The changes of growth status and glucosinolate metabolism during the germination of rocket seeds

Objective:To choice better edible rocket cultivar and germination time by investigating the effect of germination on the growth status and glucosinolates metabolism. Methods:Two cultivated varieties of rockets "Banye" and "Dongsheng" were investigated about the related indexes of length,weight,water content,free amino acid,soluble sugar and glucosinolates metabolism of the 0,2,4,6 and 8th day during germination.Results:The sprout length,fresh weight and water content of two cultivars gradually increased. In "Banye" and "Dongsheng",free amino acid content reached the peak value at day 8 with 7.68 μg/sprout and 7.64 μg/sprout,respectively.The soluble sugar content got the highest value at day 6 with 216.8 μg/sprout and 203.5 μg/sprout,respectively.And the total glucosinolates content in "Banye" and "Dongsheng" both reached the highest level at day 2 but had minimal content at day 8 with 53.74 nmol/sprout and 55.87 nmol/sprout,respectively. In addition,the isothiocyanates formation both increased to the maximum at day 4 in "Banye" and "Dongsheng",with 66.82 nmol/sprout and 89.76 nmol/sprout,respectively. Myrosinase activity reached to the highest at day 2 and day 4,respectively,but there was no significant difference between the two cultivars at day 8. Conclusions:The quality of seeds can be improved by germinating,in the period of germination,the degradation of carbohydrate was earlier than that of the protein. Glucosinolates were degraded during the germination. Temporal and spatial sequence existed in myrosinase activation and formation of isothiocyanates. In general,the 4-day "Dongsheng" sprouts were more suitable for daily diet.