The effect of oregano and rosemary essential oils or alpha-tocopheryl acetate on performance and lipid oxidation of meat enriched with n-3 PUFA's in broilers

WOS: 000225629800009The study was conducted to compare the effects of two essential oils, fed individually or in combination, with alpha-tocopheryl acetate (alpha-TA) on performance parameters and lipid oxidation of broiler meat enriched with n-3 PUFAs. Seven hundred and twenty day-old Hubbard-JV unsexed broiler chicks were used. Treatments included; control: without antioxidant; alpha-TA200: with alpha-TA at 200 mg/kg; OO150: with oregano essential oil (OO) at 150 mg/kg; OO300: with OO at 300 mg/kg; RO150: with rosemary essential oil (RO) at 150 mg/kg; RO300: with RO at 300 mg/kg; OO75+RO75: both OO and RO at 75 mg/kg; OO150+RO150: both OO and RO at 150 mg/kg. The feeding program consisted of a starter diet to 21 d and a grower diet to the end of the trial at 42 d. Both feeds contained 15 g fish oil/kg as the source of n3 PUFAs. Birds fed alpha-TA200 had significantly higher weight gains at 42 d than those fed OO150, OO75+RO75 and OO150+RO150. However, there were no differences in carcass yield, feed intake, feed conversion ratio or mortality between treatments. Neither essential oil exerted any growth-promoting effect on performance, and there was no interaction between them. Antioxidants retarded lipid oxidation as measured in TBARS, but the effect of each differed according to storage time (0, 3, 6, 9, 12 and 15 d) and meat type (breast or thigh). Alpha-TA200, RO300 and combined essential oils (EO) had higher antioxidant effects in breast meat, and OO150+RO150 in thigh meat, than the other treatments with antioxidant at zero time of storage. The ability of natural antioxidants to inhibit lipid oxidation to the end of the storage period was, in decreasing order, combinations of EOs > alpha-TA200 = OO300 = RO150 = RO300 > OO150 in breast meat; and combinations of EOs > RO at both levels > alpha-TA200 = OO150 = OO300 in thigh meat. Combinations of EOs had a greater effect than those fed individually or alpha-TA200 on inhibiting lipid oxidation, and protecting alpha-TA concentration in refrigerated meat enriched with n-PUFAs stored for 15 d. Thigh meat was more susceptible to lipid oxidation than breast meat. The combination of OO and RO, at 150 mg/kg, proved as effective as alpha-TA in retaining the sensory qualities of breast meat after 15 d storage, and was more effective than when these EOs were fed individually or at 300 mg/kg. There is a possible synergistic effect between oregano and rosemary essential oil in preventing lipid oxidation in stored meat enriched with n-3 PUFAs