The Comparison of the Effect of Flour Particle Size and Content of Damaged Starch on Rice and Buckwheat Slurry, Dough, and Bread Characteristics.

The effect of botanical origin, the flour particle size, and the content of damaged starch on flour pasting properties, dough behavior during a uniaxial deformation test, and bread characteristics were evaluated on rice and buckwheat flours. The rice flour with a median particle size D(0.5) of 60.2, 70.6, 106.8, and 189.4 µm, and buckwheat flour with a D(0.5) of 56.4, 68.4, and 95.8 µm were prepared using the same milling technology. The botanical origin of the flours was the strongest factor influencing the flour pasting properties, stress accumulated in dough during the uniaxial deformation test, loaf characteristics, texture, and sensory characteristics of breads. The flour particle size significantly influenced mainly the flour pasting properties. The effect of the content of damaged starch was the weakest among the studied factors. The flour particle size and the content of damaged starch were closely related. The flour botanical origin was the strongest factor; therefore, it seems not to be possible to predict the bread-baking potential of gluten-free flours based on the results obtained for flour of a different botanical origin. More research on flours from different plants prepared by the same milling process is required to support this hypothesis.

Rice Bran Lipidome Identifies Novel Phospholipids, Glycolipids, and Oxylipins with Roles in Lipid Metabolism of Hypercholesterolemic Children.

SCOPE: The purpose of the study is to characterize the chemical diversity in rice bran (RB) lipidome and determines whether daily RB consumption for 4 weeks may modulate plasma lipid profiles in children. METHODS AND RESULTS: Untargeted and targeted lipidomics via ultra-performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-MS/MS) are applied to identify bioactive RB lipids from a collection of 17 rice varieties. To determine the impact of RB (Calrose-USA variety) supplementation on plasma lipid profile, a secondary analysis of plasma lipidome is conducted on data recorded in a clinical study (NCT01911390, n = 18 moderately hypercholesterolemic children) before and after 4 weeks of dietary intervention with a control or RB supplemented (15 g day-1 ) snack. Untargeted lipidomic reveals 118 lipids as the core of lipidome across all varieties among which phospholipids are abundant and oxylipins present. Phytoprostanes and phytofurans are quantified and characterized. Lipidome analysis of the children plasma following RB consumption reveals the presence of polar lipids and oxylipins alongside putative modulations in endocannabinoids associated with RB consumption. CONCLUSION: The investigation of novel polar lipids, oxylipins, phytoprostanes, and phytofurans in RB extracts provides support for new health-promoting properties interesting for people at risk for cardiometabolic disease.

Modeling the Thermal Denaturation of the Protein-Water System in Pulses (Lentils, Beans, and Chickpeas).

Thermal treatment applied during the cooking of pulses leads to denaturation and even aggregation of the proteins, which may impact protein digestibility. Thermal transitions of lentil, chickpea, and bean proteins were studied using differential scanning calorimetry (DSC). Protein-enriched samples were obtained by dry air classification of dehulled seeds and were heated to 160 °C, with water contents ranging from 0.2 to 4 kg/kg on a dry basis. The DSC peaks of the resulting endotherms were successfully modeled as overlapping Gaussian functions. The denaturation temperatures were modeled as a function of the temperature according to the Flory-Huggins theory. The modeling allows for the calculation of the degree of protein transition for any temperature and moisture condition. The denaturation diagrams reflect the different protein compositions of lentil, chickpea, and bean (particularly the 11S/7S globulin ratio). Chickpea proteins were more thermally stable than those from lentil and bean. Proteins underwent an irreversible transition, suggesting that unfolding and aggregation were coupled.

Do ancient wheats contain less gluten than modern bread wheat, in favour of better health?

Popular media messaging has led to increased public perception that gluten-containing foods are bad for health. In parallel, 'ancient grains' have been promoted with claims that they contain less gluten. There appears to be no clear definition of 'ancient grains' but the term usually includes einkorn, emmer, spelt and Khorasan wheat. Gluten is present in all wheat grains and all can induce coeliac disease (CD) in genetically susceptible individuals. Analyses of 'ancient' and 'modern' wheats show that the protein content of modern bread wheat (Triticum aestivum) has decreased over time while the starch content increased. In addition, it was shown that, compared to bread wheat, ancient wheats contain more protein and gluten and greater contents of many CD-active epitopes. Consequently, no single wheat type can be recommended as better for reducing the risks of or mitigating the severity of CD. An estimated 10% of the population of Western countries suffers from gastrointestinal symptoms that lack a clear organic cause and is often referred to as irritable bowel syndrome (IBS). Many of these patients consider themselves gluten sensitive, but in most cases this is not confirmed when tested in a medical setting. Instead, it may be caused by gas formation due to fermentation of fructans present in wheat or, in some patients, effects of non-gluten proteins. A significant overlap of symptoms with those of CD, IBS and inflammatory bowel disease makes a medical diagnosis a priority. This critical narrative review examines the suggestion that 'ancient' wheat types are preferred for health and better tolerance.

