| During the storage,the Indica-Japonica hybrid rice was more susceptible to quality deterioration than the conventional rice.Studying its quality changes and storage characteristics during storage were of great significance to slow down the deterioration of the hybrid rice and choose reasonable storage method.The rice(F2 generation)of Indica-Japonica hybrid rice cultivars,Yongyou 15,Chunyou 84 and Chunyou 927 were used as research material,and their moisture content was adjusted to 13.0%,14.0%and 14.0%,respectively.The packages of ordinary white woven bags and sealed polyethylene bags(PE bags)were used as control 1(CK1)and control 2(CK2),respectively,and sealed PE bags added desiccant or deoxidizer were used as treatments for rice storage.Rice with different package were stored at room temperature for 1 year,was sampled at 3,6,9 and 12 months of storage,respectively,and the rice moisture,milling quality,appearance quality,cooking and eating quality and nutritional quality were determined.The main results were as follows:The effects of PE bag packaging,the addition of desiccant and deoxidizer on the change of moisture content during rice storage were studied.The moisture content of CK1 of the three cultivars rice rose back to the initial moisture content after storage for 6 months,and then remained high level.The moisture content of CK2 and all treatments in the three cultivars rice decreased first and then increased slightly after storage,however,remained lower than the initial moisture content.The results showed that the sealed packaging of PE bags can reduce the influence of ambient humidity on rice,and kept the moisture content of rice at a low level.The change of rice quality during storage was studied.After storage for 9 months,the CK1 of three cultivars had a certain degree of decline in the brown rice rate,milled rice rate and whole milled rice rate.However,during the whole storage period there was no change in the brown rice rate,milled rice rate and whole milled rice rate in CK2 and all treatments;The content of amylose in the controls and all treatments increased slightly;the gel consistency,alkali digestion value,the content of glutelin and prolamin of the controls and all treatments had not significant changes during whole storage period,and the contents of albumin and globulin gradually decreased.However,the content of albumin in M5(PE bag +montmorillonite desiccant 1/60g),F3(PE bag + molecular sieve desiccant 1/100g),T(PE bag+ iron-based deoxidizer 1/150g),F5+T(PE bag + molecular sieve desiccant 1/60g + iron-based deoxidation Agent 1/150g)in Yongyou 15 was significantly higher than that of CK1 after 12 months of storage.The change of chalkiness rate of the three cultivars was different.After storage for 6 months,the chalkiness rate of controls and treatments in Yongyou 15 was higher than that of storage for 3 months,while the chalkiness rate of each treatment of Chunyou 84 was lower than that of storage for 3 months.The chalkiness rate of Chunyou 927 did not change significantly during the whole storage process.The use of PE bags,desiccants and deoxidizers delayed the deterioration of rice milling quality,did not affect rice cooking and nutritional quality,and their impact on the chalkiness rate was related to the cultivars.The changes of physical and chemical properties of rice during storage were studied.The activities of peroxidase(POD),catalase(CAT)and ascorbate peroxidase(APX)of three cultivars of CK1 decreased with the prolongation of storage time,while superoxide dismutase(SOD)activity had only a slight decrease;except for the APX activity of Chunyou 84 treatment had no significant change along with storage time,the activity of APX and POD in CK2 and all treatments of the three cultivars decreased along with storage time,and the activity of CAT did not change significantly with the prolongation of storage time.After storage for 9-12 months,the activities of POD and CAT in treatment added with deoxidizer were higher than that of desiccant treatment,and also much higher than that of CK1,indicating that PE bag packaging and desiccant adding could delay the decline rate of antioxidant enzyme activity.The antioxidant enzyme activity of the deoxidizer was also higher than that of the desiccant treatment and was maintained at a high level.The MDA content in CK1,CK2 and all treatments of three cultivars decreased firstly and then remained change a little along with storage time,however,after storage for 9-12 months,the MDA content of deoxidizer treatment in Yongyou 15 and Chunyou 927 was still lower than that of without deoxidizer treatment and CK2,indicating that the deoxidizer could mitigate lipid peroxidation. |
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