Characterization and comparison of predominant aroma compounds in microwave-treated wheat germ and evaluation of microwave radiation on stability

The present study was performed to evaluate the effects of microwave (MW) output power and treatment time on moisture content, lipase and lipoxygenase activities as well as colour changes of wheat germ (WG). In addition, the key aroma compounds in different MW-power-treated WG, which is of importance to the flavour of WG products, were also investigated. The obtained results showed that MW treatment maintained the inherent colour of WG and significantly reduced the moisture content (maximum reduction of 95%) and the activities of lipase and lipoxygenase (maximum reduction of 65% and 99%, respectively). In terms of aroma compounds, with the increase of the MW output power, the content of esters, alkanes, alcohols and acids decreased, while the content of heterocyclic compounds, nitrogen-containing compounds, aldehydes and ketones increased, providing more compounds with roasted flavour and less volatiles with grass-like flavour. Therefore, MW treatment was an effective stabilization method for WG utilization.     

Low temperature increased the biosynthesis of 2-AP,cooked rice elongation percentage and amylose content percentage in rice

Rice fragrance, cooked rice elongation and amylose content are some of the traits used in determining rice grain quality. 2-acetyl-1-pyrroline (2-AP) is the major compound that is responsible for fragrance in rice.This experiment was conducted with two indica rice cultivars: Meixiangzhan 2 and Xiangyaxiangzhan. Three temperature-controlled chambers: High (32 °C from 06:00 to 17:59 and 26 °C from 18:00 to 05:59), medium (27 °C from 06:00 to 17:59 and 21 °C from 18:00 to 05:59) and low (22 °C from 06:00 to 17:59 and 16 °C from 18:00 to 05:59) were used for the study. At the onset of heading, both cultivars were transferred to the three temperature-controlled chambers. Our results showed that in both cultivars, low temperature growth had the highest 2-AP content, while high temperature growth recorded the lowest 2-AP content. Principal component analysis showed remarkable differences in the metabolomes of rice grown in high, medium and low regimes. In the grains of both cultivars, we observed significant reduction in 2-AP content after 6 and 9 months of storage, however; 2-AP retention differed greatly in both cultivars. We also reported that low temperature growth increased cooked rice elongation percentage and the biosynthesis of amylose in rice. In conclusion, our findings will provide more information to breeders working on the improvement of rice grain quality.     

Localization of amino acids in germinated rice grain: Gamma-aminobutyric acid and essential amino acids production approach

Germinated rice is popularly consumed for its high gamma-aminobutyric acid (GABA) and bioactive compounds. Supporting information on how to germinate rice with high GABA content and essential amino acids is lacking. White and colored rough rice were germinated for 0, 24, 48, 72, 96, 120 and 144 h. GABA, GABA substrates and essential amino acids were also investigated using GC-MS and MALDI-MSI. GABA was more concentrated after germination and shifted into the coleoptile. High correlation was recorded between germination time and GABA (0.79–0.83, p ≤ 0.01) and glutamic acid (0.88–0.89, p ≤ 0.01). Highest rates of GABA and glutamic production were observed within 48 h of germination in both rice varieties (26.12 and 34.28 mg/100g) and reached maximum value at 96 h (31.36 and 38.75 mg/100g). Colored rice germination showed higher GABA, GABA substrates and deficient amino acids than white rice. GABA and essential amino acids drastically increased after germination, supporting the consumption of germinated rice as a functional food.     

Variation in physicochemical properties and nutritional quality in chalky mutants derived from an indica rice

The physicochemical and nutritional quality of four chalky mutants (JM1-4) rice and their parent 93-11 were investigated. JM1 and JM4 are white-belly mutants, and JM2 is white-core mutant, while JM3 is floury mutant. JM2 is also a high amylose mutant with AAC of 29%. JM3 had the lipid content nearly three times of the parent, so it is also a high lipid mutant. JM1 had similar pasting viscosities with the parent, while JM2 and JM3 had smaller breakdown and setback than 93-11. JM2 had lower enthalpy of gelatinization, but higher enthalpy of retrogradation, so it had highest retrogradation percentage. JM3 had the highest accumulation of amino acids, fatty acids, and some major mineral elements such as P, K, Mg and Ca. The amino acids and fatty acids had negative correlation with PV, HPV and CPV. The pleiotropic effects caused by the mutations on starch and lipid metabolism deserve further investigation.     

