Sustainable plant-based ingredients as wheat flour substitutes in bread making

Bread as a staple food has been predominantly prepared from refined wheat flour. The world’s demand for food is rising with increased bread consumption in developing countries where climate conditions are unsuitable for wheat cultivation. This reliance on wheat increases the vulnerability to wheat supply shocks caused by force majeure or man-made events, in addition to negative environmental and health consequences. In this review, we discuss the contribution to the sustainability of food systems by partially replacing wheat flour with various types of plant ingredients in bread making, also known as composite bread. The sustainable sources of non-wheat flours, their example use in bread making and potential health and nutritional benefits are summarized. Non-wheat flours pose techno-functional challenges due to significantly different properties of their proteins compared to wheat gluten, and they often contain off-favor compounds that altogether limit the consumer acceptability of final bread products. Therefore, we detail recent advances in processing strategies to improve the sensory and nutritional profiles of composite bread. A special focus is laid on fermentation, for its accessibility and versatility to apply to different ingredients and scenarios. Finally, we outline research needs that require the synergism between sustainability science, human nutrition, microbiomics and food science.Peer reviewe

EFFECT OF PROCESSING ON IN-VITRO PROTEIN DIGESTIBILITY AND OTHER NUTRITIONAL ASPECTS OF NEBRASKA CROPS

Among plant based agricultural products, Nebraska ranks first nationwide in the production of Great Northern beans (GNB), second in proso millet production, and eighth in production of winter wheat. The present research was focused on the effect of processing on nutritive components and in vitroprotein digestibility of these crops with the aim of promoting their human consumption. Proso millet based extrudates had physical properties similar to commonly extruded rice but had lower expansion than corn. GNB extrudates had limited expansion and high bulk density mostly due to high fiber and protein content. Extrusion significantly reduced the anti-nutritional components in GNB flour while moderately reducing the essential folate. Extrusion significantly increased the dialyzability of the essential mineral elements Mg, P, K, and Fe in GNB, while significantly reducing dialyzability of the heavy metal Cd. Extrusion also improved the in vitroprotein digestibility of GNB flour. In contrast, extrusion had a significant negative impact (almost 50% reduction) on in-vitrodigestibility of proso millet proteins. Formation of hydrophobic aggregates was the main reason identified for the low digestibility in proso millet proteins. The effect was not specific to extrusion but was observed in all the processing techniques that involved heating above 55 °C. Among various mitigation strategies explored, enzymatic modifications of millet proteins with transglutaminase, heating in low awsolutions, or heating in chaotropic salts (e.g., CaCl2) at high concentration proved to be beneficial in at least partially preventing the low digestibility effect. Further, the results obtained from comparing in vitro digestibility of breads made from legacy and modern wheat cultivars indicated a significant improvement in digestibility of cultivars released after 1931. The old cultivar, Red Chief, and the land race cultivars, Kharkof and Turkey, had significantly lower digestibility than newer released lines. The changes incorporated by controlled breeding in the proteins of early wheat cultivars were preserved and successfully transferred to modern wheat cultivars resulting in wheats with better yield, end use characteristics and high protein digestibility. Advisor: Devin J. Ros

Iron and zinc bioaccessibility of fermented cereals : lessons drawn from Zimbabwean traditional porridges

Cereals contribute to a substantial proportion of the iron and zinc requirements of low income groups yet they are of low iron and zinc content and bioaccessibility (proportion of minerals available for absorption) due to their high level of mineral binding compounds. Fermentation is commonly practiced for the preparation of cereal products in developing countries and has potential to improve iron and zinc bioaccessibility through the reduction of mineral binding compounds. The purpose of this PhD was to evaluate the potential of fermentation to improve the iron and zinc bioaccessibility of cereal based complementary porridges commonly consumed in Zimbabwe and Africa at large. Finger millet porridges fermented at the household level were of low iron and zinc content and bioaccessibility which could not meet more than 50% of the dietary requirements of children between the ages of 1-3 years. Fermented cereals from five locations in Zimbabwe showed differences in both mineral contents and bioaccessibility that could be attributed to varietal and agricultural influences. Presence of soil iron on some cereals from Chiweshe and Chiredzi could improve the nutritional status of populations subsisting on such cereals. Of interest was the low zinc content and bioaccessibility on all cereals despite their origin suggesting the probable existence of a higher risk of zinc deficiency than iron. Food-to-food fortification using local ingredients such as baobab fruit pulp and mopane worm coupled with cereal fermentation could improve mineral nutrition in developing countries

