disease have sour mouth, sour tongue, dermatitis, digestive tract disease, and thin body; If dogs suffer from this disease, they will have black tongue and die seriously. If patients eat vitamin B1, B2, alkali acid and other complex vitamin B, they can treat this disease

(2) sorghum

Northeast China is rich in output and is the staple food of local residents

protein is similar to rice. If it is used as a staple food, protein will be insufficient. Its main protein is prolamine

vitamin A has 25 international units in 100g sorghum, BL has 400R, B2 has 100r, solanine acid and C also exist in a small amount

the cell membrane of sorghum starch is relatively strong, so it is difficult to cook and the gelatinization rate is low, which is the main reason why it is not easy to digest

generally, sorghum can be made into starch, sugar, sorghum wine, etc

{3) millet

millet is the richest and best quality of plant protein. It also has a lot of fat and is easy to digest and absorb. It is a food with high nutritional value.

physiology and quality of seeds after harvest

seeds of Cereals, beans and other plants still have vitality of human generation after harvest. If conditions are met, they also have the ability to germinate. However, during a certain period after harvest, or when environmental conditions are not suitable for germination The seeds are in dormant state, and the physiological state is relatively stable. Therefore, the storage of these cereals and beans is simpler than that of fruits and vegetables. Traditionally, these cereals are packed in straw bags, straw bags, paper bags and gunny bags and stored in warehouses. However, in the natural environment, with the change of temperature and humidity, the water content of seeds will inevitably change. If the water content increases and the enzymatic and respiratory effects are enhanced, there will be changes that are not conducive to ensuring the quality. Moreover, if damaged by insects, microorganisms, mice, etc., the appearance, taste, processing adaptability and nutritional value of the independently designed grinding plate extruder will be reduced. According to the changes of physiological functions of cereals during storage, it is mainly due to the increase of fatty acids produced by lipid decomposition due to the action of esterase, the decomposition of starch due to the action of amylase, the increase of reducing sugar and the decrease of vitamin B1, the increase of amino acids due to the decomposition of protein and the loss of seed components due to respiration. In addition, the germination rate or the activation of succinate dehydrogenase should also be reduced. This physiological and chemical change can also be used as a standard to judge the storage state and quality of cereals. During the aging of rice, there are not only the above factors, but also the hardening of rice grain structure and the decrease of water absorption

in order to suppress the above changes and maintain the quality of cereals and beans, the relative humidity should be maintained at 20% - 80%, and the temperature should be 10 ℃ - 12 ℃. Under these conditions, the reproduction of pests and microorganisms are inhibited. In addition, it is also an effective means to improve the storage effect by converting the ambient gas with inert gases such as nitrogen or carbon dioxide to reduce the oxygen concentration

packaging of cereals and other seeds

the qualitative change of brown rice and rice is mainly caused by mold invasion, enzyme action and oil oxidation. The degree of change varies greatly with the water content (environmental relative humidity) and storage temperature of rice. Stored rice suffers less damage from microorganisms or borers, and the processed brown rice has better gloss, but from the perspective of taste and chemical composition, it is basically not much different from stored brown rice

storing brown rice at low temperature can not only accurately control its water content, but also control the temperature of cereals. It is a better storage method to prevent changes in rice quality. Figure 7-2 shows the relationship between the storability, storage period, storage temperature and moisture of brown rice and rice. It can be seen from the figure that the most effective way to prevent the deterioration of rice is low-temperature storage. But in terms of rice (fine milled superior rice), it is not necessarily a practical method in terms of the current situation of circulation and economic benefits

whether it is brown rice or rice, the use of film packaging with good gas resistance can prevent the invasion or aging of mold to some extent. If inert gas conversion is carried out, the storage performance can be improved. Table 7-1 shows the results of a part of the comparative study on the use of rice with different moisture content for air packaging, nitrogen filled packaging, carbon dioxide filled packaging, vacuum packaging and low-temperature storage in terms of the same component changes, tissue physical properties, taste changes, etc. from the results, it can be considered that the effect of low-temperature storage is the best. However, inert gas conversion packaging is much better than gas packaging in maintaining quality. The results of sensory inspection by 30 inspectors using the dashboard show that the effect of gas conversion packaging is almost the same as that of vacuum packaging. In addition, the same effect can be achieved in maintaining the quality by either nitrogen filling, carbon dioxide filling, or close fitting packaging or vacuum packaging using the rapid method of carbon dioxide filling

in addition, the above measurement results have been fully confirmed according to the reduced sugar content and fat acidity, one of the aging indicators of rice, or the results of structural property tester, and the same results have been obtained for the inert gas inflatable packaging of brown rice

judging from the current situation that the circulation period of rice is relatively short, it is still too early to generally adopt inflatable packaging. However, if it is possible to carry out a large number of centralized rice milling in the future, and long-term storage

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