Search Results (111)

The focus on selecting broilers for rapid growth rates and enhanced breast muscle yield has resulted in a decline in meat quality. The differences in carcass characteristics and meat quality between Hubbard white broilers (HWs, a commercial breed) and Xueshan chickens (XSs, an indigenous breed) at market age were analyzed to determine the potential mechanisms responsible for these differences. The results show that HWs exhibited significantly better carcass performance than XSs, including the larger weight of the carcass, the breast muscle, and the thigh muscle (p < 0.01). In addition, based on HE staining analysis, HWs’ breast muscles had a considerably larger average myofiber area and diameter than those of XSs (p < 0.01). Furthermore, the physical characteristics of the meat revealed that XSs had higher redness and yellowness and also higher lightness. HW meat had a higher pH and thermal loss, but a lower shear force and drip loss than XS meat (p < 0.01). The content of saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) was, remarkably, lower in the breast muscles of HWs than of XSs (p < 0.01). In contrast, HWs had a larger concentration of monounsaturated fatty acids (MUFAs) than XSs (p < 0.01). Finally, the breast muscles of XSs had lower levels of mRNA expression for genes linked to lipid metabolism, such as fatty acid binding protein 4 (Fabp4) and peroxisome proliferator-activated receptor alpha (Pparα), and had higher levels of the phosphofructokinase muscle type (Pfkm) compared to HWs (p < 0.01). These results indicate that a lower carcass yield was observed in XSs compared with HWs, but that XSs showed better performance in terms of meat quality than HW. Full article

Background: The presence of C. perfringens in chicken meat products leads to significant economic losses for the industry and is associated with human food poisoning. It inspires creative answers for novel substances and techniques, such natural antibacterials, for improved prospects in the future. The objective of this study was to examine the antibacterial properties of thymus and star anise extracts for the suppression of Clostridium perfringens in products made from chicken meat. Methods: Thymus and star anise extracts were phytochemically analyzed using the Folin–Ciocalteu spectrophotometric method, High-Performance Liquid Chromatography (HPLC) to determine the phenolic compounds, DPPH to determine the antioxidant activity, and the agar disk diffusion assay to determine the antibacterial effect of the star anise. Following treatment with the mixture extract, an experimental application was conducted on chicken burgers. C. perfringens was also found in poultry samples. Lastly, the sensory evaluation of the chicken burger was detected. Results: The findings showed that Clostridium perfringens was present in a large number of chicken meat products, with a significant concentration in chicken thighs (84%), as well as in the mixture extract has the largest concentration of phytochemical components (TPC:123.88 ± 7.42 mg GAE/g, TFC: 69.04 ± 6.37 mg quercetin/g) with strong antibacterial action (the minimum inhibitory concentration (MIC) of the mixed extract was 3.12 mg/mL, with an inhibition zone of 13.06 ± 0.91 mm). Also, the addition of mix. extract to chicken burgers extends their shelf life, particularly when the mix content is high. Additionally, the mix. extract shows non-significant effect (p < 0.05) on the chicken burger’s sensory qualities. Conclusions: Finally, we can make use of the mix. extract of thymus and star anise as a natural preservative in chicken meat products especially the chicken burger. Full article

In this study, we designed an ultrasound transmit–receive sequence to achieve high-frame-rate vascular wall velocity estimation and high-contrast B-mode imaging. The proposed sequence extends conventional dual-transmission schemes by incorporating a third transmission with 180° phase inversion, enabling harmonic imaging via the pulse inversion (PI) method. To mitigate the frame rate reduction caused by the additional transmission, the number of simultaneously transmitted focused beams was increased from two to four, resulting in a frame rate of 231 Hz. A two-dimensional phase-sensitive motion estimator was employed for motion estimation. In vitro experiments using a chicken thigh moving in two dimensions yielded RMSE values of 3% (vertical) and 16% (horizontal). In vivo experiments on a human carotid artery demonstrated that the PI method achieved a lumen-to-tissue contrast improvement of 0.96 dB and reduced artifacts. Velocity estimation of the posterior vascular wall showed generally robust performance. These findings suggest that the proposed method has strong potential to improve atherosclerosis diagnostics by combining artifact-suppressed imaging with accurate motion analysis. Full article

