Corn Germ Research Articles

Formulation of Trichoderma asperellum TV190 for biological control of Rhizoctonia solani on corn seedlings

Environmental conditions affect biocontrol agents in a field, being appropriate formulations an alternative to overcome this problem. Formulations based on Trichoderma asperellum TV190 were prepared by emulsified mineral or vegetable oils, which protected spores from ultraviolet radiation, showing greater viability of 37–43% (mineral) and 56–63% (vegetable) than the control (8–12%). These formulations improved an antagonism of T. asperellum on Rhizoctonia solani under greenhouse conditions, reducing infected corn seedlings by 72% (mineral) and 59% (vegetable). Necrotic spot size was reduced by 90.04% (mineral) and 87.29% (vegetable). A granular formulation, prepared with degreased corn germ and T. asperellum spores, protected the corn seedlings from R. solani under greenhouse conditions, with 73% reduction of infected plants and 93% reduction of necrotic spot size. Both granular and liquid formulations were able to improve T. asperellum antagonism, suggesting that these formulations could be included in agricultural pest control strategies.

Frationation of hydrolysate from corn germ protein by ultrafiltration: In vitro antidiabetic and antioxidant activity.

In the present work, defatted corn germ was hydrolyzed by three proteases and further separated by sequential ultrafiltration with different molecular weight cutoff (100, 10, 2 kDa). Corn germ protein hydrolysate (CGPH) and their fractions were investigated for antioxidant activity, α‐glucosidase, α‐amylase, and DPP‐IV inhibitory activity. The degree of hydrolysis (DH) after 2 hr was 17.5%, 11.14%, and 2.05% for alcalase, trypsin, and flavourzyme, respectively. Trypsin hydrolysate showed the highest DPPH and ABTS+ radical scavenging and Fe2+ chelating activity, but a lower α‐glucosidase inhibitory activity. F1 fraction (<2 kDa) exhibited highest radical scavenging and α‐glucosidase inhibitory activity. While F2 fraction (2–10 kDa) showed the higher Fe2+ chelating and α‐amylase inhibitory activity, F1 fraction of flavourzyme showed the highest α‐glucosidase inhibitory and F2 fraction of alcalase and flavourzyme exhibited highest α‐amylase inhibitory activity. Hydrolysate and F1 fraction of alcalase and F2 fraction of trypsin showed the highest DPP‐IV inhibitory activity. RP‐HPLC results showed that trypsin hydrolysate had higher levels of high‐hydrophobic peptides. The amino acid composition of the F1 fractions showed high levels of hydrophobic amino acids. Thus, CGPHs may be used as a potential source of antioxidant and antidiabetic peptides in food industry and pharmaceutical application.

Effects of Different Crude Protein and Dietary Fiber Levels on the Comparative Energy and Nutrient Utilization in Sows and Growing Pigs.

Simple SummaryAccurate evaluation of the nutritional values of ingredients fed to sows is highly valuable in swine production, and those values should be kept updated with the genetic improvement of sows. In the feedstuff tables of NRC (2012), the same available energy value was assigned for growing pigs and adult sows for the same ingredient, whereas two different values were used in the feedstuff tables published in China and France (INRA). More research and efforts are required to solve these conflicts, while data gained from animal trials are limited currently. Therefore, we determined and compared the nutritional values of eight ingredients fed to both growing pigs and adult sows, and found that sows had lower available energy and nutrient digestibility when fed soybean meal or cottonseed meal compared with growing pigs, and the crude protein content is a good predictor to estimate the available energy values of ingredients fed to sows based on the values measured from growing pigs. The results of the current study can facilitate the accurate formulation of sow diets.This study was conducted to determine and compare digestible energy (DE) and metabolizable energy (ME) values and the apparent total tract digestibility (ATTD) of energy and nutrients in eight ingredients fed to both growing pigs and sows. Two experiments with 48 crossbred barrows or six non-pregnant sows were allotted to eight treatments in a completely randomized design or a pseudo Latin square with six replicated pigs per dietary treatment. The dietary treatments were formulated with two cereal ingredients: corn and wheat; two ingredients with a high protein level and a low fiber level (HPLF): soybean meal (SBM) and cottonseed meal (CSM); two ingredients with medium protein level and medium fiber level (MPMF): corn distiller’ dried grains with solubles (DDGS) and corn germ meal (CGM); and two ingredients with a low protein level and a high fiber level (LPHF): wheat bran (WB) and palm kernel meal (PKM), respectively. Adult sows had greater DE and ME values and ATTD of energy and nutrients when fed cereal ingredients compared with growing pigs, and had lower DE and ME contents and ATTD of energy and nutrients except for acid detergent fiber (ADF) when fed HPLF ingredients compared with growing pigs. Moreover, no differences were observed between adult sows and growing pigs in DE and ME contents and ATTD of energy and nutrients when fed MPMF and LPHF ingredients, except that adult sows showed a greater ATTD of crude protein (CP) when fed MPMF ingredients compared with growing pigs. Our results indicate that sows had a lower available energy and nutrient digestibility when fed SBM or CSM compared with growing pigs. Crude protein contents in ingredients should be considered when predicting DE and ME values in sows based on the DE and ME values measured from growing pigs.

