Slavomír Marcinčák

Effect of dietary supplementation of Melissa officinalis and combination of Achillea millefolium and Crataegus oxyacantha on broiler growth performance, fatty acid composition and lipid oxidation of chicken meat

This experimental study investigated the effect of feeding of lemon balm (Melissa officinalis L.) and combination of hawthorn (Crataegus oxyacantha L.) and yarrow (Achillea millefolium L.) on growth performance of chicken, meat composition, fatty acid profile and oxidative stability. Ninety one-day-old commercial broiler chicks (ROSS 308) were divided into 3 groups, and fed 41 days, as follows: control (C) with standard diet without antioxidants supplementation; second group (L) with standard diet supplemented with ground lemon balm (2%) and third group (HY) with standard diet supplemented with ground hawthorn (1%) and yarrow (1%). Final body weight and total feed intake were not influenced by plant supplementation. However, feed conversion ratio was the lowest (P<0.05) at HY. Carcass yields were not affected (P>0.05) by plants supplementation, but the proportions of various carcass parts (breast and leg) were higher in L and HY groups. Feeding of plants had no effect on the chemical composition of thigh meat. However, in breast meat fed by HY diet higher content of dry matter and crude protein (P<0.05) was found. In breast (L) the proportion of monounsaturated fatty acids was decreased and polyunsaturated fatty acids (PUFA) proportion was increased compared with control group (P<0.05). In thigh HY the proportion of saturated fatty acids was increased and PUFA was decreased compared with control. Results of thiobarbituric value method showed that supplementation with lemon balm, and mainly combination of hawthorn and yarrow in the diet significantly influenced reduction of lipid oxidation processes in thigh during chilling storage (4°C, 11 days).

Use of Premi®Test for the detection of sulphonamide residues in chicken eggs

The presence of sulphadimidine residues in eggs after a peroral administration of Sulfadimidin PG plv. sol. ad us, vet. (120 mg/hen/day) to laying hens was studied. Premi®Test, four-plate microbiological method, and HPLC were used for the detection of sulphadimidine residues. Positive findings of the Four-plate test (FPT) were confirmed by the results of Premi®Test. Using the FPT, the absence of sulphadimidine residues was confirmed 72 hours after the last sulphadimidine administration. The presence of sulphadimidine residues has been detected by Premi®Test within 8 days and by the FPT within 3 days after the last administration. As compared with the results of Premi®Test, the FPT has reported false-negative results for five days (kappa < 0.6). Conformity of results obtained by both Premi®Test and HPLC was confirmed in this study (kappa = 0.6).

Effects of vacuum packaging conditions on the quality, biochemical changes and the durability of ostrich meat

In this study, the effects of vacuum packaging conditions on the concentrations of lactic acid, malondialdehyde, pH, microbial and sensory analysis were determined during chilled storage of ostrich meat. Meat was packed as follows: vacuum packed from 1st day (VP-1), vacuum packed from 3rd day (VP-3) and non-vacuum packed (NVP). Analysis were performed at 1st, 7th, 14th, 21st day after slaughter. Meat consisted of 74.69% water, 2.29% fats, 20.95% proteins. Package conditions had significant effect on the pH (NVP: 6.54 on the 14th day, VP-1: 6.05 and VP-3: 6.07 on the 21th day p<0.001), amount of malondialdehyde (NVP: 8.62mg/kg on the 14th day; VP-1: 1.95 and VP-3: 2.55 on the 21th day; p<0.001) and total microbial count (NVP: 7.4 log CFU/g on the 14th day; VP-1: 6.7 and VP-3: 6.8 on the 21th day p<0.01). Based on these results we can assess that vacuum packed from 1st day is necessary for the 21 days storage of ostrich meat.

Post-mortem changes in the concentration of lactic acid, phosphates and pH in the muscles of wild rabbits (Oryctolagus cuniculus) according to the perimortal situation

In this study changes in the concentrations of lactate, phosphates, and pH values of water extracts of muscles of transported and hunted rabbits during ripening were determined. Concentrations of lactate were higher in the muscles of hunted rabbits. The highest differences were obtained 24h after kill/hunt. Concentrations of lactate in the muscles of hunted rabbits were decreasing, while in the muscles of transported rabbits we observed it to increase in the 7th day and then decrease in the 14th day. Higher concentrations of phosphates were found in the muscles of transported wild rabbits. During the ripening process concentrations of phosphates were decreasing in muscles of both groups. Muscles of hunted rabbits had lower pH values during the whole ripening process. Our research showed that concentrations of lactate, phosphates and pH value post-mortem depended on the perimortal situations.