This study aimed to investigate the effects of different supplemental amounts of dandelion flavonoid extracts (DFE) in diets on nutrients in chicken, slaughtering performance, blood biochemical indexes and antioxidant capacity of spent laying hens. A total of 180 560-day-old spent Hy-Line Brown laying hens were randomly divided into five groups. The control group was fed the basal diet, while the experimental groups were supplemented with DFE at levels of 1000, 2000, 4000, and 8000 mg/kg (as T1, T2, T3, and T4 group) in the basal diet, respectively. The variables measured included the content of dandelion flavonoids in layer hen thigh meat and breast meat, slaughter performance, blood biochemical indexes, and antioxidant capacity. Data were subjected to a one-way analysis of variance (one-way ANOVA) to assess the impact of DFE supplementation compared to the control group on study outcomes. The results showed that dietary supplementation with DFE can increase the content of dandelion flavonoids in layer hen meat. The contents of rutin in layer hen breast meat of groups T1, T2, T3, and T4 were 1.37, 4.41, 16.26, and 36.03 ng/g, respectively, and the contents of quercetin was 2.58, 1.36, 4.98, 12.48 ng/g. In layer hen thigh meat of groups T1, T2, T3, and T4, the contents of rutin were 11.48, 15.98, 44.43, 122.32 ng/g, and the contents of quercetin were 9.96, 13.14, 23.15, 38.09 ng/g, respectively. The addition of DFE increased the total phenol content of the feed and highly significantly elevated the total phenol content of layer hen meat (p < 0.01), and the total phenol content of chicken meat was strongly and positively correlated with the total phenol content of the feed. DFE supplementation significantly decreased abdominal fat percentage (p < 0.05) and increased crude fat content in chicken (p < 0.05). The addition of DFE reduced aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities (p < 0.05), decreased triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol (LDL-C), glucose (GLU), and malondialdehyde (MDA) contents (p < 0.05), and increased the content of albumin (ALB), total antioxidant (T-AOC) capacity and total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) activity (p < 0.05). Dietary supplementation of DFE at different concentrations could significantly increase the content of dandelion flavonoids in the muscle of spent laying hens, reduce the abdominal fat rate in hens, effectively reduce blood lipid levels, effectively increase crude fat content in thigh muscle, and enhance the body’s antioxidant capacity and liver function. Full article

This floor pen study explored the effects of feeding mineral methionine hydroxyl analogue chelates (MMHACs) zinc (Zn), copper (Cu), and manganese (Mn) on growth performance, carcass processing weight and quality, nutrient digestibility, gizzard erosion score, and bone parameters of broilers. One-day-old Ross 308 male chicks (n = 384) were randomly allocated to four dietary treatments with eight replicate pens per treatment and 12 birds per pen. The treatments were as follows: (1) inorganic trace mineral ZnSO₄ 110 ppm, CuSO₄ 16 ppm, MnO 120 ppm (ITM); (2) MMHAC Zn 40 ppm, Cu 10 ppm, Mn 40 ppm (M10); (3) Inorganic trace mineral ZnSO₄ 110 ppm, tribasic copper chloride 125 ppm, MnO 120 ppm (T125); (4) MMHAC Zn 40 ppm, Cu 30 ppm, Mn 40 ppm (M30). The birds were fed nutritionally complete wheat sorghum soybean meal-based diets from days 0 to 42 with three feeding phases including starter (days 0–10), grower (days 10–21), and finisher (days 21–42). The findings revealed that birds on the T125, M10, and M30 groups possibly had higher feed intake (p = 0.052) and higher weight gain (p < 0.063) than birds on the ITM group from days 0 to 42. Furthermore, birds fed the M30 diet had higher thigh and drumstick weights compared to those fed the ITM diet at day 42 (p = 0.05). Additionally, birds offered the M30 diet had increased ileal Cu digestibility compared to birds offered the M10 and ITM diets at day 21 (p = 0.006). Gizzard erosion scores and bone parameters were similar between the dietary treatments. Hence, the supplementation of MMHACs to broiler diets at 30 ppm may be a more suitable strategy to increase weight gain and the thigh and drumstick processing weight while maintaining the bone health of broiler chickens. Full article