A heat and mass transfer model based on multi-component heterogeneity for corn kernel tempering drying: Development and application

A 3D mathematical model for corn tempering drying was developed by considering the thermo-physical heterogeneity of different components in corn kernels. Simulated results were in good agreement with the experimental results measured by magnetic resonance imaging (MRI) and infrared thermal imaging. Corn germ showed a higher moisture and lower temperature region. The germ and hard endosperm were the source of moisture transfer in corn kernels during tempering. There was an increasing demand of corn kernels for tempering intensity with the growth of tempering drying stage. The optimized multi-stage tempering drying with variable time parameters (OTD) shortened the drying time by 24.5% and 5.63% compared with continuous drying (CD) and multi-stage tempering drying with 30 min tempering and 30 min drying (TD), respectively. In addition, the moisture gradient and temperature gradient of endosperm were at lower levels during drying stages, which was beneficial to avoid cracks caused by the wet-thermal stress.

Batch-to-batch variation in carbohydrates molecular structures, nutritive value and biodegradation characteristics in corn coproducts

This study investigated batch-to-batch variations in carbohydrates 1) chemical profile; 2) Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrates subfractions; 3) in situ ruminal degradation kinetics of neutral detergent fiber (NDF); and 4) molecular structure spectral characteristics of carbohydrates (structural carbohydrates, SCHO; cellulosic compounds, CELC; total carbohydrates, TCHO and non-structural carbohydrates, NSCHO) in corn byproducts. The second aim was to correlate the variations in carbohydrates molecular structures with carbohydrates nutritional traits. The corn byproducts selected in this study were corn gluten feed, corn germ, corn germ cake and corn gluten meal. The preprocessed corn kernels were used as control. The results revealed large differences in carbohydrate chemical composition (P < 0.001), CNCPS subfractions (P < 0.001) and rumen degradation kinetics of NDF (P ≤ 0.01) between preprocessed corn kernels and the byproducts. The contents of NDF and non-fiber carbohydrates varied (P ≤ 0.01) among the three batches of corn kernels and the byproducts. Except SCHO area, all the carbohydrates molecular spectral bands areas and ratios differed (P < 0.001) between the preprocessed corn kernels and the byproducts. Significant batch-to-batch variations were observed for different spectral parameters of the byproducts. Regression equations based on carbohydrate spectral data gives relatively good prediction power for carbohydrates chemical profile (P < 0.001; R2 = 0.55-0.80), CNCPS subfractions (P < 0.001; R2 = 0.62-0.86) and ruminal degradation characteristics of NDF (P < 0.001; R2 = 0.78-0.89). In conclusion, batch-to-batch variation was observed in nutritional values of carbohydrates in corn byproducts, and carbohydrates molecular structures spectral data might potentially be used to predict nutritive values of corn and corn byproducts for dairy cows.

