Energy value of hydrolyzed feather meal and flash-dried poultry protein for broiler chickens and pigs.

Three experiments were conducted to determine the metabolizable energy (ME) and nitrogen-corrected ME (MEn) contents of hydrolyzed feather meal (HFM) and flash-dried poultry protein (FDPP) for broiler chickens and to determine their digestible energy (DE) and ME for pigs. The energy-yielding ingredients in a reference diet (RD) were replaced at 0, 75, or 150 g/kg by HFM in experiment (Exp.) 1; at 0, 75, or 150 g/kg by FDPP in Exp. 2; and at 0, 150 g/kg HFM, or 150 g/kg FDPP in Exp. 3. Birds were fed a standard broiler starter diet from hatch to days 18 and 17 for respective Exp. 1 and 2, following which 144 birds (8 replicate cages of 6 birds per cage) were assigned to the three experimental diets in a randomized complete block design with body weight as the blocking factor. Experimental diets were fed for 5 d, and excreta were collected during the last 3 d. Twenty-four 20-kg barrows, individually housed in metabolic crates equipped with a feeder and drinker, were used in Exp. 3. The barrows were assigned to the three experimental diets in a randomized complete block design with body weight as a blocking factor. Following a 5-d adaptation period, feces and urine were collected for 5 d in a total collection method. Data were used to determine the regression-derived ME and MEn of HFM and FDPP for broiler chickens in Exp. 1 and 2, respectively. The DE and ME of HFM and FDPP for pigs in Exp. 3 were determined using the difference procedure. In Exp. 1, the inclusion of HFM linearly increased (P < 0.05) ME from 3,231 to 3,368 kcal/kg DM for 0 to 150 g/kg replacement of RD. The total tract retention of DM and metabolizability of energy linearly increased (P < 0.05) as replacement of RD with FDPP increased from 0 to 150 g/kg in Exp. 2. Inclusion of FDPP linearly increased (P < 0.01) ME from 3,425 to 3,591 kcal/kg DM. In Exp. 3, the diets containing 150 g/kg HFM or FDPP induced greater (P < 0.05) fecal DM and energy losses than the RD; however, the digestibility of energy across the three experimental diets was not different. The respective regression-derived ME and MEn of hydrolyzed feather meal for broiler chickens in the current study were 4,250 and 3,745 kcal/kg DM with corresponding values of 4,710 and 4,081 kcal/kg DM for flash-dried poultry protein. In pigs, 4,783 and 4,405 kcal/kg DM were the respective DE and ME of hydrolyzed feather meal, and 4,553 and 4,320 kcal/kg DM were the corresponding estimates for flash-dried poultry protein.

The animal production industry is presented with the challenge to develop innovative methods to meet future environmental and economic needs. One of the ways through which global animal scientists could combat this onus is to broaden the scope of conventional feed ingredients, most importantly are those feed ingredients that could supply dietary energy. The current research evaluated the energy values of two feed ingredients: hydrolyzed feather meal (HFM) and flash-dried poultry protein (FDPP) for broiler chickens and pigs. The utilizable proportions in the test ingredients were derived as digestible energy (DE), metabolizable energy (ME), and nitrogen-corrected metabolizable energy (MEn) on a dry matter (DM) basis. The derived ME and MEn concentrations in HFM were 4,250 and 3,745 kcal/kg DM, whereas those in FDPP were 4,710 and 4,081 kcal/kg DM, respectively, for broiler chickens. The respective DE and ME concentrations in HFM and FDPP for pigs were 4,783 and 4,405 kcal/kg DM and 4,553 and 4,320 kcal/kg DM. Using a combination of regression method and difference procedure, we showed that hydrolyzed feather meal and flash-dried poultry protein have substantial energy values.

Dietary Avian Proteins Are Comparable to Soybean Proteins on the Atherosclerosis Development and Fatty Liver Disease in Apoe-Deficient Mice.

