A Survey of the Levels of Selected Metals in U.S. Meat, Poultry, and Siluriformes Fish Samples Taken at Slaughter and Retail, 2017-2022.

The U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) conducts surveillance of metallic elements in U.S. meat, poultry, and Siluriformes fish samples collected immediately postmortem as part of its National Residue Program (NRP). From 2017 to 2022, 13,966 samples were analyzed under the NRP. The Federal Emergency Response Network (FERN) Cooperative Agreement Program (CAP) tests meat, poultry, and Siluriformes fish products collected at retail in the United States for metals. From 2018 to 2022, 2,902 samples were analyzed by FERN CAP laboratories. Meat and poultry samples collected by FSIS show that most metals were not detected at all or were detected infrequently. Meat is a rich source of iron and zinc, and iron was detected in 22% (1,255/5,623) and zinc was detected in 48% (2,742/5,676) of meat and poultry samples, respectively. The percentage of samples testing positive for manganese, molybdenum, lead, and cadmium were higher in the FERN CAP retail samples than in FSIS samples. Expected human exposure from average levels of lead and cadmium found in meat and poultry was compared to toxicological reference values and was not found to exceed these values. Detections of arsenic and mercury were found more often in Siluriformes fish samples (2017-2022) than in terrestrial animals. Trace amounts of arsenic and mercury were detected in 8% and 4% of Siluriformes samples, respectively, but were not detected at levels that raise concern. On the whole, both the FSIS and FERN CAP datasets provide reassuring evidence of the safety of the FSIS-regulated food supply with regard to the studied elements.

Use of a commercial tissue dissociation system to detect Salmonella-contaminated poultry products.

Successful detection of bacterial pathogens in food can be challenging due to the physical and compositional complexity of the matrix. Different mechanical/physical and chemical methods have been developed to separate microorganisms from food matrices to facilitate detection. The present study benchmarked a commercial tissue digestion system that applies both chemical and physical methods to separate microorganisms from tissues against stomaching, a standard process currently utilized by commercial and regulatory food safety laboratories. The impacts of the treatments on the physical properties of the food matrix were characterized along with the compatibility of the methods with downstream microbiological and molecular detection assays. The results indicate the tissue digestion system can significantly reduce the average particle size of the chicken sample relative to processing via a stomacher (P < 0.001) without adversely affecting either real-time PCR (qPCR) or plate counting assays, which are typically used to detect Salmonella. Furthermore, inoculated chicken treated with the GentleMACS resulted in a significant increase (P < 0.003) in the qPCR's detection capabilities relative to stomached controls. Cohen kappa (κ) coefficient and McNemar's test indicate the plating assays and PCR results agree with measurements obtained via the 3 M Molecular Detection System as defined in the MLG standard (κ > 0.62; P > 0.08). Collectively, the results demonstrate that the technique enables detection of pathogens in meat at lower levels of contamination using current industry standard technologies.

Determinant production factors to the in vitro organic matter digestibility and protein oxidation of poultry by-product meal.

The quality of poultry by-product meal (PBM) is not standardized in the industry. Several factors are detrimental to PBM and compromise its nutritional value and shelf life. Therefore, this study was conducted to determine the main PBM production factors that directly affect its in vitro organic matter digestibility (IVDOM) and protein oxidation (POX). Data on the processing of PBM samples (n = 100) were recorded in a rendering plant. Two types of PBM were used: 1) Low ash (LA, n = 66) with mineral matter (MM) content of 11% and 2) High ash (HA, n = 34) with MM above 11%. Processing traits and chemical composition of PBM were considered independent variables. The IVDOM and POX were determined in each sample and considered dependent variables. Data on independent variables were submitted to factorial and principal components (PC) analyses. In vitro organic matter digestibility data were clustered (P = 0.001) in low (778.92 g/kg), average (822.85 g/kg), and high (890.06 g/kg). The best arrangement was composed of six independent variables distributed in two PC, which explained 82.10% of the total variation. The ash concentration, oil to raw material ratio, collagen, and crude protein comprised PC1 with greater relevance and explained 58.46% of the total variance. The PC2 was composed of the processing time and temperature and explained 23.64% of the total variance. Protein oxidation data were clustered (P < 0.001) in low (265.19 nmol/mg CP), average (393.07 nmol/mg CP), and high (524.40 nmol/mg CP). Based on our results, the composition of the raw material from the slaughterhouse holds most of the information on PBM composition and digestibility. Developing improvements in the slaughtering or in the screening of the raw material that will be used by the rendering process is important to obtain a more nutritionally standardized ingredient.

