Composite malt with dark-purple rice malt improves the phenolic profile and antioxidant activity of malt extract

This research presents a modification of bioactive compounds of malt extract produced from Riceberry rice malt (RRM)–barley malt composite for malt-based beverage. Malt extract was produced by varying RRM at 20% w/w, 40% w/w, 60% w/w, 80% w/w, and 100% w/w and were analysed for total polyphenol content (TPC), phenolic acids constituent, and antioxidant activity. The 100% RRM extract was rich in TPC relative to 100% w/w barley malt extract. The composite malt extract containing 40% w/w–80% w/w RRM had enough TPC in the filtered malt extract (236–524 mg L⁻¹) and boiled hopped malt extract (216–485 mg L⁻¹) and were directly proportional to the antioxidant activity in the extract. Barley malt fraction in the malt extracts had a positive response on ferulic acid and sinapic acid, whereas RRM inclusion in malt extract increased p-coumaric acid, vanillic acid, rutin, and methyl coumarate concentration. Therefore, the cereal malt composite could provide strong oxidative stability to the malt extract and derived products.     

麦芽提取物在发酵饮料中的应用

麦芽提取物是一种完全源自谷物的天然食品,它含有丰富的麦芽糖、果糖、葡萄糖、蛋白质、小分子肽、人体必须的氨基酸和多种维生素、矿物质,还含有具有保健功能的β-葡聚糖和生育酚。用麦芽提取物生产的麦芽汁发酵饮料营养丰富,风味浓郁、独特、醇厚。与传统麦芽汁发酵饮料生产工艺相比,生产过程不需要糖化,从而使得工艺更为简单,生产周期更短,设备投入减少,降低了成本。     

以未发芽大麦替代麦芽酿造啤酒及其麦香改善研究

本文研究了利用酶制剂Ondea Pro进行大麦啤酒的生产,对其麦汁糖谱、氨基酸谱、蛋白质区分、α-氨基氮和大麦啤酒理化成分及风味物质等指标进行了检测,特别是对麦香物质呋喃酮、2-乙酰吡咯、2-乙酰-1-吡咯啉、麦芽酚、2-甲基吡嗪、乙基吡嗪、乙酰呋喃和甲基糠醛等化合物进行了分析,并邀请专业品酒委员进行了感官品评。研究结果发现,利用Ondea Pro酶生产的麦汁,能够满足酵母发酵需求,然而大麦啤酒存在明显的麦香缺陷。通过额外添加不同比例的焦香麦芽,分析大麦啤酒中主要麦香物质的变化规律,结合感官品评,结果表明添加1%的焦香麦芽酿造而成的大麦啤酒,其主要麦香物质和品评口感与麦芽啤酒接近。添加少量焦香麦芽生产的大麦啤酒市场潜力具大,极具推广价值。      

高效液相色谱法测定麦精中的低聚糖

采用高效液相色谱法对麦精中的纤维三糖和纤维四糖进行了定量测定研究,最终确定的最佳分析方法为CarbomixH-NP10:5%分析柱;示差折光检测器55℃柱温;流动相:2.5mmol/LH2SO4水溶液;流速:0.5mL/min;进样量:20μL。该方法精密度RSD<2%,回收率>97%。在此色谱条件下15min内完成了三糖和四糖的分离,结果比较理想。研究表明此新建方法准确而快速,并能适用于绝大部分食品中低聚糖的测定。     

PCR技术区分液体麦精和玉米糖浆

以食品中常见的添加剂液体麦精和玉米糖浆为实验材料,采用改良的CTAB法,SDS法,试剂盒法提取DNA,依据大麦B1醇溶蛋白基因和玉米的淀粉分支酶基因设计特异性引物。结果表明,改良CTAB法可以得到较好质量的液体麦精和玉米糖浆的DNA,用特异性引物进行PCR扩增,产物条带单一,特异性良好,说明该方法可以用来区分液体麦精和玉米糖浆。本实验为检测食品中的液体麦精和玉米糖浆奠定了研究基础。      