Evaluation of some parameters of post mortem changes of pheasant (Phasianus colchicus)

Post mortem changes were evaluated in muscle tissues of 99 male, uneviscerated pheasants (Phasianus colchicus) stored for up to 14 days at 0 and 4 °C. The control group (Group I) included regularly slaughtered and bled pheasants (n=33). From approximately 350 pheasants hunted on a single occasion, specimens were taken and, on the basis of X-ray examination performed from latero-lateral and dorso-ventral body projection of hunted pheasants, two groups were constituted: Group II included pheasants (n=33) with one or multiple shots in the muscle tissues but not in the body cavity, whereas Group III included pheasants (n=33) with shots in both muscle tissues and the body cavity. Each group was divided into two subgroups, in which uneviscerated pheasants were stored at 0 °C and 4 °C, respectively, for a maximum of 14 days. Randomly selected pheasants from each subgroup (n=4), were examined on days 0, 3, 7, and 14. The following post mortem changes in breast and thigh muscles were evaluated: pH value (in watery extract), lactic acid and ammonia concentration. Generally, low pH values were associated with higher concentrations of lactic acid, most pronounced in breast muscle. Significant differences (P<0.05) in pH – both at 0 and 4 °C storage temperature – were found for breast muscles between Groups I and II, albeit average differences were merely in the range of merely 0.1 to 0.2 units. Thigh muscles of Group I had significantly lower pH (0.2 to 0.4 units) than Groups II and III, for all study days. A statistically significant difference (P<0.05) was found between the lactic acid concentrations in breast muscles (4 °C) between groups II and III. The highest average concentrations of ammonia in the breast muscle (day 14) were determined in the Group III (4 °C), and the lowest in the group of slaughtered pheasants (4 °C). The highest average concentrations of ammonia in the thigh muscles were in Group III (0 °C), and the lowest in the group of slaughtered pheasants (0 °C). This difference was statistically significant (P<0.05). In summary, muscles from pheasants being slaughtered instead of hunted were characterised by lower pH, higher lactic acid and lower ammonia concentration at the end of the storage period.

Effect of feeding of 5% prefermented cereal-based bioproduct enriched with γ-linolenic acid on production indicators, chemical composition, fatty acid profile and lipid oxidation of broiler meat

Abstract The aim of this work was to study the effect of the addition of prefermented cereal-based bioproduct (5%; BP) enriched with γ-linolenic acid to the commercial feed for broiler chickens on the production indicators, chemical composition, fatty acid profile and lipid oxidation of the meat. BP was prepared by solid-state fermentation using fungal strain Cunninghamella elegans CCF 2591. Spelt bran was used as a substrate. A total of 80 broiler chickens (COBB 500) were used in this experiment. Half of them (experimental group) was fed with experimental feed and second half (control group) was fed only with commercial compound feed. Administration of BP to the broilers positively influenced production indicators. Broilers of the experimental group reached higher final weight, and showed lower average daily feed intake, feed conversion ratio, and feed intake compared to the control group. Meat of the experimental group consisted of the lower amount of total protein and fat. BP influenced fatty acid profile as well. Meat of the experimental group, in comparison to control, contained higher amount of unsaturated fatty acids (UFA) and lower amount of saturated fatty acids. Mainly the amount of α-linolenic acid and γ-linolenic acid was higher. Significantly higher concentration of malondialdehyde (MDA) was observed in muscles of experimental group during 7-day storage in refrigerator. Based on the results obtained we can conclude that replacing 5% of the commercial feed by BP could not only improve performance parameters of chickens, but also affect chemical composition and fatty acid content of meat.

Microbiological and chemical quality of fresh and frozen whole trout and trout fillets

The rainbow trout ( Oncorhynchus mykiss ) is considered as an important fish in the freshwater aquaculture and play a significant role in the human diet. The final quality of fish depends on the chemical and microbiological quality of fish at the time of freezing as well as on other factors including storage temperature and processing. The purpose of the study was to determine the microbiological status of 30 samples cooled and frozen trouts collected from approved farm in the Turiec region, territory of middle Slovakia. Total viable counts (TVCs), psychrotrophic bacteria, Pseudomonas spp. and also total volatile base-nitrogen (TVB-N) and pH were measured in samples of fresh (1. and 7. day of storage at 0 - 2 °C) and frozen whole trout and trout fillets. Frozen samples were stored at -18 °C during 1, 3, and 6 months. Samples were collected from the skin, muscles (sterile) and muscles after filleting. The microbiological quality of samples varied between fresh and frozen (6 th month of storage) regarding TVCs and also between samples taken from the skin and muscles after filleting compared to muscle samples collected sterile regarding all tested bacteria. A large number of bacteria (pathogens and spoilage bacteria) enter with the raw material and in particular the skin contamination had a negative impact on the increase of microbial load in fillets. All processing techniques and procedures including filleting therefore must be designed and aimed to minimise contamination and growth of microorganisms in fish. However, based on the results of TVB-N analysis, differences between fresh and frozen samples were found, but all the samples were suitable for human consumption.

