Concentration of lipids, cholesterol, and fatty acid profile in chicken breast meat affected by wooden breast myopathy frozen for up to 12 mo

The aim of this study was to examine the effects of frozen storage for 12 mo on the concentrations of lipids and cholesterol and fatty acid profile of wooden chicken breast meat. A total of 120 samples of chicken breasts were selected, according to the degree of "wooden breast" myopathy ["severe," "moderate," and "normal" (absence of myopathy)], from male chickens slaughtered at 42 d of age, from Cobb 500 strain. Part of the samples (n = 20/grade of severity) were evaluated on the day of collection and the remainder were packaged, frozen and stored at -18°C for up to 12 mo. At the beginning (collection day) and at the end of the proposed freezing period (12 mo), analyses of lipid, cholesterol, and fatty acid profile were carried out. Percentage of saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were evaluated. Meats affected by wooden breast myopathy had lower levels of PUFA that exert beneficial effects on health, such as DHA, EPA and ARA, and this profile is impaired by prolonged storage (12 mo), which results in important nutritional losses for the consumer.

Physical, chemical, and microbiological evaluation of sausages produced with chicken meat affected by deep pectoral myopathy

The purpose of the present study was to characterize the chemical composition, lipid oxidation, and physical characteristics of fresh sausages produced with meat from the pectoralis major muscle affected by deep pectoral myopathy. For the characterization of myopathy, samples were collected from broiler chickens slaughtered between 42- and 46-days old in a slaughterhouse in the state of São Paulo. The experiment consisted of samples from pectoralis major muscle of birds affected or not by DPM (normal-absence of myopathy and DPM category 3-progressive degeneration of the pectoralis minor with a greenish appearance). After classification of the samples, a part of raw products with the pectoralis minor removed, was submitted to microbiological and physical analyses for the characterization of DPM. Afterward, only the pectoralis major muscle was used to manufacture fresh sausages and 2 groups were established. The evaluated parameters were: color, pH, water-holding capacity (WHC), cooking loss (CL), shear force (SF), water activity (Aw), and chemical composition. Meat pH was higher (P < 0.05) in meats with DPM, however, WHC values were lower (71.92%), which made CL value increase (25.31%). In addition, the coloring increased and the technological characteristics of raw breasts were less favorable with the presence of DPM. All fresh sausages' color (except a* higher control group), pH, and Aw values were higher in DPM group. No effect on SF values was observed between fresh sausages. In chemical composition, only protein content increased in fresh sausages with DPM. Microbiological analyses did not indicate bacterial contamination of raw samples and fresh sausages. Data obtained in the present study suggest fresh sausages produced with breasts affected by DPM are a viable alternative and may confer more favorable qualitative characteristics to sausages than the raw marketed meat.

Effect of freezing on the quality of breast meat from broilers affected by wooden breast myopathy

The objective of the present study was to characterize possible variations in the quality of wooden chicken breast meat during freezing for 12 mo, in order to prove whether the shelf life recommended by the industry allows the storage of that type of meat without compromising its consumption. Three hundred samples of male Cobb 500 broilers slaughtered at 42 d of age were used. Part of the samples (n = 20 normal-control group; n = 20 moderate degree; n = 20 severe degree) were analyzed on the day of collection (beginning), previously kept under refrigeration (4°C). The other samples were stored (-18°C) for up to 12 mo. At the end of each proposed freezing period (3, 6, 9, and 12 mo), physical and chemical analyses were performed (per period: n = 20 normal-control group; n = 20 moderate degree; n = 20 severe degree). Color (L*, a*, and b*), pH, water-holding capacity, cooking losses, tenderness, lipid oxidation, chemical composition, cholesterol concentration, mineral profile, and collagen concentration were evaluated. The physicochemical quality of wooden chicken breast meat is significantly altered during frozen storage for 12 mo, being of inferior quality when compared to normal chicken breast meat, which can negatively affect consumer acceptance. However, it should be noted that even after 12 mo of freezing, the meats did not show oxidative rancidity.

Astaxanthin improves the shelf-life of tilapia fillets stored under refrigeration

BACKGROUND

Astaxanthin, classified as a xanthophyll, has antioxidant properties about 500 times greater than α-tocopherols and ten times greater than β-carotenes. Based on the antioxidant activity of this carotenoid, this study aimed to evaluate the shelf-life of tilapia fillets (Oreochromis niloticus) fed with astaxanthin, by determining the microbiological quality (colimetry, counts of mesophilic and psychrotrophic microorganisms), physicochemical analyses (colorimetry, pH, thiobarbituric acid reactive substances (TBARS)) and sensory analysis.

RESULTS

Tilapia supplemented with astaxanthin presented a reduction in the counts of microorganisms (mesophiles and psychrotrophics) and lower lipid oxidation index (TBARS), when compared to fillets of control fish. Colorimetric changes of fillet degradation were observed, associated with increased pH during storage, as well as loss of brightness and texture in addition to worsening of appearance and odor. These deteriorating changes were minimized using astaxanthin.

CONCLUSION

Our results demonstrate the beneficial performance of astaxanthin in the shelf-life of tilapia fillets stored under refrigeration. Therefore, dietary supplementation with astaxanthin (100 and 200 mg kg^-1 of feed) improves the microbiological and physicochemical quality of tilapia fillets during 50 days of shelf-life. © 2022 Society of Chemical Industry.

Research Note: Quality parameters of turkey hens breast fillets detected in processing plant with deep pectoral myopathy and white striping anomaly

The increase in the consumption of poultry meat intensified production, which allowed the emergence of myopathies associated with broiler and turkey meat. The aim to examine possible quality alterations in the 240 Pectoralis major muscle (breast fillets) from carcasses of turkey breeder hens. Regarding DPM, 120 samples of breast fillets from turkey of the Nicholas strain with Pectoralis minor muscle together were selected according to the occurrence of the myopathy in the Pectoralis minor muscle (tender), as follows: DPM score 2 (n = 40), DPM score 3 (n = 40), and a control group unaffected by DPM, score 0 (n = 40). Then, different 120 samples, from the same flock of birds, were selected according to White Striping (WS) anomaly in the Pectoralis major muscle (breast fillets), considering the degree of severity of the striations apparent in the muscle, as follows: moderate (n = 40), severe (n = 40) and a control group (normal) without the presence of WS anomaly (n = 40), with set up as a completely randomized design with 3 treatments for DPM and WS. We evaluated in meat of turkey breeder hens color, water-holding capacity (WHC), cooking loss (CL), shear force (SF), sarcomere length (SL) and total, soluble and insoluble collagen contents. The color parameters lightness (L*), redness (a*), and yellowness (b*) of turkey breeder hens breast fillets were altered by the occurrence of DPM and WS and as except CL, there were a difference for WHC and SF (P < 0.05). Significant differences were observed for sarcomere length (P < 0.05) between fillets without myopathies and with DPM Score 2 and 3 too. Higher values of total collagen (%) were observed for the most severe category of involvement for both myopathies. The DPM and WS affect the color and in a partial reduction texture of the breast fillets meat of turkey breeder hens and this may have a negative economic impact on the meat industry, because these are the main points evaluated by the consumer, in the most value commercial cut.

