脱脂玉米干酒糟及其可溶物在动物生产中的应用

玉米干酒糟及其可溶物(dried distillers grains with solubles,DDGS)已经在世界各国饲料中得以广泛应用。近年来,为了最大限度地降低成本,在乙醇生产过程中提取玉米油,制成脱脂玉米干酒糟及其可溶物(reduced-fat dried distillers grains with solubles,RF-DDGS),RF-DDGS中蛋白质和纤维素含量升高,油脂含量降低。RF-DDGS是一种很好的饲料原料,引起动物营养学家们的广泛关注。结合RF-DDGS的国内外研究状况,综述了RF-DDGS的生产现状,营养特点,及其在动物生产中的应用,结合目前RF-DDGS在动物生产中存在的问题和潜在应用,对RF-DDGS的进一步发展进行展望,旨在为RF-DDGS在畜禽生产中的科学应用提供依据。     

Extrusion Studies of Aquaculture Feed using Distillers Dried Grains with Solubles and Whey

Three isocaloric (3.5 kcal/g) ingredient blends containing 20, 30, and 40% distiller-dried grains with solubles (DDGS) along with 5% whey were prepared with a net protein content adjusted to 28% (wet basis [wb]). Other ingredients in the blends included soy flour, corn flour, fish meal, vitamin, and mineral mix. These blends were extruded in a single-screw extruder at 15, 20, and 25% (wb) moisture content and at 130 and 160 rpm screw speeds. Compared to previous research, the durability and unit density of the extrudates in this study were found to increase substantially by the addition of whey to the blends. Increasing the DDGS content from 20 to 40% resulted in a 5.8 and 16.8% increase in extrudate moisture content and redness, respectively, but produced a decrease of 11.2% in brightness and 3.6% in yellowness of the extrudates. Increasing the moisture content of the ingredient blends from 15 to 25% resulted in an increase of 16.1, 8.7, and 9.3% in moisture content, durability, and redness, respectively, but a decrease of 9.8 and 5.6%, respectively, in brightness and yellowness of the extrudates. Neither DDGS level nor screw speed significantly affected extrudate durability or unit density. In fact, changing the screw speed had no significant effect on many of the properties of the extrudates studied, except for moisture content, redness, and yellowness. As demonstrated in this study, ingredient moisture content and screw speed are critical considerations when producing extrudates with feed blends containing DDGS; further work is needed to optimize processing conditions and to produce floating feeds.     

Development and fecundity rate of Tribolium castaneum (Herbst) on Distillers Dried Grains with Solubles

This research focused on the influence of two samples of corn Distillers Dried Grains with Solubles (DDGS) obtained from an “old” generation dry-grind fuel ethanol plant as a food and oviposition resource for red flour beetle, Tribolium castaneum, in contrast with traditional flour (90%)/yeast (10%) diet. Larval development was significantly faster on a flour/yeast diet (18.6 d) compared to the DDGS sample 1 (44.1 d) and DDGS sample 2 (34.5 d). DDGS sample 1 had the highest larval mortality (38.7%) with a wider mortality range (6.7–66.7%) compared with flour/yeast (4.4%, range 0–14.3%) and DDGS sample 2 (7.1, range 0–26.7%). Both DDGS diets and the flour/yeast diet had no significant influence on egg incubation period or pupation time and percentage of egg hatching or pupal mortality. Additionally, fecundity was significantly lower on DDGS compared to the flour/yeast diet (18.0, 36.5, and 175.5 eggs per female on DDGS sample 1, DDGS sample 2, and flour/yeast diet, respectively). These results indicate that this type of DDGS is not a suitable developmental diet compared to the standard laboratory diet and that the addition of this type of DDGS to animal feeds should not increase feed vulnerability to flour beetle infestation. A comparison of DDGS samples by particle size indicated that the larger particle size, sample 1 was less suitable for T. castaneum oviposition and development.     

基于主成分分析的玉米DDGS物理特性评价

为对玉米DDGS的物理特性进行分析及量化评价,以国内外8个玉米DDGS为试验材料,测定分析其容重、热物理特性、摩擦特性、粉碎特性及色差指标参数,并运用主成分分析法简化物理特性指标,构架评价体系,得到每种样品的综合得分。结果表明:样品各物理特性指标间存在不同程度的差异;各物理特性指标之间存在不同程度的相关性,比热与热导率呈极显著正相关,与导温系数呈极显著负相关;热导率与平均粒径呈显著正相关;导温系数与容重呈极显著负相关;摩擦系数与休止角呈极显著正相关,与平均粒径呈极显著负相关;L*、b*与平均粒径呈极显著正相关;L*与b*呈极显著正相关。通过主成分分析提取了3个主成分,累积方差贡献率达到87.415%;主成分分析的结果表明进口玉米DDGS的物理特性较好。     

