Gastón Torrescano

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.

Shear values of raw samples of 14 bovine muscles and their relation to muscle collagen characteristics.

Raw samples of 14 muscles: Mm. biceps femoris (BF), quadriceps femoris (CF), diaphragm (DI), flexor digitorum (FD), gluteus medius (GM), infraspinatus (IE), longissimus lumborum (LL), longissimus thoracis (LT), psoas major (PM), pectoralis profundus (PP), semimembranosus (SM), semitendinosus (ST), sternomandibularis (STER) and triceps brachii (TB) from four Swiss Brown (485±15 days old) young bull carcasses and weighing approximately 300 kg were evaluated for some chemical and physical properties. PM (2.11 kg) and DI (2.24 kg) were the muscles which had the lowest Warner-Bratzler shear force values, while PP (6.66 kg) had the greatest shear force (P<0.05). FD and IE muscles had the highest concentration of total collagen content while PM and DI had the lowest (P<0.05) contents, TB and IE muscles presented the highest insoluble collagen concentration while PM and LT had the lowest (P<0.05) contents. High positive correlation between total collagen content and Warner-Bratzler shear force of raw samples was found (r=0.723; P<0.01) and between insoluble collagen content and Warner-Bratzler shear force was (r=0.661; P<0.01). Significant differences (P<0.05) were observed among muscles for differential scanning calorimetry, sarcomere length, pH and colour parameters.

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.

Changes in intramuscular fat, fatty acid profile and cholesterol content induced by zeranol implantation strategy in hair lambs.

BACKGROUND The effect of zeranol implantation strategy on intramuscular fat, fatty acid profile and cholesterol content of the longissimus dorsi muscle of hair lambs was studied. Four treatments were tested: C, control group; Z12, 12 mg zeranol; Z24, 24 mg zeranol in a single application; and RZ12, 12 mg zeranol given twice. One-way analysis of variance was employed to estimate the effect of treatments (P < 0.05). To separate the effect of the mean, orthogonal contrasts were tested: C1, C versus Z12 + Z24 + RZ12; C2, Z12 versus Z24 + RZ12; and C3, Z24 versus RZ12. RESULTS A decrease (P < 0.05) in intramuscular fat content was observed from implanting (C1 effect) and zeranol reimplantation (C3 effect). Implanted lambs exhibited an increase (P < 0.05) in monounsaturated fatty acids compared with control group (40.60% versus 35.35%). All contrasts were significant for the sum of n-6 and n-3, with values lower (P < 0.05) in the control (n-6: 0.84% and n-3: 1.38%) and higher in the RZ12 treatment (n-6: 7.55% and n-3: 14.9%). Cholesterol decreased by 78% with implantation and increasing the dose. CONCLUSION The results indicate that it is possible to induce favorable changes in the fatty acid profile and cholesterol content using a zeranol implantation strategy on hair lambs.

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.