Physicochemical and microbiome changes in queso Crema de Chiapas during ripening

Area of Science:

• Food Science
• Microbiology
• Metagenomics

Background:

• Crema de Chiapas cheese is a traditional Mexican cheese with a unique ripening process.
• Understanding the dynamic changes in its physicochemical and microbial profiles is crucial for quality control and safety.

Purpose of the Study:

• To investigate the dynamic changes in physicochemical, microbiological, and metagenomic profiles of Crema de Chiapas cheese during ripening.
• To correlate microbial diversity shifts with ripening stages and physicochemical parameters.

Main Methods:

• Physicochemical analysis (fat, salt, protein content) at 2, 29, and 58 days of ripening.
• Microbiological profiling using next-generation sequencing (NGS) and quantitative PCR (qPCR).
• Unsupervised multivariate models to analyze sample differentiation and microbial diversity.

Main Results:

• Protein and salt content varied significantly during ripening, while fat content remained stable.
• Microbial diversity shifted, with a decrease in bacterial genera and fungal/yeast populations as ripening progressed.
• Predominant bacteria included Streptococcus and Lactobacillus (increasing) and Lactococcus (decreasing). Candida etchellsii decreased, while Candida tropicalis increased.
• Potentially pathogenic bacteria (Aeromonas, Enterobacter) were absent; Chryseobacterium was detected at low levels.

Conclusions:

• Ripening significantly impacts the microbial composition of Crema de Chiapas cheese.
• Protein content is a key factor driving microbial shifts during maturation.
• The cheese matrix appears to inhibit the growth of potentially pathogenic microorganisms, ensuring a safe product.