Characterization of the FODMAP-profile in cereal-product ingredients

Cereal-based products, such as bread, are staple foods in the western diet. Due to the nature of their basic ingredients and the diversity of recipes, the amount of fermentable short-chain carbohydrates (FODMAPs) in those products may be high. This study characterized the FODMAP-profiles of a broad range of cereal-product ingredients, serving as a basis for low FODMAP product development. Different cereals, pseudo-cereals, gluten-free flours, pulses, pulse protein ingredients, commercial sprouts, and other cereal-product ingredients were analyzed, using anion-exchange chromatography with electrochemical detection. Wheat and related cereals were high in fructans. Pulses, such as peas contained high galactooligosaccharides (GOS) amounts. Whereas GOS levels in pulse protein ingredients varied, depending on their production. Gluten-free flours, for instance, rice-flour, showed low FODMAP-profiles. Amongst those, buckwheat, which does not contain any of the FODMAPs investigated, contained high amounts of other soluble non-digestible carbohydrates, namely fagopyritols; these may have a similar effect on a sensitive gut as GOS. Finally, ingredients contained mainly high levels of fructans and GOS. Yet, the analysis of commonly consumed commercial cereal products, including bread, pasta, crackers and biscuits, highlighted the relevance of lactose, fructose in excess of glucose and polyols. These products serve as benchmarks for further product development.     

Soluble arabinoxylans extracted from soft and hard wheat show a differential prebiotic effect in vitro and in vivo

Arabinoxylans (AX) are part of dietary fiber. They are currently under study due to their potential prebiotic effect. Wheat whole grain flours contain all the grain layers and, therefore, present a higher arabinoxylan content than white flour. It is known that the chemical structure of these compounds varies with the type of wheat cultivar and the tissue from which they are extracted. In this work, water soluble extractable arabinoxylans (WE-AX) from two types of wheat whole flours (hard and soft) were extracted. We characterized the molecular size distribution and the potential prebiotic effect of those extracts. The prebiotic effect was evaluated in vitro and confirmed in vivo. Bacterial group abundance (Lactobacillus, Bifidobacterium, Clostridium, Enterococcus, Bacteriodes and total bacteria) was determined by quantitative RT-PCR. The molecular size of AX from hard wheats was significantly higher than AX from soft wheats. Both extracts showed potential prebiotic activity by increasing the growth of beneficial bacteria in vitro and in vivo, decreasing the pathogens in the profile of intestinal microorganisms and increasing the amount of short chain fatty acids in the intestine. WE-AX from hard wheat showed a higher prebiotic activity. Prebiotic effect assessed in vitro and in vivo assays showed a significant correlation between both types of analysis. This finding suggests that the in vitro indices performed allow predicting the potential prebiotic effect in vivo.     

Contributions of individual and combined Glu-B1x and Glu-B1y high-molecular-weight glutenin subunits to semolina functionality and pasta quality

Durum wheat is an important food crop used primarily for pasta production. High-molecular-weight glutenin subunits (HMW-GS) encoded by the closely linked genes Glu-B1x and Glu-B1y are known for their combined effects on pasta quality, but their individual contributions and interactions remain poorly understood. In this study, we show that individual loss-of-function mutants of Glu-B1x (ΔBx6) and Glu-B1y (ΔBy8) were associated with significant reductions in gluten strength compared to the wildtype, with stronger effects in the ΔBxy double mutant. Reductions in gluten strength were reflected in reduced mixograph and alveograph parameters, gluten index, faster extrusion flow rates and increased cooking loss. Interestingly, the Glu-B1x mutation was also associated with significant increases in grain and semolina protein content, increased pasta firmness, reduced starch viscosity and increased amylose in ΔBx6 and ΔBxy. In general, the ΔBx6 mutation had stronger effects than the ΔBy8 mutation, and significant interactions between the two genes were frequent. In addition to the basic knowledge gained on the individual effects of the Bx6 and By8 subunits and their interactions, the genetic stocks developed in this study provide useful tools to study the effects of natural or synthetic HMW-GS on pasta quality parameters in a background lacking endogenous HMW-GS.     

