Effects of Varying CDS Levels and Drying and Cooling Temperatures on Flowability Properties of DDGS

Demand for alternative fuels and the need to reduce dependence on fossil fuels have triggered the growth of corn‐based ethanol production, which is expected to rise in future years. Transportation of the coproduct distillers dried grains with solubles (DDGS) from this industry occurs under various environmental conditions. Transporting DDGS is often problematic, because caking between the particles can lead to flow problems. In this study, we have prepared DDGS by combining condensed distillers solubles (CDS) with distillers wet grains and then drying. We investigated the effects of CDS level (10, 15, and 20%, wb), drying temperature (100, 200, and 300°C), and cooling temperature (–12, 25, and 35°C) on the flowability of the resulting DDGS. Statistical analyses of the resulting data found significant differences among the cooling temperature levels for angle of repose, total flow and flood indices, dispersibility, water activity, and protein dispersibility index. Additionally, significant interaction effects between CDS, drying temperature, and cooling temperature levels for angle of repose, total flow and flood indices, dispersibility, and protein dispersibility index were observed. Response surface regression on selected dimensionless flowability parameters was also applied. However, multivariate PLS regression yielded better results (R² > 0.8) than response surface plots. Understanding the effects of drying and cooling temperatures as well as CDS levels can be used to help improve the industrial processing of DDGS and improve storage and transportation.     

Physical and Chemical Characterization of Fuel Ethanol Coproducts Relevant to Value‐Added Uses

One of the fastest growing industries in the United States is the fuel ethanol industry. In terms of ethanol production capability, the industry has grown by more than 600% since the year 2000. The major coproducts from corn‐based ethanol include distillers dried grains with solubles (DDGS) and carbon dioxide. DDGS is used as a livestock feed because it contains high quantities of protein, fiber, amino acids, and other nutrients. The goal of this study was to quantify various chemical and physical properties of DDGS, distillers wet grains (DWG), and distillers dried grain (DDG) from several plants in South Dakota. Chemical properties of the DDGS included crude ash (5.0–21.93%), neutral detergent fiber (NDF) (26.32–43.50%), acid detergent fiber (ADF) (10.82–20.05%), crude fiber (CF) (8.14–12.82%), crude protein (27.4–31.7%), crude fat (7.4–11.6%), and total starch (9.19–14.04%). Physical properties of the DDGS included moisture content (3.54–8.21%), A_w (0.42–0.53), bulk density (467.7–509.38 kg/m³), thermal conductivity (0.05–0.07 W/m·°C), thermal diffusivity (0.1–0.17 mm²/sec), color L* (36.56–50.17), a* (5.2–10.79), b* (12.53–23.36), and angle of repose (25.7–47.04°). These properties were also determined for DWG and DDG. We also conducted image analysis and size determination of the DDGS particles. Carbon group characterization in the DDGS and DDG samples were determined using NMR spectroscopy; O‐alkyl comprised >50% of all DDGS samples. Results from this study showed several possibilities for using DDGS in applications other than animal feed. Possibilities include harvesting residual sugars, producing additional ethanol, producing value‐added compounds, using as food‐grade additives, or even using as inert fillers for biocomposites.     

Modeling Distillers Dried Grains with Solubles (DDGS) Mass Flow Rate as Affected by Drying and Storage Conditions