Lipid metabolism analysis in liver of different chicken genotypes and impact on nutritionally relevant polyunsaturated fatty acids of meat.

Humans and mammalian species are unable to synthesize significant amounts of polyunsaturated fatty acids (PUFA), which therefore must be introduced with the diet. In birds, lipogenesis takes place primarily in the liver, whereas adipose tissue serves as the storage site for triacylglycerols (TG, composed by 80-85% esterified fatty acids). However, both the nature (unsaturation level, n-3, or n-6 series) and the allocation (such as constituents of complexed lipids) of PUFA are very important to evaluate their function in lipid metabolism. The objective of the present investigation was to study the liver lipid metabolism, with particular attention to non-esterified fatty acids (NEFA), TG, phospholipids (PL), FADS2 gene expression, and Δ6-desaturase activity of three chicken genotypes, Leghorn (Leg), Ross 308 (Ross), and their crossbreed (LxR), by LC/MS analysis. The concentration of single fatty acids in muscle was quantified by GC-FID. The results showed that the Ross has a lipid metabolism related mainly to storage and structural roles, exhibiting higher levels of TG, phosphatidylethanolamine (PE) and phosphatidylcholine (PC) that are largely unsaturated. Meanwhile Leg showed a relevant amount of n-3 NEFA characterized by a higher phosphatidylserine (PS) unsaturation level, FADS2 gene expression and enzyme activity. The LxR seem to have a moderate trend: n-6 and n-3 NEFA showed intermediate values compared with that of the Ross and Leg and the TG trend was similar to that of the Ross, while PE and PC were largely unsaturated (mainly 6 and 7 UNS most of the metabolic energy for storage fatty acids in their tissues (TG) whereas, the Leg birds were characterized by different lipid metabolism showing in their liver a higher content of n-3 NEFA and higher unsaturation level in PS. Furthers details are needed to better attribute the lipid energy to the different metabolic portion.

Carcinogens in Food: Evaluating the Presence of Cadmium, Lead, in Poultry Meat in South India.

OBJECTIVE: Local chickens were spontaneously sampled and slaughtered in the central markets of Coimbatore, Erode, and Namakkal districts, South India. MATERIALS AND METHODS: Wet digestion was used to extract lead (Pb), cadmium (Cd), and zinc (Zn) in their blood and selected different organs (intestine, breast, liver, and gizzard), and their concentrations were measured using an atomic absorption spectrophotometer. RESULTS: Apart from the blood of chickens from Coimbatore and Namakkal, where Pb was not found, the concentrations of Pb in the blood and organs of chickens from the three towns ranged from 1.8 to 8.33 mg/kg, exceeding the maximum tolerance thresholds (0.1 mg/kg) in internal organs of poultry birds. Except for the intestine of chickens from the three areas, Cd was only found in the heart, blood, and gizzard of Erode chickens, as well as the liver and gizzard of Namakkal chickens, in concentrations ranging from 0.13 to 0.58. According to threshold level, the upper limit met the maximum limits (0.5 mg/kg). Zn was found in all sections of chickens from the three selected districts, with concentrations ranging from 4.96 to 174.17 mg/kg. CONCLUSION: Its concentrations were within the permissible limits (10-50 mg/kg) in some areas of certain chickens, but it surpassed the permissible limit in the liver of chicken from Coimbatore. Any organs and blood from local chickens sold in Coimbatore, Erode, and Namakkal areas can be hazardous to one's health.

An Analysis of Oxidative Changes and the Fatty Acid Profile in Stored Poultry Sausages with Liquid and Microencapsulated Fish Oil Additives.