Infectious bursal disease virus (IBDV) is an important pathogen affecting the poultry industry worldwide. IBDV serotype 1, including classical virulent strains (cvIBDV), variant strains (varIBDV), and very virulent strains (vvIBDV), is pathogenic for chickens. IBDV mainly infects immature B-lymphocytes in the bursa of Fabricius, weakening the humoral immune response and leading to secondary infections and increased morbidity and mortality. The Laboratory of Avian Pathology received ten live 8-week-old pullets from a laying hen operation experiencing increased mortality, prostration, diarrhea, and sudden death. Upon necropsy, the affected birds presented swollen, hemorrhagic, and edematous bursa of Fabricius, as well as hemorrhage in the breast and thigh muscles. RT-PCR confirmed that the samples from the bursa of Fabricius were positive for IBDV. Phylogenetic analysis of the VP1 and VP2 gene nucleotide sequences classified the strain, isolated in embryonated chicken eggs, as the A3B5 genotype. Amino acid sequence analysis of the VP2 hypervariable region revealed the presence of amino acid residues commonly found in vvIBDV. Additional studies are required to investigate the epidemiological situation of this genotype in Chile and to evaluate current vaccination plans and their effectiveness against new variants. Full article

The food industry continuously prioritizes methods and technologies to ensure product quality and safety. Traditional approaches, which rely on conventional algorithms that utilize predefined features, have exhibited limitations in representing the intricate characteristics of food items. Recently, a significant shift has emerged with the introduction of convolutional neural networks (CNNs). These networks have emerged as powerful and versatile tools for feature extraction, standing out as a preferred choice in the field of deep learning. The main objective of this study is to evaluate the effectiveness of convolutional neural networks (CNNs) when applied to the classification of chicken meat products by comparing different image preprocessing approaches. This study was carried out in three phases. In the first phase, the original images were used without applying traditional filters or color modifications, processing them solely with a CNN. In the second phase, color filters were applied to help separate the images based on their chromatic characteristics, while still using a CNN for processing. Finally, in the third phase, additional filters, such as Histogram of Oriented Gradients (HOG), Local Binary Pattern (LBP), and saliency, were incorporated to extract complementary features from the images, without discontinuing the use of a CNN for processing. Experimental images, sourced from the Pygsa Group databases, underwent preprocessing using these filters before being input into a CNN-based classification architecture. The results show that the developed models outperformed conventional methods, significantly improving the ability to differentiate between chicken meat types, such as yellow wing, white wing, yellow thigh, and white thigh, with the training accuracy reaching 100%. This highlights the potential of CNNs, especially when combined with advanced architectures, for efficient detection and analysis of complex food matrices. In conclusion, these techniques can be applied to food quality control and other detection and analysis domains. Full article

Genetic differences typically cause differences in the structure and function of proteins in meat. The objective of this research was to examine the biochemical characteristics and functional behavior of proteins in fresh composite meat from Thai Ligor hybrid chicken (LC) and commercial broiler chicken (BC). The composite meat samples, which comprise minced breast and thigh without skin from 20 chicken carcasses in a 1:1 (w/w) ratio, were randomly selected for analysis using the completely randomized design (CRD). Results showed that BC meat exhibited higher ultimate pH after 24 h, Ca²⁺-ATPase activity, and trichloroacetic acid (TCA)-soluble peptide content compared to LC meat (p < 0.05). While both meat types showed non-significant differences in reactive sulfhydryl (SH) levels (p > 0.05), LC meat exhibited higher hydrophobicity compared to BC meat (p < 0.05). Differential scanning calorimetry (DSC) analysis revealed a single transition peak in all samples. LC meat exhibited higher thermal stability than BC meat, with transition peaks at 91 °C and 81 °C, respectively, in non-sodium chloride (NaCl) treated samples. Samples treated with 2.5% NaCl exhibited transition peaks around 70 °C for BC and 79 °C for LC. LC meat showed higher storage modulus (G′) and loss modulus (G″) values than BC meat, suggesting a stronger gel-forming tendency. LC meat gels exhibited higher hardness, cohesiveness, gumminess, and chewiness, and a slightly lower pH (6.14 vs. 5.97) compared to BC meat gels (p < 0.05). LC meat gels displayed larger expressible moisture content (p < 0.05), although the value was approximately 6%. Compared to LC meat gels, BC meat gels appeared slightly whiter (p < 0.05). To compare the lipid oxidation of BC and LC meat gels day by day, the thiobarbituric acid reactive substances (TBARS) of gels stored at 4 °C in polyethylene bags were measured on Days 0, 4, and 8. Both BC and LC meat gels showed acceptable lipid oxidation-based rancid off-flavor after short-term storage at 4 °C, with TBARS values below 2 mg malondialdehyde (MDA) equivalent/kg on Day 8. Understanding these variations in biochemical properties and functional behavior can help optimize processing methods and produce meat products of superior quality that meet consumer preferences. Full article

