Evidence of Enzymatic and Chemical Interconversions of Barley Malt 3-Sulfanylhexanol Conjugates during Mashing.

Recent studies have highlighted in malt the occurrence of the glutathionylated precursor of 3-sulfanylhexanol (G-3SHol) at concentrations reaching hundreds of µg/kg. Here, SIDA-LC-MS/MS was used to investigate the potential conversion of G-3SHol to its dipeptide and cysteinyl analogues during mashing. At 45 and 55 °C, malt γGT and carboxypeptidase activities quickly degrade G-3SHol (up to 90% loss), first to the cysteinylglycine conjugate and then to the cysteine conjugate (up to 205% increase). No γ-glutamylcysteine S-conjugate formation is observed. At 80 °C, despite enzyme inactivation, the G-3SHol level decreases steadily because of suspected imine formation with wort aldehydes at pH 5.5. More surprisingly, CysGly-3SHol is still generated at 80 °C. This indicates the presence in the wort of as yet unidentified precursors.

Effects of laccase and cellulase on saccharification of barley malt.

Improving saccharification of barley malt is beneficial to promoting economic benefits of beer brewers, but there are few detailed reports on the application of cellulase and laccase in barley malt. So, barley malt was pretreated by cellulase and laccase, and the malt wort and brewer's spent grains were analyzed by HPLC, FTIR and SEM in this study. The concentration of malt wort was increased significantly to 8.1 (° Bx), which increased by 28.6% after barley malt was pretreated by cellulase, but laccase could not improve saccharification of barley malt. Through analysis of sugar in malt wort and cellulose and lignin components as well as physical and chemical structures of brewer's spent grains, the increase in sugar content in malt wort was mainly due to the increase in glucose because of hydrolysis of cellulose in barley malt by cellulase. Furtherly, laccase and cellulase should have a mutual inhibition when they are pretreated simultaneously.

A kinetic study on the thermal inactivation of barley malt α-amylase and ß-amylase during the mashing process.

To obtain an efficient conversion of starch into fermentable sugars and dextrins during the brewing process, mashing time-temperature profiles need to promote starch gelatinisation and enzyme activity while avoiding thermal inactivation of the amylases. This study focused on the second part of this balance by investigating the thermal stability of α-amylase and ß-amylase of Planet barley malt throughout mashing. Thermal inactivation in wort was modelled for both enzymes resulting in the estimation of thermal inactivation kinetic parameters such as rate constant of thermal inactivation kT (the rate of thermal inactivation of an enzyme at a constant temperature), activation energy for thermal inactivation Ea, decimal reduction time DT (the time needed to inactivate 90% of the enzyme activity at a given temperature) and the z-value. First-order inactivation was observed for α-amylase. For ß-amylase, fractional conversion inactivation occurred with a residual fraction of 13% of the ß-amylase activity that remained after prolonged heating at 72.5 °C. The ß-amylase protein population hence seems to consist of thermolabile and thermostable isoforms. The kinetic parameters for thermal inactivation of the enzymes were used to predict their residual activities throughout a laboratory-scale mashing process. The predicted residual activities met the experimentally determined residual enzyme activities closely, except for ß-amylase at temperatures higher than 72.5 °C. The results obtained in this work allow designing new mashing processes or tailoring existing processes towards variability in the input material, barley malt, without the need for trial-and-error experiments.

Fermentation process optimization, chemical analysis, and storage stability evaluation of a probiotic barley malt kvass.