Metabolomics of Pigmented Rice Coproducts Applying Conventional or Deep Eutectic Extraction Solvents Reveal a Potential Antioxidant Source for Human Nutrition.

Rice bran (RB) corresponds to the outer layers of whole grain rice and contains several phenolic compounds (PCs) that make it an interesting functional food ingredient. PC richness is enhanced in pigmented RB varieties and requires effective ways of extraction of these compounds. Therefore, we investigated conventional and deep eutectic solvents (DES) extraction methods to recover a wide array of PCs from red and black RB. The RB were extracted with ethanol/water (60:40, v/v) and two DES (choline chloride/1.2-propanediol/water, 1:1:1 and choline chloride/lactic acid, 1:10, mole ratios), based on Generally Recognized as Safe (GRAS) components. Besides the quantification of the most typical phenolic acids of cereals, nontargeted metabolomic approaches were applied to PCs profiling in the extracts. Globally, metabolomics revealed 89 PCs belonging to flavonoids (52%), phenolic acids (33%), other polyphenols (8%), lignans (6%) and stilbenes (1%) classes. All extracts, whatever the solvents, were highly concentrated in the main phenolic acids found in cereals (37-66 mg/100 g in black RB extracts vs. 6-20 mg/100 g in red RB extracts). However, the PC profile was highly dependent on the extraction solvent and specific PCs were extracted using the acidic DES. The PC-enriched DES extracts demonstrated interesting DPPH scavenging activity, which makes them candidates for novel antioxidant formulations.

Evidence of a Synergistic Effect between Pea Seed and Wheat Grain Endogenous Phytase Activities.

Distribution of phytic acid and phytase activity in pea seeds was analyzed and compared with those in wheat grains under identical assay conditions (55 °C, pH 5.5). Most total phytic acid content and phytase activity were found in pea cotyledons. In wheat grains, debranning resulted in a 70% reduction in phytic acid content, whereas more than 40% of the total phytase activity remained. The possibility to hydrolyze phytic acid by use of ground debranned wheat as a source of phytase in blends with pea cotyledon flour was investigated. The Michaelis-Menten parameters for each endogenous enzyme were identified and used to predict the rate of phytic acid hydrolysis. Results demonstrate a synergistic effect between the two phytase activities, enabling a 70-95% reduction of phytic acid depending on pea/wheat flour ratios in a relatively short time (4 h). This reduction appears to be able to increase zinc bioavailability but remains insufficient for iron.

Fate of SDS-insoluble glutenin polymers from semolina to dry pasta.

Pasta cooking quality is well known to be related to semolina protein content and composition, however impact of the unextractable polymeric protein content (%UPP) remains disputed. In this work different semolina samples, of variable protein contents (10.5-14.2%) and %UPP (20.2-46.3%) are studied. The changes in %UPP induced by the successive pasta processing steps (mixing, extrusion, drying) but also those occurring during resting periods at 35°C, applied in-between them, were investigated. Effect of a resting period was moderate after mixing, but pronounced after extrusion. Resting of extruded pasta at 35°C significantly increased %UPP, which can even grow beyond that of the semolina. No relationship was found between pasta viscoelastic index (VI) and semolina %UPP or protein content. However, cooked pasta VI was found related to the calculated %UPP of rested fresh pasta.

Changes in the starch-protein interface depending on common wheat grain hardness revealed using atomic force microscopy.

The atomic force microscope tip was used to progressively abrade the surface of non-cut starch granules embedded in the endosperm protein matrix in grain sections from wheat near-isogenic lines differing in the puroindoline b gene and thus, hardness. In the hard near-isogenic wheat lines, starch granules exhibited two distinct profiles corresponding either to abrasion in the surrounding protein layer or the starch granule. An additional profile, only identified in soft lines, revealed a marked stop in the abrasion at the protein-starch transition similar to a lipid interface playing a lubricant role. It was related to the presence of both wild-type puroindolines, already suggested to act at the starch-protein interface through their association with polar lipids. This study revealed, for the first time, in situ differences in the nano-mechanical properties at the starch-protein interface in the endosperm of wheat grains depending on the puroindoline allelic status.

Localization of phytase transcripts in germinating seeds of the common bean (Phaseolus vulgaris L.).

