Chemical composition of wild and feral diploid wheats and their bearing on domesticated wheats

Grain quality traits within the wheat (Triticum spp.) genepool: prospects for improved nutrition through de novo domestication

BACKGROUND

Wild relatives of wheat (Triticum spp.) harbor beneficial alleles for potential improvement and de novo domestication of selected genotypes with advantageous traits. We analyzed the nutrient composition in wild diploid and tetraploid wheats and their domesticated diploid, tetraploid and hexaploid relatives under field conditions in Germany and compared them with modern Triticum aestivum and Triticum durum cultivars. Grain iron (Fe) and zinc (Zn) concentrations, phytate:mineral molar ratios, grain protein content (GPC) and antioxidant activity were analyzed across 125 genotypes.

RESULTS

Grain Fe and Zn concentrations in wild wheats were 72 mg kg-1 and 59 mg kg-1, respectively, with improved bioavailability indicated by Phytate:Fe and Phytate:Zn molar ratios (11.7 and 16.9, respectively) and GPC (231 g kg-1). By comparison, grain Fe and Zn concentrations in landrace taxa were 54 mg kg-1 and 55 mg kg-1, respectively, with lower Phytate:Fe and Phytate:Zn molar ratios (15.1 and 17.5, respectively) and GPC (178 g kg-1). Average grain Fe accumulation in Triticum araraticum was 73 mg kg-1, reaching 116 mg kg-1, with high Fe bioavailability (Phyt:Fe: 11.7; minimum: 7.2). Wild wheats, landraces and modern cultivars showed no differences in antioxidant activity. Triticum zhukovskyi stood out with high grain micronutrient concentrations and favorable molar ratios. It was also the only taxon with elevated antioxidant activity.

CONCLUSION

Our results indicate alteration of grain quality during domestication. T. araraticum has promising genotypes with advantageous grain quality characteristics that could be selected for de novo domestication. Favorable nutritional traits in the GGAA wheat lineage (T. araraticum and T. zhukovskyi) hold promise for improving grain quality traits. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Antioxidant Properties of Gluten-Free Pasta Enriched with Vegetable By-Products

The only therapy for coeliac disease patients is to completely avoid foods containing gluten, a protein complex common in several small-grain cereals. However, many alternative gluten-free foods available on the market present nutritional deficiencies. Therefore, the aim of this research was to evaluate the composition and the antioxidant properties of gluten-free pasta enriched with 10% or 15% of tomato waste or linseed meal, two food industry by-products. The traits analysed were protein, lipid, ash and fibre content, heat damage, tocols, carotenoids and phenolics composition (by HPLC), antioxidant capacity, and pasta fracturability. The enriched pastas contained more fibre and lipids than the control, while the protein and ash values were similar. The addition of tomato and linseed waste improved tocols concentration but had no effect on carotenoids content. The free soluble polyphenols increase was similar for both by-products and proportional to the enrichment percentage, while the bound insoluble polyphenols were higher in linseed-enriched pastas. The samples with linseed meal showed the greatest antioxidant capacity and, at 10% addition, the highest fracturability value. In conclusion, the addition of tomato and linseed by-products significantly increases the presence of bioactive compounds (particularly polyphenols), improving the nutritional value of gluten-free pasta.

Effect of Debittering with Different Solvents and Ultrasound on Carotenoids, Tocopherols, and Phenolics of Lupinus albus Seeds

Lupin seeds represent a rich nutritional source of bioactive compounds, including antioxidant molecules such as carotenoids, tocopherols, and phenolics. However, before consumption, the lupin seeds must be debittered in order to remove their bitter and toxic alkaloids. This study analyzed the impact on the bioactive compounds of Lupinus albus seeds of a recent time- and water-saving debittering method, which employs alternative washing solutions (0.5% or 1% of either NaCl or citric acid), with or without the assistance of ultrasound. The results were compared with those of two control methods using water or a NaCl solution. The sonication, when it was significant, led to a large loss of bioactive compounds, which was most likely due to its extraction capability. The seeds that were debittered without ultrasound presented high concentrations of tocopherols (172.8-241.3 mg/kg DM), carotenoids (10.9-25.1 mg/kg DM), and soluble-free (106.9-361.1 mg/kg DM), soluble-conjugated (93.9-118.9 mg/kg DM), and insoluble-bound (59.2-156.7 mg/kg DM) phenolics. The soluble-free fraction showed the greatest loss after a prolonged treatment. Overall, debittering with citric acid or NaCl preserved the highest concentration of antioxidant compounds by shortening the treatment time, thus preventing extensive leaching.