Kvass is a popular low-alcohol beverage produced by the natural fermentation of dark rye bread or malt with complex microbial flora. However, few pieces of research focus on the microflora of traditional bread kvass, and the industrial kvass based on malt concentrate has some disadvantages, including the lack of viable probiotics and containing multiple artificial additives. Therefore, in the present study, based on the different homemade traditional bread kvass, the predominant species including Lacticaseibacillus paracasei, Acetobacter pasteurianus, and Saccharomyces cerevisiae were screened and identified. In addition, barley malt was used instead of bread for kvass production, and the co-fermentation conditions with three different strains were optimized as wort concentration of 7.4°Brix, cell ratio of 2/2/1 (S. cerevisiae/L. paracasei/A. pasteurianus), inoculum amount of 8%, fermentation temperature of 29.5 °C and fermentation time of 24.6 h. Moreover, the physicochemical (pH, total soluble solids, color, and alcohol content) and probiotic (microorganisms counting and antioxidant activity) properties of the barley malt kvass prepared at optimal conditions were symmetrically evaluated. Besides, compared with the commercial kvass products, the produced barley malt kvass exhibited better taste and more desirable antioxidant activity, and also maintained around 6-7 log CFU/mL of viable probiotic microorganisms during a week of storage. The present study not only enriched the biological resource of the traditional kvass, but also promoted the development of the kvass as a live-bacteria beverage.

Development and Box-Behnken design optimization of a green extraction method natural deep eutectic solvent-based for phenolic compounds from barley malt rootlets.

In recent years, attention has been turned finding new sources of phenolic compounds, antioxidant molecules, main by-products from the agri-food chain like barley malt rootlets (BMRs). Traditionally, phenolic compounds are extracted from food matrices using different procedures, for example, solid-liquid, liquid-liquid, or solid-phase extraction techniques employing organic solvents. With the advent of green chemistry, attention has been paid to the search for green, nontoxic, inexpensive, and nonflammable solvents and the natural deep eutectic solvents (NADESs) respect these characteristics. The aim of this project was to develop and optimize an environmentally friendly, inexpensive, and rapid extraction method for phenolic compounds from BMRs using natural DESs as extractive solvents. Several natural DESs were tested as extractive solvents and, among them, the best results in terms of total phenolic content were obtained using a choline chloride-malic acid (1:2 molar ratio)-based mixture. Box-Behnken experimental design guaranteed the extraction of 9.51 ± 0.83 gallic acid equivalent/g of BMRs, under the following optimal extraction conditions: 1:21 solid-to-liquid ratio, 80°C as extraction temperature, 43 min as the time of extraction, and 29% as a percentage of added water in the NADESs. Phenolic acids and flavonoids were detected in the BMRs extract through HPLC-PDA/MS analysis.

Comparison of structural and functional properties of maize starch produced with commercial or endogenous enzymes.

To explore an effective and economic method to prepare higher contents of resistant starch (RS), different enzyme treatments including single pullulanase (PUL), commercial α-amylase (AA) or/and ß-amylase (BA) with PUL, and malt endogenous amylase (MA) with PUL were used and the structural, physicochemical properties and digestibility of all modified starches (MS) were compared. All the enzyme-treated starches displayed a mixture of B and V-type diffraction patterns. The MA/PUL-MS showed higher V-type diffraction peak intensity as compared to other modified starches. Compared to the combination of commercial enzyme treatment, the combination of malt enzyme treatment led to higher apparent amylose contents (45.56%), RS content (53.93%) and thermal stability (302 °C), whereas it possessed lower solubility indices and predicted glycaemic index. The apparent viscosity and shear resistance of MA/PUL-MS were lower than that of AA/PUL-MS, whereas that of MA/PUL-MS was higher than that of BA/PUL-MS and BA/AA/PUL-MS. These findings would provide a theoretical and applicative basis to produce foods with lower GI in industrial production.

Bioactives of Pomegranate By-Products and Barley Malt Grass Engage in Cereal Composite Bar to Achieve Antimycotic and Anti-Aflatoxigenic Attributes.

