# Uncovering the Protein Conversion Potential of Alfalfa (Medicago sativa L.) and Duckweed (Lemna minor L.) Through Enzymatic Hydrolysis and Digestibility Assessment

## TL;DR

This study explores how enzymes can improve protein extraction from alfalfa and duckweed, finding that duckweed is more efficient for sustainable protein production.

## Contribution

The study introduces a novel multienzyme approach to enhance protein conversion from underutilized plant biomasses.

## Key findings

- Pre-treatment with amylolytic and proteolytic enzymes improved amino acid release from plant matrices.
- Duckweed showed higher apparent protein conversion compared to alfalfa during in vitro digestion.
- Starch-rich matrices hindered protease activity, reducing protein cleavage efficiency.

## Abstract

The growing demand for sustainable protein alternatives has increased interest in underutilized plant biomasses with high nutritional potential. This study investigated the conversion efficiency of alfalfa (Medicago sativa L.) and duckweed (Lemna minor L.) proteins through multienzyme hydrolysis, with the aim of evaluating how carbohydrate–protein matrix interactions influence enzymatic accessibility and apparent protein digestibility. Three biotechnological hydrolysis schemes were applied, involving combinations of α-amylase, amyloglucosidase, protease, pepsin, pancreatin, and bile salts, including an in vitro gastrointestinal digestion simulation. The first hydrolysis scheme demonstrated that starch-rich matrices formed a viscous medium that reduced protease mobility and limited protein cleavage. Improved substrate accessibility was achieved when plant material was pre-treated with amylolytic and proteolytic enzymes, which resulted in a noticeably higher release of free amino acids. Amino acid profiling revealed that this enzymatic sequence was the most effective for disrupting carbohydrate-associated protein fractions in both species. In vitro digestion assays indicated higher apparent protein conversion for duckweed compared to alfalfa under standardized laboratory conditions. Overall, the results confirm that appropriate multienzyme strategies can enhance amino acid liberation from complex plant matrices and highlight duckweed biomass as a promising candidate for sustainable protein valorization.