The old Hungarian poultry breeds are the hidden reserves of the Carpathian Basin’s agriculture. The aim of this study was to examine the slaughter weight, carcass merit, and certain meat properties of two of them: the Partridge-colored Hungarian Chicken (PC) and the White Transylvanian Naked-neck Chicken (TN) under semi-intensive and traditional fattening conditions. Test slaughtering of chickens was conducted at 12th and 18th weeks of age. The eviscerated body weight (and the weight of cuts) of the PC (1140 g) and the cockerels of both breeds (1148 g) was larger than that of TN (878 g) and pullets (870 g). The farming system did not influence the carcass composition. At the same time, the pullets were characterized with larger values (p < 0.001) in regards to, for example, the breast–whole leg (0.81:1), breast fillet–thigh fillet (1.29:1), breast fillet–breast bone proportion (2.40:1) in comparison to the cockerels (0.7:1, 1.10:1 and 2.17:1, respectively). Examinations of meat quality revealed that the pH-value of the thigh (5.73 vs. 5.83) and breast meat (6.21 vs. 6.43) of the PC was significantly lower. However, the lightness (L*) of breast fillet was higher (55.2) than that in the TN (49.9). In addition, the yellowness (b*) value of the breast meat and breast skin was significantly higher in the PC, but the redness (a*) of the breast skin was higher in the TN. Results showed that the farming system affects these values, too. Accordingly, the yellowness (b*) of breast meat, breast skin, thigh meat, and thigh skin was significantly higher in the traditional group. The PC showed more satisfactory results in poultry production today. However, the reddish meat of the TN should be emphasized, which is excellent and appropriate in traditional agriculture. It is argued that the indigenous chicken breeds should be supported for the chicken meat trade regardless of their competitiveness. Full article

This research aimed to enhance the diet of Thai broiler chickens (KKU 1) by assessing the impact of CABR on growth performance, carcass yield, and meat composition. A total of 320 one-day-old mixed-sex (1:1) Thai KKU 1 broiler chicks were randomly assigned to five dietary treatments incorporating CABR at levels of 0%, 3%, 6%, 9%, and 12%. The chicks were fed for a period of 56 days, divided into three phases: 1–21, 22–49, and 50–56 days. In the grower phase, birds receiving 3% and 6% CABR displayed the lowest feed conversion ratio (FCR) compared to other groups, while their body weight (BW) and BW gain (BWG) were significantly higher than those of other treatments (p < 0.05). In the finisher phase, performance differences were minimal, except for birds on the 3% CABR diet, which had greater BW than those on 9% or 12% CABR diets. Overall, throughout all phases, the inclusion of 3% CABR resulted in improved BWG and FCR compared to other groups across the study period (p < 0.05). Additionally, the 12% CABR treatment reduced dressing percentage compared to other groups, but it did not negatively impact the relative organ weights of the carcass or the quality of breast meat. Incorporating 3% and 12% CABR resulted in the highest values recorded for gross energy and ether extract in breast meat (p < 0.05). Furthermore, the gross energy of thigh meat increased with 3% to 12% CABR inclusion, peaking at the 6% CABR treatment (p < 0.05). This study found that adding 3% or 6% CABR to the diet of Thai broiler chickens improves their growth without negatively impacting meat or carcass quality. Full article

