Preparation and quality assessment of processed cream cheese by high hydrostatic pressure combined thermal processing and spore-induced germination

Abstract

This study evaluated effects of several sterilization methods on the microbial load and quality attributes of processed cream cheese (PCC). The results showed that ultra-high temperature instantaneous sterilization (UHT, 137 °C/4 s), high temperature sterilization (121 °C/10 min) and pasteurization (65 °C/30 min) coupled with germinant (l-alanine) and high hydrostatic pressure (450, 550 MPa/20 min) was able to inactivate bacterial endospores. Regarding cheese quality, pasteurization coupled with germinant and high hydrostatic pressure-treated cheeses had fewer Maillard reaction byproducts and lower fluorescence intensity, with 63% and 81% decrease in furosine content compared to UHT and high temperature sterilization, respectively. In terms of sensory properties, high hydrostatic pressure treatment maintain the cheese original color and flavour, reduced the formation of ketones and sulfide. Furthermore, high hydrostatic pressure-treated cheeses exhibited a smaller closed-loop area and higher stability, while UHT cheese were less stable due to fat globule aggregation. Therefore, pasteurization coupled with germinant and high hydrostatic pressure is a promising sterilization methods to produce long shelf-life processed cream cheese.