This study deals with the fatty acid profile and oxidative changes (TBARS) in vacuum-packed (VP) or modified-atmosphere-packed (MAP) finely-comminuted poultry sausages with liquid fish oil and microencapsulated fish oil (MC) additives. An analysis of omega-3 fatty acids (EPA and DHA) showed that their content in the samples with the fish oil additive decreased from the initial value of 0.22 g∙100 g-1 of the product to 0.18 g∙100 g-1 (MAP) and 0.17 g∙100 g-1 (VP), respectively. After in vitro digestion, the total EPA and DHA content in the sample with microencapsulated oil amounted to 0.17 g∙100 g-1 of the product. The TBARS values showed the VP samples with both forms of the fish oil additive had the lowest values on the first day of storage. Storage of the samples for 21 days caused a slight increase in the degree of lipid oxidation. The research indicated that the forms of the oil additive did not have a negative influence on the sensory features or the physicochemical properties of the sausages. The EPA and DHA levels in samples with liquid fish oil and those with oil microcapsules were sufficient for the sausage producer to declare high content of these fatty acids in accordance with the current EC regulation.

Detection of Frozen-Thawed Duck Fatty Liver by MALDI-TOF Mass Spectrometry: A Chemometrics Study.

The marketing of poultry livers is only authorized as fresh, frozen, or deep-frozen. The higher consumer demand for these products for a short period of time may lead to the marketing of frozen-thawed poultry livers: this constitutes fraud. The aim of this study was to design a method for distinguishing frozen-thawed livers from fresh livers. For this, the spectral fingerprint of liver proteins was acquired using Matrix-Assisted Laser Dissociation Ionization-Time-Of-Flight mass spectrometry. The spectra were analyzed using the chemometrics approach. First, principal component analysis studied the expected variability of commercial conditions before and after freezing-thawing. Then, the discriminant power of spectral fingerprint of liver proteins was assessed using supervised model generation. The combined approach of mass spectrometry and chemometrics successfully described the evolution of protein profile during storage time, before and after freezing-thawing, and successfully discriminated the fresh and frozen-thawed livers. These results are promising in terms of fraud detection, providing an opportunity for implementation of a reference method for agencies to fight fraud.

Characterization of Pediococcus acidilactici postbiotic and impact of postbiotic-fortified chitosan coating on the microbial and chemical quality of chicken breast fillets.

This study was carried out to characterize antioxidant activity, total phenolic content, and the phenolic and flavonoids profile of postbiotic of Pediococcus acidilactici and to evaluate the effects of postbiotics (10% and 50%) alone and in combination with chitosan coating (1%) on the microbial and chemical quality of chicken breast fillets during storage at 4 °C. Antioxidant activity and total phenolic content of the postbiotics were found to be 1291.02 ± 1.5 mg/L TEAC and 2336.11 ± 2.36 mg/L GAE, respectively. The most abundant phenolic was vanillic acid, followed by t-caffeic, gallic, and caftaric acids. The postbiotic-chitosan (50% + 1%) combination decreased L. monocytogenes and S. Typhimurium counts by 1.5 and 2.1 log10 CFU/g, respectively, compared to the control (P < 0.05). This combination decreased the total viable count (TVC), lactic acid bacteria (LAB), and psychrotrophic bacteria count compared to the control (P < 0.05). No differences were found in thiobarbituric acid (TBA) values among the samples during storage (P > 0.05). Postbiotic treatment did not significantly change the pH values and color properties of the breast fillets (P > 0.05). Postbiotic-chitosan combinations extended the shelf-life by up to 12 days compared to the control. In conclusion, the postbiotic-chitosan combination can be used to preserve and improve the microbial quality of chicken meat products.

Stable isotopes verify geographical origin of Tibetan chicken.

Due to the particularity of origin area, the yield and price of Tibetan chicken are different from those in the plain areas, which leads to chickens from the plains being disguised as Tibetan chickens. In present study, Tibetan chicken and chicken from other four provinces in plain areas were distinguished by stable isotopes and chemometric methods. The cross-validation rate was 97.6%. Secondly, correlation between mean δ13C, δ15N, δ2H and δ18O values in chicken samples and environmentalparameters was investigated. These indicators are closely related to geographical environment. δ13C and δ15N values were positively correlated with longitude (R = 0.955) and altitude (R = 0.796), respectively. δ18O and δ2H values were negatively correlated with latitude (R = 0.903) and altitude (R = 0.938), respectively. At last, we used stable isotopes to trace Tibetan chicken from the different area of Tibet. When four stable isotope ratios were combined, we can distinguish them.

