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。     

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。      

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.     

Evaluation of dried and wet distillers grains included at two concentrations in the diets of lactating dairy cows

The purpose of this study was to determine the lactation performance of dairy cows fed dried or wet distillers grains (DG) with solubles (DDGS or WDGS) at 2 dietary concentrations. A trial using 15 cows was designed as a replicated 5 × 5 Latin square with periods of 4 wk each and data collected during wk 3 and 4 of each period. Diets, on a dry matter basis, were: control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS. All diets contained 25% corn silage, 25% alfalfa hay, and 50% of the respective concentrate mixes. Dry matter intake (DMI) tended to be greater for cows fed control than DG (23.4, 22.8, 22.5, 23.0, and 21.9 kg/d for control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS). Milk yield (39.8, 40.9, 42.5, 42.5, and 43.5 kg/d) was greater for cows fed DG than control. Milk fat percentage (3.23, 3.16, 3.28, 3.55, and 3.40%) was similar for cows fed control and DG, but greater for cows fed WDGS than DDGS. Milk fat yield was greater for cows fed DG than control and tended to be greater for cows fed WDGS than DDGS. Milk fat from cows fed DG, especially 20% DG, was more unsaturated and contained more cis-9, trans-11 conjugated linoleic acid than when fed the control diet. Milk protein percentage (3.05, 3.01, 3.02, 3.11, and 3.06%) was similar for cows fed control and DG but greater for cows fed WDGS than DDGS. Milk protein yield was greater for cows fed DG than control, tended to be greater for cows fed WDGS than DDGS, and tended to be greater for cows fed 20% DG than 10% DG. Milk urea nitrogen was similar for cows fed control and DG but greater for cows fed WDGS than DDGS and tended to be higher for cows fed 20% DG than 10% DG. Ruminal ammonia concentrations were greater for cows fed WDGS than DDGS. Overall, feeding DG improved feed efficiency (1.70, 1.79, 1.87, 1.84, and 1.92 kg of energy-corrected milk/kg of DMI) by increasing yields of milk, protein, and fat while tending to decrease DMI.     

基于Illumina MiSeq高通量测序分析清香型白酒酒糟微生物群落多样性

采用Illumina MiSeq高通量测序技术对清香型白酒酒糟中微生物多样性进行研究。结果表明,酒糟样品中细菌菌群的丰富度与多样性均大于真菌,细菌菌群归属于10个门、18个纲、31个目、66个科、86个属、124个种,真菌菌群归属于5个门、11个纲、20个目、33个科、49个属、66个种。优势细菌门（相对丰度≥1.0%）为变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、厚壁菌门（Firmicutes）、拟杆菌门（Bacteroidetes）,优势细菌属为根瘤菌属（Rhizobium）、拉乌尔菌属（Raoultella）、谷氨酸杆菌属（Glutamicibacter）、红球菌属（Rhodococcus）、短波单胞菌属（Brevundimonas）、不动杆菌属（Acinetobacter）、假单孢菌属（Pseudomonas）、嗜冷杆菌属（Psychrobacter）、Devosia、嗜盐单胞菌属（Halomonas）、未分类-鼠杆菌属（unclassified-Muribaculaceae）、乳杆菌属（Lactobacillus）;优势真菌门为子囊菌门（Ascomycota）、毛霉门（Mucoromycota）及担子菌门（Basidiomycota）,优势真菌属为孢圆酵母属（Torulaspora）、伊萨酵母属（Issatchenkia）、横梗霉属（Lichtheimia）、根霉属（Rhizopus）、曲霉属（Aspergillus）、酵母属（Saccharomyces）。     

Effects of feeding alfalfa hay on chewing, rumen pH, and milk fat concentration of dairy cows fed wheat dried distillers grains with solubles as a partial substitute for barley silage

The objective of this study was to determine the effects of feeding alfalfa hay on chewing activity, rumen fermentation, and milk fat concentration of dairy cows fed wheat-based dried distillers grains with solubles (DDGS) as a partial replacement of barley silage. Thirty lactating Holstein cows (220 ± 51 DIM), 6 of which were ruminally cannulated, were used in a 3 × 3 Latin square design with 21-d periods. Cows were fed a control diet [CON; 50% barley silage and 50% concentrate mix on a dry matter (DM) basis], a diet in which barley silage was replaced with DDGS at 20% of dietary DM (DG), or a diet in which barley silage was replaced with DDGS and alfalfa hay at 20 and 10% of dietary DM, respectively (DG+AH). All diets contained approximately 20% crude protein. Compared with the CON diet, cows fed DG and DG+AH diets respectively had greater DM intake (20.1 vs. 23.1 and 22.7 kg/d); yields of milk (24.5 vs. 27.3 and 28.1 kg/d), milk protein (0.88 vs. 0.99 and 1.01 kg/d), and milk lactose (1.11 vs. 1.24 and 1.29 kg/d); and body weight gain (0.25 vs. 1.17 and 1.23 kg/d). However, compared with cows fed the CON diet, cows fed the DG and DG+AH diets respectively had lower chewing time (38.3 vs. 30.7 and 31.5 min/kg of DM intake), mean rumen pH (6.11 vs. 5.88 and 5.84), and minimum rumen pH (5.28 vs. 5.09 and 5.07) and a greater duration that rumen pH was below 5.8 (7.3 vs. 11.2 and 12.0 h/d). However, these response variables did not differ between cows fed the DG and DG+AH diets. Milk fat concentration differed among the 3 diets (3.92, 3.60, and 3.38% for CON, DG, and DG+AH, respectively), but milk fat yield was not affected by treatment. These results indicate that partially replacing barley silage with DDGS can improve productivity of lactating dairy cows but may decrease chewing time, rumen pH, and milk fat concentration, and that dietary inclusion of alfalfa hay may not alleviate such responses.     

