Veterinary Research Forum

Abstract Antioxidant potential of different milk types and thermal-treated milks may be of interest to milk processors, consumers, and nutritionists. The objectives of this study were comparison of the antioxidant potential of milk, defatted milk, whey, and deproteinized whey from cow, sheep, and goat, and also evaluation of the effect of thermal treatments (pasteurization and sterilization) on the antioxidant activity of the milk. The antioxidant potential of different milk samples and their fractions was examined using reducing power, 2,2-diphenyl-1-picrylhydrazyl, and 2,2-azinobis-3-ethylenzothiazoline-6-sulphonicacid methods. The results showed that the antioxidant potential of sheep raw milk was significantly higher than that of cow milk and goat milk. The results also indicated that thermal processing increased the reducing power and antioxidant potential of milk, and increasing heating temperature significantly increased reducing power and 2,2-diphenyl-1-picrylhydrazyl scavenging activity of milk, especially sheep milk and goat milk. Removing of whey proteins from whey of all animal species, particularly sheep, caused a significant decrease in the antioxidant potential of whey. The results of this study showed that sheep milk and its fractions are a good source of natural antioxidants, which may have higher health promotion effects on consumers from nutritional point of view.

Abstract The objectives of the present study were to investigate the effect of season and fish species on the antioxidant capacity, fatty acids profile, and vitamin E content of fish fillets from Aras River. The antioxidant potential of hydrophilic and lipophilic extracts of fish fillets was evaluated. The fillet extracts of zander and bream in summer and common carp in winter had the highest antioxidant activity. Palmitic and oleic acids were the major saturated (SFA) and monounsaturated (MUFA) fatty acids, respectively. The fatty acids C22:6n3 and C20:5n3 were the most abundant polyunsaturated (PUFA) fatty acids in all the fishes. In summer, the highest levels of SFA (44.09), total PUFA (25.97), n3 PUFA (20.71) and n3/n6 ratio (4) were found in zander. In winter, the highest amounts of total PUFA and n3 PUFA were determined in silver carp, followed by zander. The highest n3/n6 ratio was also found in silver carp. The ratio of PUFA/SFA was higher in winter than in summer for all the fishes. Vitamin E content of fishes was largely varied. In conclusion, seasonal variation changed the antioxidant potential and fatty acid composition of fish fillets. Aras River fishes, especially zander, possess excellent antioxidant activity and high nutritional quality.

Abstract Two hundred and fifty male 1-day-old broiler chicks (Ross 308) were used to investigate the effects of dietary supplementation of turmeric and cinnamon powders on meat quality and lipid peroxidation of broilers under heat stress condition. The five treatment groups were control (recommended temperature for Ross 308), heat stressed (32 ± 1 ˚C from 9:00 AM to 5:00 PM during finisher period) and heat stressed birds fed with 0.50% turmeric, 0.50% cinnamon and a blend of cinnamon and turmeric (0.25% turmeric + 0.25% cinnamon). The results showed that there were no significant differences between the treatments for ether extract, ash and crude protein contents of thigh meat at 42 day of age (p > 0.05). Heat stress decreased the pH value and dry matter (DM) content of thigh meat, whereas the consumption of all experimental diets (turmeric, cinnamon and both of them) compensated the decreased pH and DM values due to heat stress to some extent but could not restore them to the level of control treatment (p< 0.01). Furthermore, the thigh meat lightness was increased under heat stress (p < 0.05). The thiobarbituric acid reactive substances and free radicals scavenging activity were increased in thigh meat of broilers reared under heat stress (p < 0.05), while these parameters were reduced by the combination of both plants (p < 0.01). It was concluded that heat stress reduces antioxidant properties and quality of thigh meat and dietary supplementation of turmeric and cinnamon powders together can remove the detrimental effects of heat stress on meat quality.

Abstract The effect of Cinnamomum zeylanicum essential oil (CZEO) at two concentrations (0.02% and 0.04% v/w) on chemical composition, pH, water activity (aw), lipid oxidation, color stability and sensory characteristics of Lyoner-type sausage stored at 4 ˚C for 40 days was investigated. The moisture content of the control sample was higher (p < 0.05) than CZEO incorporated samples, while fat, ash and protein content were not affected by adding essential oil. At days 0 and 40, Lightness (L*) and whiteness index (WI) were significantly decreased and total color difference (ΔE) significantly increased (p < 0.05) by adding CZEO. With the exception of first day of storage, redness (a*) and yellowness (b*) were significantly increased and decreased, respectively during the rest of storage (p < 0.05). The pH values were not differing between the control samples and samples containing CZEO (p > 0.05). The water activity content fell in Lyoners with added CZEO during the storage. Incorporation of CZEO retard lipid oxidation process at the end of storage (p < 0.05). Samples containing highest amount of CZEO had higher sensory score compared to control sample. Our results pointed out that CZEO could be used as natural additive for increasing the chemical stability of Lyoner-type sausages.