Effect of freezing on the quality of breast meat from broilers affected by White Striping myopathy

The aim of this study was to evaluate possible changes in the quality of chicken breast meat containing white stripes during freezing for 12 mo. Samples of Pectoralis major muscle from male Cobb 500 broilers containing white stripes in moderate and severe degrees were used, as well as samples from a control group (normal - absence of myopathies). Part of the samples (n = 60; n = 20 for each severity degree) were analyzed on the day of collection (beginning) and the rest (n = 240) was frozen (-20°C) for up to 12 mo. At the end of each proposed freezing period (3, 6, 9, and 12 mo), color, pH, water holding capacity, cooking loss, tenderness, lipid oxidation, chemical composition, cholesterol and collagen concentrations, myofibrillary fragmentation, and sarcomere length were analyzed. Microbiological analysis of samples was performed at the beginning and after 12 mo of freezing. Myopathy linked to freezing showed results of increased meat tenderness, with reduction of crude protein and mineral matter and increase of moisture, fat, and cholesterol, without affecting the meat's collagen percentages. However, these variations with the onset of myopathy do not compromise the consumption of broiled chicken breast meat, kept frozen for up to 12 mo.

Impact of deep pectoral myopathy on chemical composition and quality parameters of chicken breast fillet

One of the current myopathies affecting the chicken meat industry is deep pectoral myopathy (DPM), also known as green muscle disease or Oregon disease, the condition is considered a major problem in poultry processing lines. Thus, the present study proposes to examine the meat quality of the Pectoralis major muscle (breast fillet) from carcasses of broilers affected by DPM in Pectoralis minor muscle (tender) and from a control group. Breast fillets samples were harvested from Ross AP95 broilers that were slaughtered at 42 days of age and were selected to the occurrence of the myopathy (score 2 and score 3) and from a control group without (score 0) the presence of myopathy. Chemical composition, cholesterol, fatty acid profile, pH, color, water-holding capacity, cooking loss, shear force, sarcomere length, and collagen were analyzed in the breast fillet. And with the results it was observed the samples classified as DPM score 2 had a higher moisture and a lower protein percentage. The higher values lipid was found in the samples from broilers affected by DPM. There was no difference (P > 0.05) fatty acid profile only to C10:0, C15:0, C17:0, C20:0, and C18:2c9,t11. Differences were detected (P < 0.05) for the pH, WHC, SF, and sarcomere length of the samples from broilers affected by DPM. The higher pH observed in the samples from birds classified as DPM score 2 and the higher WHC values were observed in the samples affected by DPM (score 2 and 3). The SF (P < 0.05) among samples, with the most tender samples (lower SF values) being those unaffected by the condition DPM (score 0). The dorsal side surface, where the Pectoralis major muscle is in contact with the Pectoralis minor muscle, higher L* values were found in the meat affected by the myopathy. Although deep pectoral myopathy affects the Pectoralis minor muscle of broilers, it can also alter the qualitative characteristics and chemical composition of the breast fillets (Pectoralis major muscle).

Effect of Aging on the Quality of Breast Meat from Broilers Affected by Wooden Breast Myopathy

This study aimed to evaluate the effects of aging on the quality of breast meat from broilers affected of wooden breast. Samples that were classified as normal (control), moderate (hardness verified only in one region of breast fillet), and severe (hardness verified in all the extension of breast fillet) were evaluated fresh and after three and seven days of aging. Normal samples and samples with a moderate degree of myopathy showed greater water-holding capacity, which may benefit the processing industry of poultry meat. During the aging process, increase was observed in total collagen concentration (from 0.41% in normal samples to 0.56% in samples with severe degree). Samples of chicken breast affected by moderate degree showed higher myofibril fragmentation index (MFI = 115) than normal chicken samples (95.65). Although chicken samples affected with severe degree of wooden breast myopathy are more tender than normal chicken breasts, they produce more exudate, which can be detrimental to the processing of poultry meat. The aging process may improve the reduction of cooking weight loss and protein loss in exudation of broilers' breasts affected by wooden breast myopathy.

Breast meat quality of turkey breeder hens at disposal age affected by deep pectoral myopathy

Deep pectoral myopathy (DPM) considerably affects the meat quality of commercial poultry, thus representing a challenge to the poultry industry. In this study, we examined the breast meat quality of turkey breeder hens at disposal age affected by different degrees of DPM. Samples were collected from Nicholas turkeys at disposal age (385 d), at an average weight of 12.5 kg, which were reared and slaughtered in the south region of Brazil. The breast was first classified according to the degree of DPM and then samples of the Pectoralis major were collected from birds affected (DPM degrees 2 and 3; n = 20 of each) and nonaffected (normal, absence of lesions; n = 20) by the myopathy. After the affected Pectoralis minor muscle was discarded, the carcasses were released for human consumption by the Federal Inspection Service. The meat affected by the myopathy exhibited color changes (L*, a* and b*) (P < 0.05), especially in the inner surface. Higher (P < 0.05) water-holding capacity, pH, sarcomere length and fat concentration and lower (P < 0.05) shear force and moisture percentage were observed when compared to the normal samples. From this study, can be concluded that the severe condition of deep pectoral myopathy which affects the Pectoralis minor muscle, causes variations in the quality of Pectoralis major muscle of turkey on disposal age. As a raw material, this type of meat has a higher fat content and greater capacity for retaining intracellular water, important attributes to the manufacture of processed products. In this way, the processing is an economically viable alternative to the commercialization of breast meat from birds affected by myopathy.

Internal quality of commercial eggs stored under conditions that simulate storage from laying to consumption

This study evaluated the effects on the internal quality of eggs of various storage environments through which eggs may pass between being laid and being consumed. Commercial eggs (N = 648) from Dekalb White hens were used. Treatments consisted of T1: 28 days at 4 °C; T2: 28 days at 20 °C; T3: 7 days at room temperature (27 °C ± 2 °C) (humidity 55%) and 21 days at 4 °C; T4: 7 days at room temperature and 21 days at 20 °C; T5: 14 days at room temperature and 14 days at 4 °C; T6: 14 days at room temperature and 14 days at 20 °C; T7: 21 days at room temperature and 7 days at 4 °C; T8: 21 days at room temperature and 7 days at 20 °C; and T9: 28 days at room temperature. The characteristics that were evaluated consisted of Haugh unit (HU), yolk index (YI), colour (L*, a* and b*), albumen pH, yolk pH and lipid oxidation. Eggs stored 28 days were darker (L*), and had greater yolk pH and lipid oxidation than fresh eggs. Eggs stored under T1 and T3 conditions had greater HU and YI than eggs stored in the other environments. The albumin pH of eggs stored at room temperature (T9) was highest of the treatments. Yellowness was increased in eggs stored under T4, T6, T8, and T9 conditions. Eggs should be stored under refrigeration as this promotes maintenance of internal quality and mitigates negative effects of previous storage conditions.