Batch-to-batch variation in protein molecular structures, nutritive value and ruminal metabolism in corn coproducts

The objectives of this study were to investigate batch-to-batch variation in 1) crude protein (CP) chemical profile; 2) the Cornell Net Carbohydrate and Protein System (CNCPS) CP subfraction profiles 3) ruminal degradation kinetics of CP; 4) the DVE/OEB2010 model estimated metabolizable protein supply to dairy cows; 5) molecular structure spectral characteristics of protein primary (amide I and II) and secondary (α-helix and β-sheet) structures among different types of coproducts and among three batches of corn coproducts using parent corn kernels of each batch as reference; and 6) to correlate the batch-to-batch variation in protein molecular structures to the corresponding variation in CP chemical composition, digestibility and metabolism in dairy cows. Corn coproducts, namely, corn gluten feed, corn germ, corn germ cake and corn gluten meal from the same wet milling manufacturer were evaluated. The parent corn kernel was used as control. The results showed large differences in the CP chemical profile (P < 0.001), CNCPS subfractions (P < 0.001) and ruminal degradation (P ≤ 0.01) except undegraded-fraction, between corn kernels and the coproducts. Batch-to-batch variation (P < 0.05) was also observed for some of the CP chemical components, subfractions and ruminal degradation parameters, however, the pattern of variation among the batches was not consistent for the different coproducts. The metabolizable protein supply to the small intestine from microbial protein, rumen undegraded feed protein and endogenous protein from the corn coproducts were different (P < 0.001) from that of corn kernels. Except corn germ, differences (P < 0.05) were observed in degraded protein balance among the three batches, with marked ranges in corn gluten feed (58.6–101.8 g/kg dry matter) and corn germ cake (16.9–76.8 g/kg dry matter). All the intrinsic protein primary (amide I and amide II) and secondary (α-helix and β-sheet) structures spectral parameters varied (P < 0.001) among the coproducts. Regression equation showed that amide I and II areas, β sheet and area ratio of amide I to II were strong predictor (R2 ranged from 0.54 to 0.98) of protein chemical profile, degradability and metabolizable protein supply to small intestine. Overall, corn processing and processing-batches caused significant variation in CP chemical composition and digestibility that was strongly related to the changes in protein molecular structures.

Retrospect and prospects of secondary agriculture and bioprocessing

Secondary agriculture plays a significant role in making a positive impact on the country’s economy. It has potential to increase the value of primary agriculture. It ensures better utilization of renewable agro-bioresources either through value addition or waste utilization. Nurseries, bio-fertilizers, bio-pesticides, compost, fruit-processed products, agro-tourism, weaving, flavours, and dyes are some of the avenues of secondary agriculture. By-products from agricultural crops like wheat and rice bran, corn gluten meal and germ, pulses meal and husk, and sugarcane bagasse, if processed appropriately for deriving industrial products could pave a way in getting better economic returns from agriculture rather using them as livestock feed. Among food crops, major post-harvest losses (30–40%) occurs in fruits and vegetables; their waste being rich in several bioactive compounds possess great potential to be added as a polyphenol rich and fibre source in food products or for the synthesis of food-grade industrial products like ethanol, citric acid and pectin etc. Wastes from floriculture industries can also be utilised for the production of several value-added products such as biofuels, bio-ethanol, compost, organic acids, pigments and dyes, incense sticks, handmade paper production, and sugar syrup. Around the world, 80% of population is dependent on traditional medicine for health care needs. The secondary metabolites from medicinal plants possess pharmaceutical properties and advancement in extraction techniques can lead to novel range of herbal products of high economic value. The market potential of agro-produce seems to be naive but opportunistic in near future. The advancement in technologies, equipments, and processes would enable enhanced secondary agriculture practices giving range of materials of better quality, yield, nutrition, and convenience. Hence, the potential of secondary agriculture and bioprocessing could be strong boost to the economy, societal status and environmental protection. In this article we have made an effort to understand the secondary agriculture, its potential to uplift the economy and strategies for value addition in different agricultural domains such as horticulture, floriculture and medicinal plants.

Oil and protein recovery from corn germ: Extraction yield, composition and protein functionality

This work aimed the recovery of oil and protein fractions from corn germ (CG) generated as a by-product during flour processing. Several oil extraction techniques were investigated: hexane at room temperature, hexane at 45°C, supercritical carbon dioxide (Sc-CO2) and Soxhlet with hexane and ethanol. Their influence on oil yield and oil composition as well as on the further protein extraction was assessed. Proteins extracted from the various meals were characterized for their protein content (19.9–48.5%), their water absorption capacity (WAC 1.34–2.79g water/g), solubility profile, and foaming (FC 25–84%) and emulsifying (EAI 84.8–246m2/g protein) capacities. The fatty acid profile of the oil was the same regardless the extraction method. Though yielding partial defatting (16.4 vs 23.8g oil/100g CG), Sc-CO2 produced oil with high phenolic content (251.8mg GAE/kg oil) and high-quality CG meal concurrently. The protein extract produced from this partially defatted meal showed interesting characteristics such as the highest protein concentration (48.5%), the highest foaming properties (FC and FS>84%), high WAC (2.33g water/g extract) and EAI (231m2/g). Defatting conditions, namely the solvent nature, temperature and pressure, influenced the functional properties of further extracted proteins by inducing changes in their conformational state.

