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The effect of high pressure processing (HPP) at 200 to 600 MPa for 2.5 or 5 min on physicochemical properties (color, pH, titratable acidity, total soluble solids content/TSSC, pulp content, particle size distribution, and viscosity), microbial counts (aerobic bacteria, yeast and mold counts), bioactive compounds (total phenolic and anthocyanin contents), and antioxidant capacities (DPPH radical scavenging capacity and ferric reducing antioxidant power) of aronia berry purée were investigated. All measurements were compared between HPP treated and untreated purées. TSSC and viscosity decreased significantly when pressurized above 400 MPa for 2.5 min and at all HPP conditions, respectively. Other physicochemical properties changed insignificantly after HPP. Pressurization at 400 and 600 MPa both effectively reduced yeasts and molds to below 1 log CFU/g, and reduced aerobic bacteria to <2 log CFU/g only when pressurized for 5 min. No significant reduction in phenolic contents or antioxidant capacities in pressurized purée was observed. Industrial relevance Purée is a feasible form of aronia berry used as food product, considering the astringent taste of whole aronia berry. The results of this study suggest that HPP will significantly reduce the microbial counts of aronia berry purée, while retaining antioxidant capacities and most physicochemical properties of aronia berry purée. The outcomes could help the food industry apply HPP to the commercial production of aronia berry purée-based food products to meet the quality standards with safety ensured. [ABSTRACT FROM AUTHOR]

Aronia berry puree was subjected to 400 and 600 MPa, 5 min high pressure processing (HPP) and then microbial shelf-life and quality changes of aronia puree during 8-week refrigerated storage were evaluated. HPP reduced the aerobic plate counts (APC) significantly and APC changed insignificantly during the 8-week storage. HPP completely inactivated yeasts and molds, and no regrowth was observed during 8-week storage. In contrast, yeasts in untreated puree increased from 4.7 to 6.1 log CFU/g. Physicochemical properties, total phenolic contents and antioxidant capacities of aronia puree had insignificant changes right after HPP and during 8-week refrigerated storage. Total anthocyanin content of untreated samples and those treated at 400 MPa decreased continuously during the storage. HPP, especially processing at 600 MPa for 5 min, could be an effective preservation technique for microbial population reduction, quality retention, and shelf-life extension of aronia puree. Industrial relevance The growing demand for minimal processed and antioxidant-rich aronia berry products has stimulated the interest of food industry. Industrial sector demands methods to extend the microbial shelf-life and maintain its quality and nutritional values of aronia berry products during refrigerated storage. The results of this study demonstrated that HPP is effective in extending the microbial shelf-life, maintaining the quality and preserving the bioactive antioxidants of aronia berry puree during 8 weeks of refrigerated storage. [ABSTRACT FROM AUTHOR]