BACKGROUND AND AIM: The type and amount of dietary protein has become a topic of renewed interest in light of their involvement in metabolic diseases, atherosclerosis and thrombosis. However, little attention has been devoted to the effect of avian proteins despite their wide human consumption. The aim was to investigate the influence of chicken and turkey as sources of protein compared with that of soybean on atherosclerosis and fatty liver disease. METHODS AND RESULTS: To this purpose, male and female Apoe-deficient were fed purified Western diets differing in their protein sources for 12 weeks. After this period, blood, liver, aortic tree and heart base samples were taken for analyses of plasma lipids and atherosclerosis. Plasma triglycerides, non-esterified fatty acids, esterified cholesterol levels and radical oxygen species in lipoproteins changed depending on the diet and sex. Females consuming the turkey protein-containing diet showed decreased atherosclerotic foci, as evidenced by the en face atherosclerosis analyses. The presence of macrophages and smooth muscle cells in plaques were not modified, and no changes were observed in hepatic lipid droplets in the studied groups either. Paraoxonase activity was higher in the group consuming turkey protein without sex differences, but only in females, it was significantly associated with aortic lesion areas. CONCLUSIONS: Compared to soybean protein, the consumption of avian proteins depending on sex resulted in similar or lower atherosclerosis development and comparable hepatic steatosis.

Comparative functional and spectroscopic analysis of spent hen meat hydrolysate by individual and combined treatment of microbial proteases.

Simultaneous (Sm) and sequential (Sq) use of microbial proteases for the hydrolysis of spent hen/chicken meat from antioxidant potential perspective is relatively unexplored and requires attention. In this work, meat was hydrolyzed using Flavourzyme (Fz) and Alcalase (Ac), each at 1, 2, and 3% for 6 h as well as using both enzymes (at 2% each) in Sm and Sq treatment. Maximum attained %DPPH-RSA (Fz:68.25; Ac:77.18; Sm:59.82; and Sq:65.97) and FRAP (mM TEAC/g) values (Fz:3.77; Ac:2.56; Sm:2.54; and Sq:3.37) were measured as a function of hydrolysis time. The highest (23.38%) and lowest (10.68%) degree of hydrolysis (DH) was obtained with 3% Ac and 1% Fz, respectively. FTIR spectroscopy clearly revealed changes in the secondary structure of proteins. SDS PAGE profiling of hydrolysates showed that Fz produces low molecular weight peptides (2-75 kDa) as compared to Ac or its combination with Ac. As per the results of this study, Sq enzyme treatment is recommended for preparing spent hen meat hydrolysate with higher functional attributes for possible use as functional food/nutraceutical.

Effects of ultrasound pretreatment on the extent of Maillard reaction and the structure, taste and volatile compounds of chicken liver protein.

To make better use of chicken liver, a byproduct of meat processing with rich proteins, the influence of ultrasound pretreatment on the extent of Maillard reaction (MR) and the properties of MR products (MRPs) of chicken liver protein (CLP) and its hydrolysate (CLPH) were investigated. The extent of MR of sonicated CLPH (SCLPHMs) was significantly higher than that of the other two MRPs. The decreased fluorescence intensity (FI) of the SCLPHMs indicated adequate reaction of d-xylose with sonicated CLPH (SCLPH). The particle size of the three MRPs was significantly larger than that of CLP, CLPH, and SCLPH, respectively. Ultrasound treatment increased the utilization of amino acids and enriched the variety of volatile compounds in all groups. Furfural was the main heterocyclic compound in the MRPs. Therefore, ultrasound pretreatment and enzymolysis of chicken liver may be a foundation for high-value development in flavors for the food industry.

How ultrasound combined with potassium alginate marination tenderizes old chicken breast meat: Possible mechanisms from tissue to protein.

The combined effects of ultrasound (intensity of 15.6 W/cm2 and sonication for 5 min) with potassium alginate (PA) marination (UPA) on tenderizing old chicken breast meat, and possible mechanisms from tissue to protein, were investigated. UPA-treated meat exhibited the lowest moisture loss and shear force (optimized tenderness). The increased fiber space benefited PA invasion to form a heat-induced barrier for harder muscle contraction and avoid moisture withdrawal. Special scale-like structures of dried myofibrillar protein (MP) and the three-dimensional network induced by interactions between PA and MP increased the tenderness. UPA treatment induced stronger electrostatic repulsion between PA molecules and more ß-sheet structures of MP, accompanied by a smallest size. The more easily heat-denatured myosin and looser myofibrils accelerated the temperature rise. More immobilized water restricted to myofibrils and moisture captured in the gel network promoted water retention. UPA treatment could be a promising technology to tenderize old chicken breast meat.

Effect of spaghetti meat abnormality on broiler chicken breast meat composition and technological quality.