Simultaneous fortification of rice with folic acid and β-carotene or vitamin A by limited-water parboiling

Rice fortification by parboiling has been used to fortify rice with a single or a combination of multiple nutrients. While several studies have demonstrated the success of rice fortification with minerals by the parboiling technique, the number of studies that used vitamins as fortificants is limited with varying results. A limited-water soaking method has been introduced as a feasible and more sustainable alternative to the conventional excess-water soaking in parboiling. This study investigated the application of limited-water soaking in the simultaneous fortification of rice with water- and fat-soluble vitamins. Pure and water-soluble forms of β-carotene and vitamin A were first compared to identify a more effective form to be combined with folic acid. Water-soluble forms of β-carotene and vitamin A were easy to incorporate into the soaking water and presented effective fortification without affecting rice milling quality, the amount of wastewater and solids in wastewater. Milled rice fortified with folic acid combined with water-soluble forms of β-carotene or vitamin A in the limited-water soaking method contributed to about 75% of the recommended dietary allowances (RDAs) for folic acid, about 173% (female) and 134% (male) of the RDAs for β-carotene, and to about 58% (female) and 45% (male) of the RDAs for vitamin A. Rice fortified with β-carotene showed a greater uptake and a more orange color compared to the others. Thus, fortification of rice with vitamins by limited-water parboiling is an efficient process to obtain fortified rice that can significantly increase vitamin intake with limited environmental impacts.     

Development of a limited-water soaking method on the fortification of rice with calcium and iron by parboiling

Fortifying rice using parboiling has been shown to have a higher retention rate of nutrients and acceptable sensory characteristics. However, the conventional soaking step employs excess water and therefore generates large amounts of wastewater containing nutrients that, when discarded without treatment, can lead to nutrient overload in soil. A limited-water soaking method to fortify rice with calcium and iron by parboiling was developed and evaluated. Fortified rice quality attributes, mineral contents, the amount of wastewater, total solids in wastewater, washing-retention and bioavailability of calcium and iron were determined and compared with properties of rice that was fortified in excess-water soaking. The limited-water soaking method on average reduced the amount of effluent by 89% and the amount of total solids in wastewater by up to 85%. Rice fortified by the limited-water soaking method showed similar color and head rice yield, and slightly lower mineral uptakes compared to conventional soaking. Rice fortified simultaneously with calcium and iron in limited-water soaking contained about 999 mg Ca and 33 mg Fe per kg milled rice, and approximately 66% of calcium and 71% of iron remained in the rice after simulated washing. Calcium and iron dilute HCl-solubility was not affected by the soaking condition. Therefore, the limited-water soaking method can reduce the cost of fortification and wastewater treatment without affecting rice quality attributes.     

An improved method for extraction of sorghum polymeric protein complexes

A method for fractionating sorghum proteins using extraction solvents and techniques designed to obtain polymeric protein structures (especially disulfide linked) was developed. Extraction and separation conditions were optimized in terms of completeness of protein extraction, sample stability, and analytical resolution. After pre-extraction of albumins and globulins, a 3-step sequential procedure involving no reducing agents was applied to ground whole sorghum flour. The three fractions obtained represented proportionally different protein polymer contents and molecular weight distribution as evidenced by comparative size exclusion chromatography. Protein composition also varied among the extracts with differences in kafirin composition and non-kafirin proteins detected in the fractions by RP-HPLC and SDS-PAGE analysis. The ability to quantify and further characterize sorghum polymeric protein complexes will be useful for additional studies linking protein structures with functionality and digestibility and variations for these properties within diverse sorghum germplasm.     