Ethanol production in 2015 was over 15 million gallons in the United States, and it is projected to increase in the next few years to meet market demands. With the continued growth in the ethanol industry, there has been enormous expansion in distillers grains production. Because the local market for distillers dried grains with solubles (DDGS) is often saturated, it is essential to transport DDGS long distances, across the United States and to international markets. Caking and agglomeration of DDGS particles in hoppers and other storage structures are typical during transportation. The current study deals with DDGS prepared by combining condensed distillers solubles (CDS) with distillers wet grains and then drying at varying temperatures. DDGS was stored in conical hoppers under varying ambient temperature, consolidation pressure, and time conditions. We investigated the effects of CDS (10, 15, and 20% wb), drying temperature (100, 200, and 300°C), drying time (20, 40, and 60 min), cooling temperature (0, 25, and 50°C), consolidation pressure (0, 1.72, and 3.43 kPa), and consolidation time (0, 3, and 6 days) levels on various flow parameters. To examine these factors, Taguchi's experimental design with an L ₁₈ orthogonal array was implemented. Response surface modeling yielded mass flow rate = f (Hausner ratio, angle of repose) with R ² = 0.99, and it predicted moisture content for good, fair, and poor flow. Results showed that drying temperature, drying time, and cooling type were the main factors in predicting mass flow rate. The Johansson model for predicted mass flow rate was calibrated with experimental data, and a new parameter, compressibility factor, with a value of 0.96 g²/(min cm³), was determined to quantify the divergence of compressible and cohesive materials (such as DDGS) for free‐flowing bulk solids. Thus, the predicted models may be beneficial for quantitative understanding of DDGS flow.     

Evaluation of Two Products Recently Introduced as Nitrification Inhibitors

This study compared the relative effectiveness of two products recently introduced as nitrification inhibitors with other materials used to inhibit nitrification. Four soils were treated with 0, 0.2, 1, 5, and 25 mg kg^?1 of nitrapyrin (NP), a new microencapsulated nitrapyrin product (ENP), dicyandiamide (DCD), a new maleic-itaconic polymer product (MIP), and ammonium thiosulfate (ATS). The soils were also treated with 200 mg N kg^?1 as urea, and percent inhibition of nitrification determined after 2 or 4 weeks of incubation. After 4 weeks, similar levels of nitrification inhibition were provided by 1 mg kg^?1 of NP (72%), 5 mg kg^?1 of ENP (79%), and 25 mg kg^?1 of DCD (73%), averaged across soil. After 4 weeks with a sandy soil, the highest rate of MIP and ATS provided 15 and 36% inhibition, respectively. MIP and ATS were ineffective at inhibiting nitrification when added to the other three soils.

Abbreviations: ATS: ammonium thiosulfate; DCD: dicyandiamide; ENP: encapsulated nitrapyrin; MIP: maleic-itaconic polymer; NP: nitrapyrin; UAN: urea-ammonium nitrate liquid fertilizer     

Drying Kinetics of Distillers Wet Grains (DWG) Under Varying Condensed Distillers Solubles (CDS) and Temperature Levels

Distillers dried grains with solubles (DDGS) is a widely used animal feed. But transportation of DDGS is often troublesome because of its stickiness. DDGS is formed by combining condensed distillers solubles (CDS) with distillers wet grains (DWG) and then drying. As a first step toward understanding drying behavior, this study's objective was to investigate batch‐drying kinetic behavior of DWG with three CDS addition levels (10, 15, and 20% wb) and three drying‐temperature levels (100, 200, and 300°C). Multiple nonlinear mathematical models were used to fit experimental drying data for moisture content versus drying rate. A new comprehensive model was developed (R² = 0.89, SEM = 18.60) from a modified Chen and Douglas model to incorporate CDS and drying‐temperature terms. Drying temperature affected drying rate more significantly than did changes in CDS level; thus, drying temperature was the main effect and CDS was a subeffect. Increasing the drying temperature increased the drying rate significantly for all levels of CDS addition. This model can be used for predicting DWG drying behavior under broad operating conditions; it can be used to help the industry produce better DDGS, which may thus result in better DDGS handling and transport characteristics.     

