Natalia Rosa-Sibakov

Context and Objectives: There is an urgent need for a dietary shift towards an increased consumption of plant protein foods. However, some nutritional and sensory challenges are associated with whole-meal grains and pulses. Fermentation is a promising technology for reducing anti-nutrients, increasing protein digestibility, and reducing starch digestibility in plant-based matrices. This study aimed to evaluate the impact of different fermentation conditions using different bacteria on the nutritional composition of grains and pulses. Methods: Milled wheat, buckwheat, and chickpeas were fermented using different bacteria or combinations of bacteria, i.e., Lactobacillus delbrueckii + Streptococcus thermophilus (Vega), Lacticaseibacillus rhamnosus (Lrham), Leuconostoc pseudomesenteroides (Lpseu), Weissella confusa alone (Wcon) or combined with Lactococcus lactis (Wcon + Lac), or Pediococcus pentosaceus (Wcon + Pen), for 24 or 48 h. Protein hydrolysis and protein and starch digestibility were measured using the O-phtaldialdehyde and Infogest methods, respectively. Starch digestibility was evaluated using the Englyst method. Dietary fibers (DF) were quantified. Results: In buckwheat, all fermentation conditions increased protein hydrolysis, especially Vega. In chickpeas, Lrham and Wcon, alone and in combination, increased protein hydrolysis. In wheat, fermentation did not increase protein hydrolysis. Protein digestibility increased only with Wcon + Pen in buckwheat. For chickpeas and wheat, fermentation did not increase protein hydrolysis, and it was lowest with Lpseu in both cases. Lpseu, Wcon + Lac, and Wcon + Pen led to increased DF in buckwheat, especially soluble high-molecular-weight (HMW) buckwheat (dextran formation). In chickpeas, no increase in DF content was observed due to the hydrolysis of oligosaccharides, but soluble HMW DF increased with Lpseu, Wcon + Lac, and Wcon + Pen (dextran formation). No significant change was observed for wheat DF. The starch hydrolysis index (HI) increased with Lrham over 48 h and Lpseu over 24 h but decreased with Wcon + Lac over 24 h in buckwheat. In chickpeas, HI was reduced in all conditions, the lowest values being with Wcon + Pen and Wcon + Lac. In wheat, HI increased with Lrham over 48 h and decreased with Wcon + Pen. Conclusions: The impact of the fermentation conditions tested differed depending on the grains. Some conditions improved the nutritional characteristics of these grains. These results show promising effects concerning the nutritional quality of grains, which need to be confirmed in finished products.

Between 702 and 828 million people around the world were affected by hunger in 2021. The prevalence of undernourishment relentlessly continues to affect the world, and particularly Sub-Saharan Africa (23.2% in 2021). Exacerbated inequalities across and within countries are undermining the nutritional adequacy and affordability of diets and threatening vulnerable groups including children under five years of age and women of reproductive age. This research presents a diet optimization approach where the objective is to evaluate the nutritional adequacy and affordability of diets across 4 African countries, namely Ethiopia, Kenya, South Africa and Uganda. The targeted population includes dyads of women of reproductive age and their children between 6 and 24 months. The mathematical programming approach allows for the theoretically contrasting of optimal outcomes of the model with data from food consumption surveys in primary and secondary cities of each country. Based on the observed food intake patterns and the nutrient deficiencies, these outcomes propose new diets modifying food intake (organized in food groups) in order to achieve nutritional adequacy while minimizing food intake changes, or, if applicable, the outcomes indicate which nutrient recommendations are unattainable under the current model setup. On average, our results show that nutritional adequacy can be attained by increasing the intake of legumes, vegetables and fruits, while reducing the intake of cereals. We include a discussion on the assessment of diet affordability and show the practical implications of evaluating healthier diets’ viability. Conclusions include paths for future research on diet optimization modelling and its implications as a means of support for designing future dietary guidelines.

Sorghum and cowpea are very compatible for intercropping in hot and dry environments, and they also have complementary nutritional compositions. Thus, the crops have the potential to improve food security in regions threatened by climate change. The aim of this study was to investigate different enzymes (carbohydrate-degrading, proteases and phytases) and lactic acid bacteria (LAB) fermentation to improve the techno-functional properties of sorghum and cowpea flours. Results show that sorghum carbohydrates were very resistant to hydrolysis induced by bioprocessing treatments. Most of the protease treatments resulted in low or moderate protein solubilization (from ca. 6.5% to 10%) in sorghum, while the pH adjustment to 8 followed by alkaline protease increased solubility to 40%. With cowpea, protease treatment combined with carbohydrate-degrading enzymes increased the solubility of proteins from 37% up to 61%. With regard to the techno-functional properties, LAB and amylase treatment decreased the sorghum peak paste viscosities (from 504 to 370 and 325 cPa, respectively), while LAB and chemical acidification increased cowpea viscosity (from 282 to 366 and 468 cPa, respectively). When the bioprocessed sorghum and cowpea were tested in breadmaking, only moderate effects were observed, suggesting that the modifications by enzymes and fermentation were not strong enough to improve breadmaking.

Oat bran is a nutritionally rich ingredient, but it is underutilized in semi-moist and liquid foods due to technological issues such as high viscosity and sliminess. The aim of this work was to improve the technological properties of oat bran concentrate (OBC) in high-moisture food applications by enzymatic and mechanical treatments. OBC was hydrolyzed with β-glucanase (OBC-Hyd) and the water-soluble fraction (OBC-Sol) was separated. OBC, OBC-Hyd and OBC-Sol were further microfluidized at 5% dry matter content. Enzymatic treatment and microfluidization of OBC reduced the molecular weight (Mw) of β-glucan from 2748 kDa to 893 and 350 kDa, respectively, as well as the average particle size of OBC (3.4 and 35 times, respectively). Both treatments increased the extractability of the soluble compounds from the OBC samples (up to 80%) and affected their water retention capacity. OBC in suspension had very high viscosity (969 mPa·s) when heated, which decreased after both enzyme and microfluidization treatments. The colloidal stability of the OBC in suspension was improved, especially after microfluidization. The addition of OBC samples to acid milk gels decreased syneresis, improved the water holding capacity and softened the texture. The changes in the suspension and gel characteristics were linked with reduced β-glucan Mw and OBC particle size.