Effect of high temperature stress during ripening on the accumulation of key storage compounds among Japanese highly palatable rice cultivars

High temperature stress during ripening increases the frequency of chalky grains, resulting in a lower market value for rice (Oryza sativa L.). Changes in starch properties and the accumulation pattern of storage proteins are proposed to be related to the occurrence of chalky grains. This study investigated changes in the accumulation of key storage compounds in the grains of Japanese highly palatable rice cultivars, subjected to high temperature stress when grown in a growth chamber and the field. The 13 kDa prolamin content was significantly reduced in a highly heat-sensitive cultivar, Tsukushiroman, whereas the 13 kDa prolamin content was not affected in a heat-tolerant cultivar, Genkitsukushi, even in a high temperature chamber condition (31/26 °C day/night), when compared with the control chamber condition (26/21 °C day/night) for both genotypes. In addition, grains grown in field conditions revealed that severely chalky grains had less 13 kDa prolamin than perfect grains in all five genotypes. Changes in amylose content and the distribution of amylopectin chain lengths did not explain the difference in grain appearance both for chamber and field experiments. These results strongly suggest that physiological processes linked with the synthesis of 13 kDa prolamin are associated with grain appearance in Japanese highly palatable under high temperature stress.     

Effects of wheat tempering and stone rotational speed on particle size,dough rheology and bread characteristics for a stone-milled weak flour

The poor technological performance of weak wheat flours means that they are usually considered difficult to be transformed into satisfactory bread. During milling, there are several settings that can affect flour characteristics. In this study, we tested two operative parameters that have the potential to affect flour quality – stone rotational speed and wheat tempering. Tempering moistures were set at 11%, 13%, 15%, and 17%, while stone rotational speeds were set at 173, 260, and 346 rpm. Both factors were found to affect operative milling parameters, notably flour yield, process productivity and specific energy consumption. Grain moisture had a significant effect on both dough rheology and bread characteristics (dough stability, tenacity, and extensibility). Dough stability was maximum at 13% moisture. Dough tenacity decreased as moisture increased, while extensibility increased as moisture increased. Bread specific volume and crumb specific volume were improved at 13% and 15% moisture. In conclusion, wheat tempering can be used to improve the potential of a weak flour and bread characteristics, while stone rotational speed affects operative parameters and white flour yield.     

Quantitative LC-MS proteoform profiling of intact wheat glutenin subunits

Methodology for the quantitative analysis of intact glutenin proteins by ESI-LC-MS was developed with 1 Da mass resolution, constituting the first published application of proteoform profiling to plant biology. Two parent lines and 28 F5 crosses were analyzed in two blocks, 14 months apart. Control sample data were used to align retention times and normalize abundance between sample sets. A total of 4622 observations of 347 distinct proteoforms between 17 899 and 88 744 Da were observed. Proteoform abundances spanned a 1000-fold range and were linear (r² > 0.990) with dilution. A novel method for the objective elimination of low intensity, noise-dominated data using replicate variability within the dataset is presented. Two abundant PTMs were detected; one known but uncharacterized Bx and Dy high-molecular-weight glutenin subunit (HMWGS) PTM and the other in 24 low molecular weight proteoform pairs. Finally, 16 abundant proteoforms were detected in progeny but not in either parent. This application should increase the statistical power of correlations between gluten complement and functional data and drive the detection of novel PTMs that may indicate differential regulation of the cellular processes related to quality.     

Breeding and biotechnological efforts in Jatropha curcas L. for sustainable yields

Jatropha is a non-edible, important bioenergy plant, which can grow in marginalized land. The seeds possess about 36% oil and this would be converted into biodiesel or biojet-fuel. Jatropha provides an option for sustainable feed and fuel production due to its inherent qualities including hardy nature, drought tolerance and surviving with limited amount of water, tolerance to unfavorable conditions and excessive moisture. However, heterozygosity, low productivity and poor understanding of its genome are the major impediments to elite line development. Further, classical breeding and advanced technological investments remain limited owing to long juvenile phase and breeding cycles. Scientific technologies that lead to identification of elite genotypes and development of high yielding elite Jatropha lines and effective methods of detoxification of seeds needs immediate priority. Efficient tissue culture system, doubled haploids (DH) and genomic tools are increasingly made available to improve the seed yield and its oil quantity through the development of geminivirus disease resistant lines. The application of advanced, sequencing technologies has presented a repertoire of genomic information for this important yet orphan crop. In the present investigation, we highlight the achievements made in Jatropha towards development of high yielding, virus resistant elite lines and hybrids with yield potential ranging from 3 to 5 tons per hectare in a year, which is a first ever report in the world. We also developed potential biotechnological tools such as genetic transformation, genome editing and next generation genomics tools including linkage maps and QTLs for accelerating breeding efforts through marker assisted selection. Because of our concerted and continuous efforts during the past 15 years, we have overcome all the obstacles and developed high yielding, disease resistant hybrids/lines, advanced cultivation technologies with thorough knowledge on Agronomy of the Jatropha crop. The Jatropha cultivation technology developed for the first time in the world, could open up new avenues for higher yield productivity of commercial viability.     