The effects of spaghetti meat (SM) myopathy and sampling location on chicken breast meat physical traits, composition, and protein functionality were investigated using 30 normal (N) and 30 SM boneless fillets. Weight, drip loss, pH, and color traits were determined on intact fillets. Proximate composition, water holding capacity, mineral profile, SDS-PAGE, myofibrillar, and sarcoplasmic protein solubility, and emulsifying properties were assessed on both the superficial (S) and deep (D) layers of the breasts. SM fillets were heavier (P < 0.0001) and exhibited greater drip loss (P = 0.0131) and higher b* index on the skin side of the muscle (P < 0.0001). Muscle condition by layer interaction effect revealed that the superficial portion of SM fillets (SM-S) exhibited the highest moisture (P = 0.0003) and fat contents (P = 0.0011) coupled with the lowest protein (P < 0.0001) and ash contents (P = 0.0458). Total and soluble collagen amounts were higher in N-S and SM-S groups compared with N-D and SM-D (P < 0.0001). SM-S group exhibited the highest calcium (P = 0.0035) and sodium (P < 0.0001) levels. Overall, the myopathy had only minor impacts on protein profiles, while the muscle layer exerted a more remarkable effect. SM fillets exhibited higher pH but a lower myofibrillar protein solubility (P < 0.0001). Salt-induced water uptake, cooking loss, and final yield values suggested a potential impairment of water-holding capacity in SM-affected meat. Sarcoplasmic and myofibrillar emulsion activity indexes were similar between the 2 muscle conditions, but the stability of the emulsions was lower in SM meat. Overall, significant layer and muscle condition by layer effects were not observed in the functional properties of the breast meat. SM exerted a profound and negative impact on breast meat composition that led to detrimental consequences on functionality traits. Given the fundamental role of protein quality for meat processing, these data suggest that a further step toward the understanding of this myopathy should be the investigation of intrinsic protein characteristics.

FTIR-based hierarchical modeling for prediction of average molecular weights of protein hydrolysates.

In the presented study, Fourier-transform infrared (FTIR) spectroscopy is used to predict the average molecular weight of protein hydrolysates produced from protein-rich by-products from food industry using commercial enzymes. Enzymatic protein hydrolysis is a well-established method for production of protein-rich formulations, recognized for its potential to valorize food-processing by-products. The monitoring of such processes is still a significant challenge as the existing classical analytical methods are not easily applicable to industrial setups. In this study, we are reporting a generic FTIR-based approach for monitoring the average molecular weights of proteins during enzymatic hydrolysis of by-products from the food industry. A total of 885 hydrolysate samples from enzymatic protein hydrolysis reactions of poultry and fish by-products using different enzymes were studied. FTIR spectra acquired from dry-films of the hydrolysates were used to build partial least squares regression (PLSR) models. The most accurate predictions were obtained using a hierarchical PLSR approach involving supervised classification of the FTIR spectra according to raw material quality and enzyme used in the hydrolysis process, and subsequent local regression models tuned to specific enzyme-raw material combinations. The results clearly underline the potential of using FTIR for monitoring protein sizes during enzymatic protein hydrolysis in industrial settings, while also paving the way for measurements of protein sizes in other applications.

Effects of ultrasonic pretreatment on the structure and functionality of chicken bone protein prepared by enzymatic method.

This study investigated the application of ultrasonic pretreatment (UP) to assist with enzymatic extraction of chicken bone protein. Relevant parameters of UP including ultrasonic power, duration of treatment and temperature were studied. The effect of ultrasound was evaluated by examining the protein structure changes (i.e. surface hydrophobicity, secondary and tertiary structures, molecular weight distribution) and their functionalities (i.e. solubility, oil holding capacity, foaming and emulsifying properties). Higher protein extraction yield and surface hydrophobicity were evident after UP, along with the changes in the secondary and tertiary structure of the protein. UP alone effects the proteins having molecule weight at about 100 kDa. Results also reveal UP was capable of enhancing the protein functionalities. Therefore, UP could be applied as a suitable technology to improve the yield and quality of the protein extracted from chicken bone by enzymatic method, and as such, facilitating the potential utilization of waste byproduct from poultry industry.

Integrative analysis of long noncoding RNA and mRNA reveals candidate lncRNAs responsible for meat quality at different physiological stages in Gushi chicken.