Invited review: The use of distillers products in dairy cattle diets

Distillers grains with solubles (DGS) is the major coproduct of ethanol production, usually made from corn, which is fed to dairy cattle. It is a good protein (crude protein, CP) source (>30% CP) high in ruminally undegradable protein (∼55% of CP) and is a good energy source (net energy for lactation of approximately 2.25 Mcal/kg of dry matter). The intermediate fat concentration (10% of dry matter) and readily digestible fiber (∼39% neutral detergent fiber) contribute to the high energy content in DGS. Performance was usually similar when animals were fed wet or dried products, although some research results tended to favor the wet products. Diets can contain DGS as partial replacement for both concentrates and forages, but DGS usually replaces concentrates. Adequate effective fiber was needed to avoid milk fat depression when DGS replaced forages in lactating cow diets. Nutritionally balanced diets can be formulated that contain 20% or more of the diet dry matter as DGS. Such diets supported similar or higher milk production compared with when cows were fed traditional feeds. Although DGS can constitute more than 30% of diet dry matter, gut fill may limit dry matter intake and production in diets with more than 20% wet DGS and that also contain other moist feeds. The fiber in DGS, which often replaces high-starch feeds, does not eliminate acidosis but minimizes its problems. Distillers solubles, which are often blended with distillers grains to provide DGS, can be fed separately as condensed corn distillers solubles. Other distillers coproducts besides DGS such as high-protein distillers grains, corn germ, corn bran, and low-fat distillers grains are becoming available.     

Ruminal degradability and intestinal digestibility of protein and amino acids in soybean and corn distillers grains products

New fractionation and fermentation technologies in the ethanol industry have resulted in the production of different forms of distillers grains (DG). Such products are reduced-fat, high-protein, and “modified” wet feeds. Characterization of protein fractions of these co-products and other commonly used feedstuffs is important for the formulation of dairy cattle diets. In situ and in vitro techniques were conducted to compare crude protein (CP) availability in 4 DG products with commonly used soybean proteins. Soybean protein products included solvent-extracted soybean meal (SBM; 44% CP), expeller soybean meal (ESBM), and extruded soybeans (ES). The DG products were conventional distillers dried grains with solubles, reduced-fat distillers dried grains with solubles (RFDGS), high-protein distillers dried grains, and modified wet distillers grains with solubles (MWDGS). Nylon bags containing 5 g of each feed were incubated in the rumen of 3 cannulated lactating cows for 2, 4, 8, 16, 24, and 48 h. The rapidly degradable CP fraction varied from 8.1 to 37.2% for SBM and MWDGS, respectively. The slowly degradable CP fraction was greatest for SBM, ES, and high-protein distillers dried grains (88.0% ± 3.7), followed by ESBM, distillers dried grains with solubles, and RFDGS (76.8 ± 4.1%). The MWDGS had the lowest slowly degradable CP fraction (61.1%). The rate of degradation of the slowly degradable CP fraction ranged from 11.8 for SBM to 2.7%/h for RFDGS. Rumen-undegradable protein varied widely (32.3 to 60.4%), with RFDGS having the greatest and SBM the lowest concentrations. Intestinal digestibility of rumen-undegradable protein (IDP) was estimated by pepsin-pancreatin digestion of ruminally preincubated (16 h) samples. The IDP was greatest for SBM, ESBM, and ES (97.7% ± 0.75), whereas IDP of DG products was 92.4% ± 0.87. Similarly, total digestible protein was greatest (99.0%) for soybean products, whereas DG products had a total digestible protein of 96.0%. Intestinal digestibility of most AA in DG products exceeded 92% and was slightly lower than for soybean products, except for Lys, where the digestibility was 84.6% for DG compared with 97.3% for soybean products. Absorbable Lys was lower for DG (7.0 g/kg of CP) compared with ESBM and ES (average of 23.8 g/kg of CP). Dried DG, ESBM, and ES provided more absorbable AA compared with SBM and MWDGS. These results suggest that the AA availability from DG products is comparable with that from soybean products.     