麦芽提取物的制备及理化性质测定

利用啤酒厂的麦芽废渣 ,通过烘干、浸提、粉碎、分筛的方法制备的麦芽提取物样品 ,分别测定其膳食纤维和谷氨酰胺含量 ,同时测定该提取物的溶胀力和持水力。结果表明 :过 10 0目筛的麦芽提取物 ,膳食纤维含量 4 1 0 8% ,溶胀力 5 34mL/g ,持水力 4 2 5mL/g ,而谷氨酰胺含量约为 3 6× 10 -6g/g。     

Effect of teff (Eragrostis tef) variety and storage on malt quality attributes

Varieties of a cereal may have a considerable influence on malting qualities owing to variations in the physicochemical properties of the grains. This research was aimed at assessing the influence of five teff varieties on malt quality attributes. The teff samples were malted using previously optimized malting conditions and mashed with the congress mashing procedure. In this research, the Kuncho teff variety was malted in a one year period after harvesting, whereas the other four varieties were malted after three years of storage. Alpha‐ and β‐amylase, and limit dextrinase activity, were in the ranges 14–68, 10–440 and 375–1072 U/kg, respectively. Extracts ranged from 54% for Dessie to 74% for Ivory teff. Free amino nitrogen, protein content, soluble nitrogen, Kolbach index, viscosity and wort colour were in the ranges 160–364 mg/L, 8.6–13.6%, 532–1048 mg/100 g, 24–50%, 1.441–1.629 mPa s and 5.9–9.0 EBC units, respectively. High‐performance liquid chromatographic analysis for individual fermentable sugars revealed that the highest value in all varieties was recorded for glucose followed by maltose. The concentration of glucose ranged from 9.49 g/L in Brown teff, to 19.42 g/L in Ivory teff, whereas maltose ranged from 2.95 g/L in Dessie teff to 16.1 g/L in Kuncho teff. All of the malt quality attributes considered in this study were markedly influenced (p < 0.05) by the type of teff cultivar. It was concluded that the use of different teff varieties yielded malts with significantly different malt quality attributes. Copyright © 2013 The Institute of Brewing & Distilling     

Mathematical modeling of crossflow microfiltration of diluted malt extract suspension by tubular ceramic membranes

The practical application of microfiltration in brewing industry is hindered by severe membrane fouling and subsequent permeate flux decline. A theoretical and experimental study on the effect of operating parameters, which influence the crossflow microfiltration of beer and beer quality was performed. A mathematical model is developed to better understanding of the fouling layer characteristics. The experiments were conducted for different ranges of pressures, temperatures and shear rates. An optimum transmembrane pressure of 1.1 bar is suggested to maximize both the steady state and average permeate fluxes. The results of numerical simulation were in a good accordance with the experimental data.     

双麦麦精对嗜热链球菌生长影响的研究

主要研究双麦麦精对嗜热链球菌生长过程的影响。通过在营养成分缺省的培养基中添加双麦麦精,采用分光光度法测定菌液吸光值(OD600),根据OD值确定对应的嗜热链球菌的活菌数,从而分析双麦麦精对嗜热链球菌生长情况的影响。利用正交实验,通过直接计数法确定双麦麦精与其他营养成分的最佳比例。结果表明,双麦麦精对嗜热链球菌的生长有明显的促进作用,可为嗜热链球菌提供充足的碳源和生长因子。双麦麦精的添加量为16g/L时效果最佳。分析比较吸光值法和直接计数法测得的生长曲线,结果表明两种方法具有良好的相似性,其中在对数期有强相关性。     

Refining the Prediction of Potential Malt Fermentability by Including an Assessment of Limit Dextrinase Thermostability and Additional Measures of Malt Modification,Using Two Different Methods for Multivariate Model Development

