Many analytical methods for antioxidant determination in foodstuffs and raw materials based on various principles have been published so far. However, not all of them are applicable to barley and ...malt. The results of total antioxidant capacity (TEAC) of barley and malt obtained with methods based on ability to eliminate radicals of 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) were compared and statistically evaluated. The average TEAC of barley determined using ABTS and DPPH ranged from 2.1 to 2.5 μmol g−1 and from 1.2 to 1.7 μmol g−1, respectively. The TEAC ranges in malt were 2.7–3.0 μmol g−1 (ABTS) and 1.8–2.6 μmol g−1 (DPPH). TEAC of barley and malt were affected by the weather conditions (year), variety and application of Zn2+ fertilizer. The ABTS and the DPPH methods represent an effective tool for the assessment of antioxidant capacity of spring barley and malt and the factors having an impact on it.
•ABTS and DPPH methods are efficient tool for determination of antioxidant activity of barley and malt.•Total antioxidant capacity of barley is dependent on growing conditions.•Weather, barley variety and Zn2+ fertilizer are the most significant factors influencing total antioxidant capacity.•Malt contains more antioxidants compared to barley.
Improving the utilization of sorghum in beer brewing has led lots of researchers carrying out studies on different varieties of sorghum. The aim of the study is to evaluate the malting properties of ...the four recently improved sorghum varieties (Samsorg 46, 47, 48 and 49). In this study, four recently improved Nigerian sorghum varieties were subjected to several tests, these include determination of a thousand corn weight, moisture content, germinative capacity, germinative energy and water sensitivity, tannin, Protein estimation, cold water extract (CWE), hot water extract (HWE), diastatic power and amylase activities using standard methods. The results obtained showed variations among the sorghum varieties in most of the parameters assessed. Samsorg 49 gave the highest weight (34.1g), for germinative capacity, variety Samsorg 46 gave the highest value (99.5%), Samsorg 46 and 48 were the most water sensitive (98%), Samsorg 46 gave the highest value for CWE (50.60%) while Samsorg 49 gave highest value for HWE (284.86%). The four grains had no tannins present. Samsorg 46 (10.02%) had the highest protein content while Samsorg 48 had the least (9.25%). The malt quality of the sorghum varieties increased with increase in germination days. Moisture content and protein content of the malts decreased with germination days, with Samsorg 48 having the lowest value (8.4%) and (6.03%) respectively. CWE, HWE and diastatic power, increased as the germination days increased with highest value in SAMSORG 46 (50.60%), Samsorg 49 (284.86%) and Samsorg 48 (14.23oL) respectively. More works need to be done, to completely evaluate their overall suitability, with various enzyme formulations to produce mashes and wort with higher brewing potentials.
Sprouting induces activation and de novo synthesis of hydrolytic enzymes that make nutrients available for plant growth and development. Consumption of sprouted grains is suggested to be beneficial ...for human health. Positive consumer perceptions about sprouted cereals have resulted in new food and beverage product launches. However, because there is no generally accepted definition of “sprouting,” it is unclear when grains are to be called sprouted. Moreover, guidelines about how much sprouted grain material food products should contain to exert health benefits are currently lacking. Accordingly, there is no regulatory base to develop appropriate food labeling for “sprouted foods.” This review describes the nutritional and technological properties of sprouted grains in relation to processing conditions and provides guidelines to optimize sprouting practices in order to maximize nutritive value. Relatively long sprouting times (3 to 5 days) and/or high processing temperatures (25 to 35 °C) are needed to maximize the de novo synthesis and/or release of plant bioactive compounds. Nutrient compositional changes resulting from sprouting are often associated with health benefits. However, supportive data from clinical studies are very scarce, and at present it is impossible to draw any conclusion on health benefits of sprouted cereals. Finally, grains sprouted under the above‐mentioned conditions are generally unfit for use in traditional food processing and it is challenging to use sprouted grains as ingredients without compromising their nutrient content. The present review provides a basis for better defining what “sprouting” is, and to help further research and development efforts in this field as well as future food regulations development.