Food is the source from where a person obtains the body's daily requirements. People's current daily habits force them to consume fast food, which is known for its poor nutritional and safety features. So, it is urgent to provide a suitable substitution product to solve this issue. The present investigation aimed to produce a bar with a dual function: nutritional and long shelf life. Two materials were chosen to support the bar manufacturing regarding their bioactive contents, barley malt grass (BMG) and pomegranate byproducts (PBD). Chemical composition, antioxidant, and antimicrobial potency were measured. Β-carotene, vitamin C, and tocopherol were determined using HPLC apparatus. Extracts' bio-safety against cell lines was determined, besides their enhancement against cell-death factors. Simulation experiments were designed to evaluate extracts' impact to extend bar shelf life. Data represented the richness of essential minerals and fibers. Results of the FTIR reflected the existence of various active groups in the contents. Phenolic fractions of PBD are distinctive for their content of ellagic (39.21 ± 5.42 mg/kg), ferulic acid fractions (31.28 ± 4.07 mg/kg) which is a known with antifungal activity. Extracts and their mix (1:1) represented inhibition zone diameters that reach 15.1 ± 1.66 mm for bacteria and 23.81 ± 1.41 mm for fungi. Extracts were shown to have better safety against the cell line strain of hepatic HL-7702, with an elevation of a harmful dose of aflatoxin (IC50 304.5 µg/mL for PBD, IC50 381 µg/mL for BMG). Sensory evaluation of fortified bars reflected a preferable application of mix (1:1) due to color attributes and panelist evaluations, the same result recorded for simulation studies. The experiment recommended applying a mix (1:1) of BMG: PBD in addition to their extracts (200 mg/kg dough) for functional bar manufacturing with antifungal properties.

Corn starch modification during endogenous malt amylases: The impact of synergistic hydrolysis time of α-amylase and ß-amylase and limit dextrinase.

To expand the utility of barley malts and decrease the cost of enzyme-modified starch production, the structural and physicochemical characteristics of corn starch modified with fresh barley malts at different hydrolysis time were investigated. The results indicated that compared to native starch, A chain (DP 6-12) of the enzyme-treated starches increased at hydrolysis time (≤12 h), but it decreased at hydrolysis time (>12 h). Inversely, B chains (DP > 13) decreased at hydrolysis time (≤12 h) and they generally increased at hydrolysis time (>12 h). The relative crystallinity decreased from 25.63% to 21.38% and 1047 cm-1/1022 cm-1 reduced from 1.042 to 0.942 after endogenous malt amylases at hydrolysis time from 0 to 72 h, and the thermal degradation temperatures decreased from 323.19 to 295.94 °C, whereas the gelatinization temperatures slightly increased. The gel strength decreased at hydrolysis time less than 12 h, but it increased at hydrolysis time more than 12 h. The outcomings would provide a theoretical and applicative basis about how endogenous malt amylases with lower price modify starches to obtain desirable starch derivatives and industrial production.

Molecular Insights into the Contribution of Specialty Barley Malts to the Aroma of Bottom-Fermented Lager Beers.

Specialty barley malts provide unique aroma characteristics to beer; however, the transfer of specialty malt odorants to beer has not yet been systematically studied. Therefore, three beers were brewed: (1) exclusively with kilned base barley malt, (2) with the addition of a caramel barley malt, and (3) with the addition of a roasted barley malt. Major odorants in the beers were identified by aroma extract dilution analysis followed by quantitation and calculation of odor activity values (OAVs). The caramel malt beer was characterized by outstandingly high OAVs for odorants such as (E)-ß-damascenone, 2-acetyl-1-pyrroline, methionol, 2-ethyl-3,5-dimethylpyrazine, and 4-hydroxy-2,5-dimethylfuran-3(2H)-one, whereas the highest OAV for 2-methoxyphenol was obtained in the roasted malt beer. Quantifying odorants in the malts revealed that the direct transfer from malt to beer played only a minor role in the amount of malt odorants in the beers, suggesting a substantial formation from precursors and/or a release of encapsulated odorants during brewing.

Use of D-optimal combined design methodology to describe the effect of extraction parameters on the production of quinoa-barley malt extract by superheated water extraction.