Prediction of malt fermentability (apparent attenuation limit — AAL) by measurement of the diastatic power enzymes (DPE), α‐amylase, total limit dextrinase, total β‐amylase, β‐amylase thermostability, and the Kolbach index (KI or free amino nitrogen — FAN) is superior to the conventional use of diastatic power (DP) alone. The thermostability of β‐amylase is known to be an important factor in determining fermentability, thus the thermostability of the other relatively thermolabile enzyme, limit dextrinase, was investigated to determine if it was also useful in predicting fermentability. To facilitate this aim, methods were developed for a rapid and cost efficient assay of both β‐amylase and limit dextrinase thermostability. Internationally important Australian and international malting varieties were compared for their total limit dextrinase and β‐amylase activity and thermostability. Interestingly, the level of limit dextrinase thermostability was observed to be inversely correlated with total limit dextrinase activity. The prediction of malt fermentability was achieved by both forward step‐wise multi‐linear regression (MLR) and the partial least squares (PLS) multivariate model development methods. Both methods produced similar identifications of the parameters predicting wort fermentability at similar levels of predictive power. Both models were substantially better at predicting fermentability than the traditional use of DP on its own. The emphasis of this study was on the identification of predictive factors that can be consistently used in models to predict fermentability, because the model parameter estimates will subtly vary depending on mashing conditions, yeast strain/fermentation conditions and malt source. The application of these multivariate model development methods (PLS and MLR) enabled the identification of further potential fermentability predicting factors. The analyses divided the predictive parameters into those defined by DP enzymes and those associated with modification (KI, FAN, fine/coarse difference, wort β‐glucan and friability). Surprisingly, limit dextrinase thermostability was not a substantial predictor of fermentability, presumably due to its negative correlation with total limit dextrinase activity. The application of these insights in the malting and brewing industries is expected to result in substantial improvements in brewing consistency and enable more specific quality targets for barley breeder's progeny selection cut‐off limits to be more precisely defined.     

啤酒大麦、麦芽中多酚类化合物HPLC指纹图谱分析技术研究

以10个进口和8个国产啤酒大麦品种及其相对应的麦芽为样本,采用高效液相色谱（HPLC）建立大麦和麦芽中14种多酚类物质的指纹图谱,并分别进行相似度分析、聚类分析（CA）和主成分分析（PCA）。结果表明,进口大麦样品的相似度（0.938～0.989）高于国产大麦样品（0.911～0.937）,而进口大麦麦芽的相似度（0.892～0.967）普遍低于国产大麦麦芽的相似度（0.956～0.981）;CA（判别距离＜5）结果和PCA结果一致,8个国产大麦和1个进口大麦样品B2聚为一类,8个国产麦芽和3个进口麦芽样品M2、M3、M4聚为一类,说明通过大麦、麦芽多酚类物质的HPLC指纹图谱技术能基本区分国产和进口大麦品质的差异。     

双麦麦精对酸奶益生菌及其感官性质的影响

双麦麦精是以大麦,其他麦类为原料通过酶解提取的一种天然营养物质。在酸奶制作过程中添加不同比例的双麦麦精,采用平板涂布的方法检测不同储存时间下,酸奶中的保加利亚乳杆菌和嗜热链球菌的活菌数。并且通过感官实验评定双麦麦精对酸奶口感、口味、色泽以及香味的影响。结果表明,当双麦麦精添加量为3%,蔗糖4%时,对酸奶中益生菌的促生长作用最好。同时验证了3%双麦麦精对双歧杆菌也有明显的益生作用。而且,3%添加量的双麦麦精在益生作用以及感官性质方面都比同等添加量的低聚果糖效果好。     

Effect of malting time,mashing temperature and added commercial enzymes on extract recovery from a Nigerian malted yellow sorghum variety

Preliminary microbiological studies carried out on sorghum grains showed that the major microorganisms found were mainly bacteria and that aflatoxin‐producing fungi were not found. The effect of added commercial enzyme preparations and different infusion mashing temperatures on extract yield, from sorghum malted at 30 °C, was studied. The infusion mashing method (65 °C) developed for mashing well‐modified barley malt produces poor extract yields with sorghum malt. The extract yield from the sorghum malt in this study was very low with infusion mashing at 65 °C, without the addition of commercial enzyme preparations. A higher extract yield was obtained from the sorghum malt, without the commercial enzyme addition, when using infusion mashing at 85 °C. Both infusion mashing temperatures (65 and 85 °C) showed an improved extract yield over the control malt when commercial enzyme preparations were used during mashing of the sorghum malt. The added enzyme preparations resulted in a higher extract yield from the germinated sorghum when infusion mashing was performed at 65 °C over mashing at 85 °C. The use of individual commercial enzymes (α‐amylase, β‐glucanase, protease, xylanase, saccharifying enzyme and combinations of some hydrolytic enzyme) increased extract yields, when complemented with the enzymes that had developed in the sorghum malt. Copyright © 2016 The Institute of Brewing & Distilling     