Physical and Flow Properties of Regular and Reduced Fat Distillers Dried Grains with Solubles (DDGS)

With the remarkable growth of the US fuel ethanol industry in the past decade, large quantities of corn-based distillers dried grains with solubles (DDGS) are now being produced. Flowability of DDGS has become a problem throughout the industry, as it is often restricted by caking and bridging during storage and transport. The objective of this study was to quantify physical and flow properties of commercially produced unmodified (9.3% db fat) and reduced fat (2.1% db) DDGS to determine if fat level affects flowability. The compressive modulus of reduced fat DDGS was 28.2% higher than unmodified DDGS, but shear stress resistance was the same (0.03 kg/m²). Carr testing indicated that reduced fat DDGS had an angle of repose 4.3% lower, and Carr compressibility 70% lower, than unmodified DDGS. However, in terms of uniformity and dispersibility, reduced fat DDGS was, respectively, 100 and 41.5% greater than regular DDGS. Jenike shear testing revealed that reduced fat DDGS had unconfined yield strength and Jenike compressibility values that were 15.7 and 40.0% lower, respectively, than unmodified DDGS, but had major consolidating stress and flowability index values that were 6.7 and 13.2% higher, respectively. For regular DDGS, the flow function curve was located closer to the shear stress axis, which indicated slightly worse flowability than the reduced fat DDGS. Overall, a reduction in the fat content did show slight improvement in some flow properties, especially compressibility. Both types of DDGS were ultimately classified as cohesive in nature. Exploration of the data using a previously developed assessment tool appeared to show that the reduced fat DDGS may have better flow. Continued research should be pursued, including an examination of the effects of other chemical constituents, as well as particle morphology. Disclaimer  Mention of a trade name, propriety product or specific equipment does not constitute a guarantee or warranty by the US Department of Agriculture and does not imply approval of a product to the exclusion of others that may be suitable. State if Meeting Presentation  No     

Fractionation of Distillers Dried Grains with Solubles (DDGS) Through a Narrowing of Particle Size Distribution Followed by Aspiration

Distiller's dried grains with solubles (DDGS) may have more value and utility if they can be separated into high protein and high fiber fractions. A variety of such separation processes have been proposed; two of the most promising processes involve three screening and three air classification unit operations. In the present study, an alternative process involving fewer unit operations is demonstrated. DDGS are subjected to a single screening, and the oversize particles are processed in a mill setup so that it narrows the particle size distribution of the oversize fraction. The milled DDGS is then processed in an air classification device known as an aspirator, which separates it into high and low terminal velocity fractions. The combination of the undersize fraction and the low terminal velocity fraction were substantially enriched in protein. The separation achieved by this process compares favorably to other reported processes while being less complex.     

Corn Distillers' Dried Grains with Solubles and Corn Distillers'Dried Grains: Dry Fractionation and Composition

Corn distillers' dried grains with solubles (CDGS) and corn distillers' dried grains (CDG) at various moisture and fat contents were pin milled and screened. Fractions of CDGS and CDG contained from 11.4–45.7% and 12.5–49.6% protein, respectively (dry basis), compared with 30% for CDGS and 25% for CDG. The highest protein shifts were obtained when CDGS at initial moisture of 21% was ground twice at 14,000 rpm and CDG at initial moisture of 21% was ground once at 14,000 rpm. Fat, ash, dietary fiber contents, and amino acid composition of CDGS and CDG fractions were also determined.     

Functional and Biochemical Alterations of Fish Meal,Soybean Meal,and Distillers Dried Grains with Solubles as Affected by a Single-Screw Extruder

The goal of this study was to investigate the effect of extrusion-forced structural changes on the extent of functional and biochemical changes of three selected protein sources that are predominantly used in aquafeed, i.e., fish meal (FM), soybean meal (SBM), and distillers dried grains with solubles (DDGS). The samples were individually extruded in a single-screw extruder using a factorial design with replicated central composite points at a temperature of 80, 110, and 140 °C; screw speed of 80, 150, and 220 rpm; and moisture content of 150, 225, and 300 (g/kg). Extrusion temperature and feed moisture significantly affected the nitrogen solubility in water (NSI), sodium dodecyl sulfate, and 2-mercaptoethanol solvents. Screw speed had only a minor effect on this value (P?<?0.05). Solubility results indicated that the contribution of hydrophobic and ionic interactions were more significant than that of the disulfide bonds, particularly for FM and SBM extrudates. For all extrudates, the highest peak viscosity was observed at the highest temperature and lowest screw speed. Extrusion processing led to considerable increase in T _g of 79 % and 67 % for the DDGS and SBM samples, and a reduction of 19 % for the FM sample, respectively. Extrusion processing increased relative protein digestibility (RPD) of the SBM extrudates the most, followed by those of DDGS and FM. Overall, the severity of the extrusion conditions adversely affected available lysine content (AL) and L* color score, but relatively increased RPD of the extrudates. SBM extrudates had the lowest reduction in AL. Despite the decrease in AL, the results for both plant-based protein extrudates were comparable in quality to those of FM. The outputs of this study provide viable information for feed formulator and feed technologist in feed and food industries.     