VALORIZATION OF PROSO MILLET AND SPENT GRAIN FOR EXTRUDED SNACK DEVELOPMENT

Fast-paced lifestyles result in consumers replacing traditional meals with on-the-go snack foods. In general, snacks are higher in saturated fats and simple sugars, and pose health concerns for consumers, which prompts the need for healthy nutritious alternatives to common snacks. Proso millet is a nutritious, and fast growing gluten free cereal. Spent grain (SG), the main by-product of brewing and distilling, contains high amount of protein and insoluble fibers. This study utilized proso millet and spent grain in the production of an extruded expanded snack, demonstrating their appropriateness as an ingredient in food production. The first objective of this study was to determine the effect of extrusion processing conditions (moisture, barrel temperature, screw speed) on the physical, chemical, and functional properties of proso millet based extruded snack. The second objective of this research was to determine the effect of distiller’s spent grain (DSG) addition level and particle size on physicochemical and functional properties of extruded snacks. The third objective of this research was to evaluate the effect of spent grain type and particle size on the physicochemical and functional properties of extruded snacks. Samples were produced using a co-rotating twin-screw 25:1 L/D laboratory scale extruder

Development of nutrient-rich Teff bread and its effects on iron status and exercise performance in female runners

Public awareness of the health benefits associated with less-utilised yet nutritious grains has led to a growing demand for healthier cereal products. This has resulted in an interest in improving the nutritional properties of refined white wheat bread, which is one of the main staple foods for most Western nations. Teff is a small-grained cereal that is rich in nutrients and particularly abundant in iron. Therefore, Teff offers the potential to provide a healthier alternative bread product. Female athletes, especially runners are at risk of iron deficiency due to increased iron loss, inadequate dietary iron and limited iron bioavailability in the diet. Good nutrition has been suggested as the first line of action to prevent iron deficiency in this population. As cereals and cereal products are a main contributor to iron in the diet, the modification of dietary iron intakes through a staple food offers a good opportunity to improve the iron status of physically active females. The aims of this research project were 1) to develop a novel, iron-rich bread product by incorporating Teff grain; 2) to explore dietary iron intervention by the means of a staple food product and to measure the effects of this intervention on iron status and exercise performance in female runners. The results indicated that the addition up to 20% of Teff (flour weight) into the bread formulation significantly (P<0.05) increased dietary iron levels without detrimental effects on bread quality. By the use of enzyme combinations, this level was increased to 30%, giving a product that provides over 75% RNI for dietary iron if daily amount of 200g of bread is consumed. A cohort of 11 female runners reported inadequate daily dietary iron intake of 11 mg/day, which was associated with overall compromised iron status. A 6-week dietary intervention resulted in significantly (P<0.05) higher total iron intakes and improved iron tissue supply but not enlarged iron stores. In terms of exercise performance, there were significant (P<0.05) improvements in submaximal VO2 at anaerobic threshold and time-to-exhaustion but not maximal VO2max peak. Moreover, improvements in submaximal gas exchange parameters and endurance were significantly (P<0.05) correlated to improved iron status. It was concluded that Teff bread is a promising iron-rich staple food alternative. It offers the opportunity to improve habitual dietary iron intakes. Favourable trends were observed between improved iron intakes, iron status and exercise performance in this study. Further research is advised to determine the bioavailability of iron from Teff bread and to confirm these findings using larger groups of participants

XVI Agricultural Science Congress 2023: Transformation of Agri-Food Systems for Achieving Sustainable Development Goals