Superheated water extraction was applied to produce quinoa-barley malt extract. D-optimal combined design was used to optimize the extraction conditions (time (min), solid-water ratio and particle size to obtain maximum protein and carbohydrate content, and minimum turbidity and pH. Quinoa flour (10%-30%), barley malt flour (70%-90%), different particle sizes (F = 420 µm, G = 710 µm), time (15-45 min), and solid-water ratio (0.1-0.2) were selected as independent variable and protein, carbohydrate, turbidity, and pH as dependent factors. Polynomials models satisfactorily fitted the experimental data with the R 2 values of .9961, .9909, .9949, and .9987, respectively. The protein and carbohydrate value was affected by superheated water extraction parameters. Our results revealed that increasing quinoa/barley malt ratio has significant effect on the turbidity and pH. The optimum extraction conditions were quinoa flour (30%), barley malt flour (70%), solid-water ratio (0.2), time (45 min), and particle size (F = 420 µm).

Barley malt-based composition as a galactagogue - a randomized, controlled trial in preterm mothers.

OBJECTIVES: Delayed or insufficient breast milk production, as well as low milk supply, is still a challenging problem to overcome, particularly in the case of preterm delivery. Herbal galactagogues might be a good way to increase milk supply, however, there is a lack of clinical studies confirming their efficacy and safety. The aim of this study was to verify the safety and effectiveness as a galactagogue of the unique galactagogue composition based on barley malt with ß -glucan and lemon balm. MATERIAL AND METHODS: The study included 117 mothers of preterm infants randomly divided into the Galactagogue Group given galactagogue and the Placebo Group. A complete data set was obtained for 80 participants, divided equally between two groups. Volume of milk expressed by mothers during the first two weeks after delivery was the primary outcome and safety of the product was the secondary outcome. RESULTS: Volume of milk recorded on participants' last visit in the Galactagogue Group was significantly higher than in the Placebo Group (95 mL vs 62.5 mL, p = 0.049). The total expressed milk volume during the study was 4209 ± 335 mL in the Placebo Group vs 6036 ± 498 mL (p = 0.003) in the Galactagogue Group. CONCLUSIONS: Supplementation with unique Galactagogue composition was safe and increased milk output which allowed achieving target minimal volume of 500 mL per day in first week of lactation in preterm mothers.

Starch hydrolysis during mashing: A study of the activity and thermal inactivation kinetics of barley malt α-amylase and ß-amylase.

Hydrolysis of starch is key in several industrial processes, including brewing. Here, the activity and inactivation kinetics of amylases throughout barley malt mashing are investigated, as a prerequisite for rational optimisation of this process. Varietal differences were observed in the activity of α- and ß-amylases as a function of temperature for six barley and malt varieties. These differences were not reflected in the resulting wort composition after mashing, using three isothermal phases of 30 min at 45 °C, 62 °C and 72 °C with intermediate heating by 1 °C/min. Thermal inactivation kinetics parameters determined for α- and ß-amylases of an industrially relevant malt variety in a diluted system showed that enzymes were inactivated at lower temperatures than expected. The obtained kinetic parameters could predict α-amylase, but not ß-amylase inactivation in real mashing conditions, suggesting that ß-amylase stability is enhanced during mashing by components present or formed in the mash.

Red rice conjugated with barley and rhododendron extracts for new variant of beer.

This study aimed to determine the effect and potential of red rice in conjunction with barley and rhododendron extracts to develop a new variant of beer. In this study red rice, barley, and rhododendron extracts were used in different combinations and the best combination was selected based on quality and sensory characteristics. The results showed that the developed beer was rich in antioxidant activity (47.68 ± 0.96) and contained a good amount of anthocyanin (35.12 ± 0.79), flavonoids (0.119 ± 0.002), and polyphenols (0.410 ± 0.002). The red rice has more dietary significance than that of polished or milled rice, further, the use of rhododendron provides a large number of secondary metabolites such as tannins, saponins, alkaloids, tannins, and flavonoids. Besides, the sensory profile of the developed beer was quite distinct in terms of aroma, taste, and color from other alternatives available in the market.

