Continuous High-pressure Cooling-Assisted Homogenization Process for Stabilization of Apple Juice

Abstract

The effect of high-pressure homogenization (HPH) at 100–200 MPa (with up to 5 passes) on the quality and storage stability of apple juice was investigated. The microbiological quality, polyphenol oxidase (PPO), peroxidase (POD), polygalacturonase (PG) and pectinmethylesterase (PME) activity, particle size distribution (PSD), apparent viscosity, turbidity, concentration of vitamin C, individual polyphenols and their total content (TPC), antioxidant activity, and colour of fresh, HPH-treated apple juice were all evaluated. The highest reduction in microorganisms (1.4 log) and oxidoreductase activity (~20%) was observed at 200 MPa, while hydrolases did not change significantly. HPH led to significant disintegration of the tissue and a decrease in viscosity. Vitamin C decreased by 62%, while TPC increased by 20% after HPH. Significant correlations were observed between antioxidant activity, TPC, and individual polyphenols. Chlorogenic, ferulic, and gallic acid were most stable at 200 MPa. The optimal shelf-life of the juice was estimated as 7 days.

High-Pressure Homogenization and Biocontrol Agent as Innovative Approaches Increase Shelf Life and Functionality of Carrot Juice

“…For what concerns color parameters, HPH increased a* and b* values while it decreased the L* value. The overall ΔE was 6.8 CIELAB units, in line with what was reported by Szczepańska et al [ 34 ], considering the high variability observed in our study. The effect of HPH on juice color seems strongly dependent on food matrices and treatments.…”

“…As already demonstrated in many publications [ 17 , 34 , 35 , 36 ], HPH treatment at 150 MPa reduces the naturally occurring microflora present in vegetable juice. In this study, a reduction ranging between 1.0 and 2.4 log cycles was observed for TMC depending on the number of HPH passes and inlet temperature of the treated juice.…”

“…Over the past years, application of the non-thermal treatment HPH has been studied to improve shelf life and organoleptic and functional properties of vegetable and fruit juices [ 8 , 19 , 22 , 34 , 35 ]. Another approach that has drawn the attention of researchers is the use of natural antimicrobials (such as essential oils or bacteriocins) [ 22 , 23 ] or biocontrol cultures [ 9 , 24 ].…”

Cabernet Sauvignon Red Must Processing by UHPH to Produce Wine Without SO2: the Colloidal Structure, Microbial and Oxidation Control, Colour Protection and Sensory Quality of the Wine

“…This result supports the high efficiency of UHPH controlling bacteria in grape juices compared with discontinuous pressurisation techniques, such as HHP, which is unable to eliminate them completely, even at pressures higher than 500 MPa/10 min (Morata et al, 2015). Also, UHPH is much more efficient than HPH, which normally needs multi-passes to reach inactivation lower than 2-log at 200 MPa (Szczepańska et al, 2021). Saccharomyces yeast starters were inoculated in both the control and UHPH musts at 5 × 10 7 CFU/mL, and the population of Saccharomyces and non-Saccharomyces yeasts was monitored every two days.…”

“…Several recent reviews have included the most important features and applications of UHPH processing (Comuzzo & Calligaris, 2019;Patrignani & Lanciotti, 2016;Zamora & Guamis, 2015). UHPH is more efficient than high-pressure homogenisation (HPH) or microfluidisation concerning the elimination of microorganisms and enzyme inactivation, which normally needs multi-passes for efficient microbial control (Szczepańska et al, 2021). Additionally, HPH or microfluidisation are used to improve colloidal stability (Leite et al, 2016;Oliete et al, 2019); however, UHPH produces nanofragmentation, with lower than average size particles stabilising better colloidal structure .…”