Kinetic, thermodynamic and optimization study of the corn germ oil extraction process

Corn germ oil (CGO) was recovered from the ground corn germ by maceration using n-hexane at the ranges of the temperature and the solvent:germ ratio (SGR) of 20–70 °C and 3:1–10:1 mL/g, respectively. The obtained CGO contained mainly the unsaturated fatty acids (87.09 ± 0.37%) with linoleic and oleic acid as the most abundant while the main saturated fatty acid was palmitic acid. The CGO extraction yield was statistically analyzed, modeled and optimized combining the response surface methodology with the 33 full factorial design with replication. All individual process variables (maceration temperature, SGR and maceration time), the interaction of maceration temperature with SGR and the quadratic terms of maceration temperature and SGR had a statistically significant influence on the CGO yield. For the kinetic modeling of the CGO maceration, three models, namely the phenomenological model, the model that included instantaneous washing and diffusion and the diffusional model, were tested. Although all models successfully described the kinetics of CGO extraction (MRPD values ≤2%), the diffusional model was less accurate. The thermodynamic analysis of CGO extraction showed that the extraction process was spontaneous, endothermic and irreversible.

A new continuous system of enzymatic hydrolysis coupled with membrane separation for isolation of peptides with angiotensin I converting enzyme inhibitory capacity from defatted corn germ protein.

In this study, separation of peptides with Angiotensin I converting enzyme (ACE)-inhibitory capacity obtained from ultrasonically pretreated defatted corn germ protein (DCGP) by using a new continuous system of enzymatic hydrolysis coupled with membrane separation (EHC-MS) was investigated. Ultrasonic pretreatment was applied to enhance the enzymatic hydrolysis rate of DCGP, as proved in our previous study. The EHC-MS system was operated in two modes which included the batch system and continuous system with continuous water and substrate feeding and was compared with the EH-offline-MS system. The selection of the membrane was based on the hydrolysate fraction which had the highest activity for inhibition of ACE. The results showed that the 1-3 kDa fraction of DCGP hydrolysates had the lowest IC50 value (0.124 mg mL-1) for inhibition of ACE. The degree of conversion (%) of DCGP and output of peptides per unit of the enzyme were significantly (P < 0.05) increased by 55.3% and 55% in the EHC-MS batch process and 79% and 473% in the EHC-MS continuous operation compared to the EH-offline-MS system. The EHC-MS using continuous water and substrate feeding operation was noted to be the best in terms of a high degree of DCG protein conversion (75.68 ± 1.34) and the output of peptides per unit of the enzyme (78.65 ± 1.13). The results revealed that the EHC-MS method with constant water and substrate feeding could show a better application in peptide production in the food industry.

Unlocking the potential of minimally processed corn germ oil and high oleic soybean oil to prepare oleogels for bakery application.

In this study, the influence of sunflower wax (SFX) concentration (1, 3, 5, 7, and 9 wt%) on the properties of oleogels prepared using expeller-pressed corn germ oil (EPC) or high oleic soybean oil (EPS) was comprehensively investigated. Overall, oleogels can be prepared from both EP oils at an SFX level ≥3 wt%. The strength of oleogels depends on SFX concentration. EPS oleogels had better rheological properties and a higher amount of platelet-like crystals than EPC oleogels. The characteristics of cookies prepared with both oleogels were evaluated and compared to cookies prepared with commercial shortening. The lipid distribution in the cookies as visualized by CLSM suggested that EPS oleogels with a 5 or 7 wt% SFX had a greater possibility of replacing commercial shortening as they exhibited even lipid distribution which enabled good air-incorporation and air retention abilities. This research provides a foundation for developing healthy bakery products by using minimally processed oil based oleogels.

