Application of infrared microspectroscopy and multivariate analysis for monitoring the effect of adjunct cultures during Swiss cheese ripening

Representative spectra of a water-soluble cheese extract by reflectance infrared microspectroscopy in the range of 4,000 to 700cm⁻¹.

Representative spectra of water-soluble extracts of cheese samples manufactured with 3 Lactobacillus adjunct strains, Lactobacillus casei A26, L. casei B21, and Lactobacillus rhamnosus, after 90 d of ripening at the spectral region of 4,000 to 700cm⁻¹.

Soft independent modeling of class analogy (SIMCA) analysis (A) and a SIMCA discriminating power plot (B) of cheese samples with adjunct Lactobacillus casei A26, L. casei B21, and Lactobacillus rhamnosus after 90 d of ripening. PC = principal component.

Soft independent modeling of class analogy (SIMCA) discriminating power plot of cheese samples with adjunct Lactobacillus casei A26, L. casei B21, or Lactobacillus rhamnosus, or without adjunct culture during ripening (1 to 90 d).

Soft independent modeling of class analogy (SIMCA) class projections of Swiss cheese samples manufactured with adjunct Lactobacillus casei A26 (A), L. casei B21 (B), or Lactobacillus rhamnosus H2 (C), or without adjunct culture (D) at different ripening days. PC = principal component.

Soft independent modeling of class analogy (SIMCA) discriminating power plots depicting changes during ripening of Swiss cheeses manufactured with adjunct culture of Lactobacillus rhamnosus H2.