氯甲基吡啶对滴灌棉田土壤微生物群落功能多样性的影响

已知硝化抑制剂氯甲基吡啶能有效抑制土壤硝化,减少氮的淋洗和硝化-反硝化损失,促进作物对氮素的吸收,但是其对干旱区滴灌条件下土壤微生物群落功能多样性的影响尚不明确。本试验研究了尿素添加氯甲基吡啶(Nitrapyrin)分次随水滴施对干旱区滴灌棉田土壤微生物碳代谢和群落功能多样性的影响。试验采用随机区组设计,设置不施氮肥[CK,0 kg(N)·hm~(-2)]、单施尿素[Urea,225 kg(N)·hm~(-2)]和尿素添加氯甲基吡啶[Urea+nitrapyrin,225 kg(N)·hm~(-2)+2.25 kg(nitrapyrin)·hm~(-2)]3个处理,重复4次,采用Biolog-ECO法进行土壤微生物碳代谢和功能多样性研究。结果表明:与不施氮肥(CK)相比,施用尿素和尿素添加氯甲基吡啶均能显著提高土壤微生物对31种碳源的代谢能力(AWCD)和代谢强度(S)(P0.05),增加土壤微生物多样性和丰富度(Shannon指数、Simpson指数、Mc Intosh指数和Richness指数)以及对各类碳源的利用能力。尿素添加氯甲基吡啶随水滴施后,土壤微生物AWCD值、碳代谢强度、Shannon指数、Simpson指数、Mc Intosh指数以及Richness指数均大于单施尿素处理,且较单施尿素处理分别提高13.83%、9.33%、1.29%、1.34%、11.26%、11.79%(P0.05),均匀度指数则低于单施尿素处理(P0.05)。PCA和聚类分析结果表明,施用尿素和尿素添加氯甲基吡啶对土壤微生物群落功能多样性均产生了显著影响,但尿素添加氯甲基吡啶与单施尿素处理差异不显著;氯甲基吡啶的添加提高了土壤微生物对聚合物、酚酸、羧酸、氨基酸以及胺类的利用,降低了对碳水化合物的利用(P0.05)。上述研究结果得出,在干旱区滴灌棉田,尿素添加氯甲基吡啶分次随水滴施可调控土壤的微生态环境,在一定程度上提高土壤微生物的代谢能力,增加微生物群落功能多样性,缓解因长期施用无机氮肥导致的土壤微生物活性的降低。     

Artificial Neural Network Modeling of Distillers Dried Grains with Solubles (DDGS) Flowability with Varying Process and Storage Parameters

Neural network (NN) modeling techniques were used to predict flowability behavior of distillers dried grains with solubles (DDGS) prepared with varying levels of condensed distillers solubles (10, 15, and 20%, wb), drying temperatures (100, 200, and 300°C), cooling temperatures (–12, 25, and 35°C), and storage times (0 and 1 month). Response variables were selected based on our previous research results and included aerated bulk density, Hausner ratio, angle of repose, total flowability index, and Jenike flow index. Various NN models were developed using multiple input variables in order to predict single‐response and multiple‐response variables simultaneously. The NN models were compared based on R², mean square error, and coefficient of variation obtained. In order to achieve results with higher R² and lower error, the number of neurons in each hidden layer, the step size, the momentum learning rate, and the number of hidden layers were varied. Results indicate that for all the response variables, R² > 0.83 was obtained from NN modeling. Compared with our previous studies, NN modeling provided better results than either partial least squares modeling or regression modeling, indicating greater robustness in the NN models. Surface plots based on the predicted values from the NN models yielded process and storage conditions for favorable versus cohesive flow behavior for DDGS. Modeling of DDGS flowability using NN has not been done before, so this work will be a step toward the application of intelligent modeling procedures to this industrial challenge.     

Treating Thin Stillage and Condensed Distillers Solubles with Phytase for Production of Low‐Phytate Coproducts

