Heavy Metals And Nutrition Assessment In Co-cultured Rice

In China and other Asian countries,heavy metal pollution is often a risk of food safety in rice production,and fertilizers and pesticides are often one of the main causes of rice pollution.In order to understand whether the adoption of the rice-fishing comprehensive breeding model can reduce the content of heavy metals in rice and improve the taste quality of rice,we have done the following research:1、In this paper,35 different rice cultivars with different forms of rice were tested,including the differences in rice husk,brown rice and polished rice,and their correlations.The results showed that there were no significant differences in the elements of Cr,Ni,Cu,Zn,As,Cd,Hg and Pb except for Cu and Zn.The other five elements were significantly different.The content of Cr and Ni was rice husk > brown rice > polished rice,and the difference was significant.The content of As and Pb was significantly higher than that of brown rice and polished rice.The difference between brown rice and polished rice was not significant.The content of Hg was rice husk and The content of brown rice was significantly higher than that of polished rice,and the difference between rice husk and brown rice was not significant.The results also showed that there was a significant positive correlation between the content of Ni,Cu,Zn,As and Cd in brown rice and polished rice.There was a significant positive correlation between the content of Cu and Cd in rice husk and polished rice,and in rice husk and brown rice.There is no significant correlation between heavy metal elements.There is also a correlation between different heavy metal elements,indicating that there is a synergistic effect on the accumulation of heavy metal elements.In general,the heavy metal content of polished rice is lower than that of rice h u s k s a n d b r o w n r i c e,s o t h e s a f e t y o f p o l i s h e d r i c e i s h i g h e r.2、This paper examined 201 rice samples(RA)symbiotic between rice and aquatic crops in 2017 and 2018 and compared them with single cultivated rice samples,including rice from the market and single cultivated rice(RM)in related literature.The content of Cr,Hg and Ni in RA rice decreased significantly,while the content of As and Zn was higher than that of RM rice in the market.The results also show that for glutinous rice,the content of Cr,Pb and Zn in the 2017 sample is higher than that in the 2018 sample,while the Hg and Ni content in the 2017 sample is lower than the 2018 sample.Regarding glutinous rice,the contents of Cr,As,Cd,Pb and Zn in the 2017 sample are higher than those in the 2018 sample,and only the Hg in the 2017 sample is higher than the 2018 sample.There is almost no difference between the rice varieties(glutinous rice and glutinous rice)in 2017 and 2018.Therefore,it is concluded that the use of rice and aquaculture integration can reduce the heavy metal c o n t e n t a n d t h u s i m p r o v e t h e f o o d s a f e t y o f r i c e p r o d u c t i o n.3、The taste indices of Rice Co-cultured with Various Aquatic Animal Crops(referred to as RA rice)have been evaluated and compared with those of the common mono-cultured rice(Japonica rice,referred as RM),through the analyses on the eating quality of all the rice samples collected from the farms,which joined the 2017 and 2018 Good Quality Rice Evaluation Competition held by the Strategic Alliances for Technological Innovation of Integrated Rice Aquaculture System of China in this study.The results showed that rice taste quality was mainly affected by the following parameters: the hardness,viscosity,elasticity,aroma,amylose and protein content of cooked rice.The cumulative contribution rate of the first three principal components reached 96.55%;By comparing the inter-annual taste quality of Indica rice and Japonica rice,the results showed that the indices of amylose,protein content and hardness of Japonica Rice in 2018 were lower than those in 2017(p<0.05),and the percentage contents and the value were 18.36%,6.95% and 4.65,respectively.Therefore,the comprehensive score of Japonica Rice in 2018 was significantly higher than that in 2017.There was no significant difference in the inter-annual comprehensive score of Indica rice,but the protein content of indica rice samples in 2018 was 7.76%,significantly lower than that in 2017(p<0.05).In addition,the aroma and viscosity contents of Indica Rice in 2018 were 6.82 and 0.62,which were significantly lower than those in 2017(p<0.05).The results of comparison between RA rice and common rice showed that the luster,hardness and viscosity of RA rice were 6.46,4.76 and 0.65,which were significantly better than common monocultured rice.Therefore,Rice Co-cultured with various aquatic animal crops could not only guarantee the food safety of rice,but also improve the taste of rice.