Study on improving antioxidant properties of raw hawthorn juice by freeze-thaw assisted enzymatic hydrolysis
In order to improve the juice yield and bioactivity of fresh hawthorn juice,enhance the quality of the juice,the freeze-thaw combined enzymatic hydrolysis method was used to optimize the preparation process of fresh hawthorn juice,increase the bioactive components of hawthorn juice,and improve its antioxidant activity.The hawthorn enzymatic hydrolysis process was optimized by single factor and response surface experiments,and the effect of freeze-thaw assisted enzymatic hydrolysis on the antioxidant performance of hawthorn juice was investigated based on the optimal enzymatic hydrolysis process.The results showed that the optimal process parameters were 98 min enzymatic hydrolysis time,47.5℃enzymatic hydrolysis temperature,and 0.22%of composite enzyme,with a hawthorn juice yield of 31.07%.Compared with the untreated hawthorn,the yield,polyphenols,flavonoids,anthocyanin,soluble solids,and soluble sugars of the freeze-thaw treatment group reached their maximum values at the 4,12,12,12,12,and 8 times,respectively,and increased by 9.34%,36.61%,51.43%,216.75%,and 20.89%,and 36.63%,respectively.Meanwhile,the redness of the hawthorn juice was increased by 1.94 times,while its yellowness was reduced by 21.91%.The study provides reference for the preparation of fresh hawthorn juice and related enzymatic hydrolysis processes.