Quality of turkeys breast meat affected by white striping myopathy

The aim of this study was to characterize the breast meat of turkeys affected by different degrees of severity (normal [NORM], moderate [MOD], and severe [SEV]) of the white striping (WS) myopathy, as well as to evaluate the influence of this myopathy on meat quality. Twenty-nine samples of the pectoralis major muscles of each treatment were obtained from Nicholas breed male and female turkeys, reared and slaughtered in the center-west region of Brazil. The whole breasts of the turkeys were used for macroscopic classification, weight evaluation, and morphometric measurements. Then, the pectoralis major muscle was separated for histological evaluation and qualitative physicochemical analyses, namely ventral and dorsal color (L∗, a∗, and b∗), pH value, water holding capacity (WHC), cooking loss (CL), shear force (SF) (Meullenet-Owens Razor Shear [MORS] and Warner-Bratzler), sarcomere length, total, soluble, and insoluble collagen contents, proximate composition (protein, lipids, moisture, and ash), cholesterol content, and fatty acid profile. The results showed that muscles affected by myopathy, both MOD and SEV, exhibited larger weights (around 2.8 kg) compared to NORM muscles (1.3 kg) and a significant increase (P < 0.05) in the diameter of the fibers. The increase in the degree of severity of the myopathy increased (P < 0.05) the value of L∗ of the dorsal part and ventral part of the muscle. No differences (P > 0.05) were observed in the pH, CL, and WHC values of the muscles, whereas the MORS and Warner-Bratzler SF of the SEV fillets resulted in significantly lower shear values (P < 0.05) compared to the NORM fillets. In addition, the MOD and SEV fillets presented lower values of protein (P < 0.05) than NORM fillets. No significant differences (P > 0.05) were observed for moisture and lipid and cholesterol contents. Meat with MOD and SEV severity of WS myopathy had higher (P < 0.05) concentrations of total and insoluble collagen. Thus, the presence of WS myopathy in MOD and SEV degrees affected a large part of the histological and quality characteristics evaluated.

Physicochemical Properties and Consumer Acceptance of Hamburgers Processed with Chicken Meat Affected by Wooden Breast Myopathy

Simple Summary

The study of meat quality of modern birds and their respective myopathies is important to understand the influence of myopathy on the meat quality of these birds. The constant genetic evolution that birds have suffered and still suffer in the present is the most plausible cause of the onset of this myopathy. The processing of by-products, such as hamburgers, enters as an alternative to avoid losses that this myopathy generates in the poultry industry, with discards of chickens affected by the different degrees of myopathy in wooden breast.

Abstract

Considering the increased incidence of wooden breast myopathy in broilers, the intake involves no threat to human health, indefinite etiology consumer rejection by appearance in such breasts, and the lack of studies on the industrial use of wooden breast. The objective of this study was evaluating the quality of hamburgers made with chicken meat affected by wooden breast. Breast samples from broilers slaughtered at 48-days-old were used. Normal (absence of myopathy), moderate degree (hardness only in one region of the breast) and severe degree (hardness over the entire length of the breast) samples were processed for the manufacture of hamburgers whose quality analyses (color, pH, cooking weight loss, shrinkage percentage, tenderness, storage weight loss, water activity, lipid oxidation, chemical composition and consumer test) were performed on non-stored samples (Day 0), and after storing at 30, 60, 90 and 120 days at −20 °C. There was a reduction (p < 0.05) in tenderness in samples of moderate-grade hamburgers (from 161.45 N to 289.40 N) after 120 days of storage. Hamburgers produced with chicken breast samples affected by wooden breast myopathy presented higher (p < 0.0001) fat concentration (5.32 g/100 g and 5.26 g/100 g, respectively, for the moderate and severe degree) than hamburgers made of normal samples (4.45 g/100 g). Lipid oxidation values increased, which exceeded the limit of rancidity detection, independent of myopathy. The consumers equally appreciated the aroma, flavor, and texture, and rated their overall acceptance as similar regardless of the quality of chicken meat. Chicken breast hamburgers with wooden breast myopathy is a viable alternative for the poultry industry.

Feeding behavior of lambs fed diets containing old man saltbush hay

Background: We hypothesized that a diet with old man saltbush hay used as an alternative source of nutrients could partially replace the concentrate in the feeding of feedlot lambs. Objective: This study evaluated the behavior and performance of lambs fed diets containing increasing levels of old man saltbush hay plus concentrate. Methods: Twenty-four castrated Santa Inês lambs at approximately eight months of age (22 ± 1.97 kg) were confined in a randomized complete design and fed diets containing 30, 40, 50, and 60% (dry matter: DM) of old man saltbush hay. Results: The intake of DM and neutral detergent fiber was not affected (p>0.05) by the level of old man saltbush hay. Intake of mineral salt decreased (p<0.01) as the proportion of old man saltbush in the diet increased. Weight gain (kg) and feed efficiency worsened (p<0.05) with 40% inclusion of old man salt bush hay. The time spent on feeding and chewing increased (p<0.05), while idle time was reduced (p<0.01) with dietary inclusion of old man saltbush. Feed efficiency decreased (p<0.05) with the inclusion of old man saltbush. Conclusion: Dietary inclusion of old man saltbush affects the feeding behavior and performance of lambs in feedlot.

Lipid Assessment, Cholesterol and Fatty Acid Profile of meat from broilers raised in four different rearing systems

Evaluated lipid and cholesterol concentration and fatty acid profile of raw breast, thigh and drumstick meat from broilers raised in different rearing systems. Were used 200 male broiler carcasses from four different rearing systems (n=50 from conventional intensive; n=50 from organic; n=50 from free-range; and n=50 from antibiotic-free) distributed in a completely randomized design with four rearing systems and 50 replications (carcasses). Breast meat from conventional broilers showed higher lipid (1.47) and cholesterol (34.13) concentration. Thigh and drumstick meat from free-range broilers had higher lipid (7.53/4.73) and cholesterol (45.55/53.65) concentration. Fat contained in breast, thigh and drumstick meat from free-range broilers showed higher levels of polyunsaturated fatty acids. Fat from breast and thigh meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Fat from thigh meat from organic broilers showed higher levels of EPA (C20:5n3) and DHA (C22:6n3). Fat from drumstick meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Meat from chickens raised in alternative rearing systems offers less risk to cardiovascular health because it presents lower concentrations of lipids and cholesterol, greater amounts of polyunsaturated fatty acids, which are beneficial for human health.

