Discards from legumes as bacteria cryoprotectants

MARTINS, GONÇALO NUNO; CARBONI, ANGELA D; AYELÉN AMELIA HUGO; GOMEZ-ZAVAGLIA ANDREA; PAULA CRISTINA MACHADO FERREIRA CASTILHO

Funchal

Encuentro; 9th CQM Annual Meeting; 2022

Centro de Quimica da Madeira

The use of microorganisms, such as lactic acid bacteria (LAB), entails several benefits for certain productive sectors. However, these bacteria may undergo deterioration and loss of viability during storage. Application of galacto-oligosaccharides (GOS) can help to reduce bacterial spoilage by protecting bacteria during conservation processes such as freezing and lyophilization.Legumes contain GOS that are removed by soaking and cooking treatments applied before consumption. In this work we evaluated the cryoprotective effect of extracts obtained byprocessing legumes, using domestic methods, on LAB.GOS-rich waters from chickpeas (Cicer arietinum L.) and lentils (Lens culinaris M. var. variabilis)were obtained by soaking (8 h, 25 °C); soaking + cooking (30 min – boiling T); and cooking (30 min– boiling T) without soaking. These extracts were screened for saccharides’ determination using High Pressure Liquid Chromatography with Refractive Index detection and then lyophilized. To evaluate the cryoprotection potential of the extracts, Lactiplantibacillus plantarum CIDCA 83114 (LP114) was added to de Man, Rogosa, and Sharpe (MRS) medium without glucose,supplementedwith 3 % of different sugars (extracts or standards) and incubated (37 °C, 24 h). After incubation, plate counts were performed on MRS agar, and the samples were divided in two groups: one was left in the freezer (-20 °C); the other was frozen, lyophilized and stored in a desiccator. The evaluation of the viability of LAB was performed immediately after the freezing or lyophilization process, and after two weeks in storage.Bacterial viability diminished after applying cryoprotection processes in all samples, however when chickpea or lentil extracts were included, this effect was less intense. During storage after freezing, the extracts obtained from the soaking + cooking processes provided greater cryoprotection than those obtained using other treatments. After lyophilization, the extractsfromcooking legumes without soaking showed greater cryoprotective power.Results suggest wastewaters obtained during industrial preparation of legumes can be valuable sources of compounds with interesting potential for the cryoprotection of LAB, with great economic impact