SCOPE: The gut microbiota is linked with human health, and by manipulating its composition, health conditions might be improved. The aim of this study was to investigate whether two barley products, ...whole‐grain barley and barley malt, caused differentiation of the cecal microbiota in rats fed high‐fat diets and whether there were correlations with the short‐chain fatty acids formed. METHODS AND RESULTS: Male Wistar rats were given barley or malt (7‐8 dietary fiber/100 g) for 4 weeks. Cellulose was used as a control, and the cecal microbiota was analyzed with next‐generation sequencing of 16S rDNA. The barley group had higher abundances of Verrucomicrobia and Actinobacteria and lower abundances of Firmicutes and Deferribacteres than the control group; the alpha diversity was also lower. At the genus level, the barley group had higher abundances of Akkermansia, Ruminococcus, Blautia, and Bilophila. Turicibacter and Roseburia were more abundant in the malt group, and Parabacteroides, Dorea and rc4‐4 were enriched in the control group. Most genera correlated with acetic and propionic acids, but Roseburia and Turicibacter instead correlated with butyric acid. Succinic acid correlated with Clostridium and Akkermansia. CONCLUSION: Bioprocessing is a potential method to modulate the gut microbiota for enhanced effects on human health.
The study assesses impact of malting process duration on malting losses and quality of malts obtained from three varieties of winter wheat, i.e.,
,
and
. The findings show that increased duration of ...the malting process (from 4 to 7 days) corresponded to greater total weight loss, with the most significant differences observed between 5-day and 6-day wheat malts. The qualitative analysis of the malts was carried out in accordance with EBC methodology. The assessments showed that the 5-day long malting process applied to the relevant wheat varieties resulted in production of high-quality malt with optimum malting losses observed in the case of
and
varieties. Slightly higher malting losses were identified in the case of
, and the malt obtained from this variety had very high contents of soluble protein (on average 5.34% d.m.) and Kolbach Index (average of 50.49%), which reflects high proteolytic activity during the grain malting process and a need to modify the malting process for this variety.
Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study ...provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium species on malting and brewing quality of naturally infected samples, selected malting barley cultivars (Optic, Quench and Tipple) were micromalted and subjected to malt and wort analysis of key quality parameters. F. poae and M. nivale decreased germinative energy and increased water sensitivity of barley. The fungal biomass of F. poae and F. langsethiae correlated with increased wort free amino nitrogen and with decreased extract of malt. DNA of M. nivale correlated with increased malt friability as well as decreased wort filtration volume. The findings of this study indicate that the impact of species such as the newly emerging F. langsethiae, as well as F. poae and the two non-toxigenic Microdochium species should be considered when evaluating the quality of malting barley.
•First report of the impact of naturally occurring FHB species on brewing quality•Diverse FHB complex comprised of Fusarium and Microdochium spp. in UK barley•Strong positive correlations found between mycotoxins and relevant producers•Toxigenic Fusarium and non-toxigenic Microdochium reduce yield quality parameters.•Brewing quality significantly impaired by M. nivale, F. poae and F. langsethiae
A metabolite profiling approach based on gas chromatography–mass spectrometry (GC/MS) was used to investigate time-dependent metabolic changes in the course of the malting process of barley. Barley ...grains were subjected to a micro-malting procedure involving steeping, germination and kiln-drying. Samples taken in the course of the malting process were subjected to an extraction and fractionation procedure covering a broad spectrum of lipophilic (e.g. fatty acid methyl esters, hydrocarbons, fatty alcohols, sterols) and hydrophilic (e.g. sugars, acids, amino acids, amines) low molecular weight barley constituents. Investigation of the obtained fractions by GC resulted in the detection of 587 distinct peaks of which 173 were identified by means of MS. Statistical assessment of the data via principal component analysis demonstrated that the metabolic changes during the malting progress are reflected by time-dependent shifts of the scores. Analysis of the corresponding loadings showed that polar metabolites were the major contributors to the malting time-driven changes in the metabolic profiles. Quantifications based on standardised peak heights revealed dynamic changes of the metabolites in the course of the different malting stages.