Miopatia White Striping em diferentes linhagens de frangos de corte e suas consequências sobre a composição e a qualidade da carne

RESUMO Avaliou-se a incidência da miopatia White Striping (WS) em três linhagens de frangos de corte machos e suas consequências sobre a composição química e a qualidade física da carne. Para determinação das porcentagens de incidência dos diferentes graus da miopatia WS (normal, moderada e severa) nas linhagens, foi utilizado um delineamento inteiramente ao acaso (DIC), com três tratamentos (linhagens A, B e C) e cinco repetições de 300 peitos cada. Para as variáveis químicas e físicas, utilizou-se um DIC em esquema fatorial 3 x 3 (três linhagens x três níveis de WS), com 15 repetições cada. Os dados foram submetidos à análise de variância e, em casos de diferenças significativas, utilizou-se o teste de Tukey (P≤0,05). As aves da linhagem A apresentaram 84,81% de peitos classificados como normais e 9,91% de peitos classificados como moderados, valores respectivamente maiores e menores que nas duas demais linhagens. Os peitos classificados com miopatia WS severa foram mais pesados e apresentaram maiores porcentagens de lipídios e umidade, e menor concentração de proteína bruta. As concentrações de colágeno total, termo solúvel e insolúvel variaram com o nível de acometimento por WS nos filés, com comportamento específico para cada linhagem.

Respostas de frangos de corte criados sob estresse por calor

Para avaliar a influência do estresse por calor por até 72 horas, e o possível efeito acumulativo do estresse sobre as respostas fisiológicas de frangos de corte criados sob condições simuladas de ondas de calor, 500 frangos de corte machos, da linhagem Cobb, foram criados em duas câmaras climáticas equipadas com sistemas de aquecimento e refrigeração, por até 45 dias. Metade das aves foram criadas sob conforto térmico (ajustado de acordo com o ideal para cada idade) e as demais aves foram submetidas a ondas de calor (32 °C ± 0,5 °C por até 72 horas) em três idades (com início aos 21, 35 e 42 dias de idade). No início de cada simulação de onda de calor e após 24, 48 e 72 horas de exposição ao calor, foram avaliados parâmetros fisiológicos como temperatura retal e frequência respiratória. Além disso foram coletadas amostras de sangue para determinação de níveis hormonais (T3 e T4) e hematócrito. O aumento da frequência respiratória das aves foi verificado após 24 horas de exposição a altas temperaturas nas três ondas de calor simuladas. Durante a terceira onda de calor não houve variação da temperatura retal. A temperatura ambiente não influenciou o valor do hematócrito e os níveis de hormônios tireoidianos T3 e T4. Submeter aves a períodos de estresse por calor agudo intermitente, como durante a simulação de ondas de calor, influencia a frequência respiratória e a temperatura retal dos frangos de corte, evidenciando o consequente efeito do estresse por calor sobre o metabolismo das aves e o equilíbrio térmico corporal. As ondas de calor não afetam a secreção de tri-iodotironina e tiroxina, e a porcentagem de glóbulos vermelhos.

Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age

We evaluated the effect of broiler age and aging process on the meat characteristics of breast fillets from female free-range broilers slaughtered at 12 weeks of age (Wk12) and 70 weeks of age (Wk70). We used breast meat from female ISA Label (n = 60) broilers. Ten samples of each broiler age were aged in an incubator (2°C ± 0.5°C) for 3 and 7 days. Ten samples for each broiler age were analysed 4 h post-slaughter (Control group). Compared with breast meat from Wk12, breast meat from Wk70 showed higher shear force (30.52 N vs 27.19; P = 0.0322) and total collagen (4.33 g/kg vs 3.77 g/kg; P = 0.0149), which were reduced during aging to 15.49 N and 3.92 mg/100 g, respectively. The aging process did not affect the lipid oxidation of breast meat from Wk70. After aging for 3 days, breast meat from Wk70 had similar protein and fat contents to those of meat from Wk12 (21.29% and 1.04%, on average, respectively). Breast meat from Wk70 also showed lower concentrations of docosahexaenoic (0.32% vs 0.65%; P < 0.0001) and eicosapentaenoic (0.01% vs 0.12%; P < 0.0001) fatty acids than meat from Wk12. The use of free-range hen meat is beneficial to the industry because of the lower storage and cooking losses, which may influence the final yield, besides its lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to promote the tenderisation of meat from free-range broiler hens.

Characteristics of carcasses and meat from feedlot-finished buffalo and Bos indicus (Nellore) bulls

The trade of buffalo meat is very limited in Brazil, where it is still considered exotic, and ~90% of it is marketed as cattle meat. The present study compared qualitative characteristics of the longissimus muscle from buffalo and cattle. Eighty uncastrated male bovids (40 Mediterranean × Murrah crossbred buffaloes and 40 Nellore cattle) with an average age of 21 months and initial average bodyweight of 350 kg and 305 kg respectively, were confined for 102 days. Buffalo carcass had lower dressing-out percentage (P < 0.0001; 52.1% vs 57.2%) than did cattle carcass; buffalo meat had greater fat cover (P < 0.0001; 13.8 vs 8.1 mm) and, consequently, lower cooling loss (P < 0.0001; 1.3% vs 1.8%) than did cattle meat; also had lower cooking loss (P = 0.0120; 29.42% vs 31.31%), lower collagen content (P < 0.0001; 4.81% vs 5.73%), higher moisture (P = 0.0027; 75.13% vs 74.55%), and lower atherogenicity index (P = 0.0008; 0.61 vs 0.70) than did cattle meat. There was no difference (P = 0.13) between buffalo and cattle regarding cold carcass weight (251 kg and 244.8 kg respectively). Tenderness, fat, and omega-6 : omega-3 fatty acid ratio were also similar in both meats. The buffalo carcass provides higher yield of cuts of high commercial value than does the cattle carcass; it has similar or better physical and chemical properties than beef and a lower percentage of polyunsaturated fatty acids, making it less susceptible to rancidity. Cattle meat has higher concentrations of C12:0 and C14:0 fatty acids, which are related to increased serum low-density lipoprotein and cholesterol concentrations, while buffalo meat is a rich source of C18:0 and C18:1n9c fatty acids, which help in the prevention of cardiovascular diseases.