Effect of storage time on the quality of chicken sausages produced with fat replacement by collagen gel extracted from chicken feet.

The objective of this study was to evaluate the use of collagen gel extracted from chicken feet on chicken sausages during 42 d of refrigerated storage. Three chicken sausages were processed: standard (SS); replacing 50% fat with commercial collagen powder (SC); replacing 50% fat with chicken foot collagen gel (SG). Sausages were stored at 4°C and analyzed every 14 d, for proximate composition, fatty acid profile, thiobarbituric acid reactive substances (TBARS) number, antioxidant activity, electrophoresis, instrumental color, water holding capacity (WHC), texture profile analysis, and quantitative descriptive analysis. Sausages SC and SG had similar behavior to the standard in the sensorial parameters of appearance and color over 28 d of refrigerated storage. SG had the highest WHC (81.05%), the lowest TBARS value (0.38 mg MDA/kg), and the highest antioxidant activity in addition to having the best atherogenicity and thrombogenicity index compared with SC treatment, making collagen gel viable to replace fat and control the effects of lipid oxidation.

Effects of wheat fiber addition on emulsion and lipid/protein stabilities of an omega-3 fatty acid-fortified chicken surimi product.

Meat, except marine sources, is a highly nutritious food but generally lacks some healthy ingredients, such as omega-3 fatty acids (ω-3 FA) and dietary fiber. However, ω-3 FA and dietary fiber could be incorporated during the manufacture of surimi-like products. In our previous study, chicken surimi was successfully developed from spent-hen breast. Although there was no (P > 0.05) difference in water-holding capacity between wheat fiber and carrageenan, an increased (P < 0.05) flaxseed oil-holding capacity was observed in wheat fiber samples. Furthermore, an addition of 5% wheat fiber resulted in optimal emulsification capacity and less cooking loss at 4°C for 14 d and at -20°C for 60 d (P < 0.05). Because of the lower (P < 0.05) purge and centrifugation losses, thiol group content, and thiobarbituric acid reactive substance value than those formulated with more flaxseed oil, 12% flaxseed oil was an optimal level in chicken surimi with 5% wheat fiber. Scanning electron microscopy results also showed better emulsification of surimi batters with wheat fiber compared with those without wheat fiber, and meanwhile, the formulation with 5% wheat fiber could hold up to 12% flaxseed oil as well. To enhance flaxseed-oil addition, semi-manufactured chicken surimi batter was successfully fortified with a combination of 12% flaxseed oil and 5% wheat fiber. This surimi-like product with dietary fiber and ω-3 FA would fit the need in the current market regarding consumers' demands for high nutritional value and improved processing characteristics.

Nanocomposite active packaging based on chitosan biopolymer loaded with nano-liposomal essential oil: Its characterizations and effects on microbial, and chemical properties of refrigerated chicken breast fillet.

Biodegradable films reinforced with bio-nanomaterials are a solution for developing active packaging systems, shelf-life extension and protection of environment against conventional packaging. This study aimed to characterize the biocompatible chitosan (CS) films formulated with nano-liposomal garlic essential oil (NLGEO) and assess the physicho-mechanical, morphology properties and also microbial and chemical changes in chicken fillets during storage time at 4 °C. NLGEO was obtained by thin-layer hydration-sonication method using glycerol and tween 80 as plasticizer and emulsifier, respectively. Different levels (0, 0.5, 1 and 2%) of NLGEO with average size of ~101 nm were added into the chitosan matrix and films fabricated by casting method. The average size, polydispersity index and zeta potential were ~101 nm, 0.127 and -7.23, respectively. Control samples showed higher values for pH, total volatile nitrogen (TVN), peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), and microbial count including total viable count (TVC), coliforms, Staphylococcus aureus and psychrotroph bacteria than treated samples. The films with higher NLGEO content represented stronger inhibitory effects. The incorporation of NLGEO improved the mechanical properties and water resistance of active films. Microstructure analysis also showed a nearly smooth surface morphology and homogenous structure with a good dispersion for NLGEO films. Significant synergistic effects in chemical and bacterial preservation of chicken fillet samples were observed by NLGEO films. The optimal mechanical and barrier properties of chitosan-NLGEO films introduced it a potential active packaging to extend the shelf life of chicken fillet.

