Effect of instantaneous high pressure treatment on chemical quality of pear juice
This paper studied the effect of Instantaneous High Pressure(IHP) treatment on chemical quality of pear juice through Ascorbic acid,amino nitrogen,total sugar and total acid of four aspects.The results indicated that:Processed under pressures from 80 MPa to 180 MPa of 6 gradients for one time.Ascorbic acid loss percentage was 13.14% under 80 MPa and 14.85% under 180 MPa.Ascorbic acid loss percentage reduced unobvious;Amino nitrogen content reduced slightly,from 24.25 mg/100 mL under 0 MPa to 23.41 mg/100 mL under 180 MPa;The content of total sugar and total acid remained invariable,maintaining about 8.0% and 0.079 g/100 mL separately.Processed respectively under the above pressures for three times.Ascorbic acid lost a lot after treating one time,with the most loss percentage of 20.41% under 160 MPa,while Ascorbic acid loss percentage reduced slightly after treatment of twice and three times,with the most Ascorbic acid loss percentage of 29.01% under 140 MPa;Amino nitrogen content assumed the even reducing tendency with treatment times increasing.It reduced most under 100 MPa,from 21.63 mg/100 mL to 17.47 g/100 mL.The content of total sugar had a slight reduction with treatment times increasing.It reduced the most under 100 MPa,from 8.28% to 7.68%.The decrement was 0.072%.The content of total acid remained nearly invariable with treatment times increasing,maintaining about 0.09 g/100 mL.