Fuel ethanol production from grains is mainly based on dry‐grind processing, during which phytate is concentrated about threefold in distillers dried grains with solubles (DDGS), a major coproduct. To reduce phytate in DDGS, Natuphos and Ronozyme industrial phytase preparations were used to treat commercially made thin stillage (TS). Changes in phosphorous (P) profile were monitored, and effects of reaction temperature, time, and enzyme concentration were investigated. Results showed that at a temperature ≤60°C for Natuphos phytase (≤70°C for Ronozyme phytase) and a concentration ≤4.8 FTU/mL of TS for Natuphos phytase (≤48 FYT/mL for Ronozyme phytase), a complete phytate hydrolysis (phytate P decreased to 0) could be achieved within 5–60 min of enzymatic treatment. Reduction in phytate P was generally accompanied by increase in inorganic P, whereas total P remained relatively unchanged. When condensed distillers solubles (CDS), the concentrated form of TS, was used as the substrate, phytate hydrolysis by each of the two enzyme preparations was as effective as on TS. Because a previous study from the author's laboratory showed that all types of P are mostly concentrated in TS and CDS but much less in distillers wet grains, phytase treatments of TS and CDS described in the present study can be an effective means in producing low‐phytate DDGS.     

Measurement and Comparison of Glass Transition and Sticky Point Temperatures of Distillers Dried Grains with Solubles (DDGS) with Varying Condensed Distillers Solubles (CDS) and Drying Temperature Levels

Distillers dried grains with solubles (DDGS) is the main coproduct of the U.S. fuel ethanol industry and has significantly impacted the livestock feed markets in recent years. Particle agglomeration and subsequent flowability problems during storage and transport are often a hindrance, a nuisance, and expensive. This paper aims at characterizing the glass transition (T_g) and sticky point (T_s) temperatures of DDGS samples prepared with varying condensed distillers solubles (CDS) levels (10, 15, and 20%, wb), drying temperatures (100, 200, and 300°C), and moisture contents (0, 10, and 20%, db), and it discusses implications on DDGS flowability behavior. Distillers wet grains were combined with specified levels of CDS and dried in a convection‐style laboratory oven to produce DDGS. Subsequently, predetermined amounts of water were added to the DDGS to achieve desired moisture content levels. To determine T_g (°C), a differential scanning calorimeter was used, whereas T_s (°C) was determined through a novel technique with a rheometer. Results indicated high correlations between observed T_s and observed T_g (R² = 0.87) data for DDGS samples. Also, the empirical model for predicted T_g = f (drying temperature, CDS level, and moisture content) based on the Gordon–Taylor model showed favorable R² (0.74). Stickiness of DDGS increased with an increase in moisture content, indicating flow problems resulting from moisture. It was found that drying temperatures and CDS levels each had significant effects on T_g and T_s as well.     

Effect of Moisture Content and Soluble Level on the Physical,Chemical, and Flow Properties of Distillers Dried Grains with Solubles (DDGS)

Distillers dried grains with solubles (DDGS) is a bulk material that has been widely used as a protein source for ruminants and nonruminants for more than two decades. DDGS is the nonfermentable processing residue (i.e., protein, fiber, fat, and ash) from fuel ethanol manufacturing. With the exponential growth of the fuel ethanol industry in the past several years, significant quantities (≈13.0 million tons in 2007) of distillers grains are now being produced. To effectively utilize these coproduct streams in the domestic market, DDGS must be transported greater distances and must be stored until final use. DDGS flow is often problematic as it can become restricted by caking and bridging that occur during shipping and storage. This flowability problem can present itself during dynamic and static flow conditions. This issue most likely results from physical or chemical interactions between particles (including particle size and shape), storage moisture, temperature, and relative humidity variations, as well as storage time. The objective of this study was to examine the effect of five moisture content levels (10, 15, 20, 25, and 30% db) on the resulting physical and chemical properties of DDGS with four soluble levels (10, 15, 20, and 25% db). To produce these materials, condensed distillers solubles (CDS) were combined with DDG, and appropriate quantities of water were added to adjust moisture contents. Carr indices were used to quantify the flowability of the DDGS samples. The results showed that both soluble level and moisture content had noticeable effects on physical and flow properties (e.g., aerated bulk density, packed bulk density, and compressibility). According to dispersibility, flowability index, and floodability index, flowability generally declined significantly (P < 0.05) with an increase in moisture content for most of the soluble levels under consideration. The color values and protein content of the DDGS were significantly affected (P < 0.05) as soluble level increased as well.     

