ACTIVIDAD ANTIOXIDANTE TOTAL EN PECHUGA DE CODORNIZ JAPONESA (Coturnix coturnix japonica) ALIMENTADA CON UNA DIETA SUPLEMENTADA CON HONGOS COMESTIBLES

La carne de codorniz japonesa (Coturnix coturnix japonica) se destina al consumo humano, por ello es importante mantener su calidad durante el almacenamiento. El objetivo fue evaluar la capacidad de la harina de Pleurotus ostreatus incluida en la dieta, para incrementar la actividad antioxidante total (AAT) de la carne. Para ello, se determinó el contenido de fenoles (CFT) y flavonoides totales (CFVT), así como actividad antiradical-DPPH• y ABTS•+, y poder reductor (PR) del extracto-acuoso de P. ostreatus (EAPO). Las codornices fueron alimentadas durante 35 días con tres dietas: control y suplementadas con P. ostreatus (1 y 2 %). La pechuga (Pectoralis major) se almacenó (10 días/2 °C/oscuridad) y se obtuvo un extracto-acuoso cárnico (EAC) para determinar la AAT. Los resultados mostraron que el EAPO presentó buen CFT y CFVT (27.3 mg EAG/g, y 16.1 mg EQc/g, respectivamente), así como 35 y 49.1 % de actividad antiradical-ABTS•+ y DPPH•, y 35 % de PR. El EAC, presentó valores de CFT, ABTS•+ y DPPH•, superiores al control (P≤0.05), no detectándose diferencias para el CFVT y PR (P≥0.05). En conclusión, la incorporación de P. ostreatus en la dieta de codorniz, incrementó la AAT del EAC durante su almacenamiento.

Effect of Lactic Acid Bacteria on Beef Steak Microbial Flora Stored Under Modified Atmosphere and on Listeria Monocytogenes in Broth Cultures

Beef steaks were inoculated with one or other of two protective strains of lactic acid bacteria, the bacteriocinogenic Lactobacillus sakei CTC 372 or the uncharacterised Lactobacillus CTC 711. They were stored under modified atmospheres (20–40% CO2). Inoculation of meat with both strains inhibited the growth of the spoilage bacteria. Neither CO2 in the pack atmosphere, inoculation with protective strains, nor a combination of both, affected formation of metmyoglobin or the development of off-odours. The formation of metmyoglobin in meat pigments and the sensory odour scores were compatible to those of fresh meat which had not undergone either oxidative deterioration or microbial spoilage. Listeria monocytogenes were inhibited in broth by meat surface microbiota containing either of the protective strains. With an initial population of 5.6 log cfu/mL, after 7 days incubation at 3°C, Listeria monocytogenes were recovered at log mean population of 2.8 log cfu/mL when neither protective strain was present. At 8°C, the population of Listeria monocytogenes recovered were reduced by about 2.5 or 1.5 log cfu/mL in the presence of Lactobacillus sakei CTC 372 or Lactobacillus CTC 711, respectively. At 25°C, the population of Listeria monocytogenes recovered from broth containing either protective strain were about 5 log cfu/mL less than the population recovered from broth containing Listeria monocytogenes only.

Combined Effect of Modified Atmosphere Packaging and Addition of Lycopene Rich Tomato Pulp, Oregano and Ascorbic Acid and Their Mixtures on the Stability of Beef Patties

Beef patties were treated with ascorbic acid, oregano extract, lycopene rich tomato pulp (LRTP) and their mixtures, packaged in modified atmosphere and stored at 2°C. Lipid oxidation (TBARS formation), metmyoglobin formation, psychrotrophic bacterial counts and sensory odour and discolouration were analyzed throughout 20 days of storage. TBA values of beef patties containing oregano were the lowest ( p < 0.05); those containing ascorbic acid and LRTP alone were also significantly lower ( p < 0.05) than the control. The formation of surface metmyoglobin was significantly delayed ( p < 0.05) by the addition of oregano alone and its mixtures with ascorbic acid and/or LRTP. Psychrotrophic bacterial counts were significantly lower ( p < 0.05) in patties treated with 500 ppm oregano. Sensory colour and odour characteristics of beef patties were in agreement with the results of lipid and pigment oxidation. The antioxidant ability of oregano was dependent on the concentration; the presence of 500 ppm extended the shelf life of beef patties by about 8 days. LRTP alone exerted a limited antioxidant effect, while its combination with oregano resulted in a reduction of the antioxidative effect of the latter.

Utilization of applesauce in a low-fat bologna-type product Empleo del pure de manzana en la elaboración de productos del tipo mortadela

Apples ( Malus pumila ) such as Anna and Dorsett Golden are varieties with limited fresh commercial usage due to their small size, high acidity and scarce red pigmentation. However, they can be pro cessed to make applesauce that can be used as an ingredient in the elaboration of meat products. A bologna-type product was produced replacing fat with 15% applesauce ( Anna, Dorsett Golden and Golden Delicious varieties) to evaluate chemical, physical and sensory properties. Mechanically deboned turkey meat and pork shoulder was used. Ten and twenty percent of backfat and regular fat were added to products with applesauce and the control sample, respectively. Addition of applesauce to the formulation had no effect on cook yield after thermal processing, which was 96%. A 25% fat reduction was accomplished in the finished product with respect to the control. Moisture increased from 56% in the control to 63% in bologna sausage with applesauce. There were no effects on texture parameters and there was a lowering effect ( p < 0.05) in L value for lightness by applesauce addition. Bologna sausage with Golden Delicious apple sauce was the sweetest as evaluated by panelists. In overall acceptability for all bologna sausages, scores ranged between acceptable and good. It is advis able to use applesauce as an ingredient in emulsion-type products like bologna sausages to replace fat and still produce an acceptable product.

The effects of ascorbic acid, taurine, carnosine and rosemary powder on colour and lipid stability of beef patties packaged in modified atmosphere

This research was aimed at evaluating the inhibition of oxidative changes of beef patties packaged in modified atmosphere (70% O(2)+20% CO(2)+10% N(2)) by natural antioxidants: ascorbic acid (500 ppm), taurine (50 mM), carnosine (50 mM), rosemary powder (1000 ppm) and their combinations with the first. Beef patties stored at 2±1°C for 20 days were evaluated for colour (L*, a*, b*, C* and H*), TBARS, metmyoglobin formation (% of total myoglobin), psychrotrophic microbial counts and sensory odour and discolouration. Rosemary, either alone or with ascorbic acid, was highly effective in inhibiting both metmyoglobin formation and lipid oxidation; sensory analysis was in agreement with these results. Ascorbic acid, ascorbic acid+taurine and ascorbic acid+carnosine treatments showed a limited inhibitory effect of myoglobin oxidation, while carnosine and carnosine+ascorbic acid were effective in inhibiting lipid oxidation. Taurine alone failed to exert any antioxidant effect. Principal components analysis confirmed these results.