Validation and application of osmolyte concentration as an indicator to evaluate fermentability of wort and malt

The objective was to develop a new simple and quick approach to predict fermentability, based on osmolyte concentration (OC). Eight malts were assayed for diastatic power, starch‐degrading enzymes [α ‐amylase, β ‐amylase and limit dextrinase (LD)] and malt OC (MOC). All malts were mashed to determine wort OC (WOC), real degree of fermentation (RDF) and sugar contents in a small‐scale mashing protocol. The results showed that MOC was correlated with malt α ‐amylase, LD, the resultant WOC, RDF and fermentable sugar (r  = 0.813, 0.762, 0.795, 0.867, 0.744, respectively), suggesting that MOC was discriminating in predicting levels of malt amylolytic enzymes, wort sugar and RDF without the mashing and fermentation process. Moreover, WOC showed stronger correlations with malt α ‐amylase, LD, RDF and fermentable sugars (r  = 0.796, 0.841, 0.884, 0.982, respectively), suggesting that WOC can be used to quickly predict wort sugar contents and RDF without a fermentation step. Furthermore, the effects of mashing temperature and duration on WOC, RDF and sugar contents are discussed. Adjusting mash temperature to 65°C or extending the mash duration dramatically increased RDF and WOC, whereas malt extract was relatively stable. Similarly, WOC showed significant correlations with RDF and fermentable sugars (r  = 0.912 and 0.942, respectively), suggesting that WOC provides a simple and reliable tool to assist brewers to optimize mash parameters towards the production of ideal wort fermentability. In conclusion, the ability of OC to predict malt fermentability and sugar content allows brewers to keep better control of fermentability in the face of variation of malt quality, and to quickly adjust mashing conditions for the consistency of wort fermentability. Copyright © 2017 The Institute of Brewing & Distilling     

北五味子麦芽酵素的制备及其抗氧化活性

以超氧化物歧化酶（SOD）活力为评价指标,通过单因素试验以及正交试验,对植物乳杆菌（Lactobacillus plantarum）发酵的北五味子麦芽酵素的发酵工艺条件进行优化;并对该酵素产品的抗氧化活性进行了研究。结果表明,植物乳杆菌发酵制备北五味子麦芽酵素的最佳发酵工艺条件为北五味子∶麦芽=2∶1（g∶g）,发酵时间为3 d、接种量为1.5%、发酵温度为41 ℃。在此最佳工艺条件下,北五味子麦芽酵素SOD酶活力为3 464.80 U/mL。抗氧化活性结果表明,该酵素对超氧阴离子自由基清除能力、羟自由基清除能力、DPPH自由基清除能力和对ABTS+自由基清除能力分别达到了26.03%、97.25%、89.10%和0.613 7 mmol/L,表明该酵素具有较好的抗氧化活性。     

Comparison of beer quality attributes between beers brewed with 100% barley malt and 100% barley raw material

BACKGROUND: Brewing with 100% barley using the Ondea^® Pro exogenous brewing enzyme product was compared to brewing with 100% barley. The use of barley, rather than malt, in the brewing process and the consequences for selected beer quality attributes (foam formation, colloidal stability and filterability, sensory differences, protein content and composition) was considered. RESULTS: The quality attributes of barley, malt, kettle‐full‐wort, cold wort, unfiltered beer and filtered beer were assessed. A particular focus was given to monitoring changes in the barley protein composition during the brewing process and how the exogenous OndeaPro^® enzymes influenced wort protein composition. All analyses were based on standard brewing methods described in ASBC, EBC or MEBAK. To monitor the protein changes two‐dimensional polyacrylamide gel electrophoresis was used. CONCLUSION: It was shown that by brewing beer with 100% barley and an appropriate addition of exogenous Ondea^® Pro enzymes it was possible to efficiently brew beer of a satisfactory quality. The production of beers brewed with 100% barley resulted in good process efficiency (lautering and filtration) and to a final product whose sensory quality was described as light, with little body and mouthfeel, very good foam stability and similar organoleptic qualities compared to conventional malt beer. In spite of the sensory evaluation differences could still be seen in protein content and composition. Copyright © 2011 Society of Chemical Industry     