Effect of freezing on the quality of meat from broilers raised in different rearing systems

We evaluated the effect of freezing (−18°C) for 12 months on the qualitative characteristics of breast, thigh and drumstick meat. Samples from male Cobb 500 broilers raised in antibiotic-free (n = 125), conventional (n = 125) and organic (n = 125) rearing systems and samples from male Hubbard ISA broilers raised in a free-range (n = 125) rearing system were used. Among the studied systems, up to the ninth month of freezing, the organic chicken breast meat showed lower (P < 0.001) water activity (aw) (0.966, on average). After 12 months of freezing, samples of antibiotic-free and organic poultry showed a pH value similar to that of fresh meat (5.94 and 5.86, respectively). Freezing for 12 months preserved the redness of drumstick meat from conventional broilers (a* = 4.86, on average) and the rearing system did not influence the aw of drumstick meat during the entire experimental period. Freezing preserved the aw of conventional and organic chicken meat samples until the ninth month of evaluation (0.978 and 0.974, respectively). Lipid oxidation in the breast, thigh and drumstick samples from the four rearing systems increased (P < 0.001) from the third month of freezing onwards. There were variations in colour, pH, aw and lipid oxidation of chicken meat among birds raised in different rearing systems. Freezing chicken meat did not prevent colour and pH changes or occurrence of lipid oxidation and did not promote a reduction of aw to levels unfavourable to microbiological development.

A comparison of the effects of post-mortem aging on breast meat from Cobb 500 and Hubbard ISA broilers

We compared the physical and chemical characteristics of the pectoralis major muscle from Cobb 500 and Hubbard ISA broilers and evaluated the effect of aging process for up to 7 days on meat quality. We used breast samples from male Cobb 500 (42 days of age; n = 60) and Hubbard ISA (85 days of age; n = 60) broilers. Twenty samples of each genotype were analysed 4 h post-slaughter (Control group). Another 20 samples of each genotype were aged in an incubator (2 ± 0.5°C) for 3 and for 7 days. Breast fillets were 23% heavier in the Cobb 500 group (306 g vs 248 g; P = 0.0009). Before aging, meat from Hubbard ISA broilers had higher (P < 0.001) water-holding capacity, which promotes the production of less exudate and possibly reduces nutritional losses during storage, which may be beneficial to the poultry industry. Despite being initially less tender, breast meat from Hubbard ISA broilers showed, during the aging process, a reduction (P < 0.05) of shear force (48.46–15.04 N), total collagen amount (6.0–4.8 g/kg) and myofibrillar fragmentation index (150.17–97.42) and had the same (P = 0.134) fat concentration (0.87 g/100 g) as that of breast meat from Cobb 500 broilers (0.93 g/100 g, respectively). Breast meat from Hubbard ISA broilers had a higher (P < 0.001) polyunsaturated fatty acid concentration, especially docosahexaenoic acid, which is beneficial to human health. Aging breast fillets for 3 days at 2°C is sufficient to tenderise the meat without reducing its juiciness, which suggests that the aging process can add value to free-range meat.

Physical and chemical characteristics of the longissimus dorsi from swine reared in climate-controlled and uncontrolled environments

The aim of this study was to evaluate the effect of ambient temperature on the physical and chemical characteristics of the longissimus dorsi muscle by comparing the quality of meat from pigs reared in a controlled and in an uncontrolled environment, the latter provided with a shallow pool. Twenty castrated male pigs of the Topigs line were randomly allotted to two treatments: a controlled environment, with constant temperature (22 °C) and relative humidity (70%); and an uncontrolled environment in a conventional shed for rearing pigs equipped with a shallow pool, where pigs were subject to climatic variations. Meat from pigs kept in the controlled environment showed a greater capacity to retain intracellular water, higher tenderness, and lower cholesterol levels than meat from pigs reared in the uncontrolled environment, but displayed higher lipid oxidation and a lower concentration of DHA. Treatments had no effect on color, pH, chemical composition, or fatty acid profile (except DHA concentration). Rearing pigs in sheds equipped with a shallow pool minimizes the effects of environmental heat on meat quality, allowing the production of high-quality meat in warm climate regions without expensive investments. Animals reared in an uncontrolled environment equipped with a shallow pool are able to produce meat with characteristics within the quality standards and with similar quality to that of meat from animals raised in controlled environment.

Physical and chemical characteristics of spent hen breast meat aged for 7 days

Consumption of poultry meat is increasing worldwide. However, little is known about the consumption and acceptability of meat from older hens and about the physical and chemical characteristics of this type of meat. This study evaluated the effect of broiler age and aging time on the physical properties, tenderness, chemical composition, and lipid profile of breast meat from broilers slaughtered at 6 (commercial age) and 70 weeks of age (broiler hens). The variables analysed were: colour, pH, water-holding capacity, cooking weight loss, shear force, total collagen, myofibrillar fragmentation index, chemical composition, total cholesterol, lipid oxidation, and fatty acid profile. Compared with commercial broilers, meat from broiler hens had higher shear force (from 33.45 N to 14.91 N after 3 days of aging), higher fat content, and lower cholesterol concentration. Additionally, it had more monounsaturated fatty acids and less polyunsaturated fatty acids than meat from commercial broilers. Collagen, fat, cholesterol levels and myofibrillar fragmentation index decreased with aging. The use of broiler hen meat as a raw material may be beneficial to the poultry industry because it has more fat and less cholesterol, higher intracellular water-holding capacity, and lower cooking loss than meat from commercial broilers. Moreover, because of the lower concentration of polyunsaturated fatty acids, broiler hen meat is less susceptible to lipid oxidation. Aging breast fillets for 3 days at 2°C is sufficient to tenderise the meat and reduce the amount of fat and cholesterol, suggesting that aging can be used as a technique to add value to poultry meat products.

Períodos de estresse térmico durante o crescimento afetam negativamente o desempenho e o rendimento de carcaça de frango de corte

O objetivo deste estudo foi avaliar o efeito da exposição de frangos de corte por até 72 horas a estresse térmico agudo, em diferentes fases do crescimento, sobre o desempenho e rendimento de carcaça. Quinhentos frangos de corte Cobb machos foram criados por até 42 dias em duas câmaras climáticas equipadas com sistemas de aquecimento e refrigeração. Duzentas e cinquenta aves foram submetidas ao estresse térmico (32°C±0,5°C), com duração de até 72 horas, com início aos 21 e 35 dias de idade. As demais 250 aves foram mantidas em conforto térmico durante todo o experimento. O calor do ambiente influenciou negativamente o peso corporal (1,595 kg) e a conversão alimentar (1,81) de frangos de corte submetidos ao estresse por calor a partir dos 21 dias de idade. Após dois períodos de estresse térmico, os frangos apresentaram menor consumo de ração (3,914 kg) e, consequentemente, menor peso (1,958 kg), quando comparados ao grupo controle (4,182 kg e 2,097 kg, respectivamente). Aves submetidas ao estresse térmico aos 21 dias de idade apresentaram redução do rendimento de peito. O peso ao abate de frangos de corte submetidos ao estresse térmico diminuiu após duas exposições ao calor. Frangos de corte submetidos ao estresse térmico agudo após 35 dias de idade apresentam pior desempenho do que frangos de corte criados em conforto térmico. Não há influência do estresse térmico sobre o rendimento de cortes comerciais da carcaça.