This study evaluated the productive performance and carcass traits of broiler chickens during the warm season in dry tropical conditions. Two hundred, 1-day-old chicks were used. Birds were fed on reduced (RED) and standard (STD) diets, and two essential oils (EOs) levels, 0 and 200 ppm. The RED diets were formulated with 10% less energy and 10% less protein than STD diets. In the starter phase, weight gain was greater (p < 0.01) in birds fed STD than birds fed RED. In the starter phase, productive variables were not affected (p ≥ 0.14) by EOs. In the finisher phase, greater feed intake (p = 0.02) and higher weight gain (p = 0.04) were observed in chickens on STD. Feed conversion ratio was similar (p = 0.97) for STD and RED. Throughout this study (1–42 d), greater feed intake (p = 0.02) and higher weight gain (p < 0.01) were found in chickens on STD. Feed conversion ratio was similar (p = 0.51) for STD and RED. Broiler chickens on EO-supplemented diets had better feed conversion (p ≥ 0.08). Hot carcass weight was greater (p < 0.01) in birds on STD. Greater yields of leg-thigh (p = 0.01), back (p = 0.01), and wings (p < 0.01) were observed in RED. Carcass yields, breast yield, pH, and meat temperature were not influenced (p ≥ 0.14) by nutrient concentrations in the diet. Carcass evaluations were not affected (p ≥ 0.11) by EOs. Body temperature was lower (p = 0.03) in birds receiving RED, however EOs had no effect (p ≥ 0.22) on body temperature. For the length of the study, at 20:00 h, broiler chickens fed on RED diets showed lower (p = 0.04) body temperatures. In conclusion, broiler chickens were under heat stress during the study, and body temperatures were reduced in chickens fed on RED diets or with EOs. Diet modification or EO-supplementation may improve feed conversion, though RED diets may have a negative effect on weight gain or carcass values. Full article

This study aimed to compare the effects of incorporating fermented feed into daily diets on the slaughter performance, meat quality, and flavor compounds of 120 domestic chickens over a 140-day period. A total of five groups (n = 24), including the control group (CK) of the Guangxi Partridge chickens received a standard base diet. The other four groups were provided with pellets that had been added with 10% fermented banana peel (Pe-10), 20% fermented banana peel (Pe-20), 10% fermented banana pulp residue (Pu-10), and 20% fermented banana pulp residue (Pu-20). The flavor compounds in the meat samples of the chickens in these groups were determined using the gas chromatographic method. The results demonstrated that the chickens in the Pe-10, Pe-20, Pu-10, and Pu-20 groups exhibited pectoral muscle percentages, thigh muscle percentages, and total fatty acid content of chest meat that were higher than those observed in the CK group. The moisture content, meat color, carcass weight, total net weight, and abdominal fat percentage of the meat samples in these experimental groups exhibited no notable differences. The flavor compounds in the meat samples of the chickens fed with the two concentrations of fermented banana peel and banana residue were found to be significantly different from those in the control group, with p-values less than 0.05. As the quantity of fermented banana peel incorporated into the daily ration was increased from 10% to 20%, a notable alteration in the flavor compounds present in the chicken samples was observed. The chickens that were provided with fermented banana peels and pulps in their diets exhibited superior slaughter performance and meat quality, particularly in the case of the Pu-10 group, in comparison to the control chickens. Full article

Rosemary (Rosmarinus officinalis L.) is a natural spice plant with an aromatic flavor and antioxidant properties that can help enhance the flavor and texture of food, as well as be used as an antioxidant source in pet feed. This study explored the effect of rosemary on the growth performance and antioxidant capacity of broiler chickens. In total, 144 healthy 1-day-old Arbor Acres broilers were randomly divided into four groups: The control group was fed a basic diet, while the positive control group was fed a basic diet supplemented with 30 mg/kg kitasamycin, and the treatment groups were fed a basic diet supplemental with 0.5% rosemary, or 2% rosemary. The average daily feed intake of broilers fed with 0.5% and 2% rosemary in 1–42 days was higher than that in the basal diet group (p < 0.05). The pH was lower in the rosemary groups than in the 30 mg/kg kitasamycin group as measured in the thigh muscle tissue (p < 0.05), and the monounsaturated fatty acid C17:1 heptadecanoic acid content of the 2% rosemary group was higher than that of the other groups (p < 0.05). With 0.5% rosemary supplementation, the activities of the serum and liver antioxidant enzymes catalase (CAT) activity and total antioxidant capacity (T-AOC) increased (p < 0.05); malondialdehyde content decreased (p < 0.05). The serum activities of CAT, total superoxide dismutase, and T-AOC increased with 2% rosemary supplementation (p < 0.05). The relative expression of liver antioxidant genes, the nuclear factor E2-related factor 2, glutathione catalase 1, and superoxide dismutase 1 increased (p < 0.05) with 0.5% rosemary supplementation. The addition of rosemary resulted in higher intestinal lactobacilli counts and lower E. coli counts. In summary, adding 0.5% or 2% rosemary to the diet improved the growth performance of Arbor Acres broilers and increased the number of intestinal probiotics, and supplementing with 0.5% rosemary yielded better results than adding 2% rosemary. This study provides valuable insights into the broader application of plant-derived antioxidants in promoting sustainable and health-focused animal farming practices. Full article

