Assessment of the stability of sheep sausages with the addition of different concentrations of Origanum vulgare extract during storage.

The aim of this study was to assess the stability of sheep sausages with the addition of different concentrations of Origanum vulgare extract during storage. Five treatments were prepared: without natural antioxidant (control), sodium erythorbate 500mg/kg (ER), and three amounts of extract (N1=4964.51mg/kg, N2=6630.98mg/kg and N3=8038.20mg/kg). From appearance sensory analysis, control treatment differed significantly compared to ER (P<0.05) and N3 (P<0.01) groups, with intense red color, agreeing with trend of a* values. On the other hand, oregano extract improved the lipid and protein stability of cooked sausages during the storage time. Regarding volatile compounds from lipid oxidation, the N2 group presented the lowest values at the end of chilled period. In conclusion, the oregano extract showed antioxidant potential equivalent to sodium erythorbate at intermediate and high levels, calculated by DPPH∙ and FRAP methods, and most of the parameters were not compromised, allowing synthetic antioxidants replaced while maintaining the nutritional and sensory quality of cooked sausages.

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.