Growing-finishing performance and carcass yield of pigs reared in a climate-controlled and uncontrolled environment

The objective of this study was to evaluate the effect of temperature on the performance and carcass yield of pigs housed in different environments. Twenty castrated male pigs of the Topigs line were assigned to two treatments: T1, controlled environment, and T2, uncontrolled environment containing a shallow pool. A completely randomized design consisting of two treatments and ten repetitions each was used. The data were submitted to analysis of variance, and means were compared by the Tukey test at a level of significance of 5 % using the SAS 9.2 program (SAS Institute, Inc., NC, USA). The results showed that rearing pigs in an uncontrolled environment during the growing and finishing phases reduced daily feed intake (1.722 and 3.164 kg, respectively) and improved feed conversion (2.15 and 2.70 kg, respectively), but did not influence the carcass yield of the animals. In conclusion, rearing pigs under different environmental conditions during the growing and finishing phases influenced animal performance without interfering with carcass yield.

Rendimentos de carcaça, cortes comerciais e não-componentes da carcaça de cordeiros Santa Inês alimentados com feno de erva-sal e concentrado

Objetivou-se com este trabalho avaliar os rendimentos de carcaça, cortes comerciais e não-componentes da carcaça de cordeiros Santa Inês alimentados com 30, 40, 50 e 60% de feno de erva-sal associado a concentrado. Foram utilizados 32 ovinos machos castrados, com 8 meses de idade e peso inicial de 22 + 1,97kg, confinados individualmente e abatidos após 60 dias de confinamento. Os pesos de carcaça quente e fria decresceram linearmente com o aumento de feno de erva-sal na dieta, no entanto, não houve efeito para o rendimento verdadeiro de carcaça (59,42%) e dos cortes: paleta (19,26%), pescoço (8,52%), costelas (26,57%) e perna (33,88%). Houve efeito linear decrescente para área de olho de lombo e espessura de gordura à medida que o nível de feno de erva-sal aumentou na dieta. Os pesos e os rendimentos de pele, fígado, coração, rins com gordura perirrenal e gorduras omental e mesentérica decresceram linearmente com a inclusão de feno de erva-sal na dieta, enquanto o conteúdo (%) do trato gastrintestinal aumentou. O aumento da proporção de feno de erva-sal na dieta de cordeiros proporciona adequados rendimentos verdadeiros de carcaça e dos cortes comerciais, no entanto, reduz a área de olho de lombo e a espessura de gordura subcutânea, medidas importantes na avaliação qualitativa da carcaça ovina.

Desempenho de frangos de corte alimentados com dietas contendo diferentes fontes de selênio, zinco e manganês, criados sob condições de estresse térmico

Avaliaram-se o desempenho e o rendimento de carcaça e partes de frangos de corte alimentados com dietas que continham selênio, zinco e manganês complexados ou não a moléculas orgânicas, criados em diferentes temperaturas. Foram utilizados 980 pintinhos machos de um dia de idade, de linhagem comercial, criados durante 42 dias em três câmaras climáticas, que proporcionaram temperaturas alta, termoneutra e baixa. Foi utilizado um delineamento inteiramente ao acaso, em esquema fatorial 3x2+1, sendo três temperaturas de criação, duas fontes de Se, Zn e Mn - inorgânica e orgânica, mais o tratamento testemunha - criação em câmara termoneutra sem adição de Se, Zn e Mn na ração, com sete repetições por tratamento. As aves criadas em condições de estresse térmico apresentaram piores resultados para consumo de ração, ganho de peso e viabilidade, sendo mais sensíveis ao calor do que ao frio. Quando criadas em ambientes quentes, a conversão alimentar foi melhor quando se utilizaram os minerais na forma orgânica. Sob temperatura neutra, as aves não necessitaram da suplementação da dieta com os minerais avaliados.

Qualidade física de ovos armazenados em diferentes condições de embalagens sob temperatura ambiente

Avaliou-se a qualidade interna de ovos de casca branca, higienizados ou não, armazenados em diferentes condições de embalagens, sob temperatura ambiente. Trezentos ovos foram distribuídos em um DIC em esquema fatorial 3x2x4+1 (3 embalagens: filme PVC, vácuo parcial e vácuo parcial com sequestrantes de gás oxigênio; 4 períodos de armazenamento: 7, 14, 21 e 28 dias; higienizados ou não; e testemunha, ovos frescos, com 4 repetições). As análises foram realizadas ao final de cada período. O vácuo parcial manteve a unidade Haugh dos ovos, e proporcionou os melhores resultados para índice gema. A manutenção de peso dos ovos foi melhor quando embalados em condição de vácuo, com ou sem sachês sequestrantes de O2. Menores valores de atividade de água foram obtidos nos ovos embalados em filme de PVC, e quando realizada a higienização. Conclui-se que a qualidade interna dos ovos decresceu com o tempo de estocagem de forma mais acentuada nos ovos embalados em filme plástico, já que a condição de vácuo preservou algumas características. Com a higienização, as condições de armazenamento dos ovos em filme de PVC devem ser melhoradas, pois a qualidade interna destes foi a mais reduzida.

Características sensoriais de ovos armazenados em diferentes embalagens sob temperatura ambiente

O presente estudo objetivou avaliar as características sensoriais de ovos, de casca branca, higienizados ou não, armazenados em diferentes condições de embalagens, sob temperatura ambiente. Foram utilizados 200 ovos, distribuídos em um DIC em esquema fatorial 3x2x4+1, sendo três condições de embalagens (filme PVC, vácuo parcial e vácuo parcial com sequestrantes de gás oxigênio), quatro períodos de armazenamento (7, 14, 21 e 28 dias), higienizados ou não, e testemunha (ovos frescos), com 4 repetições 2 ovos cada, e 10 julgadores. Foram realizadas avaliações visuais e olfativas dos ovos nos diferentes períodos de armazenamento, por análise descritiva quantitativa (ADQ) em escala não estruturadas de 9 cm. A condição de vácuo parcial mostrou que os ovos foram rejeitados pela aparência externa e interna, e odor externo da casca, principalmente se não higienizados. E ainda nesta condição, foram percebidos odores azedos e gemas opacas. Na condição de vácuo com sachês sequestrantes de O2 foram notados odores de podre, principalmente quando higienizados. Conclui-se que, ovos embalados em filme de PVC mostraram melhores aceitações em todos os atributos avaliados, independente de terem sido higienizados.

