Effect Of Ultrahigh Pressure Treatment On The Quality Of Highland Barley Seedling Juice

In this paper,the effect of ultrahigh pressure treatment on the quality of highland barley seedling juice was studied in Kunlun No.fourteen highland barley seedling.The specific research contents and results are as follows:(1)The effects of ultrahigh pressure treatment on the activities of polyphenol oxidase and peroxidase in highland barley seedling juice were studied.According to the results of single factor,response surface method was used to optimize the process,and the optimal passivation conditions of polyphenol oxidase and peroxidase were determined as follows: comprehensive consideration,When the inactivation pressure of PPO and pod was 500 MPa,the holding time was 25 min,and the p H value was4.0,the residual enzyme activity was 35.11%.(2)The effects of different holding pressure and holding time on the quality of highland barley seedling juice were studied by comparing the germicidal efficacy and physicochemical indexes of highland barley seedling juice before and after ultrahigh pressure treatment.The results showed that: with the increase of pressure and the extension of holding time,the microbial content decreased significantly,reaching the national hygienic standard of fruit and vegetable juice;The change of p H value was not significant;The content of total anthocyanins,total flavonoids and total phenols increased significantly compared with the control group,indicating that the high pressure treatment can better maintain the quality of highland barley seedling juice.(3)To study the effects of different processing parameters on the quality of highland barley seedlings during spray drying of highland barley seedlings,and obtain the best technology for spray drying of highland barley seedlings.The highland barley seedling juice was selected as raw material by ultrahigh pressure treatment.The air inlet temperature,peristaltic speed and material liquid ratio were selected as the single factor experiment.On the basis of single factor experiment,sensory evaluation was used as the response value,and the response surface method was used to optimize the spray drying process.The results showed that the best technological parameters of spray drying were: the best inlet temperature was 165,the peristaltic speed was 30 rpm,and the ratio of material to liquid was 1:3.Under this condition,the moisture content of highland barley seedling powder is 6.45% ±0.60.The content of total flavonoids was 9.36 mg/g,and the sensory value was 93 points,which was consistent with the prediction value of response surface model;The content of microorganism was in accordance with GB7101-2003 hygienic standard for solid drinks.The obtained highland barley seedling powder had uniform powder quality,bright green color and unique aroma of highland barley seedling.This study provides a useful reference for the processing of highland barley seedling related products.