Single‐Screw Extrusion Processing of Distillers Dried Grains with Solubles (DDGS)‐Based Yellow Perch (Perca flavescens) Feeds

This study was conducted to investigate the production of balanced diets for juvenile yellow perch (Perca flavescens) feeds. Six isocaloric (≈3.21 kcal/g), isonitrogenous (30.1 ± 0.4% db) ingredient blends were formulated with 0, 10, 20, 30, 40, and 50% distillers dried grains with solubles (DDGS), and appropriate amounts of soybean meal, fish meal, vitamins, and minerals. Extrusion cooking was performed using a laboratory‐scale single‐screw extruder at a constant barrel temperature profile of 40–90–100°C, and a constant screw speed of 230 rpm (24.1 rad/sec). The mass flow rate was determined during processing; it generally increased with progressively higher DDGS content. Additionally, moisture content, water activity, unit density, expansion ratio, compressive strength, compressive modulus, pellet durability index, water stability, and color were extensively analyzed to quantify the effects of DDGS content on the physical properties of the resulting extrudates. Significant differences (P < 0.05) between blends were observed for color and water activity for both the raw material and extrudates, respectively, and for the unit density of the extrudates. There were 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 blends showed high pellet durability (PDI ≥ 96.18%). Overall, it was ascertained that DDGS could be successfully included at rates of <50%, and that each of the ingredient blends resulted in viable, high quality extrudates.     

Effect of Cattle Manure and Sulfur on Yield and Oil Composition of Pumpkin (Cucurbita pepo var. Styriaca) Inoculated with Thiobacillus thiooxidans in Calcareous Soil

The effect of cattle manure and sulfur fertilizer on seed yield and oil composition of pumpkin (Cucurbita pepo var. Styriaca) under inoculated with Thiobacillus thiooxidans was investigated in a factorial study based on a randomized complete block design. Experimental factors consisted of cattle manure (M) (M₀: 0, M₁: 10; and M₂: 20 t ha^?1), sulfur (S) (S₀: 0, S₁: 250; and S₂: 500 kg ha^?1) and T. thiooxidans (B): inoculated (B₁) and non-inoculated (B₀). Results demonstrated that the application of T. thiooxidans, cattle manure, and S fertilizer decreased the soil pH. The largest number of seed per fruit (367), highest fruit yield (70.57 t ha^?1), seed iron (Fe) content (16.26 mg 100 g^?1), and seed yield (111 kg ha^?1) was obtained when 20 t ha^?1 manure was applied in combination with 500 kg ha^?1 S inoculated with T. thiooxidans. In this condition, the content of S, Fe, phosphorus (P), and nitrogen (N) in plant shoots was increased by 44.8%, 22.58%, 33.89%, and 10.38%, respectively, compared to the control. Moreover, the highest content of seed protein was observed in 10 t ha^?1 manure and 500 kg ha^?1 S fertilizer inoculated with T. thiooxidans. When 250 kg ha^?1 S fertilizer was applied, 20 t ha^?1 manure decreased seed P content sharply. At the rate of 500 kg ha^?1 S fertilizer, the highest content of seed P was obtained from 20 t ha^?1 manure. Totally, 20 t ha^?1 cattle manure, along with 500 kg ha^?1 S fertilizer as well as T. thiooxidans inoculation, improved oil and seed yield of medicinal pumpkin.     

Application of the reactive lysine procedure to estimate lysine digestibility in distillers dried grains with solubles fed to growing pigs

