麦糟的开发利用

麦糟所含的营养成分较高,可开发适用于饲料、食品等行业的产品,不仅变废为宝,而且净化了环境,增加了企业的经济和社会效益。     

用麦糟生产L-乳酸

研究采用固定化乳酸菌作用麦糟生产L-乳酸，使用一个5升蒸汽喷发反应器，通过蒸汽喷发处理使麦糟液化来获取糖浆。当1kg湿麦糟在30kg／cm^2压力下处理1分钟可从液化麦糟获得60g总糖，而且当液化麦糟添加糖化酶、纤维素酶和半纤维素酶时可生成1．3％（w／v）葡萄糖、0．4％（w／v）木糖和0．1％（w／v）阿拉伯糖。使用鼠李糖乳杆菌NBRC14710从添加吐温80的液化麦糟生产L-乳酸。     

利用啤酒麦糟进行L-乳酸生产的研究

将湿啤酒糟烘干至含水量为10％左右,再进行机械粉碎,过20-40目筛子筛分后,采用0．80％硫酸,固液比1：11,浸泡原料10h后,于121℃下预水解90rain。预水解物pH值用2．0％的氢氧化钠调至4．0左右后,添加0．20％（w／v）左右的纤维素酶,于50℃酶解5h,得到还原糖含量为8．82％的啤酒糟酶解液。将此酶解液pH调节到6．0左右,于55℃采用分批补料的发酵方式进行发酵控制,添加5．0％的碳酸钙,可得到乳酸产量为80．75g／L的发酵液。     

麦糟在国外的综合利用现状

对麦糟的综合利用现状及意义进行了分析。着重介绍了麦糟在国外食品与饲料工业中的应用。     

麦糟的干燥技术研究

本文结合生产实践和市场对成品干糟的质量要求，较深入地分析了麦糟干燥的必要性及干燥机理，并对干燥设备的正确选择提出了笔者的观点，以资参考。     

浅谈麦糟的再利用

麦糟是啤酒生产中最大量的副产物，每投入100公斤的原料麦芽，约产干麦糟25。30公斤。麦糟中含有大量的膳食纤维和蛋白质。目前国内普遍将麦糟作为饲料处理，而国外已有研究报道表明，麦糟是一种可以提取为人体所利用的良好膳食纤维来源。本文主要讨论了将麦糟进行物理改性加工及用乙醇沉淀和酶解蛋白质及淀粉的方法从麦糟中提取可溶性膳食纤维。     

Bacillus subtilis AS35发酵麦糟产β-葡聚糖酶粗酶性质的研究

研究了由Bacillus subtilis AS35发酵麦糟制备的β-葡聚糖酶的性质,研究表明,该酶在55℃~65℃时酶活力较高,最适反应温度为60℃;最适反应pH值为5.5,在pH值为4.0~7.0时有较高的稳定性,在4℃保存24h后,残余酶活超过85%;在1mmol/L的浓度条件下,Fe2+、Co2+、Ca2+,尤其是Co2+对酶活性有明显的激活作用;Pb2+、Fe3+、A13+对酶活性有明显的抑制作用。     

麦糟不溶性膳食纤维的蛋白质降解工艺研究

优化酶碱法制备麦糟不溶性膳食纤维的过程中,蛋白质酶解和碱溶的工艺条件。通过单因子和正交试验,考察加酶量、酶解温度、酶解时间、NaOH浓度、碱溶温度和碱溶时间对不溶性膳食纤维的得率和蛋白质质量分数的影响,分析因素的主次顺序,优化工艺条件并验证。结果表明在酶解温度45℃,酶解时间3.5 h,加酶量为0.09 g,碱溶温度50℃,碱溶时间45 min,NaOH浓度1 mol/L的条件下,制备得到麦糟不溶性膳食纤维的得率为29.2%,蛋白质质量分数3.1%。结果为制备优质不溶性膳食纤维提供一定参考。     

麦糟的综合利用研究

麦糟是啤酒工业的主要副产物，是麦芽、辅料的粉碎物经糖化、过滤后的滤渣，含有丰富的多糖（纤维素、半纤维素）、木质素、蛋白质等。麦糟含水量高，营养丰富，容易染菌变质，因此，对麦糟的利用主要以生产动物饲料为主，综合利用率低，产生的附加值小。麦糟中含有的多糖和蛋白质等，具有潜在的应用价值。该文综述了麦糟在饲料工业、食品工业、污水处理、培养基等方面的应用，为进一步开发麦糟的使用领域、提高麦糟的经济效益提供参考。     