Flavor and texture characteristics of microwave-cooked Kung Pao Chicken by different heat conduction effects and further aroma improvement with moderate enzymatic hydrolyzed chicken fat.

Ceramic dish cooking method (CDCM) and microwave absorption dish cooking method (MADCM) were used to obtain one-step microwave-cooked Kung Pao Chicken. Processing the optimization of recipes, steaming time and microwave time was conducted for microwave cooking methods. CDCM showed higher taste scores, better umami and sweet attributes, and better color and aroma than MADCM. The NMR and FITC fluorescence analysis results indicated that free water in chicken cooked by CDCM was lost more and tends to shift to immobilized water during the microwave heating as compared with MADCM. However, the aroma intensity by CDCM was weaker than the traditional cooking method (TCM). Electronic nose analysis also showed difference in the flavor profile from CDCM and TCM. According to the GC-MS analysis, aldehydes, the oxidation products of fats, were higher from TCM than from other cooking methods. Therefore, enzymatic hydrolyzed chicken fat at 5 g per 150 g chicken with a degree of enzymatic hydrolysis of 17.00% was used in CDCM to produce ideal fatty and meaty flavor. Both fatty and meaty flavor have increased by 52% and 60% respectively, with less off-flavor, thus, obtaining a similarity of 92% compared to TCM and with appropriate contents of volatiles such as hexanal, heptanal, (E)-2-octenal, (E)-2-decenal, (E)-2-nonenal and 2,4-decadienal.

Effects of enzymatically hydrolysed poultry byproduct meal in extruded diets on serum angiotensin-converting enzyme activity and aldosterone in cats.

Several peptides found in hydrolysed poultry byproduct meal can inhibit angiotensin-converting enzyme (ACE) activity, a property that indicates potential antihypertensive and health-promoting effects. This study aimed to assess the effects of extruded diets containing enzymatically hydrolysed poultry byproduct meal (HPM) on cat serum ACE activity and aldosterone (ALD) concentration, nutrient digestibility, and faecal characteristics. On the basis of a preliminary in vitro ACE inhibitory activity assay, a commercial HPM and a commercial conventional poultry byproduct meal (CPM) were selected for further investigation. Two isoenergetic and isonitrogenous diets were formulated: CPM diet (25.7% CPM) and HPM diet (24.7% HPM). In trial 1, the effect of diet on serum ACE activity and ALD concentration was evaluated using 8 healthy cats (4 female and 4 male, 4.1 ± 0.38 kg BW) in a crossover design, with 5 d of adaptation and blood collection on d 6. In trial 2, apparent total tract digestibility and faecal characteristics were evaluated using 12 cats (6 female and 6 male, 4.0 ± 0.72 kg BW) in a completely randomised design. Serum ACE and ALD were analysed using a mixed model, with diet as the fixed effect and cat as the random effect. Data from trial 2 were subjected to analysis of variance, and means were compared by Tukey's test. In vitro ACE inhibitory activity of HPM (90.4%) was higher than that of CPM (52.0%). Cats fed the HPM diet tended to have lower serum ACE activity than those fed the CPM diet (126 versus 142 U/l, p = 0.09). Serum ALD was not influenced by diet. Diets had similar digestibility values, and faecal consistency scores tended to be higher (firmer faeces) in cats fed the CPM diet than in cats fed the HPM diet (4.6 versus 4.0, p = 0.09). Inclusion of HPM in extruded diets may reduce cat serum ACE activity and promote good faecal consistency without affecting digestibility. Further investigations are needed to explore the potential health benefits of HPM in hypertensive cats.

