Ultrasound-Assisted Multi-Enzymatic System for the Preparation of ACE Inhibitory Peptides with Low Bitterness from Corn Gluten Meal

The promising angiotensin converting enzyme (ACE) inhibitory peptides derived from corn protein usually have strong bitterness and thus limit their use among consumers. To prepare ACE inhibitory peptides with low bitterness, two energy-efficient types of ultrasound pretreatment were introduced into the multi-enzymatic system of corn gluten meal. The results showed that Flavourzyme–Protamex sequential enzymolysis produced the peptides with high ACE inhibitory activity and the lowest bitterness compared with other enzymolysis conditions. During the optimized sequential enzymolysis, the divergent ultrasound pretreatment with a frequency of 40 kHz for 60 min exhibited higher ACE inhibitory activity (65.36%, accounting for 73.84% of the highest ACE inhibitory activity) and lower bitterness intensity of peptides, compared with an energy-gathered ultrasound. The results of the study showed that, on the one hand, divergent ultrasound pretreatment induced the highest intrinsic fluorescence of protein, with more hydrophobic amino acid residues exposed for cleavage by exopeptidases, which leads to a reduction in bitterness. On the other hand, the amino acid composition analysis proved that more Tyr, Ile, and Val moieties, instead of Leu (bitterest substance), and more peptide fractions with a molecular weight >1000 Da should be the structural features of high ACE inhibitory peptides.

Effects of rumen undegradable protein sources on nitrous oxide, methane and ammonia emission from the manure of feedlot-finished cattle

Here, the effects of sources of rumen undegradable protein (RUP) in diets on methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from the manure of feedlot-finished cattle were evaluated. We hypothesized that the use of different RUP sources in diets would reduce N loss via urine and contribute to reduced N2O, CH4 and NH3 emissions to the environment. Nellore cattle received different diets (18 animals/treatment), including soybean meal (SM, RDP source), by-pass soybean meal (BSM, RUP source) and corn gluten meal (CGM, RUP source). The protein source did not affect the N and C concentration in urine, C concentration in feces, and N balance (P > 0.05). The RUP sources resulted in a higher N2O emission than the RDP source (P = 0.030), while BSM resulted in a higher N2O emission than CGM (P = 0.038) (SM = 633, BSM = 2521, and CGM = 1153 g ha− 2 N-N2O); however, there were no differences in CH4 and NH3 emission (P > 0.05). In conclusion, the use of RUP in diets did not affect N excretion of beef cattle or CH4 and NH3 emission from manure, but increased N2O emission from the manure.

​Effect of Feeding Corn Gluten Meal in Feed Ration on Growth Performance of Commercial Broiler Chicken

Background: The productivity and profitability of commercial broiler largely depend on nutrition and growth performance and, therefore, this industry requires high quality protein sources, such as Corn Gluten meal (CGM). Many studies have been conducted on protein quality changes and other nutritional characteristics of CGM in several countries Corn gluten meal contains around 60% CP and is a byproduct of wet milling of corn, most of which is used for manufacture of high fructose corn syrup and corn flour. Being high in crude protein, it is often compared to animal protein ingredients during feed formulation. Thus, this study was intended to evaluate the effect of feeding corn gluten meal in feed ration on growth performance of commercial broiler chicken. Methods: A feeding trial was conducted in the year 2018 with an objective to assess the effect of feeding corn gluten meals (CGM) in broiler chicken. Six hundred broiler chickens (day old) were randomly allotted to three groups, comprising of fifty broiler chickens in each treatment group with four replicates. The group-I (T1) Broiler chicken were fed with composite diet containing 5% Corn Gluten meal where as Group-II (T2) received composite diets comprising of CGM 10%. The Group-III (T3) served as control group with normal broiler diet. The experimental period lasted for six weeks. Weekly body weight and feed consumption were measured in each group. Result: Diet composite of 10% of corn gluten meal had significantly (P≤0.05) higher weight gain, lower feed intake and improved FCR than T1 and T3 group. CGM supplementation can be ideally improved broiler weight gain, feed consumption and FCR.

Use of brewer’s yeast (Saccharomyces cerevisiae) in broiler feeds to replace corn gluten meal with or without probiotic additives

This study was intended to assess the effect of graded replacements of corn gluten meal with Brewer’s yeast (Saccharomyces cerevisiae), with and without Bacillus megaterium supplementation, on performance, carcass characteristics, and the gut broilers microflora composition. A total of 720 mixed sex one-day-old broiler chicks (Ross 308) were randomly assigned to six dietary treatment groups (6 replicates each) in a 3 × 2 factorial arrangement, including 3 levels of Brewer’s yeast (BY; 0, 25, and 50%, to replace corn gluten meal; CGM) in the presence (+) or absence (−) of B. megaterium used as probiotic (Pro). The results showed that broilers fed diets containing BY up to 25% had comparable body weight (BWG), feed intake (FI), and feed conversion ratio (FCR) to the birds fed only CGM, over the entire feeding period (days 1–35). Conversely, higher levels of BY (50% replacing CGM) registered the lowest BWG values (P < 0.001) and impaired FCR (P < 0.010), but without effects on FI. The BY diets did not significantly affect the main broiler’s carcass traits. The diets with Pro did not involve modifications on carcass and organs size, but a tendency to increase the gizzard weight (P = 0.094) and to decrease SIL (P = 0.076) was observed. Pro addition also, reduced the cecal pH (P = 0.040) and diminish the total coliforms (P < 0.010), Clostridium spp. (P < 0.0001), and E. coli (P < 0.0001) count, whereas LAB, Bacillus spp., and Enterococcus spp. bacteria were increased (P = 0.022; P < 0.0001, and P < 0.0001, respectively).