RESUMO
The effects of extrusion cooking alone or in combination with electron beam radiation (3.5 kGy) on vacuum-packaged beef-based snack sticks containing beef cardiac muscle were investigated. During formulation, Clostridium sporogenes PA 3679 spores were added to achieve a concentration of 4 log CFU/g. Twin-screw extrusion cooking at 72°C reduced aerobic plate counts (APCs) by 3.63 log cycles and C. sporogenes viable cell counts by 2.02 log cycles for the inoculated product. After irradiation (3.5 kGy), APCs were decreased to 1 log CFU/g when compared to 0 kGy counterparts receiving 0 kGy. Spores were not detected in irradiated inoculated samples, which contained C. sporogenes PA 3679 at levels of 3.17 to 3.50 log CFU/g after extrusion cooking.
RESUMO
Effectiveness of 0, 1.5 and 3.0% gluconic acid (G) and/or 0 and 1.5% lactic acid (L) solutions in reducing aerobic psychrotrophic bacteria plate counts (PPCs) and lactic acid bacteria counts (LACs) on vacuum-packaged beef was investigated at 0, 14, 28 and 56 days of storage. Instrumental and visual color changes were evaluated up to 28 days. Steaks treated with 1.5% L, plus 1.5% G or 3.0% G, solutions showed 2.0 and 2.5 log reductions (P<0.05) in PPCs compared to nontreated samples, respectively, at days 28 and 56. At 1.5%, G or L intervention for 0 and 14 days PPCs did not differ (P>0.05). However, PPCs were lower (P
RESUMO
Aroma notes of chuck rolls from decontaminated beef carcasses were evaluated. Carcasses were spray-treated with either water, 200 ppm chlorine or 3% lactic acid immediately after inspection and again after spray chilling. Following fabrication, each chuck roll was divided into four pieces; vacuum-packaged; and stored for 10, 40, 80 or 120 days at 4°C. At different storage times, a six-member, professional, sensory panel evaluated beefy, bloody, sour, grassy, spoiled and metallic aromatic impressions on cooked patties made from ground chuck roll pieces using a 15-point attribute scale. Psychrotrophic bacterial counts were conducted on raw, ground samples. Principal component statistical analysis showed that the first principal component described 96% of the data and, therefore, it was used as an average acceptability score that explained all aroma descriptors. Chucks from chlorine-treated carcasses tended to have higher (P = 0.08) acceptability scores, followed by lactic acid - and water-treated counterparts. The rate of change in aroma occurred faster between 10 and 40 days for lactic acid - and water-treated samples and between 40 and 80 days for chlorine-treated samples. Bacterial counts increased during storage up to 80 days; however, treatments were not different (P >0.05).