Abstract Pomegranate juice (PJ) and its products are directly used in foods due to their pleasant taste and palatability as well as preservative effects. In spite of useful effects of essential oils such as zataria multiflora Boiss essential oil (ZEO) on prolonging shelf-life of foods, their application is restricted due to their vigorous taste and aroma. In the present study, physicochemical characteristics, chemical compositions and antioxidative activities of two Iranian native plants, PJ (Rabbab-e-Neyriz cultivar) and ZEO were investigated. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power tests were used for measuring antioxidant activity. The level of total phenolic of them were also determined. Total soluble solids content, pH value, titratable acidity content and total anthocyanins content of PJ were also measured. Chemical compositions of ZEO were determined using Gas-chromatography, mass-spectrometry (GC-MS). The results of antioxidative tests indicated that the ZEO was significantly more potent (p < 0.05) than PJ. Also the phenolic content in ZEO (262.52 mg per g) was significantly higher (p < 0.05) than PJ (154.90 mg per 100g). Chemical compositions analysis of ZEO indicated that its major components were carvacrol (59.17%), linalool (23.67%), trans-caryophyllene (3.07%) and carvacrol methyl ether (2.44%). In the present study, physicochemical and antioxidative characteristics of Rabbab-e-Neyriz PJ were determined for first time. It was aslo found that ZEO in comparison with PJ had higher antioxidative activity and total phenolic content.

Abstract Meat products, especially fish meat, are very susceptible to lipid oxidation and microbial spoilage. In this study, first, gas chromatography mass spectrometry (GC-MS) analysis of Zataria multiflora essential oil (ZEO) components was done and then two concentrations of ZEO, (1% and 2%) and two concentrations of grape seed extract (GSE), (0.5% and 1%) were used in carboxymethyl cellulose coating alone and in combination, and their antioxidant effects on rainbow trout meat were evaluated in a 20-day period using thiobarbituric acid reactive substances (TBARS) test. Their effects on total volatile basic nitrogen (TVBN) and pH were evaluated as well. The main components of ZEO are thymol and carvacrol. These components significantly decreased production of thio-barbituric acid (TBA), TVBN and pH level of fish meat. The initial pH, TVBN and TBA content was 6.62, 12.67 mg N per 100 g and 0.19 mg kg^-1, respectively. In most treatments significant (p < 0.05) effects on aforementioned factors was seen during storage at 4 ˚C. The results indicated that use of ZEO and GSE as a natural antioxidant agents was effective in reducing undesirable chemical reactions in storage of fish meat.

Abstract Biogenic amines (BA) are nitrogenous compounds that possess biological activity. The source of production is the microbial decarboxylation of amino acids. This compounds are found in various types of cheese. The aim of this work was to evaluate the BA content of some traditional cheeses in West Azerbaijan province Iran. For this purpose, 70 samples of Koopeh, 10 samples of Lighvan and 5 samples of Red Salmas cheeses were obtained from local supermarkets of different cities of West Azerbaijan province. After preparation of samples, biogenic amines content was evaluated by modified HPLC method. The presence of histamine, cadaverine, putrescine and tyramine in tested cheeses were observed. Total amount of biogenic amines was highest in Red Salmas cheese with 1426.91 ppm. It followed by Lighvan cheese and Koopeh cheese with 1008.98 and 517.71 ppm, respectively. Putrescine, cadaverine, histamine and tyramine were detected in Koopeh cheese at levels up to 156.09, 282.34, 70.80, 8.48 ppm respectively. These amines were detected also in Lighvan cheese at levels up to 277.53, 342.74, 37.58, 351.12 ppm and in Red Salmas cheese samples at levels up to 438.03, 701.05, 105.21, 182.62 ppm, respectively. Large amounts of biogenic amines can indicate non hygienic conditions and contamination of used milk for cheese production.

Abstract Echinophora Platyloba D.C as a medicinal plant is used for preservation of foods and treatment of many diseases in different regions of Iran. The present study was undertaken to determine the chemical composition and investigation of the antibacterial effects of essential oil as well as methanol extract from aerial part of Echinophora Platyloba D.C against S. aureus, L. monocytogenes, S. Thyphimurium and E. coli. Chemical analysis using gas chromatography and mass spectrophotometry (GC/MS) showed that ocimene (26.51%), 2,3-Dimethyl-cyclohexa-1,3-diene (9.87%), alpha-pinene (7.69%) and gamma-dodecanolactone (5.66%) were dominant components of essential oil and the main constituents of methanol extract were o-Cymene (28.66%), methanol (8.50%), alpha-pinene (7.42%) and gamma-decalactone (5.20%). The essential oil showed strong antimicrobial activity against tested bacteria, whereas the methanol extract almost remained inactive against gram-negative bacteria. The most sensitive bacteria to essential oil and extract of Echinophora Platyloba D.C were L. monocytogenes and S. aureus. Minimum inhibitory concentration (MIC) values of essential oil against L. monocytogenes and S. aureus were 6250 and 12500 ppm, respectively. MIC of methanol extract against S. aureus and L. monocytogenes was 25000 ppm. Therefore, purifying and evaluation of antibacterial effects of the active substances of the essential oil and methanol extract of this plant for future application as antibacterial agents and food preservatives to combat pathogenic and toxigenic microorganisms is recommended.