The XVI Agricultural Science Congress being jointly organized by the National Academy of Agricultural Sciences (NAAS) and the Indian Council of Agricultural Research (ICAR) during 10-13 October 2023, at hotel Le Meridien, Kochi, is a mega event echoing the theme “Transformation of Agri-Food Systems for achieving Sustainable Development Goals”. ICAR-Central Marine Fisheries Research Institute takes great pride in hosting the XVI ASC, which will be the perfect point of convergence of academicians, researchers, students, farmers, fishers, traders, entrepreneurs, and other stakeholders involved in agri-production systems that ensure food and nutritional security for a burgeoning population. With impeding challenges like growing urbanization, increasing unemployment, growing population, increasing food demands, degradation of natural resources through human interference, climate change impacts and natural calamities, the challenges ahead for India to achieve the Sustainable Development Goals (SDGs) set out by the United Nations are many. The XVI ASC will provide an interface for dissemination of useful information across all sectors of stakeholders invested in developing India’s agri-food systems, not only to meet the SDGs, but also to ensure a stable structure on par with agri-food systems around the world. It is an honour to present this Book of Abstracts which is a compilation of a total of 668 abstracts that convey the results of R&D programs being done in India. The abstracts have been categorized under 10 major Themes – 1. Ensuring Food & Nutritional Security: Production, Consumption and Value addition; 2. Climate Action for Sustainable Agri-Food Systems; 3. Frontier Science and emerging Genetic Technologies: Genome, Breeding, Gene Editing; 4. Livestock-based Transformation of Food Systems; 5. Horticulture-based Transformation of Food Systems; 6. Aquaculture & Fisheries-based Transformation of Food Systems; 7. Nature-based Solutions for Sustainable AgriFood Systems; 8. Next Generation Technologies: Digital Agriculture, Precision Farming and AI-based Systems; 9. Policies and Institutions for Transforming Agri-Food Systems; 10. International Partnership for Research, Education and Development. This Book of Abstracts sets the stage for the mega event itself, which will see a flow of knowledge emanating from a zeal to transform and push India’s Agri-Food Systems to perform par excellence and achieve not only the SDGs of the UN but also to rise as a world leader in the sector. I thank and congratulate all the participants who have submitted abstracts for this mega event, and I also applaud the team that has strived hard to publish this Book of Abstracts ahead of the event. I wish all the delegates and participants a very vibrant and memorable time at the XVI ASC

WHOLE GRAIN PROCESSING AND EFFECTS ON CARBOHYDRATE DIGESTION AND FERMENTATION

Whole grains are a major source of dietary fibers in the human diet that provide specific nutrients to the gut microbiota and thereby plays a major role in modulating microbiota composition and increasing diversity of the gut ecosystem. A common approach of consuming whole grains is in the form of ready-to-eat extruded breakfast cereals. Studies reported herein established that extrusion conditions not only affected the physicochemical properties but also in vitro starch digestibility, β-glucan extractability and in vitro fermentation characteristics of whole grain oats. Moderate screw speed (300 rpm) led to higher slowly digestible starch (SDS) with an accompanying decrease in rapidly digestible starch (RDS). Low moisture conditions (15%) resulted in the highest resistant starch (RS) and water-extractable β-glucan (WE-BG). Extrusion moisture significantly affected WE-BG in the extrudates, with samples processed at 15% moisture (lowest) and 21% moisture (highest) having the highest concentration of WE-BG. Extrusion moisture conditions was also found to significantly affect the production of acetate, butyrate and total SCFA by the microbiota during the first 8 h of fermentation. After 24 h, samples processed at 15% moisture supported lower Bifidobacterium counts than those produced at other conditions, but had among the highest Lactobacillus counts. Besides oats, there are other whole grain cereals and their brans that have unique structural characteristics that may impart distinct effects on fermentation by the gut microbiota with subsequent effects on the host. Since dietary fiber intake has an impact on functionality of the gut microbiota, another study was conducted to establish whether the gut microbiota from individuals consuming high dietary fiber diets (G1) could metabolize the dietary fibers from grains more efficiently and produce higher concentrations of beneficial metabolites compared with donors with lower dietary fiber intakes (G2). Fecal microbiota from G1 subjects showed less decrease in diversity during fermentation and these microbiotas showed higher carbohydrate utilization and butyrate production compared with microbiota from G2 subjects. More carbohydrates were fermented from whole grains than brans. Rye induced high carbohydrate fermentability and butyrate production accompanied by low ammonia production, but only when using fecal microbiota from G1 subjects

