Impact of in vitro fermentation, enzymatic hydrolysis, and digestion on the degradation of B-casomorphin-7 in milk using Lacticaseibacillus casei and Limosilactobacillus fermentum

The objective of this study was to reduce the formation of β-casomorphin-7 (BCM-7), an opioid peptide derived from β-casein A1, associated with inflammation and gastrointestinal disorders. To achieve this, strategies involving thermal treatments and bacterial fermentation with Lacticaseibacillus casei and Limosilactobacillus fermentum, combined with enzymatic hydrolysis, were evaluated. The thermal treatment at β-casomorphin-7 100°C for 30 minutes increased the concentration of soluble proteins to 7.58 ± 0.07 mg/mL, while autoclaving at 105°C for 15 minutes had a lesser impact, resulting in 3.24 ± 0.05 mg/mL, this method was chosen as the standard to minimize protein degradation and prepare the milk for subsequent processes. Bacterial fermentation preserved the proteins during digestion, while the control showed a significant drop in soluble protein concentrations, from 5.32 ± 0.05 mg/mL to 0.19 ± 0.01 mg/mL. SDS-PAGE evidenced the degradation of milk proteins, including β-casein. The ELISA showed that L. fermentum was more efficient in reducing BCM-7, decreasing its concentration from 0.22 ± 0.01 to 0.08 ± 0.01. The combination of L. casei and L. fermentum did not result in any additional significant reduction. Thus, fermentation combined with enzymatic hydrolysis proved effective in reducing the formation of BCM-7.