The inactivation kinetics of β-glucosidase in blackberry were investigated at high hydrostatic pressure (300-600 MPa) combined with moderate temperature (35-55°C). Analysis of the obtained kinetic data revealed a dual-effect of combined pressure-temperature inactivation: the first one, designated as an instantaneous pressure kill value (IPK), which depended on temperatures and pressures, but was independent of treatment time; and the second one, a labile and stable fraction of β-glucosidase from blackberry are present and the inactivation kinetics of β-glucosidase by high hydrostatic pressure combined with temperatures are adequately described by the two-fraction model. The kinetic rate constants K L and K S of labile and stable fractions are 2.777 and 0.047 min -1, and the decimal reduction times D L and D S are 0.83 and 49.1 min at 400 MPa and 55°C. T Z representing the needs of temperature increase for a 90% reduction of the D value and the activation energy E a of the labile fraction at 400 MPa are 23.36°C and 81.95 kJ/mol, p Z representing the needs of pressure increase for a 90% reduction of the D value and the activation volume V a at 45°C are 1111 MPa and -5.02 cm 3/mol.

The effects of high pressure processing(HPP) at 300~600 MPa for 15 min on organic acids and VC in blackberry(Rubus Hull.) juice were detected by using reversed-phase high performance liquid chromatograp method and 2,4-Dinitrophenylhydrazine colorimetry method respectively.Their synergistic antioxidant capacities were also evaluated.In blackberry juice,the dominant acid was L-malic acid,which constituted 87.98% of total acids.While α-ketoglutaric acid,acetic acid,citric acid,and butanedioic acid were detected in low amounts.After application of pressure,L-malic acid and butanedioic acid were significantly changed(P<0.05).However,no significant changes in other organic acids(P>0.05).L-malic acid in juice decreased by 12.2% after 300 MPa processing for 15 min,while increased by 8.53%,6.08% and 22.35% respectively at 400~600 MPa processing for 15min.Compared with the control juice,the contents of VC were well retained and ranged from 90.10% to 97.92% at 300~600 MPa.L-malic acid enhanced the scavenging activity of VC on DPPH· with its concentration increasing,which indicated that L-malic acid synergistically enhanced the antioxidant capacity of VC.

The effects of high pressure processing(HPP)(100MPa~600MPa for 15min) on the changes of physicochemical properties and sensory quality of hawthorn rice wine were studied in this paper.The results showed that the total acid content in hawthorn rice wine increased significantly after 200MPa HPP processing(p 0.05),while the total acid content in hawthorn rice wine significantly decreased after 300MPa~600MPa HPP processing(p 0.05).The stability and refractive index had no significant differences after HPP processing(p 0.05).The total sugar content,amino acid content,pH values were significantly increased(p 0.05).The alcohol content,conductivity decreased significantly(p 0.05).The results of GC-MS indicated that after treated by 200MPa,400MPa and 600MPa for 15min,the contents of 1-butanediol,2,3-butanediol,phenylethyl alcohol,ethyl acetate,ethyl lactate,butanedioic acid,diethyl ester,benzeneacetic acid and ethyl ester were increased significantly,while the content of acetaldehyde was decreased obviously,and the contents of aroma compounds in the samples under 400MPa,15min treatment were the most significant changes among them.Sensory evaluation results showed that 400MPa treated samples had the best taste and flavor.

The effects of ultra-high pressure treatment on the flavoring compositions of Danyang yellow rice wine were investigated by headspace solid-phase micro-extraction and GC-MS.The results showed that compared with untreated Danyang yellow rice wine,Danyang yellow rice wine treated by ultra-high pressure(300 MPa,400 MPa and 500 MPa treated for 20 min respectively) had higher content of alcohols including isobutanol,isoamyl alcohol,2,3-butanediol,and phenylethanol etc.and higher content of esters including ethyl acetate,diethyl succinate and ethyl phenyl acetate etc.,however,acetaldehyde content in treated wine dropped evidently.Among wine samples treated by different ultra-high pressure,wine aroma changed greatly for 400 MPa treated wine.Sensory evaluation results showed that 400 MPa treated wine had the best taste.