Physicochemical properties and volatiles of kiwifruit pulp beverage treated with high hydrostatic pressure (HHP, 400-600 MPa/5-15 min) were investigated during 40-day refrigerated storage. Compared with heat treatment (HT), HHP ranged from 400-500 MPa was superior in retaining vitamin C, fresh-like color and volatiles, while soluble solids content and pH were not affected significantly. Furthermore, HHP improved brightness and inhibited browning of kiwifruit pulp beverage. Samples treated at 400 MPa for 15 min showed significantly higher vitamin C content and lower ∆E values over 40 days than heat-treated kiwifruit pulp beverage. The total content of alcohols, esters, acids, and ketones gradually increased, whereas the total aldehydes content decreased during storage. Interestingly, HHP treatment at 500 MPa for 15 min mostly retained important characteristic volatiles including hexanal and (E)-2-hexenal, indicating this treatment was more conducive to preserve the original fruity, fresh, grassy and green notes of kiwifruit pulp beverage than HT.
Keywords: high hydrostatic pressure; kiwifruit pulp beverage; physicochemical properties; storage; volatiles.