CHARACTERIZATION OF BARLEY (Hordeum vulgare L.) WITH ALTERED CARBOHYDRATE COMPOSITION

The concentrations of storage constituents in barley (Hordeum vulgare L.) grain impact its use for malt, food, feed, and fuel. Characterization of major grain constituents such as carbohydrates (total dietary fiber, beta-glucan, starch and its components amylose and amylopectin, starch granule size and physical properties), protein and fat and their interaction during starch enzymatic hydrolysis will facilitate diversification of barley grain utilization for improved malt, food or feed applications. Improved understanding of genes and their structure associated with beneficial grain constituents will help in barley improvement program to develop novel cultivars with desirable grain constituents. Nine barley genotypes with varying amount of amylose in grain starch were used to: (i) determine grain carbohydrate (dietary fiber, beta-glucan and starch), protein and fat concentrations, and starch composition and structure on its enzymatic hydrolysis; (ii) characterize allelic variation in granule bound starch synthase 1 (Gbss1) and starch branching enzyme 2b (Sbe2b) to understand the molecular basis for variation in grain starch amylose concentration. Nine barley genotypes included, one normal (~25% amylose), three near waxy ( 38%) starch. Total starch concentration showed significant positive correlation with thousand grain weight (TGW) and negative correlation with amylose, total dietary fiber and protein concentrations. Starch granule sizes varied with percent amylose where the increased amylose genotypes produced significantly lower volume percentage of C-type granules ( normal > increased amylose. Rapidly digestible starch (RDS) increased with a decrease in amylose concentration. Atomic force microscopy (AFM) analysis revealed higher polydispersity index of amylose in CDC McGwire and increased amylose genotypes which could contribute to their reduced enzymatic hydrolysis, compared to waxy starch genotypes. Increased β-glucan and dietary fiber concentration also reduced enzymatic hydrolysis of meal samples. Average linkage cluster analysis dendrogram revealed that variation in amylose concentration significantly (p < 0.01) influenced resistant starch concentration in meal and pure starch samples. RS is also associated with B-type granules (5-15 µm) and amylopectin FIII (19-36 DP) fraction. Gbss1 nucleotide sequences revealed considerable heterogeneity, with three genotypes with severely reduced GBSSI proteins and low amylose concentration had a 403 bp deletion in the promoter region. One previously described amino acid substitution D287V in CDC Alamo was confirmed and two new amino acid substitutions, G513W in CDC Fibar and Q312H in near waxy genotype SB94912 were identified as the likely causes of inactive GBSSI resulting in no amylose in starch granules. In the increased amylose genotype SB94983 A250T substitution was also observed, which can alter GBSS 1 enzyme specificity and could be a possible reason for increased amylose concentration. To facilitate studies of GbssI expression, positive assays for four allele variants were developed in this study. These markers may also be useful for monitoring introgression of respective GbssI alleles in barley improvement programs. The barley Sbe2b gene sequence analysis of the normal (CDC McGwire), near waxy (SB94912) and increased amylose (SH99250) genotypes, revealed 22 exons and 21 introns. The three Sbe2b alleles showed 21 polymorphic sites, present only in the introns, predicting that the processed SBE IIb transcripts to be identical in the three genotypes. The longest second intron of Sbe2b, which is known to regulate promoter activity in barley was identical between SH99250 and CDC McGwire, but SB94912 allele differed at 12 sites. The remaining nine polymorphic sites were present in introns 17, 18, 19 and 21. It is speculated that allelic variation in Sbe 2b second intron could be a reason for increased amylose concentration in SB94912. In summary reduction in amylose concentration can be due to changes in GBSS1 polypeptide, but the reasons for increased amylose starch are not yet clear. The DNA polymorphisms identified in this study can be used in a marker assisted selection strategy to follow the introgression of respective alleles in a barley improvement program