High-pressure and thermal processing of cloudy hawthorn berry (Crataegus pinnatifida) juice: Impact on microbial shelf-life, enzyme activity and quality-related attributes

The study aimed to evaluate the effect of high-pressure (HPP, 300/600 MPa for 2 and 6 min) and thermal processing (TP, 65 degrees C/30 min) on microbial shelf-life, enzyme-activity and quality-attributes of cloudy hawthorn berry juice (CHBJ) after processing and during storage (4 degrees C). The CHBJ shelf-life was at least 150 days when processed by HPP. No significant difference was observed in pH and titratable acidity (p > 0.05), while HPP significantly increased soluble sugar (p < 0.05) and simulated some fruity aroma compounds which improved the taste and flavor of CHBJ. However, HPP inhabited ineffectively enzyme-activity in comparison to TP, causing significant color changes (Delta E = 4.98 +/- 0.03-5.10 +/- 0.07) during 30-day storage (p < 0.05). Although particle size increased after HPP treatment, significant increases (68.76%-926.95%) were observed in viscosity (p < 0.05), due to enhanced extractability or modification of pectin induced by HPP, resulting in higher consistency of CHBJ. HPP is promising to extend shelf-life and improve quality-attributes of CHBJ.

Automated summary

The study demonstrated that high-pressure processing (HPP) is promising for extending the shelf-life of cloudy hawthorn berry juice (CHBJ) while improving taste and flavor, but it was less effective in inhibiting enzyme activity compared to thermal processing (TP), resulting in significant color changes and increased viscosity during storage.