The grain quality of wheat wild relatives in the evolutionary context

We evaluated the potential of wheat wild relatives for the improvement in grain quality characteristics including micronutrients (Fe, Zn) and gluten and identified diploid wheats and the timopheevii lineage as the most promising resources. Domestication enabled the advancement of civilization through modification of plants according to human requirements. Continuous selection and cultivation of domesticated plants induced genetic bottlenecks. However, ancient diversity has been conserved in crop wild relatives. Wheat (Triticum aestivum L.; Triticum durum Desf.) is one of the most important staple foods and was among the first domesticated crop species. Its evolutionary diversity includes diploid, tetraploid and hexaploid species from the Triticum and Aegilops taxa and different genomes, generating an AA, BBAA/GGAA and BBAADD/GGAAA^mA^m genepool, respectively. Breeding and improvement in wheat altered its grain quality. In this review, we identified evolutionary patterns and the potential of wheat wild relatives for quality improvement regarding the micronutrients Iron (Fe) and Zinc (Zn), the gluten storage proteins α-gliadins and high molecular weight glutenin subunits (HMW-GS), and the secondary metabolite phenolics. Generally, the timopheevii lineage has been neglected to date regarding grain quality studies. Thus, the timopheevii lineage should be subject to grain quality research to explore the full diversity of the wheat gene pool.

Colored wheat and derived products: key to global nutritional security

Ensuring food and nutritional security of fast-growing population will pose a huge challenge in future. An estimated one-half population who does not go hungry, nonetheless suffers the debilitating effects of unhealthy diets. In view of the nutritional awareness, when the major wheat breeding programs have started shifting to quality, instead of quantity in wheat, the colored wheats give a novel twist of targeting the malnutrition by enhancing the antioxidants such as anthocyanin, carotenoids, flavonoids, polyphenols etc. Moreover, changing consumer demands have picked the trend to prefer a nutritionally balanced diet over the conventional high energy diets and thus, colored wheat has opened up a hidden avenue for providing additional value to the wheat-based products. Besides providing nutrition, these pigments have the potential to replace the synthetic dyes and food colorants prevalent in the market. The review summarizes the genetics and biochemistry of the pigments of colored wheat along with their product development, nutritional status and consumer preference. The review also sheds light on the environmental effect on color accumulation and the effect of increased colorants on other quality traits of wheat.

Diploid Wheats: Are They Less Immunogenic for Non-Celiac Wheat Sensitive Consumers?

Non-celiac wheat sensitivity (NCWS) is a clinical entity induced by the ingestion of gluten that leads to intestinal and/or extraintestinal symptoms, and is diagnosed when celiac disease and wheat allergy have been ruled out. In addition to gluten, other grains’ components, including amylase trypsin inhibitors (ATIs) and fermentable short-chain carbohydrates (FODMAPs), may trigger symptoms in NCWS subjects. Several studies suggest that, compared with tetraploid and hexaploid modern wheats, ancient diploid wheats species could possess a lower immunogenicity for subjects suffering from NCWS. This review aims to discuss available evidence related to the immunological features of diploid wheats compared to common wheats, and at outlining new dietary opportunities for NCWS subjects.

Chemical, Functional, and Technological Features of Grains, Brans, and Semolina from Purple and Red Durum Wheat Landraces

A main reason of the increasing interest in cereal landraces is their potential to offer more diversified and functional staple food. For instance, landraces are an underexploited resource of pigmented varieties, appreciated for the high accumulation of phytochemicals with known health benefits. This study characterized the chemical, functional, and technological features of the bran, semolina, and grains of two durum wheat (Triticum turgidum L. subsp. durum, Desf.) landraces, named ‘Purple’ and ‘Red’ for their grain color, collected in Ethiopia and grown and sold in southern Italy as a niche product. Specifically, we analyzed the protein content, dry gluten, ash, total polyphenols, anthocyanins, proanthocyanidins, and specific phenolic acids. We also evaluated the antioxidant activity using DPPH- and ABTS-based methods. The two landraces had positive nutritional features, such as a high protein content, a rich and composite range of secondary metabolites (which include specific phenolic acids and anthocyanins), and antioxidant activities in all the fractions analyzed. The germplasm under investigation therefore has a well-justified potential to yield functional products and to diversify durum wheat-based foods.