The present work aimed to study which nutritional advantages can be obtained by malting quinoa grains. For that, three varieties of quinoa: “Negra Collana”, “Passankalla Roja” and “INIA Salcedo” were ...studied. Malting process consisted of hydration (4 h - 25 °C), germination (48 h −25 °C), drying (24 h–55 °C) and deculming (radicle removing) steps. In both, malted and unmalted grains, the following determinations were carried out: total phenolic compounds, flavonoids, antioxidant capacity, ascorbic acid, reducing sugars, protein, total fat and ash content. As main results, malting process significantly affected the nutritional properties, increasing phenolic compounds, flavonoids, antioxidant capacity, ascorbic acid and reducing sugars in all varieties. However, ash, protein and fat content were reduced due to germination metabolism, excepting in Negra Collana variety, whose protein content was increased by malting. In conclusion, only Negra Collana and Pasankalla Roja varieties received advantages from malting: Malted Negra Collana quinoa would contribute with proteins and minerals, while Pasankalla Roja would contribute with ascorbic acid, reducing sugars and bioactive compounds, being useful as ingredients for the formulation of new products.
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•Colored quinoa grains presented higher content of phenolics and flavonoids.•Malting (germination + drying) increases up to 40% antioxidant capacity of quinoa.•Malting increases 49% phenolics and 62% flavonoids of quinoa.•Colored quinoa obtained better nutritional improvements than white quinoa by malting.•Malted quinoa provides reducing sugars, ascorbic acid and bioactive compounds.
Malting quality will be greatly deteriorated when barley plants suffer from post-anthesis drought stress, however there is a marked difference among barley genotypes in the responses of malting ...quality to drought stress, and the molecular mechanisms underlying the genotypic difference remain unclear. We made transcriptome and metabolome analysis on the developing grains of two barley genotypes differing in the responses to drought stress. Post-anthesis drought treatments led to decreased grain weight and β-glucan content, increased grain protein content and β-amylase activity. Drought stress enhanced H2O2 and heat-shock protein accumulation in the two barley genotypes, with the drought-tolerant genotype showing higher capacity of scavenging H2O2 and reducing misfolded protein accumulation than the drought-susceptible genotype. Moreover, the drought-tolerant genotype was more efficient in redistributing assimilates stored in the vegetative tissues into the developing grains. After re-watering to relieve drought stress, the drought-tolerant genotype can further modify auxin transport and ethylene signaling, enhancing redistribution of assimilates into grains. Transcriptome comparisons and weighted correlation network analysis (WGCNA) identified some key genes regulating the responses of malting quality traits to drought stress, such as RLK-LRR, β-glucosidase and HSP . In conclusion, less change of main malting quality traits in the drought-tolerant genotype under post-anthesis drought stress is attributed to its higher capacity of alleviating the stress injury through scavenging ROS and redistributing the metabolites stored in the vegetative organs into the developing grains.
•ROS and flavonoids play key roles in response to drought stress.•HSP affects protein processing and abscisic acid signaling under drought stress.•Drought stress reduces kernel weight and increases protein and beta-glucan content in barley grains.•Higher capacity of scavenging ROS and redistributing the metabolites is favorable forbetter malting quality under drought.
Bound phenolics in foods, a review Acosta-Estrada, Beatriz A.; Gutiérrez-Uribe, Janet A.; Serna-Saldívar, Sergio O.
Food chemistry,
06/2014, Letnik:
152
Journal Article
Recenzirano
•Phenolic in food matrices are in bound as soluble conjugates or insoluble forms.•Processing foods release insoluble bound phenolics into more bioactive moieties.•Quantitative methods must be ...developed that reduce the variation in extractability.
Among phytochemicals, phenolic compounds have been extensively researched due to their diverse health benefits. Phenolic compounds occur mostly as soluble conjugates and insoluble forms, covalently bound to sugar moieties or cell wall structural components. Absorption mechanisms for bound phenolic compounds in the gastrointestinal tract greatly depend on the liberation of sugar moieties. Food processes such as fermentation, malting, thermoplastic extrusion or enzymatic, alkaline and acid hydrolyses occasionally assisted with microwave or ultrasound have potential to release phenolics associated to cell walls. Different kinds of wet chemistry methodologies to release and detect bound phenolic have been developed. These include harsh heat treatments, chemical modifications or biocatalysis. New protocols for processing and determining phenolics in food matrices must be devised in order to release bound phenolics and for quality control in the growing functional food industry.
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