Application of micronutrients and insurance herbicides in corn growing technologies

Studies have found that growing maize for grain on light low-humus soils of the left-Bank Polesie of Ukraine wih the use of microelements on the increased background of mineral nutrition provided the best indicators of economic efficiency. It is recommended to sow early- maturing (80 %) and mid-maturing- (20 %) hybrids with FAO 150-250 on the background of mineral fertilizers N120P60K60, applying herbicide MaizeTer power in the 3-5-leaf phase of a crop and fulfil out-off-root spraying crops with complex preparations “Rosaliq Aquatic” or ” Germ corn “. Key words: maize, insured herbicides, micro-fertilizers, early-maturing, mid-maturing, hybrids.

Effects of post-weaning supplementation of immunomodulatory feed ingredient on body weight and cortisol concentrations in program-fed beef heifers

The objective of this study was to determine the effects of an immunomodulatory feed ingredient during post-weaning on growth and cortisol concentrations of beef heifers. Commercial Angus heifers (n = 72) from 2 AI sires were blocked (n = 9) by BW and randomly assigned to one of 2 pens per block. Each pen (4 heifers/pen) per block was randomly assigned to either one of 2 treatments, Celmanax (CEL) or corn germ (CON). The heifers were fed a commercial total mixed ration (TMR) twice daily from d 0 to 60 to gain 0.75 kg/d. The feed was top-dressed once daily with either 72g of Celmanax (CEL) or corn germ (CON) per pen. Body weight (BW) was collected on d −1, 0, 15, 30, 45, 60, and 61. Blood samples were collected on d 0, 15, 30, 45, and 60. Two heifers per pen (n = 32) were randomly selected for a transportation challenge to evaluate stress response on d 62 or 63 of the study. Sixteen heifers (n = 8 CEL; n = 8 CON) were randomly selected for a corticotropin-releasing hormone/arginine vasopressin (CRH/AVP) challenge and an intravenous glucose tolerance test (IVGTT) on d 64 and 67 of the study. The pen was the experimental unit, and data were analyzed by ANOVA or repeated measures analysis as appropriate. Feed efficiency and BW gain were increased (P = 0.04) in CEL heifers compared to CON heifers. Serum cortisol concentrations were decreased (P < 0.01) in CEL heifers compared to CON heifers on d 30 to 60 post-weaning. Serum cortisol concentrations were decreased (P < 0.05) in CEL heifers compared to CON heifers throughout the transportation challenge. Serum cortisol concentrations were decreased (P < 0.05) in CEL heifers compared to CON heifers during the CRH/AVP challenge from 60 to 150 min post-infusion. Treatment did not influence (P = 0.29) plasma insulin or glucose (P = 0.63) concentrations during the IVGTT. In summary, supplementation of Celmanax post-weaning increased BW gain and reduced cortisol concentrations in challenged beef heifers.

153 Creation of a feed composition database: Machine learning techniques for automated classification of corn grain products, preliminary results

Abstract Feed composition tables are a commonly used to develop research projects and to develop animal diets. Currently, the National Animal Nutrition Program aims to create a living database containing feed composition information using large datasets provided by commercial laboratories. Using large datasets should ensure representative nutritional values for feeds included in the database; however, managing large datasets requires computer codes to manage and classify feeds correctly. Thus, the objective of this project was to develop 2 models based on supervised machine learning techniques for automated classification of corn grain product samples. The database used in the study contained 88,057 samples of corn grain products resulting from the screening procedure previously described by Tran et al (2016). Two types of supervised machine learning models were developed: decision tree and random forest. Parameters included for feed classification were: dry matter, crude protein, neutral detergent fiber, ash, fat, and starch. Models were trained and validated using 70 and 30% of the dataset, respectively. The decision tree and random forest correctly classified 98.3 and 98.8% of validation dataset, respectively. For each corn grain product the performance of the decision tree and random forest were: corn germ = 91 and 91%; corn germ meal = 97 and 95%; corn gluten feed, dry = 99 and 100%; corn gluten feed, wet = 100 and 100%; corn gluten meal = 99 and 100%; corn grain, dry = 99 and 99%; corn grain, high moisture = 100 and 100%; corn grain, steam-flaked = 34 and 53%; corn hominy feed = 83 and 88%; and corn screenings = 44 and 60%, respectively. In conclusion, the random forest was superior to the decision tree approach for classifying corn grain products. Further development is required to improve the performance of models for classifying corn grain steam-flaked and corn screenings

