title: In vivo and in vitro addition of dried olive extract in poultry.
abstract: A freeze-dried powder from organic olive (Olea europaea) juice extract, contains 8.82% polyphenols and a minimum of 2.5% hydroxytyrosol (3,4-dihydroxyphenylethanol), an effective free radical scavenger and the major antioxidant in the byproduct (dried olive extract, DOE). Myricetin, a bioflavonoid extract from the bark powder of the bayberry tree (Myrica cerifera), also has many beneficial biological properties and antioxidative capacity. While well-known as antioxidants, the capacity of these compounds to retard lipid oxidation in foods containing unsaturated fatty acids has not been widely evaluated. Thus, a study was conducted to assess the capacity of DOE to (1) enhance the growth of poultry, (2) determine the effectiveness of DOE (administered in vivo) as an antioxidant in post-mortem tissue and further processed meat, and (3) compare the in vitro antioxidative capacity of hydroxytyrosol and myricetin. DOE was administered ad libitum in water at 6 and 12 mg per bird per day for 6 weeks in a factorial design: 3 diets (control plus two treatment levels) × 2 blocks × 2 replications. There was no enhancement of feed consumption, body weight (BW), or feed conversion by DOE; overall means for these measurements were 5.49 kg per bird, 3.32 kg per bird, and 1.65 g feed per g live BW, respectively. Diagnostic examinations of two birds per pen at the end of the study revealed no adverse effects due to consumption of DOE, a generally recognized as safe substance. The byproduct, administered in vivo, did not retard lipid oxidation in fresh, heated, or NaCl (1.0% w/w)/heated/stored meat as assessed by absorbance values for thiobarbituric acid reactive substances at 532 nm and 2,2-diphenylpicrylhydrazyl at 517 nm. Both the byproduct and hydroxytyrosol are highly water-soluble and may have been unavailable as an antioxidant in the tissue of broilers that did not consume water for 4-6 h prior to processing. As an additive in processed thigh meat, 6 and 12 mg of DOE (2.5% hydroxytyrosol) per 3 mg of meat, although not as effective as myricetin (95% purity), reduced oxidation. Further assessment revealed that hydroxytyrosol from the DOE, added at (1)/38 the concentration of myricetin, was almost 50% as effective.
authors.affiliation: Department of Animal Science University of California, Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Annie J
authors.initials: AJ
authors.lastname: King
authors.forename: Johanna K
authors.initials: JK
authors.lastname: Griffin
authors.forename: Fahkirah
authors.initials: F
authors.lastname: Roslan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D002645:Chickens / Q000254:growth & development*; D004032:Diet / Q000662:veterinary*; D005419:Flavonoids / Q000008:administration & dosage; D005503:Food Additives; D005612:Freeze Drying; D005638:Fruit / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D008460:Meat; D031658:Olea / Q000737:chemistry*; D010626:Phenylethyl Alcohol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000032:analysis; D010936:Plant Extracts / Q000008:administration & dosage*; D059808:Polyphenols / Q000008:administration & dosage / Q000032:analysis; D011200:Poultry
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D005503:Food Additives; D010936:Plant Extracts; D059808:Polyphenols; C005975:3,4-dihydroxyphenylethanol; C040015:myricetin; D010626:Phenylethyl Alcohol