Lentil Starch Content and its Microscopical Structure as Influenced by Natural Fermentation

Abstract

Lentil seeds (Lens culinaris var. vulgaris, cultivar Magda‐20) were allowed to ferment naturally at different lentil flour concentrations (79 g/L, 150 g/L and 221 g/L) and temperatures (28 °C, 35 °C and 42 °C). During fermentation, samples were taken at 24 h intervals. The changes in starch content in all samples were studied. Scanning electron microscopy (SEM) was used to investigate changes in samples fermented for 96 h at two different concentrations (79 g/L and 221 g/L) and two different temperatures (28 °C and 42 °C). A considerable decrease in starch content was observed at 0 h of fermentation, defined as the time when the lentil flour was completly suspended at the established temperature. Once fermentation began, flour concentration and temperature modified starch content. Fermentation brought about a general decrease in starch content and a 32—37 % dry matter content was found in the samples after 96 h. Microscopical studies showed that endocorrosion, i.e., breakdown starting from the center of starch granules, was the main pattern observed during lentil fermentation.

Thermal processing effects on the functional properties and microstructure of lentil, chickpea, and pea flours

“…Thus, in the previously reported studies, soaking and cooking treatments resulted in swelling and enlargement of some of the starches as well as a more flattened surface (Aguilera et al, 2009). Some of the starches had more amorphous extracellular material after cooking, or endocorrosion and breakages occurred in the starch granules after fermentation (Sotomayor et al, 1999). However, the integral starch granule structure was still maintained, and the protein matrix adhering to the starch granules was still visible, although alterations to the protein structure were found (Blaszczak, Doblado, Frias, Vidal-Valverde, Sadowska, & Fornal, 2007).…”

“…The discernible globular or irregular particles attached to or located between the starch granules were the protein bodies or fragments of protein matrix disrupted during milling. Particles might also have included mineral and fiber components, as reported by other workers (Aguilera, Esteban, Benitez, Molla, & Martin-Cabrejas, 2009;Sotomayor, Frias, Fornal, Sadowska, Urbano, & Vidal-Valverde, 1999). The roasted flours (Fig.…”

Phenolic Compounds and Allelopathic Potential of Fermented and Unfermented Wheat and Corn Straw Extracts

“…[35] Same activity could be, as well, an origin of significant decrease of pcoumaric acid (by 25 %) in fermented corn straw samples. [37] Doubling of myricetin was, as well, recorded in corn, while rutin increased in both samples at same levels after fermentation (12 %) likely due to converting their gallate forms in non-gallate ones, by esterase activity. Considering that PAD activity depend on the isomeric forms of phenolic acids, this increment could be attributed to the novo synthesis of some isomers of mentioned acids during fermentations, which was already earlier recorded.…”

Bioactive phenolic compounds of cowpeas (Vigna sinensis L). Modifications by fermentation with natural microflora and with Lactobacillus plantarum ATCC 14917

“…The decrease in some quercetin glycosides, quercetin 3-O-glucoside and quercetin 3-O-galactoside, could be the origin of the strong increase in quercetin ( Table 2). According to Sotomayor et al 38 and Reddy et al, 39 the microorganisms participating in natural fermentation produce a consistent pH lowering, which could activate some enzymes that hydrolyse the quercetin glycosides, thus yielding quercetin.…”