具有抗氧化活性青稞酒糟蛋白酶解液对H2O2诱导HepG2 细胞的保 护作用

为实现青稞酒糟的高值化利用,该研究在提取青稞酒糟蛋白基础上,以DPPH自由基清除率和还原力为指标优化了青稞酒糟蛋白酶解液的制备工艺,并对该酶解液的体外抗氧化活性和细胞保护作用进行了探究。结果表明：青稞水酒糟和青稞白酒糟均含有丰富的蛋白质,含量分别为31.46 g/100 g和18.47 g/100 g;超声纤维素酶法辅助碱提酸沉法对青稞水酒糟的蛋白提取率高达76.10%（m/m）,白酒糟的为29.88%;碱性蛋白酶最适合用于青稞水酒糟蛋白的酶解,其最佳酶解条件为：料液比1:60（m/V）,超声时间15 min,酶添加3.7%（m/m）及酶解时间3.5 h,此条件下制得的青稞水酒糟蛋白酶解液的DPPH自由基清除率高达95.02%;不同浓度的青稞水酒糟蛋白酶解液对HepG2细胞活力没有负面影响;随着青稞水酒糟蛋白酶解液浓度的升高,对经H2O2 诱导的细胞内ROS逐渐降低,酶解液浓度为5.0 mg/mL（m/V）时可使受损细胞内的ROS比损伤组低约50%。该研究成果可为青稞水酒糟蛋白酶解液的制备及其在保健食品、化妆品中的高值化利用提供参考。     

白酒酒糟发酵后饲喂产蛋鸡效果试验

青海省地处青藏高原,盛产青稞,这里的居民素有豪饮的习俗,因而以青稞为原料的酿酒业十分发达。据统计,每年约有２５万ｔ的白酒酒糟出厂,其资源十分丰富。酒糟经发酵后,蛋白质含量提高,适口性好,而价格低,是一种可利用的丰富的蛋白质资源。目前,酒厂酒糟大多被农...     

青稞酒糟中β-葡聚糖提取工艺优化及理化特性分析

以青稞酒糟为原料,通过单因素和响应面分析对碱法提取β-葡聚糖的工艺进行优化研究。利用傅里叶红外光谱(fourier transform infrared spectroscopy, FTIR)和高效排阻色谱-示差折射光检测器-多角度激光散射仪(high performance exclusion chromatography-differential refraction light detector-multi-angle laser scatterer, HPSEC-RID-MALLS)联用测定提取物中β-葡聚糖的结构和分子量,并对其加工特性及流变特性进行分析。结果显示最优提取条件为青稞酒糟与水以1:11料液比,pH 8.5条件下,80℃,600 rpm搅拌,提取β-葡聚糖3.5 h,β-葡聚糖提取率为16.29%。傅里叶红外光谱检测结果表明,提取样品中具有β-葡聚糖特征吸收峰,含有一定量蛋白质。提取物中β-葡聚糖重均分子量为7.84×104^{。提取物在}高温和中性偏碱性条件下稳定,并呈现出良好的流变学特性。本试验提供了一种青稞酒糟中提取β-葡聚糖的方法,为青稞酒糟的综合加工、资源消耗降低及增值化利用提供新思路。     

萌动青稞的研究进展

萌动谷物的研究越来越受到广大学者的关注,特别是萌动青稞。萌动青稞是一种新型的功能性食品,因其具有良好的口感和较高的营养价值而受到人们的喜爱。通过比较青稞萌动前后营养成分的变化、萌动后青稞的生理功效,以及国内外萌动青稞产品的研发现状,综述了国内外萌动青稞研究进展,为我国萌动青稞的开发与利用提供参考。     

青稞β-葡聚糖的研究现状与展望

通过查阅青稞β-葡聚糖国内外相关文献,从其结构特性、保健功能、提取工艺、食品应用等方面进行整理与总结,主要介绍了青稞β-葡聚糖的多聚体结构、凝胶特性和流变特性,预防结肠癌、降低胆固醇等生理作用,水提取等提取工艺,以及现已开发的青稞类面食、饮品、食物赋形剂等产品。结果发现青稞β-葡聚糖的提取分离工艺已日渐完善,为进一步将其开发成其他产品提供了技术支持;再结合其多样的保健功能及理化性质,各类青稞β-葡聚糖产品已在市场上不断涌现,并且逐渐被青睐绿色健康产品的消费者所选择,因此其在食品工业,尤其在保健食品市场上具有良好的发展势头。最后本文展望了青稞β-葡聚糖的市场前景与研究发展方向,为青稞β-葡聚糖相关保健品的开发提供依据和借鉴。     

青稞膳食纤维面包的加工及品质评价

将从青稞中提取得到的膳食纤维作为辅料开发青稞膳食纤维面包。以青稞膳食纤维面包的感官评价得分作为标准,选择青稞膳食纤维用量、干酵母用量、水的用量以及烘烤时间4个因素进行单因素实验,再进行正交实验,以确定制作青稞膳食纤维面包的最佳制备工艺参数。结果表明:青稞膳食纤维添加量为20%、干酵母添加量为1.2%、水添加量为44%、烘烤时间为20 min时面包品质最佳。此面包膳食纤维含量高,能刺激肠壁蠕动,达到排毒保健的效果,且具有较好的口感、外形及色泽,是一款味美营养、富含膳食纤维、保健价值较高的产品。     

