Study On Screening Evaluation And Processing Impact Of Se-enriched High-quality Rice In Jiangjin District,Chongqing

Selenium is an indispensable micronutrient of the body,which is closely related to the growth,development and occurrence of diseases.The intake of selenium has a U-shaped relationship with human health,and the intake of selenium is excessive or insufficient.Will cause certain harm to the health of the body.Selenium exists in the organism in two chemical forms: organic selenium and inorganic selenium.Its metabolism and physiological functions in the body depend on their existing forms.Different forms of selenium can supplement human selenium.The effect is different.Compared with inorganic selenium,organic selenium is easier to digest and absorb by the body and has higher bioavailability.Therefore,it is extremely important to determine the content,form and bioavailability of selenium in the diet.Selenium cannot be produced by the cells of the body,and can only be taken from the outside world.Dietary intake is the most important way for the accumulation of selenium in the human body.During the growth of rice,the inorganic selenium adsorbed in the soil can be converted into organic selenium to obtain selenium-containing rice.Eating selenium-containing rice is considered to be a safe and effective way to supplement selenium.The quality of different varieties of rice is quite different.Processing will change the quality of rice.Relevant studies have shown that selenium is mainly distributed in the pericarp and seed coat of the rice grains,and the selenium contained in the rice will be lost if the cortex is removed by milling.Due to the thermal volatility and instability of selenium compound,common household cooking methods will also change the content and form of selenium in rice,and affect the bioavailability of selenium in rice.This article first selects 19 kinds of seleniumcontaining rice from 7 villages and towns in Jiangjin District,Chongqing City as the research object.The pure brown rice is obtained through hulling,and the brown rice is milled for different times to obtain rice with different processing accuracy.The determination is carried out by hydride generationatomic fluorescence spectrometry.The selenium content in different pure brown rice,cortex and polished rice was compared with high-quality rice to evaluate the basic composition,appearance and taste quality of rice with different selenium content.Finally,the selenium-enriched rice was treated with normal pressure,microwave,high pressure and extrusion.The gastrointestinal system digests rice processed by different processing methods,and the changes in selenium content,form and bioavailability of selenium-enriched rice before and after processing are measured.It is expected to provide data support for the selection of excellent rice varieties in Jiangjin District of Chongqing City and consumers’ selection of selenium-enriched high-quality rice,provide a basis for the appropriate processing of selenium-containing rice and effectively retain nutrients,and provide a basis for the production and production of selenium-enriched rice foods Theoretical reference.Under the main research results:(1)Select 19 selenium-containing rice varieties from 7 villages and towns in Jiangjin District,Chongqing City,and explore the relationship between their selenium content and the milling rate and selenium loss.The total selenium content of brown rice ranges from 0.0273-0.3467 mg/kg.Among them,Yuxiang 203,Jing 1 You Huazhen,Q Xiang You 100 and Jing Liang You 510 are varieties with higher selenium content.There are significant differences in the selenium content of different varieties of brown rice in the same area(P<0.05),and the same variety of rice planted in different regions has significant differences in selenium content(P<0.05).Selenium is unevenly distributed in the rice cortex,and is affected by the variety and planting environment.The distribution of selenium in different rice is different,and the milling rate,the selenium content of rice bran and the loss of selenium during the milling process are also different,Yuxiang 203 The selenium content in the rice bran of Hejing 1 Youhuazhen is high,up to 0.82 mg/kg,which can be used as a selenium-enriched byproduct during processing.All the tested samples showed that with the extension of the milling time,the rice milling rate increased,and the higher the processing accuracy,the greater the loss rate of selenium.Due to the physical properties of different rice varieties,the milling rate of rice grains and the grain shape and hardness of the rice grains Closely related,the physical properties of different varieties of pure brown rice are different,the milling rate is different during the milling process,and the selenium loss rate is different.Among them,the selenium loss rate of Mianyang 838 is the highest,and the selenium loss rate is 44.39% after milling for 80 s.Jing 1 You Huazhen and Jing Liangyou 510,Q Xiangyou 100 planted in Baisha Town and Yuxiang 203 planted in Zhongshan Town have a small amount of selenium loss during the milling process.After 80 s of cumulative milling,the first grade rice The selenium content can still reach the selenium-enriched level.(2)Research on the quality evaluation of different varieties of selenium-containing rice at the same processing accuracy level.The basic components of the tested variety Zhongyuxiang 203 are the closest to the high-quality rice Huatian Gongmi;the appearance quality test found that Qxiangyou 100 has a slender shape,Mianyang 838 is short and wide,and the aspect ratio of Yuxiang 203 is not significantly different from that of Huatian Gongmi.,The shape is similar,but the broken rice rate is relatively high.The process of multi-machine whitening and light milling should be used to ensure the whole rice rate;the cooking characteristics test found that Yuxiang 203,Jing1 Youhuazhen,Mianyang838 and Gang The cooking characteristic parameters of You 177 are close to that of Huatian Gong rice,and it has good cooking characteristics.The gelatinization test shows that Mianyang 838 has good thermal stability and strong gelling properties,and is easy to age.Gangyou 177,Mianyang 838 and T excellent 203 has better thickening ability,Yuxiang 203 is easy to fully absorb water and gelatinize,the rice texture is soft and sticky,and the taste is good;the texture characteristics test found that T You203,Shenliangyou 871 and Yuxiang 203 rice have low hardness and stickiness.,Stickiness,elasticity,chewiness,texture quality close to Huatian Gongmi,good palatability;rheological test results show that the tested varieties present pseudoplastic fluid characteristics,non-Newtonian fluid,performance The rheological properties of the weak gel are shown,and the gel strength of the rice paste is higher than that of Huatian Gongmi.The taste value test results show that Yuxiang 203,Jing 1 You Huazhen,Longliangyou 1206,K You 893 and Shenliang You 871 is a variety with higher eating value,Yuxiang203 is the highest,slightly lower than Huatian Gongmi,and has better eating quality.Comprehensively available,the tested variety Zhongyuxiang 203 has the best quality,high-quality,high-selenium-rich rice with various indicators similar to Huatian Gongmi.(3)Select selenium-rich rice samples to carry out in vitro evaluation studies on selenium content,form and bioavailability of different processing methods.Screw extrusion processing resulted in the loss of 43.05% of selenium in selenium-enriched rice.Normal pressure,high pressure,and microwave treatment would not have a significant impact on the selenium content(P>0.05);all four processing methods reduced the Se Met in rice.Se(Ⅳ)is completely lost after microwave,high pressure and extrusion treatment.Microwave treatment will increase the content of Me Se Cys in vitro simulation.The results of gastrointestinal digestion experiments found that after gastrointestinal digestion of samples treated with normal pressure,high pressure and microwave,the bioavailability of selenium was significantly higher than that of untreated samples by 45.69%,74.99%,67.93% and 50.38%respectively;selenium-enriched rice The main selenium forms after gastrointestinal digestion are Me Se Cys and Se Met.Se(Ⅳ)is not detected after gastrointestinal digestion;processing can increase the bioavailability of Se Met in selenium-rich rice,and the availability of Se Met in samples after extrusion It is 43.19%,42.27% after high pressure treatment,46.69% after microwave treatment,47.49%under normal pressure,compared with untreated samples,they are significantly improved.