Introgression of the Powdery Mildew Resistance Genes Pm60 and Pm60b from Triticum urartu to Common Wheat Using Durum as a 'Bridge'

Powdery mildew, caused by the fungus Blumeria graminis f. sp. tritici (Bgt), has limited wheat yields in many major wheat-production areas across the world. Introducing resistance genes from wild relatives into cultivated wheat can enrich the genetic resources for disease resistance breeding. The powdery mildew resistance gene Pm60 was first identified in diploid wild wheat Triticum urartu (T. urartu). In this study, we used durum as a ‘bridge’ approach to transfer Pm60 and Pm60b into hexaploid common wheat. Synthetic hexaploid wheat (SHW, AABBA^uA^u), developed by crossing T. urartu (A^uA^u) with durum (AABB), was used for crossing and backcrossing with common wheat. The Pm60 alleles were tracked by molecular markers and the resistance to powdery mildew. From BC₁F₁ backcross populations, eight recombinant types were identified based on five Pm60-flanking markers, which indicated different sizes of the introgressed chromosome segments from T. urartu. Moreover, we have selected two resistance-harboring introgression lines with high self-fertility, which could be easily used in wheat breeding system. Our results showed that the durum was an excellent ‘bridge’ for introducing the target gene from diploid T. urartu into the hexaploid cultivated wheat. Moreover, these introgression lines could be deployed in wheat resistance breeding programs, together with the assistance of the molecular markers for Pm60 alleles.

European Database of Carotenoid Levels in Foods. Factors Affecting Carotenoid Content

Many studies indicate that diets including carotenoid-rich foods have positive effects on human health. Some of these compounds are precursors of the essential nutrient vitamin A. The present work is aimed at implementing a database of carotenoid contents of foods available in the European market. Factors affecting carotenoid content were also discussed. Analytical data available in peer-reviewed scientific literature from 1990 to 2018 and obtained by HPLC/UHPLC were considered. The database includes foods classified according to the FoodEx2 system and will benefit compilers, nutritionists and other professionals in areas related to food and human health. The results show the importance of food characterization to ensure its intercomparability, as large variations in carotenoid levels are observed between species and among varieties/cultivars/landraces. This highlights the significance of integrating nutritional criteria into agricultural choices and of promoting biodiversity. The uncertainty quantification associated with the measurements of the carotenoid content was very rarely evaluated in the literature consulted. According to the EuroFIR data quality evaluation system for food composition tables, the total data quality index mean was 24 in 35, reflecting efforts by researchers in the analytical methods, and less resources in the sampling plan documentation.

[The content of yellow pigments in durum wheat (Titicum durum Desf.) grains: biosynthesis, genetic control, marker selection]

Зерно с высоким содержанием каротиноидных пигментов ценится за ярко-желтый цвет пасты, производимой из него, и провитаминную (витамин А) и антиоксидантную активность пигментов. Цель настоя- щего обзора – обобщение современных знаний о биосинтезе и генетическом контроле накопления пигментов в зерне твердой пшеницы и оценка основных результатов исследований и селекции за последние двадцать лет за рубежом и в России. Признак «концентрация каротиноидных пигментов в зерне» (Ypc) относится к раз- ряду количественных. Тем не менее превалирование сильных аддитивных эффектов генов и высокая насле- дуемость способствовали значительному прогрессу в селекции по этому признаку. Методами молекулярного маркирования локусов количественных признаков (QTL), контролирующих синтез каротиноидных пигментов и значения индекса желтизны (IY), установлено их распределение по всем хромосомам генома твердой пшеницы. Основные генетические локусы, определяющие более 60 % варьирования признака, были картированы в хромосомах 7AL и 7BL. Вклад этих локусов связан с аллельными вариациями, влияющими на активность фермента фитоенсинтетазы (PSY). В других хромосомах были локализованы минорные генетические факторы, из которых наиболее значимы QTL, расположенные в хромосомах 3AS (ассоциирован с геном LCYE-ликопин- ε-циклаза) и 4ВS (аллель Lpx-B1.1c). При этом показано, что аллель Lpx-B1.1c вносит вклад в снижение актив- ности липоксигеназы, окисляющей каротиноиды в процессе изготовления конечных продуктов. Рассмотрены и обсуждены проблемы использования молекулярных маркеров в селекционных программах, нацеленных на увеличение концентрации пигментов в зерне и улучшение цветовых характеристик пасты.

