Low-intensity pulsed electric field processing prior to germination improves in vitro digestibility of faba bean (Vicia faba L.) flour and its derived products: A case study on legume-enriched wheat bread

This study investigated the effect of low-intensity pulsed electric field (PEF) (0.3-0.7 kV/cm) and/or germination (0-72 h, 20 °C) on faba beans prior to flour- and breadmaking. PEF (0.5 and 0.7 kV/cm) had no significant effect on the germination performance of faba bean but had a positive effect on in vitro starch and protein hydrolysis of PEF-treated beans germinated for 72 h. The incorporation of flour from soaked, germinated, PEF-treated, and PEF-treated+germinated faba beans into wheat bread, at 30% mass level, improved the nutritional composition (total starch and protein contents) and protein digestibility but it reduced the specific volume and increased the density, brownness, and hardness of the bread. This finding shows for the first time that PEF-treatment (<0.7 kV/cm) of faba beans followed by germination (72 h) improved in vitro starch and protein hydrolysis of its flour and the protein digestibility at gastric phase of its enriched wheat bread.

Pretreated Green Pea Flour as Wheat Flour Substitutes in Composite Bread Making

The present study aimed to assess the impact of substituting wheat flour with three different pretreated green pea flour at different addition levels (10-50%) on fresh bread quality during a 7-day storage period. Dough and bread enriched with conventionally milled (C), pre-cooked (P), and soaked under-pressure-steamed (N) green pea flour were evaluated for their rheological, nutritional, and technological features. Compared to wheat flour, legumes had lower viscosity but higher water absorption, development time, and lower retrogradation. Bread made with C10 and P10 showed similar specific volume, cohesiveness, and firmness to the control, whereas addition levels beyond 10% decreased specific volume and increased firmness. During storage, incorporating legume flour (10%) delayed staling. Composite bread increased proteins and fiber. C30 had the lowest rate of starch digestibility, while pre-heated flour increased starch digestibility. In conclusion, P and N can be considered valuable ingredients for making soft and stable bread.

Rheological Approaches of Wheat Flour Dough Enriched with Germinated Soybean and Lentil

Germination is a convenient technique that could be used to enhance the nutritional profile of legumes. Furthermore, consumers’ increasing demand for diversification of bakery products represents an opportunity to use such germinated flours in wheat-based products. Thus, this study aimed to underline the effects of soybean germinated flour (SGF) and lentil germinated flour (LGF) on the rheological behavior of dough during different processing stages and to optimize the addition level. For this purpose, flour falling number, dough properties during mixing, extension, fermentation, and dynamic rheological characteristics were evaluated. Response surface methodology (RSM) was used for the optimization of SGF and LGF addition levels in wheat flour, optimal and control samples microstructures being also investigated through epifluorescence light microscopy (EFLM). The results revealed that increased SGF and LGF addition levels led to curve configuration ratio, visco-elastic moduli, and maximum gelatinization temperature rises, while the falling number, water absorption, dough extensibility, and baking strength decreased. The interaction between SGF and LGF significantly influenced (p < 0.05) the falling number, dough consistency after 450 s, baking strength, curve configuration ratio, viscous modulus, and maximum gelatinization temperature. The optimal sample was found to contain 5.60% SGF and 3.62% LGF added in wheat flour, with a significantly lower falling number, water absorption, tolerance to kneading, dough consistency, extensibility, and initial gelatinization temperature being observed, while dough tenacity, the maximum height of gaseous production, total CO2 volume production, the volume of the gas retained in the dough at the end of the test, visco-elastic moduli and maximum gelatinization temperatures were higher compared to the control. These results underlined the effects of SGF and LGF on wheat dough rheological properties and could be helpful for novel bakery products development.

Preliminary Investigations into the Use of Amylases and Lactic Acid Bacteria to Obtain Fermented Vegetable Products

Legumes are valuable sources of proteins and other functional components. However, the high starch content can be an impediment in developing new vegan food formulations. Enzyme-assisted hydrolysis was used to hydrolyze the starch from chickpea and broad bean vegetable milk to further develop vegetable lactic acid-fermented products. The antioxidant activity of legumes was tested, and it was observed that the overall antioxidant activity (DPPH radical scavenging ability) significantly increased after enzyme-assisted hydrolysis while total phenols content decreased. The obtained vegetable milk was then fermented using exopolysaccharides-producing lactic acid bacteria. A significant decolorization was observed after fermentation in the case of broad bean-based products. Rheological behavior of the fermented products was determined using small amplitude oscillatory measurements and the three-interval thixotropy test. Results showed higher complex viscosity values for broad bean-based products, which displayed a weak gel-like structure. The starter cultures used for vegetable milk samples fermentation influenced the resistance to flow.

Impact of Germination and Fermentation on Rheological and Thermo-Mechanical Properties of Wheat and Triticale Flours

Common cereal processing through germination and fermentation usually has an important impact on the technological performance of the flours, mainly because of the activation of endogenous enzymes acting on macromolecules. The aim of the present study is to estimate the effect of germination and fermentation, using a mixture of Lactobacillus casei and Kluyveromyces marxianus subsp. marxianus, on the rheological properties of different wheat and triticale varieties. Moreover, the thermo-mechanical behaviour of the white wheat flour-based dough, including germinated grain flour or sourdough was also tested. Grains germination and sourdough fermentation exerted a high influence on the rheological behaviour of the flour-based suspensions. Germination affected the structure and stability of the suspensions, resulting in samples with viscous behaviour prevailing over the elastic one. The temperature ramp tests revealed that germination together with fermentation lead to higher resistance to temperature changes. In agreement with the results of the rheological investigations on rheometer, the Mixolab test performed on flour obtained from germinated grains revealed lower dough stability and protein weakening at temperature increase. On the other hand, a significant improvement of the pasting properties of the dough was obtained when adding sourdoughs to the wheat flour.