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During beer fermentation, the yeast used itself has the ability to produce the enzyme glucosidase, as one of the fermentation byproducts. The enzyme glucosidase from the glycosidically bound in aromatic compounds in beer can release certain monoterpene alcohols, resulting in a change in beer aroma. The amount of glucosidase enzyme produced in fermentation varies greatly depending on the yeast strain used, different fermentation temperatures and other variable fermentation parameters. We found out, that the addition of ABV Aromazyme increases the glucosidase activity in beer, which can result in an increased efficiency of extraction yield of aromatic compounds from hops into beer. [ABSTRACT FROM AUTHOR]

We used two commercial yeast species, changed the original extract and the amount of inoculum, and choose between two fermentation temperatures. We found that fermentation kinetics were affected by all parameters, with the effect of temperature being the most pronounced. The results showed that temperature, in combination with the yeast strain used, had the greatest effect on attenuation and alcohol content of the beer. We found little effect of the tested factors on FAN and the bitterness of the beer. [ABSTRACT FROM AUTHOR]

The phenolic compounds in beer mostly originate from barley malt, whereas minority is derived from hops. The content of phenolic compounds in the final product depends on the quality and quantity of raw materials and production process. Phenolic compounds have a decisive influence on the physical and sensory stability of beer. At the same time, their sufficient intake, taking into account moderate alcohol consumption, is associated with the prevention of chronic diseases. Researches of recent years are focused mainly on protein - polyphenol interactions, but potential of phenolic compounds as antioxidants shifted interest toward preserving these compounds from the raw materials to the final beer. In general, their content is found to increase significantly during malting and mashing, but decrease markedly during the subsequent fermentation and storage. By selecting the appropriate raw materials and adequate control of technological parameters, the conditions for the release and retention of phenolic antioxidants can be optimized. However, further researches are needed to provide a clear insight into the fate of phenolic compounds during beer production. [ABSTRACT FROM AUTHOR]

Phenolic compounds obtained from Camelina sativa oil were analysed according to their antioxidative properties in bulk lipid system. The extract of phenolic compounds was prepared by use of solvent extraction. The results indicate that camelina oil extract added to model lipid system retarded the process of lipid peroxidation. The extract was able to decrease the formation of primary oxidation products determined as conjugated dienes and peroxide value in lipid system incubated at temperature 65 °C. Additionally, the induction time (IT) of bulk lipid system enriched with extract as determined by Rancimat test was extended by 10%. [ABSTRACT FROM AUTHOR]

The impact of malting on the profile of the phenolic compounds and the antioxidant properties of two buckwheat varieties was investigated. The highest relative increases in phenolic compounds were observed for isoorientin, orientin, and isovitexin, which are consequently major inducible phenolic compounds during malting. Only a minor relative increase was observed for the most abundant phenolic compound, rutin. The radical-scavenging activity of buckwheat seeds was evaluated using ABTS and DPPH assays. A considerable increase in total phenolic compounds and higher antioxidant activity were observed after 64 h of germination, whereas kilning resulted in decreased total phenolic compounds and antioxidant activity. Higher antioxidant activities for extracts were found for buffered solvents than for pure methanol and water. Changes in the composition of the phenolic compounds and increased antioxidant content were confirmed by several methods, indicating that buckwheat malt can be used as a food rich in antioxidants. [ABSTRACT FROM AUTHOR]

Abstract: In this work, quantitative correlations between the antioxidant properties and the total phenolic content (TPC) of different oil cake extracts were studied. The oil cakes from camelina (Camelina sativa), linseed (Linum usitatissimum), rapeseed (Brassica napus), and two varieties of white mustard (Sinapis alba) were analysed as potential sources of antioxidant compounds. Two solvents of different polarity were used to obtain the extracts, resulting in great variation in antioxidant activity. The highest phenolic content was observed for white mustard, followed by camelina, rapeseed and linseed. The antioxidant properties were evaluated by determination of their reducing capacity, free radical scavenging activity and metal chelating ability, by the β-carotene bleaching method and as the effectiveness of inhibition of conjugate diene and triene formation in the bulk oil. The methanolic extracts exhibited higher reducing power (max. rapeseed), 2,2-diphenyl-1-picrylhydrazyl (DPPH·) scavenging activity (max. rapeseed) and chelating ability (max. linseed), while the ethanolic extracts were more efficient in the β-carotene bleaching test (max. camelina). White mustard extracts inhibited conjugate diene and triene formation the most. These various antioxidant activities were compared to the synthetic antioxidant butylated hydroxytoluene (BHT). A lack of positive correlations among the different antioxidant activity assays and total phenolic contents was observed. [Copyright &y& Elsevier]