Physio-biochemical, antioxidant and oxidative stability of Turkey meat-fed diet incorporated with different level of organic chromium.

The aim of this study was to evaluate the effects of organic chromium (Cr) on physico-biochemical and oxidative stability of turkey meat. Ninety-six (16th weeks) male turkeys were distributed into 16 groups (4 diet × 4 replicates × 6 birds each). Four dietary treatments (T1, T2, T3 and T4) were formulated with supplementation of 0.0, 250, 500 and 750 µg Cr/kg diets, respectively. Cholesterol and fat contents in meat reduced (p < 0.05) in T4 (750 µg Cr/kg) but no difference was observed in pH and drip loss. No significant effect was recorded on water holding capacity (WHC) and extract release volume (ERV) of fresh meat but the effect (p < 0.05) was observed on WHC and ERV in refrigerated meat. No significant difference was observed in DPPH (1, 1-diphenyl-2-picrylhydrazy) and ABTS (2, 2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) of fresh breast and thigh meat but effect (p < 0.05) was noticed in refrigerated meat of turkey fed T4. Lipid oxidation (free fatty acids and Thio-barbituric acid reactive substances-TBARS) were improved in fresh as well as refrigerated meat from birds fed diet supplemented with 750 µg Cr/kg (T4). Whereas, peroxide value was improved (p < 0.05) only in refrigerated meat. Thus, it may be concluded that inclusion of Cr at 750 µg/kg diet with basal diet improved in desirable physio-biochemical properties, antioxidant and oxidative stability of male turkey meat under cold chain.

Rapid detection of trace formaldehyde in food based on surface-enhanced Raman scattering coupled with assembled purge trap.

It has been remained a challenge to detect trace formaldehyde in complex samples, such as rice flour and duck blood products. In this study, a purge-trap device was designed and used for volatile target detection, which avoided interference adsorptions on enhanced particle surfaces during subsequent surface-enhanced Raman spectroscopy (SERS) analysis. The device produced a low detection limit for formaldehyde of 1 × 10-4 µg/mL in the concentration ranges of 4 × 10-3-4 µg/mL and 1 × 10-4-3 × 10-3 µg/mL. In the process of the detection of duck blood and rice flour, partial least squares regression (PLSR) was adopted for sample analysis. The formaldehyde concentration was calculated and compared to the actual value from the above model with R2 of 0.97, which indicated high accuracy and stability. These results suggested that the proposed method was reliable and suitable for rapid analysis of trace formaldehyde in real products.

Detection of ethinyl estradiol and resorcylic acid lactones in poultry meat according to the national residue plan.

The aim of this study was the detection of ethinyl estradiol and resorcylic acid lactones (zeranol and taleranol) in poultry meat samples as unauthorized substances included in the Italian national residue plan. The samples were purified by a solid phase extraction using a C18 column combined with alumina, and the analytes were detected by two specific enzyme-linked immunosorbent assay (ELISA) kits. As they were collected in the frame of official control activities, the method was also validated according to the Commission Decision 2002/657/EC requirements for screening methods with qualitative purpose. Specificity and detection capability were the performance criteria considered for the validation study, and the latter parameter showed a value of 0.5 µg/kg for both the investigated compounds. Such result was well comparable with the data reported by using chromatographic techniques as confirmation methods, and therefore, the ELISA kits tested in this study could be used for the screening of large numbers of samples.

Chemical compositions and sensory characteristics of pork rib and Silkie chicken soups prepared by various cooking techniques.

Meat soup is an important diet with desirable taste and abundant nutrients. Unveiling the chemical composition of soup will help to understand the health effects. In this work, pork ribs and Silkie chicken were used to prepare soups by boiling, steaming and four-stage stewing, respectively. The chemical composition and sensory qualities of these soups were obviously influenced by the cooking technique. Silkie chicken and pork rib soups prepared by four-stage stewing technique had particle size smaller than 850 nm, smaller chromatic aberration, higher stability, higher levels of free amino acids, lower levels of fat and total triglycerides than the other two techniques. More abundant flavor and taste characteristics were also detected. The high temperature boiling technique could promote the accumulation of the mineral elements in soup. According to healthy and sensory concerns, stewing was the best choice for preparing soups of pork rib and Silkie chicken.