Two experiments were conducted to measure the reactive Lys concentration in corn distillers dried grains with solubles (DDGS). In expt 1, reactive Lys was measured in 33 sources of DDGS using two procedures: the homoarginine procedure and the furosine procedure. The concentration of reactive Lys in DDGS was then correlated with the concentration of standardized ileal digestible (SID) Lys in DDGS fed to growing pigs. In expt 2, a factorial experiment was conducted using four ratios of condensed distillers solubles (CDS) and wet distillers grain (WDG). The ratios (wt/wt) of CDS to WDG were 0:100, 20:80, 40:60, and 100:0, and four subsamples from each combination were freeze-dried or oven-dried at 50, 75, or 100 degrees C. The dried samples were designated DDG, DDGS 20, DDGS 40, and CDS, respectively. All subsamples were analyzed for total Lys and for reactive Lys using the homoarginine procedure. Results of expt 1 showed that only 74.1% of total Lys was reactive if measured by the homoarginine procedure and 83.5% was reactive if measured by the furosine procedure. The concentration of SID Lys in DDGS was correlated with the concentration of reactive Lys measured by the homoarginine procedure ( r (2) = 0.70, P < 0.05) and by the furosine procedure ( r (2) = 0.66, P < 0.05). In expt 2, the concentrations of total Lys and reactive Lys were reduced ( P < 0.05) when addition of CDS or drying temperature of the samples was increased, but the reduction was greater ( P < 0.05) when both CDS addition and drying temperature were increased at the same time. After oven-drying at 100 degrees C, 75.7% of total Lys was reactive in DDG, but only 27.6 and 10.2% were reactive in DDGS 20 and DDGS 40, respectively. In conclusion, reactive Lys is correlated with the concentration of SID Lys in DDGS, and addition of CDS exacerbates the negative effects of heating on the concentration of total Lys and reactive Lys in DDGS.     

Characteristics of Vegetable‐Based Twin‐Screw Extruded Yellow Perch (Perca flavescens) Diets Containing Fermented High‐Protein Soybean Meal and Graded Levels of Distillers Dried Grains with Solubles

A twin‐screw extrusion study was performed in replicated trials to produce vegetable‐based feeds for juvenile yellow perch. Two isocaloric (3.06 kcal/g) experimental diets were balanced to contain 20 and 40% distillers dried grains with solubles (DDGS) and a constant amount (20%) of fermented high‐protein soybean meal (PepSoyGen) as the fishmeal protein replacers; crude protein content was targeted at 40%. A fishmeal‐based diet was used as a control. Extrusion conditions included conditioner steam (0.11–0.16 kg/min), extruder water (0.11–0.19 kg/min), and screw speed (230–300 rpm). Increasing DDGS from 0 to 40% led to a considerable rise in bulk density, lightness L*), yellowness (b*), and unit density but to decreases in water activity (a_w) and expansion ratio by 12.6, 14.4, 23, 21, 31, and 13%, respectively. The lowest unit density of 791.6 kg/m³ and highest bulk density of 654.5 kg/m³ were achieved with diets containing 20 and 40% DDGS, respectively; changes in DDGS content did not affect extrudate moisture, absorption index, or thermal properties. Raising DDGS from 0 to 40% resulted in an increase in water solubility and redness (a*) by 13.4 and 35%, respectively. All extrudates had high durability (>98%), and low a_w of less than 0.5. Overall, this study yielded viable feeds for yellow perch.     

Residual Effects of Novel versus Traditional Organic Amendments for Rain-fed No-till Barley: Yield,Nutrient Uptake,and N2O Emissions

Organic amendments recycle nutrients, but N₂O emissions are both environmental and agronomic concerns. We conducted a 4-year field experiment to determine no-till barley (Hordeum vulgare L.) yield and nutrient uptake and soil N₂O emissions following a single application of six amendment treatments: (1) no amendment (Check); (2) synthetic N fertilizer (Fert); (3) fresh beef cattle feedlot manure (ManureF); (4) beef cattle feedlot manure compost (CompostR); (5) beef cattle feedlot manure composted with cattle mortalities (CompostM); and (6) separated solids from anaerobically digested cattle feedlot manure (ADM). Barley grown in Year 1 (2006), Year 2 (2007), and Year 4 (2009) (with Year 3 (2008) under fallow) had higher grain yields from ManureF (4.73 Mg ha^?1) in Year 2 and ADM (6.30 Mg ha^?1) in Year 4 (p < 0.05) than other treatments. The grain N and P contents were not affected (p > 0.05), but N uptake over 3 years (112.8 kg N ha^?1 yr^?1), and P uptake in Year 1 (19.1 kg ha^?1 yr^?1) and Year 2 (14.3 kg ha^?1 yr^?1) from ManureF, were higher (p < 0.05×) than other treatments. The cumulative N₂O emissions from ManureF in Year 1 (1.488 kg N ha^?1) and from ADM in Year 2 (1.072 kg N ha^?1) were higher (p < 0.05) than other treatments while the fraction of applied N emitted as N₂O was small (0.00 to 0.79%) and not affected by treatment. However, the percentages of applied N emitted as N₂O from compost and ADM were similar to synthetic fertilizer and livestock manure.     

