Effect Of Storage Temperature And Preservative Treatment On The Quality Of Baby Ginger

Ginger(Zingiber officinale Roscoe)is a perennial herbaceous plant of the ginger family ginger.The ginger picked in the tender period is called baby ginger.The growth cycle of baby ginger is short,its shelf life is concentrated.Its metabolism is vigorous,moisture content is high.So,it is not resistant to storage.During the storage period,it is easy to lose water,browning,mildew and rot.In this study,the effects of different storage temperature,different preservatives and complex preservatives on the quality indexes(decay index,weight loss rate,hardness,crispness and color difference value)and active ingredients(gingerols,total flavonoids,total phenols,gingerols and amino acids)of Baikou baby ginger during storage were studied,in order to optimize storage condition of baby ginger.The main conclusions are as follows:(1)Selection of the best storage temperature.The pretreated baby ginger was stored at3±1,6±1,9±1,12±1 and 25±1 ? respectively.The rotting index of baby ginger stored at12±1 ? and 25±1 ? for 16 d and 12 d was over 50%,which was no longer suitable for storage.The hardness and brittleness of baby ginger decreased with the storage time.The hardness and brittleness of baby ginger were higher at 6 ? after 24 d,and the color difference value changed the least.The contents of total phenols,total flavonoids and gingerols stored at 6 ? were higher,which was beneficial to the maintenance of functional components.The comprehensive evaluation model established by principal component analysis showed that 6 ? was the best storage temperature for bbay ginger.The effect of temperature on the volatile substance of baby ginger during storage.The main type of volatile substances of baby ginger was hydrocarbons,which accounted for more than75.31 % of the total volatile substances content.Among them,curcumene and zingiberene were the unique volatile substances of baby ginger.The volatile substances content of baby ginger stored at 6 ? had little change,indicating that 6 ? had little effect on the volatile substances content of baby ginger.(2)The effect of preservatives on the storage quality of baby ginger.Calcium lactate,chitosan oligosaccharide and 1-methylcyclopropene(1-MCP)can keep the quality of baby ginger.The comprehensive analysis of the indexes in the storage showed that: 0.6 %calcium lactate,100 mg/L chitosan oligosaccharide and 500 ng/L 1-MCP had the highest comprehensive quality score,which could effectively maintain the quality of baby ginger during storage,delay the increase of gingerol content and prolong the storage period.Among them,0.6 % calcium lactate and 100 mg/L chitosan oligosaccharide can effectively maintain the quality of baby ginger for more than 16 d.(3)Compared with the single preservative treatment,0.6 % calcium lactate+100 mg/L chitosan oligosaccharide treatment is more conducive to the preservation of the quality and functional components of bbay ginger,delaying the increase of gingerol content of baby ginger during storage.The comprehensive evaluation model score of the combined treatment is higher during the whole storage,which indicated that chitosan oligosaccharide and calcium lactate have synergistic effect on the storage of bbay ginger.(4)The changes of amino acid content of baby ginger were analyzed under the three fresh-keeping methods of 0.6 % calcium lactate+100 mg/L chitosan oligosaccharide,0.6 %calcium lactate and 100 mg/L chitosan oligosaccharide.The results showed that: Baby ginger contained at least 17 kinds of amino acids,of which Aspartic acid(Asp)content was the most abundant,accounting for 24.32% in fresh baby ginger.The amino acid content of baby ginger showed a downward trend during storage.After 24 d,100 mg/L chitosan oligosaccharide treatment group maintained the highest contend of total amino acids(354.17mg/100g).The treatment of 0.6 % calcium lactate+100 mg/L chitosan oligosaccharide had a good effect on the maintenance of essential amino acids,which was94.31 mg/100 g.Medicinal amino acids,flavor amino acids,branched chain amino acids and aromatic amino acids all decreased to varying degrees with the prolonged storage of baby ginger.