Effect of fungal gamma-linolenic acid and beta-carotene containing prefermented feed on immunity and gut of broiler chicken

ABSTRACT Gamma‐linolenic acid (GLA) is a fatty acid from the ω‐6 family. It is able to deliver a wide range of health benefits arising from its anti‐inflammatory effects. An insufficient supply of GLA from agricultural and animal sources resulted in the development of a fermentation technique using lower filamentous fungi, which have the ability to accumulate high concentrations of GLA and beta‐carotene during solid‐state fermentation of cereals. The goal of this study was to observe the influence of the addition of prefermented cereal product, containing high amounts of GLA and beta‐carotene, into the feed of broiler chickens on their immune status, and also the number of lactic acid bacteria and enterobacteria in gut content, which has never been studied before. Immunostimulation in the GLA group was manifested by a significant increase in the oxidative burst of phagocytes, CD4+CD8‐ lymphocytes in blood, and the CD4: CD8 ratio. Upregulation of gene expression for IgA in the GLA group indicates that the B‐lymphocytes were stimulated at a local gut level. In the caecum, increased mRNA expression for mucin‐2 and insulin‐like growth factor was observed in the GLA group, which could contribute mainly to the protection of the intestinal mucosa and to better growth and regeneration of skeletal muscles. Improved immune activation and protection of the intestinal mucosa were subsequently reflected in a change of the microbial composition in gut contents; a significant reduction of enterobacteria occurred after GLA administration. We can conclude that prefermented cereals containing fungal GLA and beta‐carotene represent a low‐cost supplement for broiler diet having a beneficial health effect.

Effect of Fungal Solid-State Fermented Product in Broiler Chicken Nutrition on Quality and Safety of Produced Breast Meat

The aim of this work was to analyse the effect of addition of 10% (w/w) fermented bioproduct into commercial broiler feed on fatty acid profile, lipid oxidative stability, and sensory properties of chicken breast meat. The fermented bioproduct was prepared by fermentation of cornmeal by filamentous fungi Umbelopsis isabellina CCF 2412 in solid-state fermentation (SSF) process and the final bioproduct was enriched with gamma-linolenic acid and beta-carotene. In the experiment, 80 pieces of 1-day-old chickens COBB 500 were used. Half of them (control group) were fed only with commercial feed. Chickens of the experimental group were fed with commercial feed, and, from the 11th day of age until the time of slaughter (39th day), 10% of commercial feed was replaced with fermented bioproduct. Application of fermented bioproduct into commercial feed mixture positively influenced profile of fatty acids in breast meat. The amount of gamma-linolenic, alpha-linolenic, and oleic acids in fat of breast muscles was increased and n-6/n-3 ratio was significantly decreased. Profile and content of PUFAs did not change after thermal treatment of meat. Oxidative stability of fat and sensory properties of the meat during the storage (4°C, 7 days) of meat were not affected by fermented bioproduct.

Effect of feeding of prefermented bioproduct containing gamma-linolenic acid and beta-carotene on selected parameters of broiler chicken meat quality

The aim of the work was to evaluate the effect of addition of prefermented bioproduct with a increased content of polyunsaturated fatty acids (especially gamma-linolenic acid) and beta-carotene into commercial feed on the selected qualitative parameters. The chemical composition, the color, the loss of water, the pH and the concentration of lactic acid of the meat of broiler chickens (COBB 500) were monitored. Bioproduct was prepared from corn scrap, which was fermented using the lower filamentous fungus Umbelopsis isabellina CCF2412. The prepared material was mixed into the commercial compound feed intended for broiler chickens at a ratio of 10%, and was fed from the 11 th day of age of the chickens until the time of slaughter. The obtained results were compared with the results of control group, which was represented by broiler chickens fed only with a commercial compound feed. Feeding of bioproduct, in terms of chemical composition, affected mainly the fat content in breast and thigh meat, which was lower in the experimental group. Meat color (measured by colorimetric assay) was not affected and differences were significant only at a value a*, which was higher in the experimental group. Statistically significant differences in the water losses of meat were not recorded, but the feeding of bioproduct affected the pH of the meat, and also the concentration of lactic acid and both parameters were higher in the meat of control group.