青稞挤压改性处理及青稞面条的试验研究

以青稞粉为原料,采用挤压改性方法加工青稞预糊化粉,研究改性前后青稞粉的品质变化,不同配比青稞预糊化粉的粉质特性及改性操作条件对青稞面条品质特性的影响规律,为青稞面条产品的研发提供实践基础。结果表明,改性处理后,青稞内部形成细致多孔的海绵体,大分子营养物质被降解,淀粉稳定性增强;面条蒸煮损失率与淀粉的糊化程度间具有相关性。在适宜加工条件下制备的青稞预糊化粉,可以制作出青稞含量达60%,煮熟增重率为77.0%,蒸煮损失率为12.0%的青稞面条产品。     

青稞的营养功能及其高值化利用研究进展

近年来,青稞因其丰富的营养组成及独特的生物活性而受到广泛关注。青稞中抗性淀粉、Lunasin多肽、独特的脂肪酸和非淀粉多糖组成以及丰富的酚类物质令其在抗癌、降血糖、降血脂等方面具有良好的发展潜力,然而其加工利用程度低,高附加值产品少,限制了青稞产业的发展。本文从特色营养功能成分、生物活性、加工利用技术和高附加值产品开发现状四个方面对青稞研究进展进行了总结,以期促进青稞的深入研究和应用,为青稞产业持续发展提供进一步支持。     

糌粑及其研究进展

糌粑是由青稞经除杂、清洗、晾干、翻炒、磨粉等工艺制成的粉状食物,也被称为青稞炒面。糌粑作为高原特色食品,具有热量高、营养丰富、酥软香甜、抗旱耐饥、易于保存和制作的特点,便于游牧民们携带及食用。介绍了糌粑、糌粑主要营养成分的研究近况及糌粑产品的加工利用现状,并指出了糌粑今后的研究方向。     

萌动青稞米酒的工艺研究及理化性质分析

为促进中国青稞产业的发展,开发高附加值青稞产品。以萌动青稞为原料,采用单因素试验和正交试验进行萌动青稞米酒的制备及工艺优化,并分析其营养组成和香气成分。以感官评价为基础,通过测定酒精度、糖度和酸度,得到萌动青稞米酒的最佳制备工艺:甜酒曲添加量0.8%,培养时间60 h,培养温度28℃。相比于青稞米酒,萌动青稞米酒中总酚、黄酮和γ-氨基丁酸(GABA)含量明显高,蛋白质、膳食纤维、β-葡聚糖和淀粉含量低。萌动青稞米酒中检测出102种挥发性化合物,以醛类、醇类、酯类物质化合物为主。试验结果丰富了青稞产品种类,对青稞新型饮品的开发具有一定指导意义。     

响应面法优化白酒糟富里酸的提取工艺

根据腐殖质的成因和白酒糟形成过程之间的相关联系,以鲜、干白酒糟为原料提取白酒糟富里酸,分析干、鲜白酒糟中富里酸的含量变化;对比水浴提取和超声提取条件下的富里酸得率,确定提取方法;单因素和响应面优化法确定最佳提取工艺条件。结果表明,鲜白酒糟中富里酸含量高于干白酒糟;超声提取法优于水浴提取法;富里酸的最佳提取工艺为固液比1∶8.4（g∶mL）,pH值11.2,超声时间32 min,超声功率360 W,超声温度45 ℃,富里酸得率达6.29%。     

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。     

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。     

Barley distillers grains as a protein supplement for dairy cows

Dried distillers grains produced from a mix of 65% barley and 35% corn were evaluated in digestion and lactation experiments. Dried barley distillers grains had 56% NDF, 29% CP, 3% amino acid N, 2.5% NDIN (55% of total N), and 1.8% ADIN (39% of total N). Wet barley distillers grains had 38% NDF, 27% CP, 2.7% amino acid N, .5% NDIN (12% of total N), and .8% ADIN (19% of total N). Digestibility of DM and N was similar among lactating dairy cows fed diets containing approximately 25% corn silage DM, 15% alfalfa silage DM, 15% alfalfa hay DM, plus varying amounts of a corn-barley concentrate mix and supplemental CP from soybean meal, barley distillers grains, or from 1:1 mixture of soybean meal and barley distillers grains. Digestibility of ADIN, NDF, and ADF increased with increasing amounts of barley distillers grains in the diet. Similar diets were fed to 60 Holstein cows for 84 d in a lactation experiment. Source of supplemental protein did not affect milk production (22.5 kg/d), FCM (20.4 kg/d), milk fat percent (3.6%), or DM intake (19.0 kg/d). Milk protein percent was decreased by feeding barley distillers grains. It was concluded that barley distillers grains were an acceptable protein source for dairy cows and that ADIN and NDF might not be appropriate measures of the nutritional value of this product.     

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.     

