No abstract

This study evaluated the effects of low doses of gamma radiation (up to 2.0 kGy) on the survival and growth of Listeria monocytogenes and on technological characteristics of RTE cooked hams, formulated without and with 50 and 150 mg/kg of sodium nitrite, after 30 days of cold (4°C) storage. The radiation reduced from 0.33 kGy in uncured and RTE50 to 0.25 kGy in RTE150 and after storage, a reduction (p > .05) in the Listeria growth in the cured samples. Irradiation had no effect (p > .05) on the pH, water activity, residual nitrite, lipid oxidation, or CIELCH color indices of RTE hams, regardless of the nitrite content. Higher TBARS values, chroma, and hue angle were observed (p < .05) in uncured samples than in cured ones. The RTE50 with irradiation by 1.0 to 2.0 kGy can be used to ensure the Listeria safety. Practical applications Meat RTE products post‐thermal manipulation, like in slicing operations, may result in an enhanced microbial risk, especially regard to Listeria postprocessing contamination. Therefore, post‐lethality treatments like gamma irradiation are of interest to the industry to ensure food safety. Combining the lower doses of irradiation with low nitrite content in RTE meats could be used to guarantee microbial safety, minimizing irradiation‐induced quality changes, and contributing to the sensory and technological characteristics of the products.

This study evaluated a microwave (Mw) cooking method for determining beef toughness using the Warner–Bratzler slice shear force (WBsSF) protocol. Longissimus thoracis muscles were aged for 1, 10, 19, and 28 days at 4C. They were then either cooked on a clam‐shell grill until reaching an internal temperature of 72C, in a Mw for 100 s at maximum power (Mw100) or for 140 s at 60% of maximum power (Mw60). Cooking loss and shear force (SF) values were higher in Mw samples than in grilled ones. SF assessment by grill and Mw100 were able to discriminate tenderness by aging times in the same way as the sensory panel. The SF measured in a grilled sample had higher repeatability (R = .74) and correlation with sensory scores (r = −.79) than Mw100 (R = .61; r = −.62) and Mw60 (R = .51; r = −.53). Mw100 can be considered as an appropriate alternative for the WBsSF protocol. Practical applications Tenderness is the most important attribute for consumers. Many studies have evaluated tenderness in meat and different protocols for cooking. This work was intended to optimize and evaluate the use of the microwave as a cooking method for shear force determination, against a standard protocol and establish the correlation to sensory tenderness.