Proteolysis, lipolysis, texture and sensory properties of cheese ripened by Monascus fumeus

Abstract

Monascus spp. are fungi that have been applied in food production for centuries and produce a range of bioactive metabolites. The objective of this study was to investigate the characteristics of proteolysis, lipolysis, textural and sensory properties of internal mold-ripened cheese ripened by Monascus fumeus x08. The contents of pH 4.6-soluble nitrogen, 12% trichloroacetic acid-soluble nitrogen and 5% phosphotungstic acid-soluble nitrogen changed significantly during the ripening of the Monascus-ripened cheese. The peptides in the Monascus-ripened cheese were evaluated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and reversed-phase high-performance liquid chromatography. During ripening, many low-molecular-weight peptides (MW < 14400) were found to increase significantly and the ratio of hydrophobic to hydrophilic peptides decreased to 0.81 and 0.34 in the Red-O (outer) and Red-I (interior) parts of the cheese, respectively. The content of total free fatty acids (15 acids, C4:0–C18:3) was significantly increased and the content of unsaturated fatty acids reached 47.89 mg/g fat on day 42 of ripening. The sensory attributes of the Monascus-ripened cheese was assessed using quantitative descriptive analysis. Compared with blue cheese, purchased from a local market, the odor and taste intensity of the Monascus-ripened cheese were significantly lower, while the color intensity and overall receptivity were significantly higher. M. fumeus x08 can be used as a secondary starter to make Monascus-ripened cheese and may be particularly acceptable to consumers in China.