Long noncoding RNAs (lncRNAs) play important roles in transcriptional and posttranscriptional regulation. However, the effects of lncRNAs on the meat quality of chicken hasn't been elucidated clearly yet. Gushi chickens are popular in China because of their superior meat quality, particularly the tender flesh, and unique flavor. Gushi chickens are popular in China because of their superior meat quality, delicate flesh, and unique flavor. We performed RNA-Seq analysis of breast muscle from Gushi chicken at two physiological stages, including juvenile (G20W) and laying (G55W). In total, 186 lncRNAs and 881 mRNAs were differentially expressed between G20W and G55W (fold change ≥ 2.0, P < 0.05). Among them, 131 lncRNAs presented upregulated and 55 were downregulated. We identified the cis and trans target genes of the differentially expressed lncRNAs, and constructed lncRNA-mRNA interaction networks. The results showed that differentially expressed mRNAs and lncRNAs were mainly involved in ECM-receptor interaction, glycerophospholipid metabolism, ubiquitin-mediated proteolysis, and the biosynthesis of amino acids. In summary, our study utilized RNA-seq analysis to predict the functions of lncRNA on chicken meat quality. Furthermore, comprehensive analysis identified lncRNAs and their target genes, which may contribute to a better understanding of the molecular mechanisms underlying in poultry meat quality and provide a theoretical basis for further research.

[Meat quality in broilers reared in different housing systems].

Meat quality was assessed in Cobb-500 cage vs. floor-housed broilers slaughtered at 38 vs 49 days of age. Broilers (105 birds per housing system) were reared since 1 day of age in conditions of vivarium of Center for Selection and Genetics «Zagorskoye EPH¼. Fat content in breast meat was significantly higher (p<0.05) at both slaughter ages in cage-housed broilers (2.0 and 2.7% at slaughter age 38 and 49 days, respectively) compared to floor-housed (1.6 and 2.2%). Protein content in breast meat was higher in floor-caged broilers. Total collagen content in thigh meat of floor housed broilers (789.88 mg/100 g) was 1.5 fold higher compared to cage-housed (515.80 mg/100 g, p<0.05). Fatty acid profiles of meat were mostly affected by the type of meat (red vs white) and to a lesser extent by housing system and slaughter age. Water-holding capacity in red meat significantly differed between slaughter ages and between housing systems at slaughter age 38 days (р<0.05): at slaughter age 38 days water-holding capacity in red meat was 67.3 in cage-housed broilers vs. 70.1% in floor-housed; at slaughter age 49 days 74.9 vs. 76.0%, respectively. The five-point scores of sensory taste evaluation for the meat of floor-housed broilers (4.55 and 4.91 for breast meat at slaughter ages 38 and 49 days; 4.40 and 4.90 for thigh meat) were better compared to cage-housed (4.47 and 4.83 for breast meat at slaughter ages 38 and 49 days; 4.37 and 4.70 for thigh meat). The conclusion was made that meat quality estimated by a set of the relevant parameters was marginally better in floor housed broilers in compare to cage-housed.

Classification of Chicken Parts Using a Portable Near-Infrared (NIR) Spectrophotometer and Machine Learning.

Identification of different chicken parts using portable equipment could provide useful information for the processing industry and also for authentication purposes. Traditionally, physical-chemical analysis could deal with this task, but some disadvantages arise such as time constraints and requirements of chemicals. Recently, near-infrared (NIR) spectroscopy and machine learning (ML) techniques have been widely used to obtain a rapid, noninvasive, and precise characterization of biological samples. This study aims at classifying chicken parts (breasts, thighs, and drumstick) using portable NIR equipment combined with ML algorithms. Physical and chemical attributes (pH and L*a*b* color features) and chemical composition (protein, fat, moisture, and ash) were determined for each sample. Spectral information was acquired using a portable NIR spectrophotometer within the range 900-1700 nm and principal component analysis was used as screening approach. Support vector machine and random forest algorithms were compared for chicken meat classification. Results confirmed the possibility of differentiating breast samples from thighs and drumstick with 98.8% accuracy. The results showed the potential of using a NIR portable spectrophotometer combined with a ML approach for differentiation of chicken parts in the processing industry.

The effect of structural change on the digestibility of sarcoplasmic proteins in Nanjing dry-cured duck during processing.