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。     

Ration formulations containing reduced-fat dried distillers grains with solubles and their effect on lactation performance,rumen fermentation,and intestinal flow of microbial nitrogen in Holstein cows

Sixteen multiparous lactating Holstein cows were used in 2 experiments to evaluate the effects of reduced-fat dried distillers grains with solubles (RFDG) on milk production, rumen fermentation, intestinal microbial N flow, and total-tract nutrient digestibility. In experiment 1, RFDG was fed at 0, 10, 20, or 30% of diet dry matter (DM) to 12 noncannulated Holstein cows (mean ± standard deviation: 89 ± 11 d in milk and 674 ± 68.2 kg of body weight) to determine effects on milk production. In experiment 2, the same diets were fed to 4 ruminally and duodenally cannulated Holstein cows (mean ± standard deviation: 112 ± 41 d in milk; 590 ± 61.14 kg of body weight) to evaluate the effects on rumen fermentation, intestinal flow of microbial N, and total-tract nutrient digestibility. In both experiments, cows were randomly assigned to 4 × 4 Latin squares over 21-d periods. Treatments (DM basis) were (1) control (0% RFDG), (2) 10% RFDG, (3) 20% RFDG, and (4) 30% RFDG. Feed intake and milk yield were recorded daily. In both experiments, milk samples were collected on d 19 to 21 of each period for analysis of milk components. In experiment 2, ruminal pH was measured; samples of rumen fluid, duodenal digesta, and feces were collected on d 18 to 21. Microbial N was estimated by using purines and DNA as microbial markers. Milk yield was not affected by treatment and averaged 34.0 ± 1.29 kg/d and 31.4 ± 2.81 kg/d in experiments 1 and 2, respectively. Percentage of milk protein tended to increase in experiment 1; estimates were 3.08, 3.18, 3.15, and 3.19 ± 0.06% when RFDG increased from 0 to 30% in the diets. However, milk protein concentration was not affected in experiment 2 and averaged 3.02 ± 0.07%. Percentage of milk fat was not affected and averaged 3.66 ± 0.05% and 3.25 ± 0.14% in experiments 1 and 2, respectively. Total ruminal volatile fatty acids and ammonia concentrations were not affected by treatment and averaged 135.18 ± 6.45 mM and 18.66 ± 2.32 mg/dL, respectively. Intestinal microbial N flow was not affected by treatment; however, purines yielded higher estimates of flow compared with DNA markers. When averaged across treatments, intestinal flow of microbial N was 303 and 218 ± 18 g of N/d, using purines and DNA as the markers. Dry matter, organic matter, neutral detergent fiber, and nonfiber carbohydrate digestibility tended to increase with increasing inclusion of RFDG. Results from these experiments indicate that dairy rations can be formulated to include up to 30% RFDG while maintaining lactation performance, volatile fatty acids concentration, and intestinal supply of microbial N.     

Ruminal and intestinal degradability of distillers grains plus solubles varies by source

Currently in the dairy industry, there is a concern about the variability in the nutrient content among sources of distillers grains plus solubles (DG), but little research has evaluated the variability in metabolizable AA among sources. The ruminal degradability of crude protein (CP) in soybean meal (SBM), dried DG from 5 sources (DG1, DG2, DG3, DG4, and DG5), and 1 source of wet DG (WDG) were determined using 2 lactating ruminally cannulated Holstein cows. Feeds were incubated in the rumen for 3, 6, 12, 18, 24, and 36 h. Intestinal CP digestibility via pepsin and pancreatin and AA profiles were measured on residue from 12-h ruminal incubation of feeds. Ruminal undegradable protein (RUP) was less for SBM (46.4%) than for DG. The WDG (53.6%) had less RUP than dried DG. The RUP concentrations of DG3 (59.1%) and DG5 (60.3%) were lower than DG1 (71.7%) and DG4 (67.5%), with DG1 having more than DG2 (63.7%) and DG4. Intestinal digestibility of RUP was greater for SBM (86.7%) than DG. The DG2 (76.8%) and DG3 (74.2%) had greater intestinal digestibility compared with DG1 (59.2%), DG4 (63.0%), and DG5 (68.1%). The intestinal digestibility in WDG (65.8%) was similar to all other DG except for DG1, which was lower. Total digestibility of CP was greater in SBM (93.9%) compared with DG. Among the DG sources, the CP in DG2 (85.3%) and DG3 (84.9%) was more digestible compared with DG1 (70.7%), DG4 (74.9%), and DG5 (80.8%) but not WDG (81.9%). Based on the milk protein score (MPS), which is an estimate of the proportion of milk protein that a protein source can sustain until the first limiting AA is depleted, Met was the first limiting AA in SBM and Lys in DG. The concentrations of essential AA in the RUP were not different among DG sources, but the greater MPS in WDG (0.306) compared with the dried DG (0.240) sources indicated that WDG may have been the more ideal RUP source; but, the MPS of the metabolizable protein indicated that the protein quality of WDG was similar to that in DG2, DG3, and DG5. In conclusion, protein degradability and digestibility differed greatly among DG sources, but these differences were actually not as prominent in the concentrations of metabolizable AA and MPS among these sources.