Chemical Composition, Tocopherol and Carotenoid Content of Seeds from Different Andean Lupin (Lupinus mutabilis) Ecotypes

Andean lupin (Lupinus mutabilis) seeds are appreciated for their high protein and lipid contents and have potential applications as ingredients in food, cosmetic, and pharmaceutical industries. Nevertheless, the information about the seed composition (especially in lipophilic antioxidants) of ecotypes from distinct cropping areas is currently limited. Thus, the aim of the present research was to assess the morphological characteristics, chemical composition, tocopherol and carotenoid contents of the seeds of 33 Andean lupin ecotypes from different Peruvian regions, along with three L. albus, one L. angustifolius and one L. luteus controls. Significant differences were noted among the Andean ecotypes for all analyzed features. The protein, lipid and ash contents were 32.0-46.9, 13.6-18.6 and 2.7-4.4 g/100 g dry matter (DM), respectively. The seeds were rich in tocopherols (172.1-249.8 mg/kg DM; γ-tocopherol was 98% of total tocols) and low in carotenoids (0.69-2.89 mg/kg DM). Debittering increased the tocopherol content (227.0-378.2 mg/kg DM), probably because of the soluble components loss, although the carotenoid concentration remained unchanged. The Andean lupins had higher protein, lipid and tocopherol contents than L. albus and L. angustifolius; the L. luteus values were within the L. mutabilis range. These results suggest that L. mutabilis harbors nutritional characteristics that are well suited to modern food trends.

Effects of several production methods on technological, textural and sensorial properties of emmer (Triticum turgidum ssp. dicoccum) bulgur

In recent years, the interest in primitive wheat species including emmer (Triticum turgidum ssp. dicoccum) wheat and their characteristics have increased due to natural food trends. Bulgur is a nutritious and healthy product with long shelf life, produced from hard wheat species without the need for any additives. The basis of this study was to reveal the potential for bulgur production by the six production methods, combinations of three cooking (traditional, autoclave, microwave) and two drying (hot-air, microwave) methods of emmer wheat. In addition to some physical, chemical and technological properties of emmer wheat, yield, color, cooking time and textural and sensorial properties of the bulgur samples were investigated and statistically significant differences (p < 0.05) were recorded among the bulgur samples. Autoclave cooking had a negative effect on color and got the lowest sensorial acceptability scores. Microwave drying increased fine bulgur formation and shortened the cooking time. The volume and weight increase indexes were increased more than hot-air drying thanks to physical effects of microwave drying on the structure. According to the texture analysis results, microwave cooking increased the adhesivity, and microwave drying increased hardness and springiness. In conclusion, emmer wheat have great potential for bulgur production, and traditional cooked + hot air dried samples had better bulgur properties in overall.

A comparison of the nutritional value of Einkorn, Emmer, Khorasan and modern wheat: whole grains, processed in bread, and population-level intake implications

BACKGROUND

Interest in alternatives to the traditional wheat Triticum aestivum among farmers, millers, bakers, and consumers is increasing. The Altergrain project aimed to compare the Belgian-soil cultivated Einkorn (1K), Emmer (EMM), Khorasan (KH), and modern wheat (MW) with respect to nutritional values of kernels, breads made from these cereals, and population-level nutrient intake implications.