To evaluate the effect of structural change on the digestibility of sarcoplasmic proteins in Nanjing dry-cured duck during processing, carbonyl content, sulfhydryl (SH) group, disulfide (S-S) group, surface hydrophobicity, particle size, secondary structures, and in vitro digestibility were determined. During processing, carbonyl content increased; SH groups turned into S-S groups; α-helix turned into ß-sheet. From marinating to early dry-ripening stage, surface hydrophobicity increased but particle size decreased, whereas these had opposite tendencies at the late dry-ripening stage. The in vitro digestibility of pepsin decreased at drying-curing and drying-ripening stages, whereas the one of pancreatic proteases kept stable until late drying-ripening stage. We concluded that salting, drying, and protein oxidation caused the denaturation and aggregation during processing. The oxidation and aggregation of sarcoplasmic proteins of Nanjing dry-cured duck resulted in a loss of nutritional quality during drying-ripening stage.

Efeito da evisceração retardada sobre a conservação de carne de aves (Gallus domesticus) resfriada / Effect of retarded evisceration on conservation of poultry (Gallus domesticus) refrigerated meat

Analisou-se 60 amostras de carcaças de frangos, abatidos em matadouro industrial, divididos em dois lotes de 30. No primeiro tratamento, adotou-se um processamento normal de matança e no segundo, houve um retardo na evisceração de 40 minutos. Realizou-se análises microbiológicas (CBHAM - contagem de bactérias heterotróficas aeróbias mesófilas e CBHAP - contagem de bactérias heterotróficas aeróbias psicrotróficas) e físico-químicas (pH, tempo de filtração e BVT-bases voláteis totais), no 1° e 7° dias após o abate, com as carcaças conservadas à temperatura de 3 ± 1 °C. Os valores médios encontrados no primeiro e segundo tratamento no primeiro dia, foram respectivamente: 5,1 x 10 3 UFC/g e 3,3 x 10 3 UFC/g para CBHAM; 6,3 x 10 3 UFC/g e 4,4 x 103 UFC/g para CBHAP; 5,59 e 5,52 para pH; 6,77 minutos e 6,43 minutos para tempo de filtração; 10,38 mgN/100g e 10,46 mgN/100g para BVT. No 7° dia, os valores médios no primeiro e segundo tratamento, foram respectivamente: 2,1 x 10 4 UFC/g e 1,1 x 10 5 UFC/g para CBHAM; 2,5 x 10 5 UFC/g e 4,0 x 105 UFC/g para CBHAP; 5,51 e 5,59 para pH; 10,13 minutos e 10,55 minutos para tempo de filtração; 10,48 mgN/100g e 10,33 mgN/100g para BVT. O teste estatístico, através da análise de variância, demonstrou que nos dois tratamentos houveram diferenças significativas entre o 1 ° e 7° dia, na prova de filtração e na CBHAP. Não foram encontradas diferenças significativas entre os dois tratamentos para nenhuma das análises realizadas.

Were analyzed 60 poultry carcass slaughtered at an industrial plant. The carcasses were divided into two groups of 30, in the first group a normal slaughter process was followed wile in the other group evisceration was retarded by 40 minutes. Microbiological (CBHAM - heterotrophyc aerobic mesophylic bacterial counting and CBHAP - heterophyc aerobic psicrophyc bacterial counting) and physicochemical (pH, filtration timeand BVT-total volatile basis) determination were performed at the 1st and 7th days after the slaughter and lhe carcasses were maintained at 3 ± 1 °C. The mean value for the first day (1st and 2nd groups respectively) were: 5,1 x 10 3 UFC/g and 3,3 x 10 3 UFC/g for CBHAM; 6,3 x 10 3 UFC/g and 4,4 x 10 3 UFC/g for CBHAP; pH 5.59; and 5.52; filtration time 6.77 minutes and 643 min,; and 10.38 mg N/100g and 10.46 mgN/100g for BVT In lhe 7th day the mean values were respectively: 2.1 x 10 4 UFC/g and 1.1 x 10 5 UFC/g for CBHAM; 2.5 x 10 5 UFC/g and 4.0 x 10 5 UFC/g for CBHAP; the pH were 5,51 and 5.59; the filtration times were 10.13 minutes and 10.55 minutes; and the BVT 10.48mgN/100g and 10.33 mgN/100g. The variance analyses showed significant differences between the 1st and 7th days for CBHAP and filtration times for both groups. There was no significant differences between the two treatments for the parameters analyzed.