Tender coconut water fortified with edible bird's nest protein hydrolysate subjected to sterilization and high hydrolytic pressure processes: Qualities, acceptability and changes during refrigerated storage

The qualities and acceptability of tender coconut water (TC) fortified with edible bird's nest protein hydrolysate (TCBH) subjected to sterilization and high hydrostatic pressure (HHP) under different conditions were investigated. Lower (p < 0.05) a*-, b*- and ΔE*-values, browning index and α-amino group content were observed for all TCBH samples treated with HHP (TCBH-HHP) than sterilized counterparts. Acceptable microbiological quality was found for all TCBH-HHP samples, regardless of treatment time (5–20 min). Similar acceptability was found between TCBH treated with HHP for 5 min (TCBH-HHP5) and the control, while there was slight difference in volatiles. TCBH-HHP5 was selected and stored at 4 °C for 30 days, and qualities and acceptability were monitored. TCBH-HHP5 showed the acceptable microbiological quality within 30 days. Similar likeness for all attributes was attained. Nevertheless, slight changes in color, turbidity and reducing sugar content were found in TCBH-HHP5 after 30 days. Although sterilization effectively inhibited microbial growth, drastically negative alteration in quality, especially discoloration was noticeable. Thus, HHP for 5 min served as a promising process to maintain quality of TCBH during 30 days of refrigerated storage.