New angiotensin-converting enzyme inhibitory peptide from Coix prolamin and its influence on the gene expression of renin-angiotensin system in vein endothelial cells

Coix seed, which is a traditional Chinese medicine, has been used to treat hypertension for thousands of years. It has been shown that Coix prolamin peptides display high levels of angiotensin I converting enzyme (ACE) inhibitory activity. Hence, we purified the ACE inhibitory peptides from Coix prolamin hydrolysates and evaluated the influence of the most potent peptide on the renin-angiotensin system (RAS) genes expression in human umbilical vein endothelial cells (HUVECs). In this study, Coix prolamin peptides were sequentially separated by ultrafiltration, ion exchange chromatography, gel filtration chromatography and RP-HPLC, while the peptide structure was analyzed by mass spectrometry. Next, in silico proteolysis, pharmacophore and molecular docking were further applied to screen and optimize the structure of peptides. Finally, a novel ACE inhibitory peptide VDMF was obtained, in which its influence on the gene expression of RAS signaling pathway in AngⅡ-injury HUVECs was evaluated by quantitative real-time PCR. VDMF significantly down-regulated ACE, AngII type 1 receptor (AT1R) and ACE2 mRNA expression in comparation with model group, while up-regulating Mas gene expression. Hence, we obtained a novel antihypertensive candidate that was derived from the Coix peptides, which could involve a multi-modulation mechanism that regulates blood pressure.     

Biofortification of sweet corn hybrids for provitamin-A,lysine and tryptophan using molecular breeding

Traditional sweet corn is poor in provitamin-A, lysine and tryptophan, deficiency of which causes serious health problems. Here, parental lines of two shrunken2 (sh2) -based sweet corn hybrids viz., ASKH-1 and ASKH-2 were targeted for introgression of crtRB1 and opaque2 (o2) genes through marker-assisted backcross breeding. Gene-based markers; umc1066 (SSR) and 3′TE-InDel were utilized for foreground selection of o2 and crtRB1, respectively in BC₁F₁, BC₂F₁ and BC₂F₂ generations. Background selection employing 102–113 polymorphic SSRs led to >90% recovery of recurrent parent genome. Reconstituted hybrids recorded high mean provitamin-A (18.98 μg/g) with a maximum of 7.7-fold increase over original hybrids (3.12 μg/g). High mean lysine (0.39%) and tryptophan (0.10%) with an average enhancement of 1.71- and 1.79-fold, respectively was recorded among reconstituted hybrids over original versions (lysine: 0.23%, tryptophan: 0.06%). Improved hybrids exhibited high phenotypic resemblance with their original hybrids. The average cob yield (11.82 t/ha) and brix (17.66%) of improved hybrids was at par with their original versions (cob yield: 11.27 t/ha, brix: 17.04%). These biofortified sweet corn hybrids rich in provitamin-A, lysine and tryptophan hold immense significance as multinutrient-rich balanced food. This is the first report to stack sh2, crtRB1 and o2 genes to improve nutritional quality in sweet corn.     