Abstract: In this study, the antioxidant activities of Camelina sativa methanolic extracts were evaluated by different chemical assays: reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH·) assay, the β-carotene bleaching method and the metal chelating activity assay. An LC–MS profiling method was used for a comprehensive study of the phenolic compounds and their representation in camelina seeds, cake and oil. For this purpose, 4-vinyl derivatives of hydroxycinnamic acids were synthesized by thermal decarboxylation of the corresponding phenolic acids and sinapine was isolated from kale (Brassica oleracea) applying a new method and confirmed by NMR. The results revealed that besides the total phenolic content and antioxidant activity, seeds and cake also possess a similar phenolic profile. In addition to sinapine and 4-vinyl derivatives, other antioxidants were successfully identified: ellagic acid, protocatechuic acid, p-hydroxybenzoic acid, sinapic acid, salicylic acid, catechin, rutin, quercetin and quercetin glucoside. Since after oil pressing most of the phenolic compounds remain in the seed residues, only a few compounds were identified in the oil. Camelina cake was found to have the best reducing power and radical scavenging activity, whereas camelina oil, with a relatively low phenolic content, exhibited the highest iron-chelating capacity and the best inhibitory action against β-carotene discolouration in an emulsified system. [Copyright &y& Elsevier]

Abstract: The compounds 4-vinylphenol (4-VP), 4-vinylguaiacol (4-VG), 4-vinylsyringol (4-VS) and 4-vinylcatechol (4-VC) were prepared by thermal decarboxylation of the corresponding hydroxycinnamic acids p-coumaric, ferulic, sinapic and caffeic acid, respectively. For confirmation of the synthesised products LC–MS followed by NMR analysis was used. To evaluate their antioxidant potential, their reducing power and efficiency in scavenging the alkylperoxyl radical generated in an emulsion system, the 2,2-diphenyl-1-picrylhydrazyl (DPPH ) radical and the superoxide anion radical () were determined. All tested 4-vinyl derivatives revealed weaker antioxidant activity in a homogeneous polar medium than the corresponding phenolic acids. In the emulsion system the activity for 4-vinyl derivatives was higher than was the activity of their corresponding phenolic acids, with 4-VG as the most active among the tested phenolic compounds. [Copyright &y& Elsevier]

Abstract: A kinetic approach was used to evaluate the efficiency of eight phenolic acids (chlorogenic, protocatechuic, caffeic, p-coumaric, sinapic, umbellic, rosmarinic and ferulic) in scavenging the alkylperoxyl radical generated in the β-carotene–linoleic acid emulsion system, the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH ) and the superoxide anion radical (). The efficiency of the phenolic acids was estimated at the initial stage (t =10s) and expressed as the rate of DPPH radical scavenging (R S DPPH ), the rate of radical scavenging (R FF) and the rate of β-carotene bleaching (R B). The R S DPPH value for caffeic acid, followed by sinapic acid, showed the highest response in scavenging DPPH radicals. According to its R FF value rosmarinic acid in comparison to the other investigated phenolic acids exhibited the highest response in radical scavenging. Among the investigated phenolic acids, ferulic acid exhibited the lowest R B value indicating the strongest response in alkylperoxyl radical scavenging in the β-carotene–linoleic acid emulsion system, while in the presence of chlorogenic acid β-carotene bleached most rapidly. The effectiveness of the phenolic acids in scavenging free radicals was also determined at a fixed endpoint. The results for the antioxidant activity coefficient in the β-carotene–linoleic acid emulsion system showed good agreement with those obtained from the kinetic data. While the results for DPPH and scavenging obtained from the kinetic approach did not necessarily reflect the amounts of these free radicals that were scavenged at the end of the observation period and indicate that the kinetic data are a better discriminator for comprehensive characterisation of an antioxidant. [Copyright &y& Elsevier]