High‐Purity Tocored Improves the Stability of Stripped Corn Oil Under Accelerated Conditions

Abstractγ‐Tocopherol‐5,6‐quinone (tocored) is of importance among the γ‐tocopherol (γ‐T) oxidant products and found in corn germ oil. Investigation on tocored is impeded in part by the difficulty to access high purity tocored. In this present study, high‐purity tocored is successfully prepared, and its antioxidant activity, together with γ‐T and TBHQ (positive control) in increasing concentrations in stripped corn germ oil is evaluated by Rancimat and Schaal oven tests. The stabilization factor in the Rancimat tests increases significantly (p &lt; 0.05) along with an increase in the levels of antioxidants. Furthermore, tocored exhibits higher stabilization than γ‐T in the Schaal oven tests, although its efficacy gradually increases up to 100 mg kg–1 and decreases significantly at higher levels (from 100 to 500 mg kg–1), drawn from the comprehensive parameter A (considering both efficiency and strength) changes (5.06–11.21). In addition, the curves illustrating the residual contents of tocored and γ‐T run in different ways when the four levels are taken into consideration, further bearing the above results. Tocored tends to be a potent natural antioxidant for edible corn germ oil preservation.Practical Application: The present work provides more clear procedures for high‐purity tocored synthesis. Furthermore, tocored may be a potential natural antioxidant that is especially suitable for lipid base food substrates. The results of the present work contribute to the deeper understanding of the antioxidant activity of γ‐tocopherol. The antioxidant activity of tocored is higher than γ‐tocopherol in Schaal oven test. Tocored is a bright orange‐red substance that affects the appearance of the edible oil. Meanwhile, γ‐tocopherol is well known for its valuable health benefits, and appropriate measures should be adopted to store oils (corn oil, soybean oil, and so on) rich in γ‐tocopherol to control transformation in order to keep stability optimal. To some degree, the practical applications of the present results are also related to the processing and storage of edible oils.

Production of ACE inhibitory peptides from corn germ meal by an enzymatic membrane reactor with a novel gradient diafiltration feeding working-mode and in vivo evaluation of antihypertensive effect

Abstract This study investigated the performance of an enzymatic membrane reactor (EMR) with a new gradient diafiltration feeding (GDF) working-mode on the production of peptide with potent angiotensin-converting enzyme (ACE) inhibitory activity from corn germ meal (CGM) under the selected conditions. The antihypertensive effect of the released peptide was evaluated in vivo. Results showed that the protein conversion rate and the peptide yield were 81.94% and 80.20%, respectively, when the EMR-GDF worked for 660 min, and the corresponding IC50 value of the released peptide was 0.83 mg/mL. In vivo experimental results indicated that the high-dose corn germ peptide significantly reduced the systolic blood pressure (SBP) by 18.22 and 28.6 mmHg in acute oral and long-term intragastric administration tests, respectively. The corn germ peptide could also inhibit the ACE activities in kidney, lung, and heart of rats and regulate the level of endothelium-derived vasoconstrictor and relaxing factors in serum.

Formation, characterization, and potential food application of rice bran wax oleogels: Expeller-pressed corn germ oil versus refined corn oil

The expeller-pressed (EP) corn germ oil oleogels were prepared using rice bran wax (RBX) at different concentrations (3, 5, 7, and 9 wt%). Their structural properties, including color, hardness, thermal behavior, rheological property, and crystal structure were evaluated. The performance of oleogels for potential food application was examined by incorporating oleogels into cookies as a fully replacement for commercial shortenings. Overall, RBX could form oleogels in both refined and EP corn germ oils at a concentration ≥3 wt%. Refined corn oil produced a stronger gel than crude corn oil. When comparing cookie characteristics, cookies made with both types of oleogels showed similar properties with commercial cookies. This result indicates that oleogels made by refined and EP corn germ oil together with RBX have the potential to imitate the functionality of commercial shortening in the baking industry.

