Evaluation of oxidative stability of lamb burger with Origanum vulgare extract.

The objective was to evaluate replacement of sodium erythorbate with a natural antioxidant (oregano extract) on physicochemical and sensory stability of lamb burgers, and determine the appropriate amount. Five treatments were prepared, including control (without antioxidant), sodium erythorbate, and three concentrations of oregano extract (13.32, 17.79 and 24.01mL/kg), based on antioxidant capacity determined using the Folin-Ciocalteu, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods, respectively. Burgers containing oregano extract, at the concentration determined by FRAP method, had higher oxidative stability, evidenced by an 80% reduction (P<0.001) in thiobarbituric acid reactive substances, effective inhibition of protein oxidation (P<0.01) and less colour loss during frozen storage. Oregano extract did not impair (P>0.05) consumers' sensory acceptance of the lamb burgers. Under the conditions tested, addition of 24mL/kg of oregano extract could be recommended as a natural antioxidant in lamb burgers.

Evaluation of antioxidant capacity of 13 plant extracts by three different methods: cluster analyses applied for selection of the natural extracts with higher antioxidant capacity to replace synthetic antioxidant in lamb burgers.

The aims of this study were: to evaluate the total equivalent antioxidant capacities (TEAC) and phenolic contents of 13 plants extracts; to select the most promising extracts regarding reducing activity using cluster analysis multivariate statistical technique; and to analyse evaluate sensory acceptance of lamb burgers produced with the most promising natural antioxidants replacing sodium erythorbate. Plant extracts were evaluated regarding TEAC by DPPH(•) and FRAP methods, and total phenolics contents by Folin-Ciocalteau assay. The TEAC values ranged from 0.50 to 9.06 g trolox/100 g dry weight (dw) and from 43.6 to 472.32 µmol trolox/g dw for DPPH(•) and FRAP methods, respectively, and the total phenolic contents from 5.98 to 74.01 mg GAE/g dw. Extracts from Origanum vulgare, Melissa officinalis, Origanum majorana L. and Rosmarinus officinalis were grouped as the ones with higher antioxidant capacities by cluster analysis. All burgers produced with each one of these four plant extracts or with sodium erythorbate showed no differences (P > 0.05) regarding consumers' sensory acceptance. In conclusion, it is possible to replace sodium erythorbate in lamb burgers by any of the four natural extracts selected without compromising sensory acceptance of this meat product.

Liberação intraocular de ofloxacina associada a lente de contato biossintética em ceratite bacteriana experimental em cães / Introcular release of ofloxacin associated with biosynthetic contact lens in experimental bacterial keratitis in dogs

Avaliou-se a concentração de ofloxacina liberada por uma lente de contato de membrana de celulose biossintética, para tratamento de ceratite bacteriana experimental em cães, pela inoculação de Staphylococcus aureus intraestromal. Comparou-se o tratamento com a lente de contato biossintética impregnada com ofloxacina à terapia tópica convencional. Realizou-se avaliação microbiológica e dosagem de ofloxacina no humor aquoso por meio do método de cromatografia líquida de alto rendimento (HPLC). Houve diferença estatística na contagem de colônias bacterianas entre os olhos com ceratite e os demais grupos, no primeiro dia de coleta. O biomaterial, impregnado com ofloxacina, promoveu liberação gradual durante o período de avaliação, aos três e sete dias; no terceiro dia, o grupo tratado com a lente de contato obteve mediana de 3,72μg/mL, enquanto o grupo tratado com colírio resultou em 49,56μg/mL. Apesar do valor inferior, o grupo com lente de contato atingiu a concentração inibitória mínima, sendo eficaz no controle da infecção bacteriana.

The concentration of ofloxacin released by contact lens made of biosynthetic cellulose membrane was evaluated for the treatment of experimental bacterial keratitis in dogs by intrastromal inoculation of Staphylococcus aureus. The biosynthetic contact lens impregnated with ofloxacin was compared with the conventional topical therapy. The microbiological evaluation and the determination of ofloxacin in aqueous humor were evaluated by high performance liquid chromatography (HPLC). There was not statistical difference in the counting of bacterial colonies among the eyes with keratitis and other groups, on the first day of collection. The biomaterial, impregnated with ofloxacin, promoted gradual release during the evaluation period, at three and seven days; on the third day, the group treated with the contact lens obtained a median of 3.72μg/mL, while the group treated with eye drops resulted in 49.56μg/mL. Despite the lower value, the group with contact lens reached the minimum inhibitory concentration, which was effective in controlling the bacterial infection.