ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Sustainable approach from underutilized Leucaena leucocephala biomass by polyphenols composition and protein functional properties assessment

Iván Balderas-León, Anaberta Cardador-Martínez, Diana Karina Baigts-Allende, Carlos Arnulfo Velázquez-Carriles, and Jorge Manuel Silva-Jara

Departamento de Farmacobiología, Centro Universitario de Ciencias Exactas E Ingenierías (CUCEI), Universidad de Guadalajara, Guadalajara, México

E-mail: jorge.silva@academicos.udg.mx

Received: 9 February 2024  Accepted: 28 April 2024

Abstract:

The seeds of Leucaena leucocephala (LL), a legume tree native to Mexico, are traditionally harvested and utilized as food ingredients in regional dishes. In this study, the usefulness of LL biomass was investigated and processed in flours using the wholegrain seed (WS) and pods for polyphenols identification, whereas the cotyledon (CT) for protein concentrates functional characterization was used. The WS flour exhibited carbohydrates as the main macronutrient, followed by proteins (30.59%). Water-extracted polyphenols from pods flour (544.29 mg/L) were higher compared to the WS flour (165.85 mg/L). The predominant polyphenols in all samples were flavonols, specifically catechins. Although, in comparison to the mixtures of methanol–water (315.14 mg/L) and ethanol–water (471.22 mg/L), pods had about threefold polyphenols content than WS flours extracts. Protein fractionation in CT was higher than in WS flour, with globulins being the most abundant fraction in both materials (44.73 and 55.2%, respectively). Structural analyzes indicated a higher presence of structural elements in globulins, evident in FTIR spectra and SDS-PAGE analysis. Globulins displayed bands around 50, 37, and 22 kDa, while glutelins exhibited a unique band at 50 kDa. Globulins also demonstrated a higher essential amino acid content. The functional properties of globulins and glutelins were pH-dependent. Globulins solubility (72.53%), emulsifying (35.13%), foaming (138.66%), water holding (3.17 g/g), and oil absorption (1.20 g/g) capacities were higher compared to glutelins (62.42%, 31.69%, 66.70%, 2.86 g/g, and 0.52 g/g, respectively). These findings suggest that LL biomass holds potential as a sustainable source of natural ingredients for food development.

Keywords: Plant protein; Legume; Protein solubility; Chemical composition

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03492-5

Chemical Papers 78 (9) 5513–5525 (2024)