Características físico-químicas e sensoriais de embutido fresco de aves de descarte preparado com diferentes antioxidantes naturais

Objetivou-se avaliar o efeito de diferentes antioxidantes naturais em embutidos frescos formulados com carnes provenientes de aves de descarte nas características físico-químicas e sensoriais do produto. O experimento foi realizado no Departamento de Tecnologia - Laboratório de Tecnologia dos Produtos de Origem Animal da FCAV/Unesp - Campus de Jaboticabal. Para tanto, foram utilizadas 45 aves de postura, com aproximadamente 80 semanas de idade, distribuídas em um delineamento inteiramente casualizado em esquema fatorial 4x4, sendo quatro tipos de condimentos (controle, alecrim, cravo-da-índia e orégano) e quatro períodos de armazenamento (zero, três; seis e nove dias a 4°C), o que totalizou 16 tratamentos e três repetições. Foram ainda avaliadas as características de umidade, pH, cor, perdas por cozimento, força de cisalhamento, número de TBARS e análise sensorial. As médias obtidas foram comparadas pelo teste de Tukey a 5% de significância. Houve interação entre o período de armazenamento e o condimento utilizado em todas as características avaliadas. O tratamento que continha cravo da Índia foi o que recebeu as menores notas na análise sensorial. A utilização do orégano diminuiu a oxidação do embutido, além de ter agradado os provadores na análise sensorial.

Avaliação do modelo de produção e da inclusão de gordura nos parâmetros qualitativos e sensoriais do hambúrguer ovino

Carnes de 48 cordeiros Ile de France criados nos modelos orgânico e convencional, provenientes da dissecação da paleta foram submetidas à elaboração de hambúrguer, com fonte de gordura adicionada, nas proporções de 20 e 30%. Os modelos de produção (P<0,01) e o teor de gordura (P<0,01) influenciaram o pH dos hambúrgueres, entretanto apenas os modelos de produção afetaram a luminosidade (P<0,05) e o teor de vermelho (P<0,01), mas não influenciaram a capacidade de retenção de água, a perda de peso ao cozimento e o número de ácido 2-tiobarbitúrico (TBARS) dos hambúrgueres, com valores de 62,8%, 24,6% e 1,81mg malonaldeído/kg de amostra, respectivamente. No hambúrguer orgânico, houve menor força de cisalhamento (0,68kgf/cm²) em relação ao convencional (0,97kgf/cm²). Os teores de gordura afetaram a capacidade de retenção de água (P<0,05). Para perda de peso ao cozimento, força de cisalhamento e número de TBARS, os valores foram de 24,65%, 0,82kgf/cm² e 1,81mg malonaldeído/kg de amostra, respectivamente. Os modelos de produção e os teores de gordura não influenciaram a cor, o sabor, a maciez e a aceitação global dos hambúrgueres. Os modelos de produção e os teores de gordura não influenciaram a atividade de água na temperatura de 20,55ºC, no entanto, em temperaturas mais baixas, os hambúrgueres orgânicos tiveram maior atividade de água em relação aos convencionais.

Evaluation of some biomonitoring markers in occupationally exposed populations to acrylonitrile

In the present work we studied acrylonitrile (AN) occupationally exposed populations and respective control individuals working in a Portuguese plant producing acrylic textile fibers. Three subgroups of individuals were considered: controls (C), workers of the continuous polymerization (CP) area, and workers of equipment maintenance (MM). Besides aiming to contribute to a better understanding of the hazardous exposure of man to AN, the study aimed to help validate and optimize the use of a combination of methods applied to human populations exposed to genotoxic compounds. Three main compartments related to the dose or effect of the hazardous compound were evaluated using various assessment methods: 1) internal dose (genotoxicity in urine, indicators of oxidative stress, induction of cytochromes P450); 2) biological effective dose (hemoglobin adducts); and 3) early biological effects (chromosomal aberrations, sister chromatid exchanges). Although concern with exposure to AN has long been the subject of numerous studies, they have been carried out essentially in animals and using in vitro systems. The significant differences (P < 0.01) found in the chromosomal aberrations of MM are in agreement with the highly significant levels of hemoglobin adducts described in another study performed in the same population. Hemoglobin adducts were also sensitive in detecting a hazardous exposure in the case of CP. The results obtained for the lipid peroxidation indicator used seem to confirm the AN capability of inducing lipid peroxidation in vivo. From the results available it seems that chromosomal aberrations as well as hemoglobin adducts are accurate and sensitive biomonitoring markers for AN exposure.

Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile

Acrylonitrile (AN) is an important intermediary for the synthesis of a variety of organic products, such as artificial fibres, household articles and resins. Although acute effects are the primary concern for an exposure to AN, potential genotoxic, carcinogenic and teratogenic risks of AN have to be taken seriously in view of the large number of workers employed in such industries and the world-wide population using products containing and possibly liberating AN. An understanding of the effect of acrylonitrile must be based on a characterization of its metabolism as well as of the resulting products and their genotoxic properties. Tests for mutagenicity in bacteria have in general been positive, those in plants and on unscheduled DNA synthesis doubtful, and those on chromosome aberrations in vivo negative. Wherever positive results had been obtained, metabolic activation of AN appeared to be a prerequisite. The extent to which such mutagenic effects are significant in man depends, however, also on the conditions of exposure. It appears from the limited data that the ultimate mutagenic factor(s), such as 2-cyanoethylene oxide, may have little opportunity to act under conditions where people are exposed because it is formed only in small amounts and is rapidly degraded. The carcinogenic action of AN has been evaluated by various agencies and ranged from 'reasonably be anticipated to be a human carcinogen' to 'cannot be excluded', the most recent evaluation being 'possibly carcinogenic to humans'. Animal data that confirm the carcinogenic potential of AN have certain limitations with respect to the choice of species, type of tumors and length of follow up. Epidemiological studies which sometimes, but not always, yielded positive results, encounter the usual difficulties of confounding factors in chemical industries. Exposure of workers to AN should continue to be carefully monitored, but AN would not have to be considered a cancer risk to the population provided limitations on releases from consumer products and guidelines on AN in water and air are enforced. AN is teratogenic in laboratory animals (rat, hamster) at high doses when foetal/embryonic (and maternal) toxicity already is manifest. Pregnant workers should not be exposed to AN. In view of the small concentrations generally encountered outside plants, women not professionally exposed would appear not to be at risk of teratogenic effects due to AN. Future research should concentrate on the elucidation of the different degradation pathways in man and on epidemiological studies in workers including pregnant women, assessing also, if possible, individual exposure by bio-monitoring.