Total replacement of fishmeal with poultry by-product meal affected the growth, muscle quality, histological structure, antioxidant capacity and immune response of juvenile barramundi, Lates calcarifer.

The present study investigates if the total replacement of dietary fishmeal (FM) with poultry by-product meal (PBM), supplemented with methionine influences the muscle fatty acids composition, normal gut morphology, histological traits of the liver, muscle, and gill, liver enzymes, immune and antioxidant response, and stress-related gene in juvenile barramundi, Lates calcarifer in relation to growth and feed utilization. Barramundi (3.58±0.01g) were randomly distributed into six 300 L seawater recirculating tanks (25 fish/tank) and fed two formulated isonitrogenous and isolipidic diets for 6 weeks. The control diet had FM as the sole animal protein source, whereas other test diet had only PBM as an animal protein source. Dietary PBM affected the fish performance and feed utilization. Regarding muscle fatty acid profile, total saturated fatty acids and monounsaturated fatty acids elevated while total PUFA particularly n-3 LC-PUFA and EPA decreased in PBM fed fish than control diet fed fish. Liver, muscle, gill, and intestinal histology showed no obvious alteration in control diet fed fish, however, more lipid droplets and hepatic vacuolization in the liver, necrotic myotome in muscle, hyperplasia in secondary lamellae in gill and short and broken folds in the intestine were observed in PBM fed fish. Similar to light microscopy observation of intestinal morphology, the transmission electron microscopy (TEM) analysis revealed shorter and smaller microvilli in fish fed PBM. Histopathological alterations in the liver of PBM fed fish were further associated with the elevated levels of aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH) and the significant upregulation of stress-related genes, HSP70 and HSP90. Also, a negative influence on lysozyme activity, and antioxidant enzymatic activities were recorded in fish fed PBM. Overall, it can be concluded that a total substitution of FM protein by methionine supplemented PBM negatively influenced the growth performance, liver health, histological traits of different organs, immune and antioxidant response, and expression of stress-related genes in juvenile barramundi.

Comparative analysis of characteristic volatile compounds in Chinese traditional smoked chicken (specialty poultry products) from different regions by headspace-gas chromatography-ion mobility spectrometry.

This article presents investigation of the flavor profile on 5 different regional Chinese smoked chicken samples using gas chromatography-ion mobility spectrometry analysis methods. Five batches of samples were obtained over the course of 6 mo. A total of 34 flavor substances were identified in the 5 smoked chicken samples, including 10 aldehydes, 7 alcohols, 4 ketones, 2 hydrocarbons, 3 heterocyclic compounds, 4 esters, 2 ethers, and 2 phenolic compounds. The whole spectral fingerprint visually displayed flavor differences and relations in 5 types of smoked chicken with local characteristics. Moreover, the orthogonal projections to latent structures discriminant analysis model revealed that these samples could be separately classified into 5 groups. Multivariate statistical analysis showed that 20 chemicals with higher Variable Importance for the Projection values were the key contributors to the differences of flavor in these 5 kinds of smoked chicken. N-nonanal, heptanal, n-nonanal, heptanal, furfurol, and hexanal were the main common flavor compounds in the 5 types of Chinese smoked chicken, whereas linalool, alpha-terpineol, 1,8-cineole, and anethole were the main characteristic flavor compounds of Goubangzi chicken (No. 1); gamma-butyrolactone, 2-acetylfuran, 2-methoxyphenol, 2-acetylpyrrole, and limonene were determined as the key flavor compounds of Liaocheng chicken (No. 2); the concentration of octanal and n-nonanal was higher in Tangqiao chicken (No. 3); butyl acetate was the key contributor to the flavor compounds of Jinshan chicken (No. 4). 2-Heptanone and 2-pentylfuran had a high correlation with Zhuozishan chicken (No. 5). The different raw materials and ingredients used, especially the method of preparation and cultural differences, in different regions of the country in China were the main reasons leading to the similarities and differences of volatile compounds in the 5 kinds of Chinese traditional smoked chicken.