Cooking loss in retail beef cuts: The effect of muscle type, sex, ageing, pH, salt and cooking method.

The aim of the study was to compare cooking losses in beef (striploin and cube roll) during various cooking methods (grilling, roasting, broiling) in two different cooking devices (convection oven and clamshell grill). A total of 400 samples of meat were cooked (an internal temperature of more than 70 °C) and analysed. Cooking losses of slices of striploin ranged between 24.5% and 34.8%, with losses of 25.9-35.8% when whole cuts of meat were roasted. Losses fell within similar ranges (24.7-33.7%) for cube roll. Beef after 21 days of dry ageing showed generally lower cooking losses. Principal component analysis confirmed a strong negative correlation between cooking losses and salt content, saltiness and juiciness, which were positively correlated with one another. The majority of the sensory properties were positively correlated with pH, while their relationship with Warner-Bratzler (WB) test was negative. Roasting in a convection oven would seem to be the most suitable method of cooking striploin, followed by broiling in a convection oven, with grilling in last place. The highest score for the majority of sensory properties and the lowest WB values were recorded in meat roasted in a convection oven, particularly in the meat of bulls aged for 21 days.

Occurrence of Foodborne Agents at Food Service Facilities in the Czech Republic.

HIGHLIGHTS: Contamination of food service facilities in the Czech Republic by foodborne agents was determined. Bacillus cereus, Staphylococcus aureus, and Escherichia coli were detected in almost 50% of samples. The occurrence of B. cereus, S. aureus, and E. coli depended on the season of the year. Regular monitoring of food service facilities for agents of foodborne disease is necessary.

Short communication: Pasteurization as a means of inactivating staphylococcal enterotoxins A, B, and C in milk.

Our aim was to assess the effect of pasteurization temperature on inactivation of staphylococcal enterotoxins (SE). Milk samples were inoculated with log 4.38 to 5.18cfu/mL of 40 different Staphylococcus aureus strains having the ability to produce types A, B, or C SE and incubated at 37°C for 24h to develop SE. This incubation was followed by heat treatment for 15 s at 72, 85, and 92°C. Samples were analyzed for Staph. aureus count by plate method and, specifically, for SE presence. An enzyme-linked immunofluorescent assay on a MiniVIDAS analyzer (bioMérieux, Marcy l'Étoile, France) was used to detect SE, which were determined semiquantitatively based on test values. The Staph. aureus count in milk before pasteurization did not affect the amount of SE. Before pasteurization, SEB was detected in the lowest amount compared with other SE types. Staphylococcal enterotoxins were markedly reduced with pasteurization and inactivated at pasteurization temperatures to an extent depending on the amount in the sample before pasteurization. After pasteurization at 72°C, SE were detected in 87.5% of samples (35/40), after pasteurization at 85°C in 52.5% of samples (21/40), and after pasteurization at 92°C in 45.0% of samples (18/40). We determined that SE may still persist in milk even when Staph. aureus bacteria are inactivated through pasteurization. Although pasteurization may partially inactivate SE in milk, a key measure in the prevention of staphylococcal enterotoxicosis linked to pasteurized milk consumption is to avoid any cold chain disruption during milk production and processing.