Monitoring of exposure to acrylonitrile by determination of N-(2-cyanoethyl)valine at the N-terminal position of haemoglobin

A selected ion monitoring gas chromatography-mass spectrometry (GC-MS) procedure was developed to determine the interaction product formed by acrylonitrile (ACN) with the N-terminal amino group in haemoglobin. The product, N-(2-cyanoethyl)valine (CEV), was analysed following its release from the protein by a modified Edman degradation procedure. Quantitation was achieved using N-(2-cyanoethyl)-[2H8]Val-Leu-Ser as internal standard. The limit of detection of the assay was 1 pmol CEV/g globin. A close to linear dose-response relationship was found for adduct formation in rats treated with ACN by gavage. On the basis of a linear extrapolation, a dose of 1 mg/kg body wt yielded 248 pmol CEV/g globin. Two groups of workers who were exposed to ACN contained 1984 +/- SD 2066 (n = 9) and 2276 +/- SD 1338 (n = 7) pmol CEV/g globin respectively. These values were highly significantly greater (P < 0.01 following a one-way analysis of variance with a logarithmic transformation of the data) than those in a group of control workers in the same factory (31.1 +/- SD 18.5 pmol CEV/g globin, n = 11). The concentrations of N-terminal CEV in globin samples from 13 smoking and 10 non-smoking mothers and from their newborns were determined. Adduct levels in the smokers averaged 217 +/- 85.1 pmol CEV/g globin, significantly higher than the levels in non-smokers, which were undetectable. Individual values in the mothers were very highly correlated with the levels in their babies (which averaged 99.5 +/- 53.8 pmol CEV/g globin), which demonstrates that transplacental transfer of ACN occurs. Significant correlations were also found between the number of cigarettes smoked per day by the mother and the CEV levels in both the mothers' and newborns' globin. There was, however, no correlation between the CEV levels and those of the ethylene oxide adduct N-(2-hydroxyethyl)valine in samples from either the mothers or babies.

Genotoxicity of nitrosated red wine and of the nitrosatable phenolic compounds present in wine: tyramine, quercetin and malvidine-3-glucoside

Phenolic compounds and biogenic amines are known to be present in some foodstuffs which become directly genotoxic after nitrosation in vitro. Red wine has previously been shown to be genotoxic and this activity has been attributed mainly to flavonoids. Besides flavonoids, red wine contains a multiplicity of compounds, including biogenic amines. Using the Ames assay and the SOS chromotest, this study has shown that red wine and some of the nitrosatable molecules present in wine become directly genotoxic on nitrosation in vitro: these include the phenolic molecules tyramine, quercetin and malvidine-3-glucoside, whereas phenylethylamine and histamine were negative on nitrosation. Interestingly, quercetin had been predicted to be negative after nitrosation, using the CASE methodology. The concentrations of these three positive nitrosatable compounds in wine were determined by HPLC. Comparison of these concentrations and their respective levels of genotoxicity suggests that the genotoxicity after nitrosation is probably attributable to other molecules. It is also possible that synergistic effects may occur between various nitrosatable compounds in wine.

Oxygen species and the genotoxicity of quercetin

Quercetin has been extensively studied in various short-term assays for genotoxicity. The patterns of genotoxicity of quercetin for different genetic endpoints are subject to a variety of factors (pH, antioxidants, metabolism) whose precise role in each test remains unclear. In the present study we report on the possible effect of oxygen-derived species on the activity of quercetin in the Ames assay and in the SOS chromotest. Our results seem to suggest that superoxide dismutase (SOD) does not account for the levels of mutagenicity detected in the presence of S9 or S100. The latter may, however, contain other factors of antioxidant defense which may prevent the oxidative degradation of quercetin. Since this degradation occurs at pH values above neutrality and the SOS-inducing activity is higher at pH 6.0, it is concluded that the response of quercetin in the SOS chromotest is due to quercetin itself at acidic pH. The SOS-inducing activity at pH 7.4 is enhanced by SOD, but it cannot be unambiguously concluded that this effect in the SOS chromotest might only be due to protection against the oxidative degradation of quercetin.

Genetic toxicology of flavonoids: the role of metabolic conditions in the induction of reverse mutation, SOS functions and sister-chromatid exchanges

Glycosides of flavonols such as quercetin, are found in the edible portions of most food vegetables. Flavonols present in plants as glycosides can be freed during fermentation. We have compared the DNA-damaging activity of quercetin, rutin (3-o-rutinoside of quercetin) and a fermented flavonoid-containing beverage, red wine, for different genetic end-points under different metabolic conditions. The genotoxicity of quercetin, rutin and commercial red wine has been studied for the induction of: (i) reverse mutation in the Ames assay; (ii) SOS functions in the SOS Chromotest; (iii) sister-chromatid exchanges (SCEs) in human lymphocytes. While in the Ames assay the mutagenicity of quercetin is enhanced by the presence of rat liver microsomal enzymes (S9) or the respective cytosolic fraction (S100), genotoxicity is reduced when the induction of SOS responses is assessed using the SOS Chromotest. Similarly, the induction of SCEs is lowered when testing in the presence of liver enzymes. Rutin has no activity whatsoever. Detection of activity of red wine in the three assays is not dependent upon hydrolysis by glycosidases and its content of quercetin accounts almost entirely for the levels of genotoxicity detected. The results suggest that the putative genotoxic metabolites of quercetin vary for different genetic end-points considered and that the metabolic fate of flavonoids might partly account for the conflicting data about their genotoxicity in vivo and carcinogenic activity.

Urinary mutagenicity in occupational exposure to mineral oils and iron oxide particles

Mutagenicity in the urine of workers occupationally exposed to mineral oils and iron oxide particles and age matched workers only exposed to mineral oils was investigated using the Salmonella/mammalian microsome assay. Both groups of workers included smokers and non-smokers. Mutagenicity was significantly higher in the group of workers exposed to both mineral oils and iron oxide particles, the statistical significance of the difference being similar to that found when total non-smokers were compared with total smokers irrespective of occupational exposure. When only non-smokers of both groups of workers were compared, the extent of mutagenicity in the urine of workers exposed to iron oxide particles was still significantly higher, suggesting that smoking did not exhibit a significant enhancing effect on urinary mutagenicity of workers exposed to mineral oils and iron oxide particles, but instead seemed to enhance urinary mutagenicity similarly in both groups of workers. Whether or not this conclusion can be drawn may depend, among other factors, on the variability of the Ames assay. To cope with this particular problem, the possible usefulness of a mutagenicity factor is discussed.