The effect of dietary inclusion of Moringa oleifera leaf powder (MLP) on the growth, meat quality, carcass characteristics, hematobiochemical profile, and cecal bacteria of broiler chicken was investigated in this research trial. In this study, 192-day-old Arbor Acre broiler chicks were assigned in a completely randomized design to three groups: control, antibiotic, and MLP. A standard basal diet was given to the control group, while the antibiotic group received 75 mg/kg chlortetracycline, and the MLP group received 100 mg/kg M. oleifera leaf powder supplemented basal diet. Each group was further divided into eight replicates consisting of eight birds each, and the trial ran for 35 days. Among the groups, the MLP-fed broilers achieved the highest final body weight (FBW), average daily gain (ADG), and average daily feed intake (ADFI). Notably, the FCR for the whole experimental period was lower in the MLP group, indicating a more efficient use of feed for growth. Supplementation of MLP with basal diet significantly increased (p < 0.05) the weight of thighs and drumsticks relative to live weight %, while the spleen and abdominal fat weight (% of live weight) were significantly decreased (p < 0.05). Adding MLP to the diet improved the meat quality of broilers, as indicated by the highest pH of meat at 45 min and the lowest cooking loss (%) observed in this group. MLP exhibited hypocholesterolemic and hypolipidemic effects, with the lowest total cholesterol and triglyceride levels compared to non-supplemented groups. The hematological profile revealed that the MLP group exhibited the highest RBC count and Hb level, while also showing the lowest H/L ratio. Moringa supplementation significantly (p < 0.05) modulated the cecal bacterial population, reducing pathogenic E. coli and Shigella spp. while increasing beneficial Lactobacillus spp. and the total aerobic plate count (TAPC). In conclusion, Moringa oleifera leaf powder (MLP) can be used as a natural feed supplement for promoting the growth, meat quality, healthy blood, and sound health of broilers. Full article

This study aimed to assess the impact of Chlorella vulgaris supplementation in broilers’ diet, alone or in combination with vitamin E, on meat quality parameters, nutritional value, and oxidative stability during storage time. An experiment was conducted on 180 COBB 500 broiler chickens (14 days old), assigned into six treatments, following a 2 × 3 factorial arrangement. A corn–soybean meal diet was supplemented with three levels of C. vulgaris (0% in group C1, 1% in E1, 2% in E2), two levels of vitamin E (0% in C1, 250 ppm in C2), and a combination of them (1% C. vulgaris + 250 ppm vitamin (E3), 2% C. vulgaris + 250 ppm vitamin (E4)). Dietary incorporation of C. vulgaris, including those supplemented with vitamin E, resulted in a significant increase in meat protein content. DPA and DHA levels increased by 2.01-fold and 1.60-fold in the 2% C. vulgaris + vitamin E group. The PUFA/SFA ratio was increased across all dietary treatments (p < 0.0001). HPI and h/H registered the highest values as a result of 2% C. vulgaris supplementation, being linked with a positive effect in lowering cholesterol levels. Supplementation with 2% C. vulgaris and vitamin E exhibited a 1.45-fold increase in vitamin E concentration in thigh meat compared to the control group, being the highest level registered in thigh meat in this experiment. Metmyoglobin concentrations registered lower values in the thigh meat of the experimental groups, while deoxymyoglobin increased in the same groups when compared to the control group. The inclusion of C. vulgaris (1% and 2%) in combination with vitamin E (250 mg/kg) in broiler diets exhibited the best prevention of lipid oxidation after 7 days of refrigerated storage, defined by the highest efficiency factors assessed in terms of secondary oxidation products. Full article