玉米DDGS近红外光谱模型转移研究

为探讨玉米DDGS近红外光谱模型转移应用效果,实现不同仪器间模型共享,以FOSS DS2500F型为主仪器、TR3750-5000型为从仪器,采用近红外光谱基线平移的方法来实现原始光谱转移,分别从水分、粗蛋白质、粗脂肪、氨基酸等组分的建模参数即交互验证标准差(SECV)、交互验证决定系数(1-VR)和外部样品验证预测模型的光谱差异性、系统偏差(Bias)、预测平均标准偏差(SEP)、预测结果准确率等,多维度评估光谱转移后所建预测模型效果。通过验证和评估,从DS2500F型仪器原始光谱转移到TR3750-5000型仪器建立的水分、粗蛋白质、粗脂肪、氨基酸等预测模型SECV、1-VR值与TR3750-5000型仪器原始光谱建立的预测模型无显著差异;验证集样品试验结果显示,转移后的预测模型光谱、系统偏差(Bias)、预测平均标准偏差(SEP)以及准确率与TR3750-5000型仪器原始预测模型对比效果基本一致。结果表明,从DS2500F原始光谱转移到TR3750-5000型仪器建立的玉米DDGS水分、粗蛋白质、粗脂肪、氨基酸等预测模型是完全可以替代TR3750-5000型仪器原始预测模型,可提高模型利用率,具有良好的实用性和共享性,适用于饲料生产企业日常玉米DDGS质量控制。     

性别对猪肉品质特性的影响

以去势公猪和母猪的背最长肌为材料,测定其理化指标,研究性别对猪肉品质特性的影响。结果表明：性别对猪肉的品质特性有明显影响。与母猪背最长肌的水分含量（75.16%）相比,去势公猪背最长肌的水分含量（74.40%）偏低;而去势公猪背最长肌的脂肪含量是母猪的2.5 倍左右;宰后pH24 值为5.85,相对母猪肉pH24 5.66较高;保水性较好;但其红度值为0.52,相对母猪肉红度值0.92较小;蒸煮损失为24.05%,相对母猪肉蒸煮损失21.76%较大;嫩度较差,去势公猪肉剪切力为5.10 kg,而母猪肉剪切力为3.79 kg。综合各项指标得出,去势公猪肉较宜于加工优质生鲜肉产品,但应注意改善产品的色泽和嫩度;而母猪肉由于在蒸煮损失和嫩度方面占优,较宜于加工灌肠等肉制品。     

The susceptibility of animal feed containing Dried Distiller's Grains with Solubles to Tribolium castaneum (Herbst) infestation

Understanding the susceptibility of commercially available animal feeds which contain Dried Distiller's Grains with Solubles (DDGS) to insect infestation is the first step in developing a pest management strategy for a stored product. This study is a nascent analysis of animal feed containing DDGS susceptibility to Tribolium castaneum (Herbst) infestation, one of the most important post-harvest insect pests world-wide. Three types of animal feed containing 5–10% DDGS in their formula mixtures were obtained from two feed manufacturers in Indiana, USA including: crumbled poultry feed, pelletized juvenile frog feed, and pelletized adult frog feed. Besides commercially available animal feed, laboratory manufactured feed were simulated by mixing Flour/Yeast (F/Y), T. castaneum normal laboratory diet, with 10, 20, 30, 40, and 80% DDGS (% based on weight). Larval developmental time was used to evaluate feed susceptibility to T. castaneum infestation. The T. castaneum larval period was significantly increased when fed on pelletized adult frog feed, pelletized juvenile frog feed, and crumbled poultry feed (29.8 ± 0.5, 26.0 ± 0.3, and 21.9 ± 0.3 d respectively), compared with F/Y (16.1 ± 0.3 d). The larval period was significantly decreased however, when fed on ground poultry feed (15.5 ± 0.2 d). Insect development on laboratory manufactured feeds was similar to F/Y regardless of DDGS ratios added in this study (15.9–16.9 d). These results suggested that first; particle size (PS) was one of the influential factors on susceptibility of commercially available animal feed to T. castaneum apart from feed chemical composition, and second, adding 10–80% DDGS to the laboratory manufactured feed did not change feed susceptibility to T. castaneum infestation.     

