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.

Effect on tumor growth inhibition activity of Gekkoswinhonis Guenther with different extent of broiling on H22 tumor-bearing mice / 药学学报

This study was designed to investigate the effect on tumor growth inhibition activity of lizards (Gekkoswinhonis Guenther) with different extent of broiling. Samples were prepared by a traditional drying method combined with broiling on clay tiles. Four groups of samples were all dried before broiling. Group A was without broiling; group B was mildly broiled; group C was moderately broiled; and group D was heavily broiled. Crispiness was detected by the sizes of the generated fragments of different groups and crispiness increased with broiling. Sensory evaluation of vision and olfaction was performed, and scores were generated by evaluators. Moderately broiled group had the highest total score in sensory evaluation. Water content and content of water-soluble extracts were detected according to Chinese Pharmacopoeia. With the increasing broiling extent, content of water-soluble extracts increased while water content decreased. Soluble protein concentration was detected by bicinchoninic acid (BCA) kit and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with the same crude drug content. Soluble protein concentration decreased with the increasing broiling extent. With equal loading of proteins at the same concentration, soluble protein diversity was detected by SDS-PAGE. Band difference was marked by red boxes. Soluble protein molecule weights showed significant difference with the increasing broiling extent. H22 tumor-bearing mice model was established and used to detect tumor growth inhibition rate and immune organ index. Life quality of mice was evaluated. Mice treated with Gekkoswinhonis Guenther had better appetites and higher average weights compared with positive control group treated with fluorouracil (5-FU). Animal experiments were approved by the Ethics Committee of Beijing University of Chinese Medicine. Group A had the highest tumor growth inhibition rate (34.11%), followed by Group B (29.14%) and Group D (28.43%), Group C (21.98%) had the lowest tumor growth inhibition rate, but sensory evaluation was on the contrary. These results indicated that moderately broiling improved sensory evaluation but reduced the tumor growth inhibition activity of Gekkoswinhonis Guenther. The best tumor growth inhibition activity appeared when water content was 7.71%.

Influence of Cooking (Microwaving and Broiling) on Cylindrospermopsin Concentration in Muscle of Nile Tilapia (Oreochromis niloticus) and Characterization of Decomposition Products.

Cylindrospermopsin (CYN) has become increasingly important as a freshwater algal toxin, showing cytotoxic effects. This toxin is able to bioaccumulate in freshwater food webs, representing a serious human health problem. Normally, fish is cooked before consumption, and CYN concentration can be altered. For the first time, the effects of microwaving and broiling for 1 and 2 min on CYN concentration and its decomposition products in fish muscle (Oreochromis niloticus) contaminated in the laboratory were investigated, using UPLC-MS/MS and Orbitrap. The results show that cooking the fish reduced unconjugated CYN levels by 11, 10 and 15% after microwaving for 1 and 2 min, and broiling for 2 min, respectively, compared to control fish. Different CYN decomposition products with m/z 416.1234 (7-epi-CYN) and m/z 336.16663 (diasteroisomers C-3A, C-3C, C-3D, C-3E, C-3F) are generated in fish samples submitted to cooking. Based on the relative abundance of the decomposition products, the possible degradation pathways taking place by microwaving may be through the formation of 7-epi-CYN and m/z 336.16663 compounds, whereas in the case of broiling the last route is the only one observed in this study. The influence of cooking and the toxicity characterization of the degradation products generated in CYN-contaminated fish are of importance for more realistic risk evaluation related to their consumption.