Enzymatic degradation of FODMAPS via application of β-fructofuranosidases and α-galactosidases- A fundamental study

Cereals and pulses often contribute to the intake of Fermentable Oligo-, Di-, Monosaccharides, and Polyols (FODMAPs) due to high amounts of fructans or galactooligosaccharides (GOS). FODMAPs can trigger symptoms of Irritable Bowel Syndrome (IBS) and therefore, the development of foods and beverages with a lower FODMAP-content are favourable for IBS patients. Enzyme technology is a promising tool to reduce the FODMAP-content in foods and to maintain product quality. This fundamental study investigates the efficiency of invertase, inulinase, and α-galactosidase as potential food additives to reduce the total FODMAP content of food ingredients. Extracts of high FODMAP ingredients, such as wheat and lentil, and standard solutions of various fructans and GOS were incubated with invertase, inulinase and α-galactosidase for 1 h and 2 h. Contents of oligosaccharides before and after treatment and related IBS-triggering reaction products were quantified using ion chromatography. Inulinase showed a high degradation yield (over 90% of degradation) for both GOS and fructans. For invertase only low degradation yields were measured. α-Galactosidase showed the highest efficiency in decomposing GOS (100% of degradation) and led to non-IBS triggering degradation products. This indicates a high potential for a combined inulinase/α-galactosidase treatment for products containing both fructans and GOS.     

Mass spectrometry imaging of BARLEYmax fructooligosaccharides

BARLEYmax is a novel hull-less barley cultivar lacking activity of a key enzyme required for starch synthesis (SSIIa), resulting in a grain with reduced total starch, higher dietary fiber, and higher fructan content. In this study, we examined the quantitative differences in fructan among 2 hull-less barley lines (BARLEYmax and Mannenboshi) and 2 peeled barley lines (Glutinous barley rice and Hindmarsh). We found that BARLEYmax had a higher fructan content, particularly 2 types of fructooligosaccharides (FOS), namely kestose and nystose, the important components of fructan that have some beneficial effects for human health. We established a mass spectrometry imaging (MSI) method to further investigate the content and localization of FOS in the barley lines. We found that kestose, nystose, and fructosyl-nystose showed increased molecular ion intensities in BARLEYmax compared with those in other barley lines. These results confirmed that the loss of SSIIa activity in BARLEYmax leads to a decrease in starch in the cytoplasm and an increase in fructan in the vacuole as an energy store. Overall, these findings demonstrate that MSI analysis is helpful for understanding FOS localization in cereal grains and for visual comparison among matured grains.     

Camelina sativa,a short gestation oilseed crop with biofuel potential: Opportunities for Indian scenario

Camelina is an oilseed crop which is being commercially produced globally as feedstock for biodiesel. Being a non-edible oil bearing low input crop owing to its low fertilizer and water requirement, fits well for biofuel production. In India, targets for biofuel blending has been set by New Biofuel Policy-2018 and to meet these targets efforts are being made to harness the potential of available feedstock in the country. Among these feedstock, contribution of short gestation oilseed bearing crop has been very important. Camelina has been introduced in India during 2009–10 as experimental crop by DIBER, DRDO. Since then various efforts have made to standardize the production technology of this crop under various agro-climatic regions of the country, crop improvement, oil quality analysis and development of high energy by-products. Camelina has various advantages to offer for Indian biofuel sector. This paper reviews the potential of this crop for Indian Biofuel scenario.     

Variation in avenanthramide content in spring oat over multiple environments

Avenanthramides (AVNs), a group of phytochemicals which are unique to oats, provide health benefits through antioxidant activity and other bioactivities. In this study, we explored genotype-by-environment interactions and heritability for AVN concentrations in oats. Avenanthramide concentrations were quantified for 100 breeding lines and cultivars at three locations over two years. While year and environment had an influence on AVN concentrations, with the influence of year being more apparent than that of environment within a year, genotype had the largest impact on AVN concentration. All three major AVNs were found to be heritable. Two methods of calculating heritability on a line mean basis were used. The statistical method yielded heritability estimates of 0.34, 0.39, and 0.41 for AVN 2c, AVN 2p, and AVN 2f, respectively. By comparison the traditional plant breeding method yielded heritability estimates of 0.82, 0.88, and 0.89 for AVN 2c, AVN 2p, and AVN 2f, respectively, indicating that expected gains will be dependent on the scale of the breeding program, the number of target environments, and climate variability. The estimated heritabilities and the 11-fold range in AVN concentrations in the 100 genotypes studied provided evidence that variability for AVN concentration should allow breeding progress for higher AVN concentration.