Nonstarter Lactobacillus Strains as Adjunct Cultures for Cheese Making: In Vitro Characterization and Performance in Two Model Cheeses

Milk acidification kinetics. (-----) Lactobacillus plantarum I33, (----) Lactobacillus rhamnosus I75, (——) L. plantarum I87, (–•– •–) L. rhamnosus I78, (-----) Lactobacillus curvatus I48, (——), Lactobacillus delbrueckii ssp. lactis I92, (——) L. rhamnosus I73.

Principal components analysis of reverse-phase-HPLC profiles of the soluble fraction in trichloroacetic acid 8% wt/vol of milk cultures of fast nonstarter lactobacilli (NSLAB) strains and other lactic acid bacteria assayed in the same conditions: a) score plot. NSLAB33, NSLAB75, NSLAB87, NSLAB78, NSLAB48, NSLAB92, and NSLAB73: Lactobacillus plantarum I33, Lactobacillus rhamnosus I75, L. plantarum I87, L. rhamnosus I78, Lactobacillus curvatus I48, Lactobacillus delbrueckii ssp. lactis I92 and L. rhamnosus I73, respectively. Lh15807, LhSF133, and LhSF209: Lactobacillus helveticus isolated from whey starters, LlAb1 and LbYSDY: L. delbrueckii ssp. lactis and Lactobacillus delbrueckii ssp. bulgaricus from commercial starters, StMo11 and St5-C: Streptococcus thermophilus from commercial starters. b) Loading plot: the variables (peaks of the chromatogram) with highest influence on principal components 1 and 2 (PC1 and PC2) are labeled with characters 1, 2, 3 and 5 in increasing order of retention time. Peaks with low impact on PC1 and PC2 are not labeled.

Proportion of strains of nonstarter lactobacilli resistant to increasing concentrations of NaCl and KCl.

Population of starter streptococci (dotted lines, open symbols) and adjunct lactobacilli (solid lines and symbols) in Cremoso cheeses during ripening. Symbols: +: control cheeses (streptococci); ○, ●: cheeses with Lactobacillus rhamnosus I73; ♢, ♦: L. rhamnosus I77; □, ■: Lactobacillus casei 90, △, ▴: Lactobacillus plantarum I91. Nonstarter lactobacilli in control cheeses remained always below 10⁵ UFC/g and are not shown.

Population of starter streptococci (dotted lines, open symbols) and adjunct or nonstarter lactobacilli (solid lines and symbols) in Pategrás cheeses during ripening. Symbols: +,×control cheeses; ○, ●: cheeses with Lactobacillus rhamnosus I73; ♢, ♦: L. rhamnosus I77; □, ■: Lactobacillus casei 90; △, ▴: Lactobacillus plantarum I91.

Acidification curves for Cremoso cheese makings with a starter of Streptococcus thermophilus (control cheeses, +) plus an adjunct culture of Lactobacillus rhamnosus 73 (●), L. rhamnosus 77 (♦), Lactobacillus casei 90 (■), and Lactobacillus plantarum 91 (▴).