Abstract: The antioxidant properties of phenolic diterpenes in several rosemary (Rosmarinus officinalis) extract formulations were investigated. Carnosic acid, carnosol and methyl carnosate were identified and quantified by high-performance liquid chromatography (HPLC) and carnosic acid was found to be the most abundant phenolic compound in the rosemary extracts investigated. To describe the antioxidant properties the free radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH ) test and the antioxidant activity coefficient in the β-carotene–linoleic acid emulsion system, C AA, were assayed. In both assays, extracts with higher total phenolic contents were superior in antioxidant activity. To interpret the antioxidant properties the kinetic approach was used. A power function was found to best represent the time dependence of the content of free radicals scavenged, as well as the content of β-carotene bleached in the presence of rosemary extracts. The rate of free radical scavenging, RS , and the rate of β-carotene bleaching, RB , were estimated and suggested as new parameters to describe the antioxidant activity of rosemary extracts. The kinetic data were interpreted in terms of differences in the reactivity of antioxidant compounds. [Copyright &y& Elsevier]

This research aimed to study the dynamic changes in phenolic antioxidants between the germ and the rest of the germinated seed of wheat and spelt and to evaluate the whole grain flour from germinated seeds as a functional supplement. Longer germination resulted in higher TPC, DPPH, and ABTS values when considering the entire germinated seed, while the optimal germination time was not consistent when considering the germ and the remaining germinated seed separately. While in the germinated seed (without germ) the majority of TPC was determined to be bound phenolics (up to 92%), the extractable form dominated in the germ (up to 69%). The most abundant phenolic antioxidants in germinated wheat and spelt seeds, trans-ferulic acid, cis-ferulic acid, and p-coumaric acid, increased significantly with germination. Only breads with 5% germinated spelt or wheat flour were suitable for the production of a food product, showing higher extractable TPC, antioxidant activity, individual phenolic acids, and improved specific volume, and were preferred because of their appearance, aroma, and color. The PCA biplot showed that the addition of 15% and 30% germinated flours had the greatest positive impact on phenolic properties, while breads with the addition of 5% germinated flour had the greatest positive impact on specific volume and color. [ABSTRACT FROM AUTHOR]

In the present study, the partial substitution of common white wheat flour for a bread recipe with variously bioprocessed wholegrain spelt was investigated. The addition of 1% and pasteurised 5% "germinated + enzymatic treated" spelt flour to wheat flour significantly improved the specific volume of the bread, but their texture profile analysis and sensory evaluation were not satisfactory. A higher percentage of added bioprocessed spelt flour darkened the colour of the bread. Breads with the addition of more than 5% of bioprocessed spelt flour were unacceptable in terms of quality and sensory parameters. The highest extractable and bound individual phenolics were found in breads with 5% "germinated + fermented" spelt flour (GFB5) and 5% pasteurised "germinated + enzymatic treated" spelt flour (GEB5P). A strong positive correlation was determined between trans-ferulic acid and TPC and DPPH• radical scavenging activity. The GEB5P bread showed the highest increase in extractable and bound trans-ferulic acid content, by 320% and 137%, respectively, compared to the control bread. Principal component analysis showed differences between the control bread and enriched breads in terms of their quality, sensory and nutritional properties. Breads with 2.5% and 5% "germinated + fermented" spelt flour had the most acceptable rheological, technological and sensory characteristics, in addition to a substantial improvement in their antioxidant content. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different fermentation types increased the extractable:bound phenolics ratio of bioprocessed spelt. • Extractable trans -ferulic acid increased the most in yeast-fermented germinated seeds (2922%). • Bound cis -ferulic acid increased the most in yeast-fermented raw spelt seeds (466%). • Spontaneous fermentation of germinated and enzymatic-treated seeds decreased intracellular oxidation the most. • Extractable hydroxycinnamic acids were more efficient in-vivo antioxidants than the bound form. Lactic acid, alcoholic, combined and spontaneous fermentation of raw, germinated and enzymatic-treated spelt seeds significantly improved the content of extractable and bound phenolics and considerably increased the extractable:bound ratio, and therefore positively affected the accessibility of the spelt antioxidants. The highest extractable and bound individual phenolic contents and in vitro antioxidant activities of extracts were obtained following fermentation of germinated spelt seeds with Saccharomyces cerevisiae , while for enzymatic-treated seeds, Lactobacillus plantarum (alone or with S. cerevisiae) was the most effective. For extractable phenolics, trans -ferulic acid increased the most in yeast-fermented germinated seeds (2922%); for bound phenolics, cis -ferulic acid showed the greatest relative increase in yeast-fermented raw spelt seeds (466%). Spontaneous fermentation of germinated and enzymatic-treated samples decreased intracellular oxidation most effectively, probably due to apigenin derivatives. Cellular uptake of bound hydroxycinnamic acids was significantly higher than that of extractable hydroxycinnamic acids; however, the latter were more efficient in vivo antioxidants. [ABSTRACT FROM AUTHOR]

