Nutritional, Functional, and Technological Characterization of a Novel Gluten- and Lactose-Free Yogurt-Style Snack Produced With Selected Lactic Acid Bacteria and Leguminosae Flours

Abstract

Aiming at meeting consumers’ requirements for healthy foods, dietary needs (vegetarianism, lactose- and gluten-free), as well as the nutrition recommendations of the Health Authorities in terms of protein, fibers and bioactive compounds, the present study proposes a novel yogurt-style snack made with plant-derived ingredients. The biotechnological protocol includes the fermentation of a thermal-treated blend of cereal and legume flours by the selected lactic acid bacteria (LAB) Lactoplantibacillus plantarum DSM33326 and Levilactobacillus brevis DSM33325. The yogurt-style snack was characterized by protein and fiber concentration of 3 and 4%, respectively, and a low-fat content. Compared to the unfermented control, the yogurt-style snack was characterized by a significant higher concentration of free amino acids and lower contents of the antinutritional factors, i.e., phytic acid, condensed tannins, saponins and raffinose (up to 90%) mainly due to the LAB metabolic activity. Hence, an in-vitro protein digestibility of 79% and improvements of all the nutritional indexes related to the quality of the protein fraction (e.g., GABA) were achieved at the end of fermentation. According to the Harvard Medical School recommendations, the novel snack can be potentially classified as low-glycemic index food (53%). Antioxidant properties of the fermented snack were also improved by means of increased the total phenol content and radical scavenging activity. High survival rate of the starter LAB and a commercial probiotic (added to the snack) was found through 30 days storage under refrigerated conditions. The biotechnological protocol to make the novel snack here proposed is suitable for the large-scale application in food industry, giving a platform product with a peculiar and appreciated sensory profile.

Plant-Based Alternatives to Yogurt: State-of-the-Art and Perspectives of New Biotechnological Challenges

“…were used at different percentages in water, usually from 15% to 35%. This amount was selected to achieve optimal PBYL texture after gelatinization at high temperature [ 14 , 23 , 27 , 32 , 33 , 34 ]. Similar ratios were also used for cereal-legume blends including, for example, rice, soy, oat, barley and emmer flours [ 13 ], or rice, lentil, and chickpea flours [ 14 ].…”

“…Nevertheless, high concentration of fibers can be obtained by using whole grains, as in the case of YL products obtained with oat flakes and brown rice [ 27 , 34 ]. Besides dietary fibers, the use of pseudocereals and legumes also allows to obtain high level of high biological-value proteins, as reported when quinoa, soy, lupin, lentil and chickpea flours were used as the main YL ingredients [ 11 , 14 , 33 , 41 ]. Such products were characterized by protein content ranging from 3% to 5% depending on the inclusion rate of the protein source.…”

“…Phenolic compounds also can be present in non-dairy yogurt, depending on the type of plant-derived ingredients used. For example, high total phenols content was found in quinoa YL products (from 4 to 10 mmol/kg) [ 33 ], while relatively lower concentrations were observed when brown rice, oat flakes, and cereal–legume blends were used [ 13 , 14 , 27 , 34 ].…”

“…A PBYL formulation including a mixture of lentil and chickpea (5% w / v each) and rice flours (10% w / v ) was proposed to overcome the poor protein quality usually found in commercial PB alternatives to milk products [ 14 ]. The formulation also contained a high level of dietary fibers (4% w / v ).…”

“…Starch gelatinization via the application of proper heating treatments was proposed to increase the viscosity of plant ingredients before fermentation, thus also preventing phase separation and decreasing the entity of endogenous microbes before starter inoculation [ 13 , 14 ].…”