The Effect Of The Storage Times And Temperatures On Nutritional Composition Of Foxtail Millet And Millet

Foxtail Millet is a typical representative of small grain crops.It has strong vitality in arid areas.It is rich in fat,starch,yellow pigment and vitamins.It is a kind crop with both medicinal and edible value.Its nutritional and health care function is irreplaceable by other cereal crops.Because of its unique ecological conditions,Shanxi Province has created the unique quality of foxtail millet products,and the quality of foxtail millet largely determines its nutritional value and market value.In this paper,three factors affecting the quality of foxtail millet and millet,including variety,storage temperature and storage time,were analyzed,and the changes of nutritional components of Jingu 21,Changnong 35,Datong 30 and zhangza10 under different storage time（10 days,30 days,50 days,70 days,90 days）and storage temperature（30℃,20℃,4℃,-20℃）,respectively,in order to improve the quality of foxtail millet storage and targeted storage provide theoretical basis to promote the industrialization and large-scale development of foxtail millet.The main conclusions of this paper were as follows:1.Effects of different storage time and temperature on fat content of foxtail millet and millet.Aging is one of the important factors affecting the quality deterioration of foxtail millet and millet.With the extension of storage time and the rise of temperature,the quality of foxtail millet and millet was seriously affected.The main reason of aging was lipid peroxidation,the results showed that the fat content of foxtail millet and millet decreased with the extension of storage time;the fat content of foxtail millet and millet increased first and then decreased in the early stage of storage,which may be due to the late ripening effect in the early stage of storage,so that the fat content first increased and then decreased;when the storage time was 10 days,the fat content of foxtail millet and millet under high temperature treatment（20℃ and 30℃）was significantly lower in the low temperature treat ment（4℃ and-20℃）,when the storage time was from 10 days to 50 days,the fat content of foxtail millet ranged from 4.10% to 5.90%,while that of millet ranged from 4.15% to 6.45%.When the storage time was more than 50 days,the fat content of foxtail millet and millet under high temperature treatment（20℃ and 30℃）was significantly lower than that under low temperature treatment（4℃ and-20℃）.2.Effects of different storage time and temperature on starch content of foxtail millet and millet.With the extension of storage time,the starch content of foxtail millet and millet showed a slow decline trend,and the decline range was not large.The optimal storage temperature of foxtail millet and millet was 4℃,which was not suitable for storage at 30℃.During the storage process,when the foxtail millet was stored within 10 days,it increased first and then decreased at high temperature（30℃ and 20℃）,with the maximum increase of 2.39%.Due to the late ripening effect during storage within 10 days,the reducing sugar was partly converted into starch.3.Effects of different storage time and temperature on yellow pigment content of foxtail millet and millet.With the prolongation of storage time and the increase of temperature,there were significant differences among different foxtail millet and millet varieties.The optimum storage temperature of foxtail millet and millet was 4℃,which was not suitable for storage at 30℃.With the prolongation of storage time,the content of yellow pigment in foxtail millet and millet basically decreased.However,the content of yellow pigment in different varieties of foxtail millet increased slightly within 30 days after storage at high temperature（20℃ and 30℃）,and the maximum increase was 8.94%.It is related to the chemical composition of grain tissue,metabolic characteristics,rancidity caused by lipid peroxidation in the late storage period Trends.4.Effects of different storage time and temperature on Vc content of foxtail millet and millet.With the extension of storage time,the content of yellow pigment in foxtail millet and millet showed a downward trend;when the storage time was within 30 days,there was no significant difference in the content of Vc in foxtail millet with temperature.The maximum variation range of Vc content in foxtail millet was 2.22 mg·g^-1 to 2.46 mg·g^-1,and the maximum variation range of Vc content in millet was 1.59mg·g^-1 to 1.90 mg·g^-1.When the storage time was more than 30 days,the difference between foxtail millet and millet with temperature reached a significant level,the variation range of Vc content in foxtail millet was 1.50 mg·g^-1 to 1.95 mg·g^-1,and that of millet was 1.45 mg·g^-1 to 1.98 mg·g^-1;the optimum storage temperature of foxtail millet and millet was 4℃,which was not suitable for storage at 30℃.5.With the extension of storage time,the fat content,starch content,yellow pigment content and Vc content of different varieties of foxtail millet and millet showed a gradual decrease.For foxtail millet,combining the four indexes of fat,starch,yellow pigment and Vc content,the storage temperature of Jingu21 and Datong 30 should not exceed 70 days higher than 20℃;the storage temperature of Changnong 35 and Zhangza 10 is high.It should not exceed 50-70 days at 20℃.After 90 days of storage under low temperature storage conditions,the difference in nutritional composition of each variety was small.For millet,combining the four indicators of fat,starch,yellow pigment and Vc content,the storage temperature of Jingu 21 and Datong 30 should not exceed 20℃ for more than 70 days;the storage temperature of Changnong 35 and Zhangza 10 is high.It should not exceed 50-70 days at 20℃.After 90 days of storage under low temperature storage conditions,the difference in nutritional composition of each variety was small.