Effects of nitrogen application on malt modification and dimethyl sulfide precursor production in two Japanese barley cultivars

BACKGROUND: Nitrogenous components have a great influence on both malt and beer qualities. Barley storage proteins are degraded during the germination process, in which amino acids and small peptides are released. Some of these compounds relate to dimethyl sulfide precursor production in the malting process. In this study, barley and malt qualities were investigated using two Japanese barley cultivars, Sukai Golden and Mikamo Golden, with several different nitrogen (N) treatments. RESULTS: Nitrogen top‐dressing treatments efficiently increased N and sulfur (S) concentrations in grains. A difference in malt modification was induced by these treatments without any change in protease activity in malts. S‐Methyl methionine (SMM) concentration in malt of Sukai Golden with low‐N treatment was 1.8–2.1 times higher than that with higher‐N treatments. Methionine concentration in malts was not significantly affected by N treatments of both cultivars, while grain S level was not consistent under any treatments. CONCLUSION: Results show that low‐N treatment increases SMM concentration in malts despite major S‐containing amino acids of malts being not highly affected by the difference in nutrient status of grains. Further investigations are necessary into aspects of both metabolic profiles in barley germination and SMM degradation in the kilning process. Copyright © 2008 Society of Chemical Industry     

The chemical composition,the nutritive value and the functional properties of malt sprout and its components (acrospires,rootlets and husks)

The components of malt sprouts were effectively separated by manual winnowing into acrospires (15·3%), rootlets (40·1%) and husks (43·7%). The bitter taste was located in the acrospires. Percent recovery of protein and fibre was, respectively, 95·2 and 87·2 of malt sprouts. The acrospires were rich in protein (30·3%) and sugars (45·7%) but low in calcium (1·94 g kg⁻¹), fibre content (4·6%) and essential amino acids. They had moderate functional properties. The rootlets were rich in calcium (19·9 g kg⁻¹) and in protein (31·9%), which had a good nutritive value (low in phytic acid and polyphenols content). They had a moderate fibre content (10·7%). Consequently, they had the highest water absorption, oil absorption and emulsification capacities. The rootlets had relatively low foam capacity but the highest foam stability. The husks were rich in fibre content (25%) but moderate in protein content (12·4%), which was rich in essential amino acids. The husks were relatively low in calcium (11·83 g kg⁻¹) and phosphorus (6·53 g kg⁻¹) contents and in vitro protein digestibility (68·9%). Their functional properties were influenced by high fibre and moderate protein contents. The first limiting amino acids were sulphur-containing ones in the malt sprouts, the acrospires and the rootlets, but it was leucine in the husks. © 1997 SCI.     

甘草、诃子提取物复合抗氧化剂对葵花籽油抗氧化作用的研究

目的研究甘草、诃子提取物复合抗氧化剂对葵花籽油抗氧化作用的影响。方法采用Schaal烘箱法和ABTS法,评价复合抗氧化剂对葵花籽油的抗氧化作用。结果 Schaal烘箱加速氧化实验中,甘草提取物比诃子提取物对葵花籽油的抗氧化作用更强,复合抗氧化剂均表现出协同抗氧化作用,其中,0.007%甘草提取物=0.013%α-生育酚、0.015%甘草提取物+0.005%抗坏血酸、0.007%诃子提取物+0.013%α-生育酚和0.003%诃子提取物+0.017%抗坏血酸对葵花籽油的抗氧化作用较强,均优于其单一抗氧化剂和人工合成抗氧化剂丁基羟基茴香醚(BHA)、2,6-二叔丁基-4-甲基苯酚(BHT),弱于2-叔丁基对苯二酚(TBHQ)。ABTS法中,多数复合抗氧化剂间表现出协同作用,其中,诃子提取物与抗坏血酸复配比例为5:1和3:1时清除ABTS自由基能力最强。结论复合抗氧化剂对葵花籽油具有协同抗氧化作用。