In vitro Evaluation of Corn Germ Meal as Ruminant Feed

The present study was taken up to assess the chemical composition and in vitro nutritional worth of corn germ meal (CGM) in comparison to conventional oilseed cakes used in livestock feeding. The CP content of protein sources varied from 18.59% in CGM to 49.41% in soybean meal (SBM). CGM had the highest ether extract (EE) content, neutral detergent fibre (NDF), acid detergent fibre (ADF) and total carbohydrates. However, total ash, acid detergent insoluble crude protein (ADICP) and neutral detergent insoluble crude protein (NDICP) was lowest in CGM. In vitro net gas production in CGM (267.91 ml/g DM/24 h) was higher (P<0.05) than other conventional oil cakes. The digestibility of organic matter varied from 85.12% in DMC (deoiled mustard cake) to 96.19% in SBM. The ME availability was highest (P<0.05) in CGM (9.63 MJ/kg DM). Ammonical nitrogen in CGM was lower (P<0.05) than SBM and GNC (groundnut cake).The total volatile fatty acids (TVFA) production (mM/dl) was highest (P<0.05) in GNC (12.56) and lowest (P<0.05) in CGM (9.31). Methane production was lowest (P<0.05) in CGM than other conventional oil cakes. Hydrogen recovery (%) was higher (P<0.05) in CGM (65.76) and SBM (65.78) than other protein sources tested. Fermentation efficiency (%) was higher (P<0.05) in SBM (77.02) and GNC (76.75) while volatile fatty acids utilization index (VFA UI) was higher (P<0.05) in CGM (2.92) and DMC (2.84) than other protein sources tested. The results revealed that CGM can be used as a potential protein source for ruminants.

Effect of multi-frequency counter-current S type ultrasound pretreatment on the enzymatic hydrolysis of defatted corn germ protein: Kinetics and thermodynamics

Abstract In this paper, the impact of ultrasound pretreatment on the kinetics and thermodynamics of defatted corn germ protein (DCGP) enzymatic hydrolysis was evaluated. The enzymatic hydrolysis kinetics and thermodynamics were studied for traditional method and ultrasonic pretreatments with a single-frequency counter-current S type (20 KHz) (SFU) and a multi-frequency counter-current S type (20, 28, 35 and 40 KHz) (MFU). The results showed that the traditional, SFU and MFU pretreated enzymatic hydrolysis of DCGP followed the First-order kinetic model. Again, the SFU and MFU pretreatments enhanced the enzymatic hydrolysis of DCGP. Compared to traditional enzymatic hydrolysis, the reaction rate constant values were increased by 50.0%, 54.7%, 47.8% and 52.3% for SFU pretreated enzymatic hydrolysis, and 58.0%, 58.5, 53.6% and 54.7% for MFU pretreated enzymatic hydrolysis at 20, 30, 40 and 50 oC respectively. Also, the results showed that the SFU and MFU ultrasound pretreatments of DCGP reduced the thermodynamic parameters which included the activation energy (Ea), enthalpy (ΔH), entropies (ΔS) and Gibbs free energy (ΔG) in enzymatic hydrolysis reaction.

Preparation, identification, and activity evaluation of antioxidant peptides from protein hydrolysate of corn germ meal

Information on antioxidant peptides derived from corn germ meal (CGM) is seldom reported. In this paper, three novel antioxidant peptides including Met–Gly–Gly–Asn (MGGN; 377.42 Da), Met–Asn–Asn (MNN; 377.42 Da), and Met–Glu–Asn (MEN; 392.43 Da) were purified from the most active fractions of corn germ meal hydrolysate, and their activity was evaluated by radical scavenging, oxygen radical absorbance capacity, cellular antioxidant activity (CAA), and intracellular reactive oxygen species scavenging assays. MNN had a higher value for the CAA assay (1,213.79 μmol of QE/100 mmol) and could be most effective in preventing conditions favorable to intracellular oxidative stress. Finally, electron paramagnetic resonance spectroscopy directly verified the above experimental results by measuring the number of •OH trapped in the system. Thus, CGM could be considered as a potential source of antioxidant peptide and MNN might be regarded as a natural antioxidant. Practical applications CGM is a by-product of corn industrial that includes ground corn germ and other parts of the corn kernel. In the past, some of them were discarded by factories in China. In this study, three novel antioxidant peptides were isolated from the hydrolysate of CGM, which greatly increased its economic value. In addition, these peptides have huge potential to serve as antioxidants in pharmaceutical, cosmetic, and functional food industries.