Sensory Evaluation of Baked Foods Incorporating Different Levels of Distillers' Dried Grains with Solubles from Soft White Winter Wheat

Baguettes, cinnamon rolls, and chocolate chip cookies containing 0, 12.5% or 25% distillers’ dried grains with solubles (DDGS) from soft white winter wheat substituted for flour (w/w) were evaluated by an experienced panel to determine how much DDGS could successfully be incorporated into baked products. Panelists were unable to differentiate control cookies from those containing 12.5% DDGS. Attribute analyses of seven flavor and four texture traits were conducted, and overall acceptability was determined for products found to be different in their sensory properties. Both the control and experimental cinnamon rolls and chocolate chip cookies were rated as highly acceptable. The baguettes containing DDGS were found to be less acceptable than the control because of a stronger flavor and/or off-flavor.     

Investigating Dried Distiller's Grains with Solubles vulnerability to Tribolium castaneum (Herbst) infestation by using choice and no-choice experiments

Demand for Dried Distiller's Grains with Solubles (DDGS) in international markets and the United States has increased during the past few years. Knowledge of DDGS supplemented animal feed vulnerability to insect infestation is critical for safe feed storage. To assess this vulnerability, it is necessary to know how DDGS is susceptible to insect infestation, while stored as raw ingredient. This research focused on the susceptibility of different types of DDGS (raw and ground) to red flour beetle, T. castaneum, infestation under 30% and 50% relative humidity (r.h.) regimes. Larval period at 30% r.h. increased 2–3 fold on raw DDGS diets with larger particle sizes (PSs) compared with their normal laboratory diet, a mixture of flour and yeast (9:1) (F/Y). However, grinding DDGS samples and increasing the r.h. to 50% decreased the amount of time required for insect development thus increasing DDGS vulnerability to T. castaneum infestation compared with raw DDGS at r.h. of 30%. As was expected, T. castaneum egg and pupal development were not affected by diet or humidity. The results suggested that DDGS as a raw ingredient at 30% r.h. was not a suitable food source for T. castaneum and given a choice, the majority of T. castaneum adults prefer laboratory diet over DDGS. Additionally, fecundity was significantly lower on DDGS compared with the control diets (F/Y and ground corn (GCORN)). These results indicated that these types of DDGS were not suitable developmental diets compared with the F/Y diet if stored at 30% r.h. with larger PSs.     

Twin-Screw Extrusion Processing of Distillers Dried Grains with Solubles (DDGS)-Based Yellow Perch (<Emphasis Type="Italic">Perca flavescens</Emphasis>) Feeds

Increases in global aquaculture production, compounded with limited availabilities of fish meal for fish feed, has created the need for alternative protein sources. Twin-screw extrusion studies were performed to investigate the production of nutritionally balanced feeds for juvenile yellow perch (Perca flavescens). Five isocaloric (~3.06 kcal/g) ingredient blends, adjusted to a target protein content of 36.7% db, were formulated with 0%, 10%, 20%, 30%, and 40% distillers dried grains with solubles (DDGS) at an initial moisture content of 5–7% db, with appropriate amounts of fish meal, fish oil, whole wheat flour, corn gluten meal, and vitamin and mineral premixes. During processing, varying amounts of steam (6.9–9.7 kg/h) were injected into the conditioner and water (6.7–13.1 kg/h) into the extruder to modulate the cohesiveness of the final extrudates. Extrusion cooking was performed at 226–298 rpm using a 1.9 mm die. Mass flow rate and processing temperatures generally decreased with progressively higher DDGS content. Moisture content, water activity, unit density, bulk density, expansion ratio, compressive strength and modulus, pellet durability index, water stability, angle of repose, and color were extensively analyzed to quantify the effects of varying DDGS content on the physical properties of the final extrudates. Significant differences (P < 0.05) among the blends were observed for color and bulk density for both the raw and extruded material, respectively, and for the unit density of the extruded product. There were also significant changes in brightness (L), redness (a), and yellowness (b) among the final products when increasing the DDGS content of the blends. Expansion ratio and compressive strength of the extrudates were low. On the other hand, all extruded diets resulted in very good water stability properties and nearly all blends achieved high pellet durability indices. In summary, each of the ingredient blends resulted in viable extrudates.     