脂肪酶水解麦糟中脂肪的反应动力学研究

脱脂是制备麦糟膳食纤维的重要工序。实验利用脂肪酶水解麦糟中脂肪,采用单因素实验和响应曲面法考察并优化影响反应速率的因素。在优化的条件下,依据中间复合物学说,建立酶促动力学方程。结果表明:在p H 7.0,温度40℃,加酶量0.32 g,CMg2+为0.108 mol/L条件下,反应速率达0.67 mg/m L·h,酶促动力学方程为dCS/dt=V=1.4×CS/CS+6.288。结果可为应用脂肪酶水解麦糟中脂肪的生产强化和工程设计提供技术参考。     

青稞酒糟的高附加值利用及在具保健功能面膜中的应用

青稞酒糟作为青稞白酒的副产物,产量大,营养丰富,然而目前主要作为饲料和农肥,且其易腐败变质,产品利用率和附加值低。本研究提出一种青稞酒糟的高附加值开发应用,利用酸性蛋白酶水解酒糟,全面释放青稞酒糟潜在的活性物质。把经过酶解的酒糟提取液用于制作具有保湿、抗氧化、美白、抗紫外等功能的无纺布面膜。产品经专业机构人体功能测试具有显著效果。     

芝麻香型白酒糟醅中氨态氮的测定

建立了分光光度法检测酒糟中氨态氮的方法,并对芝麻香型白酒蒸馏前后酒糟中氨态氮的含量进行了检测。测定酒糟中氨态氮的相对标准偏差(RSD)为2.81%~3.85%,回收率为101.31%~104.45%。该方法具有操作简便,精密度好,准确度高的特点,可用于日常芝麻香型白酒酒糟中氨态氮的检测并指导优化芝麻香白酒生产工艺。     

夏冬两季青稞酒发酵过程中酒醅微生物菌群多样性分析

运用高通量测序技术(high-throughput sequencing)研究夏冬两个季节青稞酒醅发酵过程中的微生物菌群结构和生物多样性.结果 显示,在青稞酒醅发酵过程中,夏季酒醅细菌种群多样性要高于冬季,而夏季真菌种群多样性低于冬季;真菌属水平上,夏季微生物组成比冬季更为丰富,在发酵过程中,夏季的青稞酒醅中Pichi...     

酒糟酸水解液发酵生产木糖醇的研究

采用热带假丝酵母(Candida tropicalis 1779)发酵酒糟酸水解液生产木糖醇,分别利用单因素实验和正交实验考察了影响发酵效果的工艺条件。发酵在250mL摇瓶发酵瓶中进行。结果表明,当种子龄27h、接种量20mL和氮源添加量20mL时发酵效果最好。该条件下发酵液中木糖醇浓度为11.85mg/mL,木糖利用率为45.62%。发酵实验表明酒糟酸水解液作为碳源发酵生产木糖醇具有可行性。      

黄水酯化液在浓香型大曲酒丢糟中的应用

作者对黄水加大曲粉、酒糟、酒尾、窖泥等发酵制备的酯化液,用以拌糟醅回窖发酵,糟酒的质量明显提高。     

Effects of partially replacing barley silage or barley grain with dried distillers grains with solubles on rumen fermentation and milk production of lactating dairy cows

Dried distillers grains with solubles (DDGS) has been commonly used as a dietary protein source for lactating dairy cows. However, there is a paucity of data evaluating the use of DDGS as a partial replacement of forage or grain. The objective of this study was to determine the effects of partially replacing barley silage or barley grain with corn/wheat-based DDGS on dry matter intake (DMI), chewing activity, rumen fermentation, and milk production. Six ruminally cannulated lactating Holstein cows were used in a replicated 3 × 3 Latin square design with 21-d periods. Cows were fed the control diet (CON: 45% barley silage, 5% alfalfa hay, and 50% concentrate mix), a low forage (LF) diet or a low grain (LG) diet, in which barley silage or barley grain was replaced by DDGS at 20% of dietary dry matter, respectively. All diets were formulated to contain 18% crude protein and fed as total mixed rations. Compared with CON, cows fed the LF diet had greater DMI (26.0 vs. 22.4 kg/d), yields of milk (36.4 vs. 33.0 kg/d), milk protein (1.18 vs. 1.05 kg/d), and milk lactose (1.63 vs. 1.46 kg/d), but milk fat yield was not affected. The LF diet decreased chewing time compared with the CON diet (29.7 vs. 39.1 min/kg of DMI), but did not affect rumen pH and duration of rumen pH below 5.8. Compared with CON, feeding the LG diet tended to increase minimum and maximum rumen pH, but did not affect DMI, milk yield, and milk composition in this study. These results indicate that a partial replacement of barley silage with DDGS can improve the productivity of lactating dairy cows without negatively affecting rumen fermentation and milk fat production. Barley grain can also be partially replaced by DDGS in diets for lactating dairy cows without causing negative effects on productivity.     