Non-Starch Polysaccharides in Wheat Beers and Barley Malt beers: A Comparative Study.

Non-starch polysaccharides (NSPs) in beers attract extensive attention due to their health benefits. The aim of this work was to investigate and compare NSPs including arabinoxylan, arabinogalactan, ß-glucans, and mannose polymers in wheat and barley malt beers as well as the influence on its quality. NSPs in wheat beers (1953-2923 mg/L) were higher than that in barley malt beers (1442-1756 mg/L). Arabinoxylan was the most abundant followed by arabinogalactan. In contrast to barley malt beers, wheat beers contained more mannose polymers (130-182 mg/L) than ß-glucan (26-99 mg/L), indicating that more arabinoxylan, arabinogalactan, and mannose polymers came from wheat malt. The substitution degree of arabinoxylan in wheat beers (0.57-0.66) was lower than that in barley malt beers (0.68-0.72), while the degree of polymerization (38-83) was higher (p < 0.05) than that in barley malt beers (38-48), indicating different structures of arabinoxylan derived from barley malt and wheat malt. NSPs, especially arabinoxylan content, positively correlated (p < 0.01) with real extract and viscosity of beers. Furthermore, wheat and barley malt beers were well separated in groups by principal component analysis.

Accurate quantification of small and large starch granules in barley and malt.

The proportion of small and large starch granules in barley and malt is often neglected, leading to underestimation of their importance in processes in which they are used. This study aimed to accurately determine the volume and number based percentages of small and large starch granules for three barley varieties, their micro-malted malts and three commercial malts. Quantitative starch isolation was performed and starch granule proportions were estimated using microscopic and image analysis, taking the non-sphericity of the large starch granules into account. Results show that barley starch consists of 32-39 volume% of small starch granules. Upon malting, this percentage is reduced to 17-27 volume%, showing that small granules are hydrolyzed faster than large granules during this process. The analyzed commercial malt samples have a small starch granule content of 22-25 volume%. Malt hence still contains a substantial amount of small starch granules, which can be expected to impact processing.

Characterization of a putative glycoside hydrolase family 43 arabinofuranosidase from Aspergillus niger and its potential use in beer production.

During the mashing process for brewing beer, incomplete degradation of arabinoxylan in barley malt may cause an intense filterability problem. The present study cloned a putative arabinofuranosidase (AnAbf), one of the debranching enzymes, from Aspergillus niger, to explore its application for improving filterability. Recombinant AnAbf (rAnAbf) showed activity towards both synthetic and natural substrates, such as 4-nitrophenyl α-l-arabinofuranoside (pNPαAraf) and malt water extractable arabinoxylan (WEAX), which was maximized at a temperature of 50 °C and pH of 5.5. Metal ions did not increase the activity of rAnAbf, indicating a difference in its C-terminal domain from that of type II GH43 family members. rAnAbf also exhibited a synergistic effect with ß-xylanase against WEAX. The filtration rate of the wort increased by 12.8% after supplementing with rAnAbf during the initial stage of mashing. A slight decrease in viscosity and an unexpected increase in turbidity were observed.

Effects of lactagogue of four total alkaloids of barley malt via dopamine D2 receptor in postpartum hypogalactia rat / 中草药