RESULTS

Ancient wheats 1K, EMM, and KH contain lower total carbohydrate content than MW. Further, ancient wheats are higher in both protein and crude ash content. Vitamin E levels in breads prepared using 1K and EMM were higher than those in MW, but those prepared from KH had lower vitamin E levels than MW. Breads prepared using ancient wheats have higher total phenol content (TPC) than those from MW. Baking caused a decrease in vitamin E and TPC in bread prepared from ancient wheat, the exception being the one prepared using KH, which had a higher TPC than MW. When replacing bread made from MW with those made from ancient grains, no differences were observed with respect to conformance with the Belgian Recommend Daily Requirements.

CONCLUSION

Ancient wheats from Belgian soil are as nutritive as MWs even after being processed into bread. At the kernel level, nutritional differences are present, but only small differences are present in terms of nutritional intake when nutrition parameters are calculated for consumed bread. © 2020 Society of Chemical Industry.

Changes in stability, tocopherols, fatty acids and antioxidant capacity of sacha inchi (Plukenetia volubilis) oil during French fries deep-frying

Sacha inchi (Plukenetia volubilis) oil (SI) is appreciated for its nutritional and sensorial characteristics. The aim of this study was to evaluate SI changes during French fries deep-frying at 170 °C or 180 °C up to 119 and 50 min, respectively; commercial soybean oil (SO) was tested as control. SI had high α-linolenic acid (53.8%), linoleic acid (33.4%) and total tocopherols (2540.1 mg/kg). During frying tocopherol content, oil stability and antioxidant capacity (ABTS, DPPH) decreased following zero-order kinetics; γ-tocopherol showed the strongest decrease. Notwithstanding the high SI unsaturation and the commercial antioxidant (TBHQ) in SO, SI showed slightly higher or similar hydrolysis (free fatty acids and diacylglycerols), similar primary (K₂₃₂, oxidized-triacylglycerols) and lower secondary (K₂₆₈, triacylglycerol oligopolymers) oxidation. Because of the high tocopherol content, SI showed lower degradation than SO. Thus, SI is suitable for short-term deep-frying; additionally, it may enhance the nutritional value and the flavour of fried foods.

Bioactive compounds, nutritional benefits and food applications of colored wheat: a comprehensive review

The consumers' demands have changed from energy providing diet to a diet with a balanced nutrient profile along with metabolic, physiological and functional health benefits. They are seeking colorants derived from natural sources to enhance the nutritional and antioxidant value of foods. Colored wheat (Triticum aestivum) contains many phytochemicals, responsible for numerous health benefits. Colored wheat (blue, black, purple and red) contains a good amount of anthocyanins and carotenoids that are primarily located in the outer aleurone layer. Food regulatory and safety authorities and food processing industries are trying to minimize the usage of synthetic food colorants and dyes. Colored wheat is imperative for food processing industries as high-value pigments present in the bran layer (milling industry co-product) can easily be extracted and utilized as functional foods and natural colorants. The extracted pigments such as anthocyanin can replace synthetic dyes currently used in food, drug and cosmetics. Additionally, natural additives improve the nutritional value, appearance, texture, flavor, and storage properties of food products. This review presents a brief knowledge of the nutritional composition of colored wheat including phytochemicals and bioactive compounds like flavonoids, phenolic compounds, their health benefits, methods and technologies used for processing and extraction as well as the effects of processing on these compounds.

Genome-wide association study of agronomic and quality traits in a world collection of the wild wheat relative Triticum urartu

Triticum urartu (2n = 2x = 14, subgenome A^u A^u ), a wild diploid wheat progenitor, features broad allelic diversity for a number of traits of agronomic relevance. A thorough characterization of the diversity of T. urartu natural accessions may provide wheat breeders with new alleles potentially contributing to wheat improvement. In this study, we performed an extensive genotypic and phenotypic characterization of a world collection of 299 T. urartu ex situ accessions, developing 441 327 single nucleotide polymorphisms and recording trait values for agronomic and quality traits. The collection was highly diverse, with broad variation in phenology and plant architecture traits. Seed features were also varied, and analyses of flour quality reported 18 distinct patterns of glutenins, and carotenoid concentrations and sedimentation volumes in some cases surpassing those of cultivated materials. The genome-wide molecular markers developed on the collection were used to conduct a genome-wide association study reporting 25 highly significant quantitative trait nucleotides for the traits under examination, only partially overlapping loci already reported in wheat. Our data show that T. urartu may be considered a valuable allele pool to support the improvement of wheat agronomy and quality.

