Browsing by Author "Pena, I."

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    Effect of dietary Quillay polyphenols on the oxidative quality of broiler meat
    (2019) Fellenberg, M. A.; Pena, I.; Ibanez, R. A.; Vargas-Bello-Perez, E.
    This study evaluated the effect of the dietary inclusion of Quillaja polyphenols on the antioxidant status of the animal and the oxidative quality of meat. One hundred and twenty-eight broiler chickens were assigned to the following experimental groups, T0: basal diet (control), T1: 500 mg/kg of extract 1 + basal diet, T2: 1000 mg/kg of extract 1 + basal diet, T3: 2000 mg/kg of extract 1 + basal diet, T4: 500 mg/kg of extract 2 + basal diet, T5: 1000 mg/kg of extract 2 + basal diet, T6: 2000 mg/kg of extract 2 + basal diet, and T7: 100 mg/kg of a-tocopherol (Vit E) + basal diet. Quillaja extract 1 was composed by 10% of extracts soluble in water, with 90% of particles smaller than an 80-mesh sieve, without additives. Quillaja extract 2 was composed by 8% total phenols, 2% of tannins and 0.2% of saponins. The animals were slaughtered on d 42 and samples of intra-cardiac blood and tissue samples (liver, breast and thigh) were taken and assigned to treatments of 0, 2, 4 and 6 d of refrigeration. Feed conversion and FRAP (Ferric Reducing Ability of Plasma) index were not affected by treatments. Compared with extract 1 treatments, control had higher lipid oxidation in liver (basal and induced oxidation) and thigh (induced and induced with Fe). Compared to extract 2 treatments, control induced higher lipid oxidation + Fe. Overall, the Quillay polyphenol extracts had the same protective effects against lipid oxidation as compared to those from Vit E group in broiler thigh tissue. This study is important for those producers looking to ameliorate lipid oxidation problems in meat.
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    Effect of dietary vitamin E supplementation on glutathione concentration and lipid and protein oxidation of refrigerated broiler meat
    (2019) Fellenberg, M. A.; Pena, I.; Ibanez, R. A.; Vargas-Bello-Perez, E.
    This study evaluated the effect of dietary supplementation of vitamin E on glutathione content, and lipid and protein oxidative stability during refrigerated storage of broiler meat. Ninety one-d-old chicks were randomly assigned to one of two groups. The control group had a basal diet and the vitamin E (Vit E) group received 200 mg/kg alpha-tocopheryl-acetate as a supplement for 42 d. Lipid oxidation was assessed by the thiobarbituric acid reactive substances (TBARS) method, protein oxidation was estimated by carbonyl content and glutathione was measured by thiol content. Oxidised protein content in breast tissue remained stable during 6 days of refrigerated storage at 4 degrees C. In thigh tissue, the oxidised protein content significantly increased at 4 d of storage and then decreased. The TBARS content of meat of chickens supplemented with Vit E was lower than that from control during all time points of refrigerated storage. Meat from Vit E treated chickens had lower TBARS content than control meat when estimated at temperature-induced lipid oxidation conditions. In control meat, the TBARS content increased until 4 days of cold storage and then decreased at 6 days. The glutathione content of refrigerated breast tissue in all treatments remained constant during the first 4 d of refrigerated storage but exhibited a decrease thereafter. This research confirms that Vit E supplements in chicken feed protect their meat from lipid oxidation.
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    Sustainable management and use of a medicinal emblematic plant in Chile: Buddleja globosa Hope
    (2013) Wilckens, P.; Fernandez, M. P.; Gomez, M.; Pena, I.; Montenegro, G.
    Buddleja globosa Hope is a well-known native, medicinal plant because of its digestive and cicatrizing properties. Due to the increasing domestic and international demand, B. globosa abundance and distribution in Chile has resulted in the intensive exploitation of the plant's natural habitat, without consideration of the plant's regenerative capacity. The main objective of this research was to establish the B. globosa growth cycle and model its regeneration cycle. This would allow for more productive, efficient and sustainable use and management of this species, thus ensuring its long-term conservation. We selected two study sites, one wild and another one cultivated. In each one, ten individuals were marked as control treatments, for further observations, in order to quantify the monthly growth dynamics. Fifteen plants selected at random were marked in each site under study to know the regeneration rates with three pruning methods: apical, medium and basal (5 plants per treatment). The results showed significant differences between the control and management treatments on plants grown in the valley, and among the wild plants of the mountains. The biomass growth rates achieved in the treatments of pruning, and the period that those were maximum at both sites, allows us to recommend harvesting of B. globosa under a medium pruning management in January for the valley. For the mountain zones, it is suggested to conduct a partial apical-type harvest in December: this would allow that a part of the plant achieves the end of the flowering stage, which will contribute to seed dispersal and natural reproduction of the species.