Objective: To explore the regulatory effect of malt alkaloid on prolactin (PRL) secretion in the model rat with postpartum hypogalactia induced by bromocriptine based on dopamine D2 receptor, and determine the active fraction of the malt with galactogogue effect. Methods: The postpartum hypogalactia model was established by intragastric administration of bromocriptine mesylate. After the model was successfully established, all groups were given corresponding drug treatment. The concentration of serum PRL, estradiol (E2) and progesterone (P) in each group was detected by ELISA kits. HE staining was used to observe the pathologic changes of breast tissue. RT-PCR was used to determine the mRNA levels of prolactin receptor (PRLR) and dopamine D2 receptor (DRD2) in pituitary gland of rats. Results: Compared with the control group, the levels of serum PRL, P, and E2 were significantly decreased in the model group as well as the mRNA expression of the pituitary PRL cells. But the mRNA expression of the pituitary DRD2 in the model group was significantly increased compared with the control group. Compared with the model group, the malt total alkaloid significantly increased the volume of mammary lobule and dilated the duct. There was a lot of milk in the duct and acinar in the malt total alkaloid group. Besides, the total alkaloids increased the concentration of serum PRL, P, and E2 and the mRNA expression of the pituitary PRL cells, and decreased the mRNA expression of the pituitary DRD2. Conclusion: The primary the active fraction of malt for galactogogue action is total alkaloids, and its mechanism may be related to promoting PRL secretion, increasing serum PRL receptor level and decreasing the mRNA expression of dopamine D2 receptor.

The Influence of Steeping Water Change during Malting on the Multi-Toxin Content in Malt.

The aim of this study was to assess the impact of steeping water change and Fusarium graminearum contamination level on different multi-toxin types and concentrations in barley malt. Malt samples were subjected to two micromalting regimes-steeping water change and the other with no steeping water change. Malt was contaminated with different F. graminearum contamination levels (0%, 10%, and 20%). The results indicate that malt with higher F. graminearum contamination levels ensured higher concentrations of toxins. Higher fungal metabolite concentrations were determined in samples exposed to freshly-changed steeping water, especially zearalenone and its derivates whose values were three to four times higher than in samples with no water change. Zearalenone-4-sulfate showed four (in 10% contamination) and even thirty times (in 20% contamination) higher concentrations than in samples with no water change. Water change during malting resulted in higher levels of multi-toxins in the final product.

Potential of UV and SWIR hyperspectral imaging for determination of levels of phenolic flavour compounds in peated barley malt.

In this study, ultra-violet (UV) and short-wave infra-red (SWIR) hyperspectral imaging (HSI) was used to measure the concentration of phenolic flavour compounds on malted barley that are responsible for smoky aroma of Scotch whisky. UV-HSI is a relatively unexplored technique that has the potential to detect specific absorptions of phenols. SWIR-HSI has proven to detect phenols in previous applications. Support Vector Machine Classification and Regression was applied to classify malts with ten different concentration levels of the compounds of interest, and to estimate the concentration respectively. Results reveal that UV-HSI is at its current development stage unsuitable for this task whereas SWIR-HSI is able to produce robust results with a classification accuracy of 99.8% and a squared correlation coefficient of 0.98 with a Root Mean Squared Error of 0.32 ppm for regression. The results indicate that with further testing and development, HSI may potentially be exploited in an industrial production environment.

Barley Products of Different Fiber Composition Selectively Change Microbiota Composition in Rats.

SCOPE: Several dietary fiber properties are suggested to be important for the profiling of the microbiota composition, but those characteristics are rather unclear. Whether different physico-chemical properties of barley dietary fiber influence the gut microbiota composition is investigated. METHODS AND RESULTS: Seven diets containing equal amounts of dietary fiber from barley malts, brewer's spent grain (BSG), and barley extracts, resulting in varying amounts of ß-glucan, soluble arabinoxylan, and insoluble arabinoxylan in the diets were given to conventional rats. Malts increased microbiota alpha diversity more than BSG and the extracts. The intake of soluble arabinoxylan was related to Akkermansia and propionic acid formation in the cecum of rats, whereas ß-glucan and/or insoluble arabinoxylan were attributed to some potentially butyrate-producing bacteria (e.g., Lactobacillus, Blautia, and Allobaculum). CONCLUSION: This study demonstrates that there is a potential to stimulate butyrate- and propionate-producing bacteria in the cecum of rats with malt products of specific fiber properties. Moreover, BSG, a by product from beer production, added to malt can possibly be used to further modulate the microbiota composition, toward a higher butyric acid formation. A complex mixture of fiber as in the malts is of greater importance for microbiota diversity than purer fiber extracts.