Our study aimed to investigate the effect of cellulase, xylanase, esterase, α-amylase and protease on the enhanced release of phenolics from spelt seeds, and to demonstrate the co-effect of enzymatic treatment, germination or fermentation on the spelt phenolics content and their in vitro and cellular antioxidant activities. Bound phenolics of spelt seeds were successfully released by different combinations of cellulase, xylanase, feruloyl esterase, α-amylase and protease. Samples treated with all five enzymes together showed significantly improved extractable p -coumaric, ferulic and p -hydroxybenzoic acid contents, particularly efficient antioxidant activity in ABTS•+ scavenging activity and the highest extractable TPCs. By combining enzymatic treatment with germination and fermentation, extractable TPCs were increased by 28% and 458%, respectively. A combination of enzymatic treatment with germination and fermentation led to enormously increased extractable trans -ferulic acid content (5899% and 8263%, respectively). The bound fraction of enzymatic treated raw seeds showed lower decrease in intracellular oxidation than the corresponding extractable fraction, but a 24-fold higher uptake of hydroxycinnamic acids. Principal component analysis showed some similarities between extractable and bound fractions of enzymatic treated raw, germinated and fermented samples, mainly due to the increase in extractable acids content (biochemical parameters), especially cis -ferulic, caffeic and p -hydroxybenzoic acids. [Display omitted] • Enzymatic treatments significantly improves the extractable TPCs and antioxidant activity of raw seeds. • Extractable trans -ferulic acid content increased the most in enzymatic treated germinated or fermented seeds. • Combined biotechnological processes release bound phenolics more efficiently than single ones. • Extractable fractions of enzymatic treated raw, germinated and fermented seeds expressed cellular antioxidant activity. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present study was to determine polyphenolic composition, related antioxidative and antimicrobial properties of grape skin extracts from 14 grape varieties (seven white and seven red grape) grown in Dalmatia (Croatia). The content of total phenols, flavonoids, catechins, flavanols and individual polyphenols ((+)-catechin, (−)-epicatechin, epicatechin gallate, procyanidin B1 and procyanidin B2, quercetin glucoside, resveratrol monomers, piceid and astringin) was variety dependent. Antioxidant properties were determined as DPPH radical-scavenging ability (IC 50), ferric reducing/antioxidant power (FRAP), Fe2+-chelating activity (IC 50), and using β-carotene bleaching assay. The high antioxidant capacity of all extracts, both red and white, has been observed and related to the relative amounts of polyphenolic compounds with good antioxidant properties. The antimicrobial activity was screened by broth microdilution test using Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative bacteria (Escherichia coli O157:H7, Salmonella Infantis, Campylobacter coli). It was confirmed against all tested organisms. Minimum inhibitory concentrations (MICs), were found in the range 0.014–0.59mg of gallic acid equivalents (GAE)/ml, with lower MICs of white cultivars, especially against Campylobacter and Salmonella. [Copyright &y& Elsevier]

• Combined stress of 25 mM NaCl and 50 mM sorbitol promoted the accumulation of phenolics. • Mechanical stress increased ROO and decreased DPPH, ABTS + and O 2 − scavenging activities of bound antioxidants. • Ferulic, p -coumaric, caffeic and p -hydroxybenzoic acids prevailed among bound antioxidants. • Despite considerable lower content, extractable antioxidants were quite more heterogeneous. • Yeast cells exposed to germinated seed extracts showed no effects on intracellular oxidation. The aim of this study was to investigate the effects of germination of spelt seeds under different stress conditions on the antioxidant characteristics of their extractable and bound phenolics. Germination under combined stress of 25 mM NaCl and 50 mM sorbitol without subsequent mechanical stress had considerable impact on total phenolics contents and scavenging activities against different free radicals (DPPH, ABTS +, O 2 −, ROO). Alkaline hydrolysis of extracts from germinated seeds provided the majority of their phenolic acids, where ferulic and p- coumaric acids were the most representative. The phenolics liberated from their bound form also had greater antioxidant activities. For the extractable phenolics, p -coumaric hexoside increased the most (146%), while among the bound phenolics identified, the highest relative increase was for p -coumaric acid (171%). The germinated seeds showed no effects on intracellular oxidation in cells of the yeast Saccharomyces cerevisiae. [ABSTRACT FROM AUTHOR]