Wholemeal Spelt Bread Enriched with Green Spelt as a Source of Valuable Nutrients

The aim of this study was to evaluate the nutritional value of wholemeal bread prepared from the flour of spelt wheat (Triticum aestivum ssp. spelta) that was enriched by the addition of freeze-dried spelt grain (at proportions of 4%, 8%, and 12%, respectively, in relation to the flour weight). The spelt grain used in the study was harvested at the milk dough stage (the so-called green grain). Green spelt grain was characterized by a significantly higher content of minerals namely P, Mg, Ca and Zn compared to ripe spelt grain. Additionally, it contained significantly higher amounts of amino acids (Asp, Thr, Ser, Gly, Ala, Cys, Val, Met, Ile, Leu, Phe, Lys), lipids, as well as monounsaturated fatty acids (MUFA), and omega-3 and omega-9 acids. However, it had a lower content of palmitic, stearic, and linoleic acids, polyunsaturated fatty acids (PUFA), and omega-6 acids. The results showed that the nutritional value of bread was improved by the green spelt grain, however the ω6/ω3 ratio in bread enriched with green spelt grain was slightly less favorable than in control bread. Among all the products tested, bread enriched with a 12% proportion of green spelt grain was characterized by the highest content of almost all the amino acids (except for Pro, Cys, and Met), as well as in Mg, Zn, Mn, Cu and Fe. In addition, overall acceptability of this bread was the highest. Bread enriched with 8% of green grain contained the highest amount of P, Ca, Pro, linoleic acid, PUFA, and ω 6 acids, while bread enriched with 4% of green spelt grain had the highest content of palmitic acid and saturated fatty acids.

Development, identification, and characterization of blue-grained wheat-Triticum boeoticum substitution lines

Diploid wild einkorn wheat, Triticum boeoticum Boiss (A^bA^b, 2n = 2x = 14), is a wheat-related species with a blue aleurone layer. In this study, six blue-grained wheat lines were developed from F₈ progeny of crosses between common wheat and T. boeoticum. The chromosome constitutions of these lines were characterized by fluorescence in situ hybridization (FISH) using the oligonucleotide probes Oligo-pTa535-1, Oligo-pSc119.2-1, Oligo-pTa71-2, and (AAC)₇. Multicolor FISH using Oligo-pTa535-1, Oligo-pSc119.2-1, and Oligo-pTa71-2 identified all 42 common wheat chromosomes, while Oligo-pTa535-1 and (AAC)₇ discriminated the 14 chromosomes of T. boeoticum. FISH revealed that all six blue-grained lines were wheat-T. boeoticum 4A^b (4B) disomic substitution lines. The substitution lines were validated by genotyping using the wheat 55 K single nucleotide polymorphism (SNP) array containing 53,063 markers. These 4A^b (4B) substitution lines represent novel germplasm for blue-grained wheat breeding. The FISH probes and SNP markers used here can be applied in the development of blue-grained wheat-Triticum boeoticum translocation lines.

Fatty Acid Composition, Phytochemistry, Antioxidant Activity on Seed Coat and Kernel of Paeonia ostii from Main Geographic Production Areas

Paeonia ostii is an important woody oil plant cultivated in China on a large scale. Its seed oil is enriched with unsaturated fatty acids and a high content of alpha-linolenic acid (ALA), which are beneficial to human health. The aim of this research is to determine the qualitative traits characteristic of P. ostii seed from various production areas in China. In this study, seed quality traits were evaluated on the basis of proximate composition, content of fatty acids, tocopherol, secondary metabolites, and the antioxidant activity of seed coat (PSC) and kernel (PSK). A high content of total fatty acids (298.89–399.34 mg g⁻¹), crude protein (16.91%–22.73%), and total tocopherols (167.83–276.70 μg g⁻¹) were obtained from PSK. Significant differences were found in the content of palmitic acids (11.31–14.27 mg g⁻¹), stearic acids (2.42–4.24 mg g⁻¹), oleic acids (111.25–157.63 mg g⁻¹), linoleic acids (54.39–83.59 mg g⁻¹), and ALA (99.85–144.71 mg g⁻¹) in the 11 main production areas. Eight and seventeen compounds were detected in PSC and PSK, respectively. A significantly higher content of total phenols was observed in PSC (139.49 mg g⁻¹) compared with PSK (3.04 mg g⁻¹), which was positively related to antioxidant activity. This study indicates that seeds of P. ostii would be a good source of valuable oil and provides a basis for seed quality evaluation for the production of edible oil and potential ALA supplements from the promising woody oil plant.

