Effect of natural antioxidants in Spanish salchichón elaborated with encapsulated n-3 long chain fatty acids in konjac glucomannan matrix.

The effect of natural antioxidants on physicochemical properties, lipid and protein oxidation, volatile compounds and free fatty acids (FFA) were determined in Spanish salchichón enriched with n-3 fatty acids encapsulated and stabilized in konjac matrix. Phenolic compounds of beer residue extract (BRE), chestnut leaves extract (CLE) and peanut skin extract (PSE) were also identified and quantified. Five batches of salchichón were prepared: control (CON, without antioxidants), butylated hydroxytoluene (BHT), BRE, CLE and PSE. The main phenolic compounds were catechin and benzoic acid for BRE, gallic acid and catechin for CLE and catechin and protocatechuic acid for PSE. Statistical analysis did not show significant differences on chemical composition among treatments. Reductions in luminosity (P<0.05) and pH (P<0.001) were observed with the CLE batch, whereas the other colour parameters were not affected by the addition of natural antioxidants. Finally, the inclusion of antioxidants (P<0.001) decreased the hexanal content, whereas the FFA content increased by the addition of natural extracts.

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.

Peanut skin extract reduces lipid oxidation in cooked chicken patties.

The objectives of this study were to evaluate the antioxidant capacity of peanut skin extract and its effect on the color and lipid oxidation of cooked chicken patties over 15 d of refrigerated storage. The extract was obtained using 80% ethanol and evaluated in terms of total phenolic content, reducing power based on the ferric reducing ability of plasma (FRAP) reagent, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The patties were made with ground thigh fillets, chicken skin, and 2% salt. They were homogenized and divided into the following two groups: a control treatment without antioxidants and a peanut skin treatment with 70 mg gallic acid equivalent (GAE)/kg per patty. Analyses of the fatty acid profiles, instrumental colors (L*, a*, and b*) and thiobarbituric acid reactive substances (TBARS) were performed on d 1, 8, and 15 of storage at 1±1ºC. The peanut skin extract resulted in a phenolic content of 32.6±0.7 mg GAE/g dry skin, an antioxidant activity (FRAP) of 26.5±0.8 6 µmol Trolox equivalent/g dry skin, and an efficient concentration (EC50) of 46.5 µg/mL. The total unsaturated fatty acid was approximately 73%, and 39% of this fatty acid content was monounsaturated. The peanut skin extract slowed the decrease in the a* values (P<0.05) but reduced the L* and b* values compared to the control samples during storage (P<0.05). Lipid oxidation was minimized by the peanut skin extract (P<0.05), which resulted in a maximum value of 0.97 malondialdehyde (MDA)/kg compared to values that were close 19 mg MDA/kg patties in the control sample at the end of storage period. Thus, it can be concluded that although peanut skin extract causes little color change, it can be applied as a natural antioxidant to cooked chicken patties because it efficiently inhibits lipid oxidation in this product during refrigerated storage.