Intestinal digestibility of amino acids in rumen-undegraded protein estimated using a precision-fed cecectomized rooster bioassay: II. Distillers dried grains with solubles and fish meal

The objectives of this experiment were to measure intestinal digestibility of AA in the rumen-undegraded protein fraction (RUP-AA) of distillers dried grains with solubles (DDGS) and fish meal (FM) samples and to determine whether these feeds contain a constant protein fraction that is undegradable in the rumen and indigestible in the small intestine, as assumed in the French Institut National de la Recherche Agronomique (Paris, France) and Scandinavian AAT-PBV (AAT = AA absorbed from small intestine; PBV = protein balance in the rumen) models. Five sources of DDGS and 5 sources of FM were obtained from Feed Analysis Consortium, Inc. (Champaign, IL). To obtain the rumen-undegradable protein fraction, samples were ruminally incubated in situ for 16 h in 4 lactating cows, and the collected rumen-undegraded residues (RUR) were pooled by sample. Subsamples of the intact feeds and RUR were crop-intubated to 4 cecectomized roosters, and total excreta were collected for 48 h. Intact feeds, RUR, and excreta were analyzed for AA. Basal endogenous AA loss estimates were obtained from fasted birds and were used to calculate standardized digestibility of RUP-AA and AA in the intact feeds. Indigestibility coefficients of the intact feeds were calculated as (100 − % standardized AA digestibility), and indigestibility of the RUR was calculated as [(100 − % ruminal degradation of AA) × (100 − % standardized RUP-AA digestibility)/100]. Results indicate that standardized digestibility of feed-AA differs from RUP-AA for DDGS samples but not for FM samples, and that standardized digestibility of individual AA differs within samples. For the DDGS samples, standardized feed-AA and RUP-AA digestibility values were most often lowest for His and Lys and highest for Met and Trp. For FM samples, standardized feed-AA and RUP-AA digestibility values were most often lowest for His and highest for Trp. Results also indicate that DDGS and most FM samples do not contain a constant protein fraction that is both undegradable in the rumen and indigestible in the small intestine. Indigestibility values of RUR were lower than in intact feeds, suggesting that the feed ingredients used in this experiment contain a protein fraction that is indigestible in the intestine but partly degradable in the rumen or digestible in the intestine after rumen incubation, or both.     

Utilization of African grains for sourdough bread making

Abstract: Acha and Iburu flours were singly subjected to sourdough fermentation with previously selected autochthonous starters. Sourdoughs were used (30%, wt/wt) as aroma carriers and acidifiers during short time fermentation with the addition of baker's yeast. Acha and Iburu sourdough breads were compared to wheat sourdough bread started with the same strains and to breads made with the same formula but using baker's yeast alone. During Acha and Iburu sourdough fermentations, starter lactic acid bacteria reached almost the same cell density found in wheat sourdoughs. Acidification was more intense. Iburu sourdough bread had the highest total titratable acidity, the lowest pH, and contained the highest levels of free amino acids and phytase activity. The values of in vitro protein digestibility did not differ between Acha sourdough and wheat sourdough breads, while Iburu sourdough bread showed a slightly lower value. Acha and Iburu sourdough breads showed lower specific volume and higher density with respect to wheat sourdough breads. Nevertheless, Acha and Iburu sourdough breads were preferred for hardness and resilience. As shown by sensory analysis, Acha and especially Iburu sourdough breads were appreciated for color, acid taste and flavor, and overall acceptability. Practical Application: This study was aimed at evaluating the technological and nutritional properties of the African cereals Acha and Iburu. Sourdough fermentation and the use of selected starters increased the nutritional and sensory qualities and the potential application for bakery industry.     

Antimicrobial‐Producing Lactic Acid Bacteria Isolated from Raw Barley and Sorghum

From a total of four thousand presumed lactic acid bacteria, obtained from raw, unmalted sorghum and barley, 308 isolates were shown to exhibit inhibitory activity against the indicator strain Listeria innocua 4202. Six of these inhibitor‐producing isolates were selected for further study on the basis of their relatively wide antimicrobial spectrum, which showed that these producers inhibited several Gram‐positive bacteria, including a range of beer spoiling bacteria. The proteinaceous nature, anti‐microbial activity against closely related species, heat resistance and pH stability of the inhibitory substances produced by these six bacteria identified these compounds as bacteriocins. All six isolates were shown to secrete the inhibitory compounds into the cell free supernatants. Bacteriocins produced by five of the six producers were purified to homogeneity. Further analytic data was obtained for three of the inhibitory compounds by means of mass spectroscopy and/or N‐terminal amino acid sequencing.