The energy content of wet corn distillers grains for lactating dairy cows

Forty-five energy balances were completed with 12 multiparous, lactating Holstein cows in a study designed to determine the energy content of wet corn distillers grains. Treatments were applied in a repeated switchback design and consisted of total mixed diets containing 31.4% corn silage, 18.4% alfalfa hay, and either 30.7% rolled corn and 16.7% soybean meal or 17.0% rolled corn and 31.2% wet corn distillers grains (dry matter basis). Replacement of corn and soybean meal with wet corn distillers grains reduced dry matter intake 10.9% but did not affect milk production. Neither digestible nor metabolizable energy were affected by diet composition. Heat and milk energy output did not differ by diet, but body energy retained was 2.8 Mcal/d less in cows fed the wet corn distillers grains diet. Multiple regression estimates of maintenance metabolizable energy requirement and partial efficiencies of metabolizable energy used for lactation and body energy deposition did not differ by diet. Pooled estimates were 136.2, 0.66, and 0.85, kcal of metabolizable energy/ body weight0.75 per day, respectively. Calculated by difference, wet corn distillers grains was estimated to contain 4.09, 3.36, and 2.27 Mcal/kg of dry matter as digestible, metabolizable, and lactational net energy, respectively. These energy estimates were 7 to 11% and 10 to 15%, respectively, greater than those reported for dried corn distillers grains by the 1989 and 2001 dairy NRC publications.     

Milk production and composition from cows fed wet corn distillers grains

Twelve lactating Holstein cows were utilized in a repeated switchback design to evaluate milk production and milk fat composition responses to wet corn distillers grains. Total mixed diets consisted of 31.4% corn silage, 18.4% alfalfa hay, and either 50.2% of a concentrate mix that contained mostly corn and soybean meal or 19.4% of a concentrate mix that contained mostly corn and 31.2% wet corn distillers grains. The first 4 wk of each 6-wk period were for adaptation to diets; data were collected during wk 5 and 6 of each period. Although dry matter intake (22.1 vs. 19.7 kg/d) was lower when cows were fed the wet corn distillers grains diet, milk production (30.7 vs. 30.8 kg/d) was similar for cows fed both diets. Milk fat (3.60 vs. 3.85%) was slightly higher, and protein (3.06 vs. 2.84%) was lower, when cows were fed the wet corn distillers grains diet. Milk fat from cows fed wet corn distillers grains contained lower concentrations of saturated fatty acids and higher concentrations of long-chain and unsaturated fatty acids. The feeding of wet corn distillers grains increased the proportion of unsaturated fatty acids in milk fat without changing milk production.     

Relation of intake to digestibility of diets containing soyhulls and distillers dried grains

Fifty-four multiparous Holstein cows were used to compare the influence of intake on digestibility of three diets. All diets contained a 50:50 ratio (dry basis) of ammoniated corn silage and concentrate. The control concentrates consisted of corn, oats, and soybean meal. The two test concentrates contained either 43.8% soyhulls or 71.6% corn distillers dried grains with solubles. Each diet was fed at three intakes. Dry cows were fed one times maintenance intake, cows producing 10 to 20 kg milk daily were fed at twice maintenance, and cows producing 27 to 49 kg daily were fed ad libitum (four times maintenance). Digestibilities of DM for the control, distillers grains, and soyhull diets, respectively, were: for dry cows, 84.1, 66.6, and 78.8%; for medium producers, 76.6, 53.8, and 74.2% and for high producers, 60.5, 44.3, and 62.8%. At ad libitum intake, the DM, NDF, ADF, and CP digestibilities were lower for control than for the soyhulls diet. Discounts per unit of maintenance of 9.3, 11.2, and 6.8% were obtained for the control, distillers grains, and soyhull diets. These results confirm the generally accepted concept of energy discounts for grain-soybean meal diets, but discounts were higher than reported previously. Compared with the control diet soyhulls appears to lower, and distillers grains increase, the discount.     

Sorption isotherm of corn distillers dried grains with solubles (DDGS) and its prediction using chemical composition

Corn distillers dried grains with solubles (DDGS) has high feed value due to its nutritive contents. The ratio of wet distillers grains (WDG) and condensed distillers solubles (CDS) added during the production process determines the chemical composition of DDGS. Effect of changing this ratio on water sorption behaviour of DDGS, at different temperature, was studied. Five mathematical models were evaluated to explain the sorption behaviour of DDGS. Prediction of sorption isotherm from chemical composition using a four-component model was also investigated. DDGS followed a BET Type III isotherm with higher equilibrium moisture content at increasing relative humidity. Difference in the sorption isotherm curves of DDGS samples reduced as equilibrium relative humidity increased. Equilibrium moisture content of DDGS samples reduced with lowering of CDS quantity added during production process. Modified Halsey equation was found suitable for mathematically explaining the sorption behaviour of DDGS. Binding energy of water molecule with DDGS increased with lowering of CDS level. Sorption behaviour of DDGS can be predicted from the chemical composition of protein, sugar, minerals, starch, fibre and glycerol. Increase in CDS level increased the percent relative deviation of predicted values calculated using the modified four-component model and might be due to the interaction between the chemical compounds present in the samples.     

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.