Carotenoid Pigment Content in Durum Wheat (Triticum turgidum L. var durum): An Overview of Quantitative Trait Loci and Candidate Genes

Carotenoid pigment content is an important quality trait as it confers a natural bright yellow color to pasta preferred by consumers (whiteness vs. yellowness) and nutrients, such as provitamin A and antioxidants, essential for human diet. The main goal of the present review is to summarize the knowledge about the genetic regulation of the accumulation of pigment content in durum wheat grain and describe the genetic improvements obtained by using breeding approaches in the last two decades. Although carotenoid pigment content is a quantitative character regulated by various genes with additive effects, its high heritability has facilitated the durum breeding progress for this quality trait. Mapping research for yellow index and yellow pigment content has identified quantitative trait loci (QTL) on all wheat chromosomes. The major QTL, accounting for up to 60%, were mapped on 7L homoeologous chromosome arms, and they are explained by allelic variations of the phytoene synthase (PSY) genes. Minor QTL were detected on all chromosomes and associated to significant molecular markers, indicating the complexity of the trait. Despite there being currently a better knowledge of the mechanisms controlling carotenoid content and composition, there are gaps that require further investigation and bridging to better understand the genetic architecture of this important trait. The development and the utilization of molecular markers in marker-assisted selection (MAS) programs for improving grain quality have been reviewed and discussed.

Anthocyanins in cereals: Composition and health effects

Coloured (black, purple, blue, pink, red, and brown) cereal grains have gained much attention recently due to attractive nutritional values. A major type of pigments responsible for the colours as well as the health benefits of the cereals are anthocyanins. Focusing on the recent updates, this review summarises the chemical composition of the anthocyanins in diverse cereals including maize, rice, wheat, barley, sorghum, millet, and rye. There is a great diversity in anthocyanin composition among various cereals. Special cereal genotypes with much enhanced anthocyanin content (e.g., endosperm of rice kernels rich in anthocyanins) have been developed by genetic means. The coloured cereals as potential ingredients for functional food production have been subjected to extensive research for health benefits. Both in vitro and in vivo studies on the health effects of the anthocyanins from the cereals have been summarised. The claimed health benefits include anti-oxidation, anti-cancer, glycemic and bodyweight regulation, neuroprotection, retinal protection, hypolipidemia, hepatoprotection, and anti-ageing. These health effects suggest potential uses of the cereal anthocyanins for positive human nutrition. However, clinical and human studies are needed to confirm these claimed health effects.

Tocotrienols and tocopherols in colored-grain wheat, tritordeum and barley

Colored-grain spring and winter wheat, spring tritordeum and barley (blue aleurone, purple pericarp, and yellow endosperm) from the harvests 2014 and 2015 were evaluated for tocol contents by HPLC-FD. Higher content of total tocols was found in spring wheat varieties compared with winter varieties. Four tocols (β-tocotrienol, α-tocotrienol, β-tocopherol, and α-tocopherol) were identified in wheat and tritordeum varieties. Dominant tocols in purple- and blue-grained wheat and yellow-grained tritordeum were α-tocopherol and β-tocotrienol, whereas spring barley varieties differed from wheat and tritordeum by high α-tocotrienol content. Tocol content was significantly affected by genotype and in a lesser extent in some varieties and lines also by rainfall and temperatures during crop year. Higher rainfall and lower temperatures caused in most varieties higher tocol contents. Purple- and blue-grained wheat lines with higher tocol, anthocyanin and phenolic acids with health benefits may be useful for breeding new varieties.