Effect of chemical and physical properties of Dried Distillers Grains with solubles (DDGS) on Tribolium castaneum (Herbst) development

Dried Distillers Grains with Solubles (DDGS) has been used as a grain-based supplement in animal feed. The focus of this study was to investigate the effects of chemical and physical characteristics that may affect DDGS susceptibility to Tribolium castaneum (Herbst) infestation. Multiple regression-based models were built to determine if the diet’s chemical and physical characteristics affect T. castaneum development. Based on the regression models, diet particle size was the most influential factor in larval development. Larval weight increased more rapidly on T. castaneum normal laboratory diet, 90% flour/10% brewer’s yeast (F/Y), followed by ground DDGS, compared to raw DDGS with different particle sizes. To determine the effect of diet particle size on larval development, experiments were conducted to increase particle size by pelletizing F/Y using a rotary drum granulation apparatus. T. castaneum larval stage lasted significantly longer on F/Y granules with a particle size of 1.4 mm or larger. Although the chemical properties of DDGS (protein, fat, fiber and ash content) were not significant predictors of T. castaneum larval development, larval developmental time and weight gain on ground DDGS was significantly slower than on F/Y, highlighting the potential importance of nutritional factors not accounted for in our analysis. Our results conclude that storing DDGS as raw ingredient and in the granule or pellet form with large particle size may help limit T. castaneum infestations. Although granulation or pelletization may not be economically feasible for small manufacturing plants, larger producers may benefit from the reduced risk of insect contamination associated with secondary feeders such as T. castaneum.     

Chemical Composition of Distillers' Dried Grains with Solubles (DDGS) from Soft White Wheat, Hard Red Wheat and Corn

The chemical composition of distillers' dried grains with solubles (DDGS) produced from two varieties of soft white wheat, a blend of hard red wheats, and corn was determined. On the average, the concentration of protein increased 2.4–3.1 times, crude fiber 2.6–3.8 times, and lipid 1.4–2.4 times. The carbohydrate decreased by 30–50% in DDGS compared to the corresponding starting grain. The ash in DDGS was 3.8–7.8 times that of the original grain. Many of the differences (p < 0.05) in the concentration of lipid, protein, and crude fiber among the starting grains were also present in the DDGS products.     

The Neutral Detergent Fiber, Acid Detergent Fiber, Crude Fiber, and Lignin Contents of Distillers' Dried Grains with Solubles

Distillers’ dried grains with solubles (DDGS) were prepared from two cultivars of soft white winter wheat, a blend of red wheats and corn. DDGS made from the three whole wheat grains and corn contained, on a dry weight basis, 30–55% neutral detergent fiber (NDF), 10–14% acid detergent fiber, 7–9% crude fiber, and 2–4% lignin, an increase of 3–4 times over that contained in the unconverted whole grains. The significantly higher concentration of DDGS NDF isolated without sodium sulfite (vs with sodium sulfite) in the detergent solution was not due entirely to increased levels of residual protein.     

Barley Neutral Lipid Changes During the Fuel Ethanol Production Process and Product Acceptability from the Dried Distillers Grains

Changes in lipids were traced from the parent barley through the fuel production process to the finished dried distillers grains (DDG). Free fatty acids (FFA) increased from 6% to 22% while the triacylglycerols (TAG) decreased from 73% to 56% during processing. Minor quantitics of ethyl esters of fatty acids, not found in the parent barley, were formed during fermentation. The fatty acid profile of the monoand diacylglycerol and TAG bands remained constant over processing, indicating that these fractions were attacked by nonspecific hydrolysis. During processing, the FFA composition changed with an increase in saturated fatty acids and a decrease in unsaturated fatty acids. Consumer taste panelists preferred commercial and ground barley supplemented granolas over granolas containing either full fat or defatted barley DDG. Trained taste panel results indicated that defatting the DDG did not result in improved product acceptability.     

基于电子鼻技术的猪肉脯品质判别分析

为实现猪肉脯品质的快速判别,采用电子鼻技术对12 个品牌3 个批次共108 个猪肉脯样品进行分析检测,同时依据GB/T 31406—2015《肉脯》对样品的蛋白质、水分、氯化物、脂肪及总糖含量进行品质评判,选取电子鼻响应曲线中120～150 s稳定数据段的平均值作为表征变量,结合主成分分析和k最近邻法（k=3）建立猪肉脯品质等级的判别模型。结果表明,所建模型的理论判别准确率可达89.81%,基于电子鼻技术的猪肉脯品质判别具有一定的可行性。