MAIN CONCLUSION: The work provides the first-time evidence of tissue-specific expression of a phytase gene in the germinating seeds of Phaseolus vulgaris. Phytase enzyme plays a major role in germinating seeds. It is also active during N2 fixation within nodules of legumes. The effect of phosphorus (P) deficiency on phytase gene expression and localization in N2-fixing root nodules has been recently studied in hydroaeroponic culture of Phaseolus vulgaris. In this study, phytase gene transcripts within the germinating seed tissues of the P-inefficient P. vulgaris recombinant inbred line RIL147 were in situ localized with a similar RT-PCR recipe as that used for nodules. Our results show that the phytase gene expression was mainly localized in the outer layers, vascular cells and parenchyma of germinating seeds whereas it was localized in the inner and middle cortex of nodules. Image analysis quantified higher fluorescence intensity of the phytase transcript signal in the seed embryo than in radicles, cotyledons or the nodule cortex. Furthermore, the phytase activity was 22-fold higher in cotyledons (43 nmol min(-1) g(-1) dry weight) than in nodules (2 nmol min(-1) g(-1) dry weight). The K m and V m values of phytase activity in cotyledons were also significantly higher than in nodules. Interestingly, the amplified sequence of cDNA phytase exhibited highest homology with the Glycine max purple acid phosphatase (NM_001289274) 90 % for germinating seed as compared to nodule phytase cDNA displaying 94 % homology with the Glycine max phytase (GQ422774.1). It is concluded that phytase enzymes are likely to vary from seeds to nodules and that phytase enzymes play key roles in the use of organic P or N2 fixation, as it is well known for germination.

Exposure or release of ferulic acid from wheat aleurone: impact on its antioxidant capacity.

The relationship between the aleurone cell integrity and the exposure or release of bioavailable ferulic acid (FA) with the antioxidant capacity of aleurone in in vitro and under simulated gastric conditions was explored. The antioxidant capacity of aleurone was increased by around 2-fold when its median particle size was reduced to under 50 µm. The opening of aleurone cells increased the physical exposure of FA bound to the insoluble polysaccharides, which seemed to be responsible of the increased antioxidant capacity. Synergistic combination of xylanase and feruloyl esterase was found to be the most efficient enzymatic treatment releasing up to 86% of total FA in bioaccessible forms. This enzymatic treatment significantly enhanced the radical scavenging activity of aleurone by up to 4-fold, which overlapped the overall antioxidant potential estimated from the total content of FA in aleurone. The improvement in the antioxidant capacity of aleurone was also observed in the simulated gastric digestion by inhibition of lipid oxidation.

Iron and zinc in vitro availability in pearl millet flours (Pennisetum glaucum) with varying phytate, tannin, and fiber contents.

Simulations of gastro-intestinal digestion, used to estimate in vitro iron and zinc availability, were performed on two kinds of samples: (i) samples with decreased phytate contents from whole pearl millet flour and (ii) nondephytinized or dephytinized samples from two pearl millet grain fractions, a decorticated fraction with low fiber and tannin contents and a bran fraction with high fiber and tannin contents. Iron and zinc in vitro availabilities of whole pearl millet flour were significantly improved by phytate degradation, even if the IP6 were not all degraded. Total dephytinization of decorticated fraction led to a marked increase in iron and zinc in vitro availabilities, but that of bran fraction had no effect on either iron or zinc in vitro availability. Even if phytates are involved in reducing in vitro iron and zinc availability in pearl millet flour, fibers and tannins play an important role by chelating a high proportion of iron and zinc in grain hulls.

Puroindolines form ion channels in biological membranes.

Wheat seeds contain different lipid binding proteins that are low molecular mass, basic and cystine-rich proteins. Among them, the recently characterized puroindolines have been shown to inhibit the growth of fungi in vitro and to enhance the fungal resistance of plants. Experimental data, using lipid vesicles, suggest that this antimicrobial activity is related to interactions with cellular membranes, but the underlying mechanisms are still unknown. This paper shows that extracellular application of puroindolines on voltage-clamped Xenopus laevis oocytes induced membrane permeabilization. Electrophysiological experiments, on oocytes and artificial planar lipid bilayers, suggest the formation, modulated by voltage, of cation channels with the following selectivity: Cs(+) > K(+) > Na(+) > Li(+) > choline = TEA. Furthermore, this channel activity was prevented by addition of Ca(2+) ions in the medium. Puroindolines were also able to decrease the long-term oocyte viability in a voltage-dependent manner. Taken together, these results indicate that channel formation is one of the mechanisms by which puroindolines exert their antimicrobial activity. Modulation of channel formation by voltage, Ca(2+), and lipids could introduce some selectivity in the action of puroindolines on natural membranes.