Impact of Compost Application during 5 Years on Crop Production,Soil Microbial Activity,Carbon Fraction,and Humification Process

Compost amendment is considered as a practical tool to increase the soil organic matter (SOM), which contributes to agricultural sustainability. The objective of the present work was to evaluate the impacts of organic soil management over 5 years on orchard prune production (Prunus salicina), microbial activity, soil carbon (C) fraction, and stabilization degrees of soil humification. Plot experiment was designed with two different soil managements: i) for minimizing anthropogenic disturbances, only mulching of orchard residues derived from prune tree plot area was applied to soil surface (S + V); and ii) the amendment of composted manure was annually practiced in addition to the utilization of orchard residues inside the plot area (S + V + C). After 5 years, the soil with the continuous compost application (S + V + C) showed higher productivity of Prunus salicina (21.4%), greater fruit diameter (7.8%), and heavier fruit weight (22.4%) than the soil without compost application (S + V). Nutrient content in foliar analysis showed no difference between the two treatments (S + V and S + V + C). By contrast, the amended soil by compost (S + V + C) increased the SOM and water-soluble C fraction in parallel with the increase of microbial parameters (microbial biomass C, adenosine triphosphate (ATP), basal respiration, and dehydrogenase). Analyzing soil humic acid character by chemical spectra techniques of Fourier-transform infrared (FT-IR) spectra and ¹³C nuclear magnetic resonance (¹³C-NMR), gradual reformation of a more stabilized structure was shown in both soils (S + V and S + V + C), due to the selective biodegradation and humification process after the amendments over 5 years. Especially, in the soil treated with compost application (S + V + C), the increase of functional C groups (aromatic and carboxylic groups), which reinforce the recalcitrant character of soil humified fraction, was clearly observed. The continuous application of composted manure for the duration of 5 years improved the orchard soil fertility as well as productivity.

Abbreviations: ATP, adenosine triphosphate; CPMAS, cross-polarization magic angle spinning; EC, electrical conductivity; FT-IR, Fourier-transform infrared; HA, humic acid; HS, humic substance; INTF, iodonitrotetrazolium formazan; K, Potassium; LSD, least significant differences, N, nitrogen; NMR, nuclear magnetic resonance; O, oxygen; OM, organic matter; MBC, microbial biomass C; P, phosphorous; SD, standard deviation; SE, standard error; SOM, soil organic matter; TOC, total organic carbon; WSC, water-soluble C; WS-Ch, water-soluble carbohydrate     

Comparison of Modified Dry‐Grind Corn Processes for Fermentation Characteristics and DDGS Composition

Three different modified dry‐grind corn processes, quick germ (QG), quick germ and quick fiber (QGQF), and enzymatic milling (E‐Mill) were compared with the conventional dry‐grind corn process for fermentation characteristics and distillers dried grains with solubles (DDGS) composition. Significant effects were observed on fermentation characteristics and DDGS composition with these modified dry‐grind processes. The QG, QGQF, and E‐Mill processes increased ethanol concentration by 8–27% relative to the conventional dry‐grind process. These process modifications reduced the fiber content of DDGS from 11 to 2% and increased the protein content of DDGS from 28 to 58%.     

