Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

Abstract

Summary The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05‐8, KTU05‐9 and KTU05‐10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48‐h fermentation at solid‐state conditions and compared with that in samples after submerged fermentation and in the control nonfermented samples. The lupin variety, fermentation conditions and the Pediococcus strain were found to have the significant effect on the FAA profile and BA contents in fermented lupin; the interaction between analysed factors was F(5.989) = 1755.321 (P < 0.0001) and F(5.660) = 130.736 (P < 0.0001), respectively. A weak correlation was found between amino acid His and histamine (r = 0.3709; P = 0.0005) and between Phe and phenylethylamine (r = 0.3914, P = 0.0002) in lupin samples, but the significant correlations between amino acid Tyr and tyramine and between Lys and cadaverine were not found. By optimising the fermentation technology, it is possible to increase the nutritional value and functionality of lupin.

Modulation of the nutritional value of lupine wholemeal and protein isolates using submerged and solid‐state fermentation with Pediococcus pentosaceus strains

“…The total titratable acidity (TTA) and LAB count were determined according to methods described by Bartkiene et al . ().…”

“…Sample preparation and determination of BAs in lupine samples were performed according to the method of Ben‐Gigirey et al . (), with some modifications (Bartkiene et al ., ,b). Perchloric acid (0.4 mol L −1 , 10 mL) containing a known amount of 1.7‐diamino‐heptane used as an internal standard was added to 3 g of lupine sample, and the mixture was homogenised with Ultra‐Turrax (IKA Labortechnik, Staufen, Germany) and centrifuged at 3000 g for 10 min.…”

Perspectives of lupine wholemeal protein and protein isolates biodegradation

“…Regarding the NEAAs profile of nonfermented and SMF or SSF lupine samples, a significant influence of the analysed factors on all the studied NEAAs ( P ≤ 0.0001) was found, and the interaction of the examined factors was also significant ( P ≤ 0.0001). The process conditions affect the LAB metabolites excreted, which can influence the AAs in the fermentable substrate (Bartkiene et al ., ). The proteolytic enzymes excreted by LAB release AAs from the substrate, and this metabolism depends on the characteristics of the LAB strain used (Bartkiene et al ., ).…”

“…Lupine (Lupinus angustifolius) is recognised as a valuable source of nutrients. Lupine seeds contain significant amounts of protein, fat, minerals and dietary fibre and are increasingly used as a dietary protein source in European countries (Bartkiene et al, 2016a). The dietary value of lupine proteins is higher than that of beans or peas, which is mainly due to the high concentrations of the essential amino acids (EAAs), lysine (Lys), leucine (Leu) and threonine (Thr) (Starkute et al, 2016).…”

“…Many factors can affect the functional properties of plant proteins. We previously investigated the biodegradation of lupine wholemeal and protein isolates/concentrates by several different lactic acid bacteria (LAB) strains and the resultant changes in lupine chemical composition Bartkiene et al, 2016a). Based on the results, we hypothesised that the bioavailability of lupine seed protein could be affected by the activity of trypsin inhibitors, the free amino acids (AAs) profile, biogenic amines (BAs), antioxidant capacity of the substrate, isoflavone content and the molecular weight of new peptides formed and their properties, among others.…”