333: Effect of Fermentation by Lactobacillus Acidophilus 150 Probiotic Strain on Bioavailability and Digestibility of Milk Protein Concentrate

Introduction

Milk protein concentrate (MPC) is a valuable source of high-quality proteins, commonly used in functional food formulations. Enhancing its digestibility and amino acid bioavailability can improve its nutritional quality, making it suitable for various dietary applications. Lactic acid fermentation with probiotic strains, such as Lactobacillus acidophilus 150, is a promising approach to improve MPC digestibility and increase the Digestible Indispensable Amino Acid Score (DIAAS). This study aims to evaluate the impact of fermentation on MPC digestibility and protein quality, while providing the added benefit of probiotics.

Methods

The fermentation of MPC was conducted using probiotic L. acidophilus 150 strain for 48 hours. Samples were collected in every 4 hours to monitor changes in optical density (OD600 nm) and pH as indicators of bacterial growth and acid production. The DIAAS of fermented samples were determined by in vitro digestion model using the standardized INFOGEST protocol.

Results

During the fermentation process, a gradual decrease in pH - from the initial pH 6.76 to 3.98 - and an increase in OD600 nm (from 0.191 up to 0.423) were observed, indicating active lactic acid production and bacterial proliferation. In vitro digestion results revealed that fermentation improved the digestibility and amino acid availability of MPC, with higher DIAAS values recorded at the later stages of fermentation.

Significance

Fermenting milk protein-based products with probiotic strains delivers the combined advantage of enhanced protein quality and probiotic health benefits. This study demonstrates the potential of L. acidophilus fermentation to improve the digestibility and DIAAS of MPC, making it a valuable approach for developing high-quality, probiotic-enriched nutritional products.

Authors: Kálmán Botond Süli, Erika Bujna, Quang D. Nguyen, Mercy Mukite Barasa