Granular Packing Influences Bulk Density of DDGS

As the quantity of ethanol produced continues to increase, the amount of distillers dried grains with solubles (DDGS), the primary coproduct of ethanol manufacturing, has become more widely available. Currently, the main consumer of DDGS is the livestock industry, but new value‐added uses are garnering interest. With the increase in the availability of, and demand for DDGS, transportation has become an important issue because DDGS must be shipped increasingly long distances using railways. Rail transportation is expensive, especially considering the quantities of DDGS that can be loaded onto unit trains. DDGS often has low bulk density and poor flowability characteristics. This study examined compression effects on particle arrangements as quantified by bulk density and compressibility of the DDGS. Mean loose bulk density was 446.18 kg/m³. A linear relationship (R² = 0.982 for 50 N applied force and R² = 0.959 for 1 kN applied force) was observed between the applied stress (≈0.0–0.0065 and ≈0.0–0.13 MPa, respectively) and the resulting packed bulk density (≤470.21 and ≤555.03 kg/m³, respectively). Compressive stress increased curvilinearly (R² = 0.994 for the 50 N load and R² = 0.997 for the 1 kN load) as the applied strain increased (≈0.0–0.007% and 0.0–24.0%, respectively). As the loading increased, compressibility increased 5.11–19.22%. Bulk restitution after loading was removed was 0.53–0.61. Required storage volume is reduced when the bulk density is increased. But flowability characteristics should improve as the compressibility, and thus the bulk density, of the product is reduced.     

Extractability and Molecular Modifications of Gliadin and Glutenin Proteins Withdrawn from Different Stages of a Commercial Ethanol Fuel/Distillers Dried Grains with Solubles Process Using a Wheat Feedstock

Extractability and molecular modifications of gliadin and glutenin proteins withdrawn from different stages of a commercial ethanol fuel/distillers dried grains with solubles (DDGS) process using a wheat feedstock were investigated. Materials were taken postliquefaction (PL), postdistillation (whole stillage), and postdrying (DDGS) during the process and then fractionated to separate the gliadins and the soluble high‐ and low‐molecular‐weight glutenins following a modified Verbruggen extraction method. Each fraction was characterized based on the extraction efficiencies within various aqueous alcohols of propan‐1‐ol, electrophoretic patterns, intrinsic and extrinsic fluorescence, free and total sulfhydryl content, and total disulfide bond levels. Findings indicated significant changes to the composition of extracted proteins and modifications to the protein structure (i.e., surface properties and conformation) throughout the ethanol/DDGS process, beginning with the first step of production (PL, ≈83°C). Overall, processing resulted in a shift toward an unextractable gluten matrix, accompanied by increases in hydrophobicity, disulfide bridging, and excessive protein aggregation.     

Selected Factors Affecting Crude Oil Analysis of Distillers Dried Grains with Solubles (DDGS) as Compared with Milled Corn

With increasing production of distillers dried grains with solubles (DDGS), both fuel ethanol and animal feed industries are demanding standardized protocols for characterizing quality. AOCS Approved Procedure (Am 5‐04) was used for measuring crude oil content in milled corn and resulting DDGS. Selected factors, including sample type (milled corn, DDGS), sample origin (ethanol plant 1, 2, 3), sample particle size (original matrix, <0.71 mm, <0.50 mm mesh opening; the last two materials were obtained by grinding and sieving), solvent type (petroleum ether, hexane), extraction time (30, 60 min), and postextraction drying time (30, 60 min) were investigated by a complete factorial design. For milled corn, only sample origin and extraction time had significant effects (P < 0.05) on crude oil values measured, but for DDGS, besides those two factors, sample particle size, solvent type, and drying time also had significant effects. Among them, the particle size of DDGS had the most effect. On average, measured oil content in DDGS ranged from 11.11% (original matrix) to 12.12% (<0.71 mm) and to 12.55% (<0.50 mm). For measuring the crude oil content of DDGS, particle size reduction, 60 min of extraction, and 60 min of drying are recommended. Regardless of the underlining factors, the method was very repeatable (standard errors <0.05). The observed particle size effect on crude oil analysis of DDGS suggests the need for similar confirmations using other analytical methods.