Effects of different levels of salt and temperature on some physico-chemical and colour properties of microwave-dried beef round (M. semitendinosus)

PurposeThe aim of this work was to study the effect of the different levels of salt and the temperature on some physico-chemical and colour change properties of microwave-dried beef round (M. semitendinosus).Design/methodology/approachThe samples were pretreated with different temperatures (0°C, 40°C and 50°C) and salting (0, 1.5, 2.5%). Later these samples have been dried by the microwave energy at 540 W for seven minutes. Some physical properties (water activity, moisture content, change in diameter, change in thickness, change in shrinkage ratio) and texture, colour and microscopic surface structure analysis were conducted in dried beef round samples.FindingsAs a result, the colour and moisture were the most affected factors. Also, physical and microstructural characteristics were affected by salting and pre-drying. In addition, while the textural structure did not show a significant difference, meat weight and water activity varied.Research limitations/implicationsMeat obtained from a local butcher in Konya was used as the study material. In addition, only a special part of the meat (M. semitendinosus) was used in the study. In the drying process, the parameters were determined as 540 W and 7 min. These are the limitations of the research.Originality/valueAll changes that can occur in the physical properties of the meat after the drying process were examined. The structure of beef round samples formed by microwave drying was shown by using electron microscope. The effects of pretreatment such as salting and pre-drying have been examined on microwave drying.

Influence of Cook Method and Degree of Doneness on Beef Flavor Attributes in Round Steaks

ObjectivesIt has been well established that cooking method, marbling level, and cooked internal temperature endpoint affect beef flavor, the most important driver of consumer acceptance. However, beef cuts respond differently to cooking method and cooked internal temperature endpoint based on their inherent chemical characteristics.Materials and MethodsTreatments were: beef cuts (inside round, bottom round, and eye of round); USDA beef quality grade (upper two-thirds Choice and Select); cooking methods (pan grill, stir fry, stew no marinade, stew marinade, and roast); and internal cook temperature endpoints (58, 70, and 80°C). The pan grill cook method included 0.25 and 0.75 in samples from each muscle type. The stir fry cook method treatment was limited to 0.25 in cuts, which were cut into 1.00 in strips prior to cooking. The marinated and non-marinated stew cook method treatments included 0.25 and 0.75 in samples from each muscle. These samples were then cut into 0.25 × 1.00 × 1.00 in and 0.75 × 1.00 × 1.00 in samples prior to cooking. Stew marinated samples were marinated with 118 mL water, 90 mL lemon juice, 30 mL canola oil, 5 mL salt, and 2.5 mL pepper. Two lb roasts were cut from bottom round and eye of round subprimals and inside round subprimals were cut into 2.00 in roasts prior to cooking. An expert descriptive beef flavor and texture attribute panel evaluated each sample using 16-point scales for flavor and texture attributes. Warner-Bratzler shear force (WBSF) were determined. The trained panel results and WBSF values were analyzed using Proc Means and Proc GLMMIX procedures of SAS (version 9.4, SAS Institute, Cary, NC) with a predetermined α of 5%.ResultsQuality grade impacted flavor for the inside round (P < 0.05). USDA quality grade had minimal effect on tenderness as expected, as beef round cuts are highly active muscles in the animal and contain considerable amounts of connective tissue. Cooking method and internal cook temperature endpoint, or cooking time for the stewing cooking treatment, impacted beef flavor to a greater extent (P < 0.05). When pan fried, thicker cuts resulted in more positive flavor attributes. For cuts that were roasted, cooking to higher internal temperatures resulted in higher levels of beef identity, roasted, and umami flavors and less serumy/bloody flavors, as well as decreased tenderness (P < 0.0001), especially in inside round roasts. Marinated round cuts were more tender than their non-marinated counterparts (P < 0.0001). Cuts that were thinner and had longer cooking times were more tender but had more off-flavor attributes (P < 0.05).ConclusionCut thickness, cooking method, length of cooking or internal cook temperature endpoint, and presence of marinade affected flavor and texture of bottom round, eye of round, and inside round cuts. This data will be useful in providing consumer and food service personnel recommendation on how to maximize the flavor and texture of beef round cuts.

Microbial quality and shelf life prediction of vacuum-packaged ready to eat beef rounds containing gum arabic

Research has shown that gum arabic from Acacia senegal var. kerensis can be used in beef rounds, at a level of 2.5% of the formulated product weight, as a binder and texture modifier. However, the effect of gum arabic addition on the microbial quality and shelf life of the resulting meat product has not yet been reported. Thus, the objective of this work was to study the microbial quality of beef rounds containing 2.5% gum arabic and to study shelf life based on the growth parameters of Total Viable Counts (TVC) and Lactic Acid Bacteria (LAB). Beef round samples were injected at 30% with curing brines containing gum arabic and cooked through boiling. The growth kinetics of LAB and TVC were studied for vacuum packaged sliced beef round samples stored at 7 oC and 15 oC for a period of 21 days. Baranyi and modified Gompertz models were used to fit the LAB and TVC data obtained using DMFit. Results of microbial analysis indicated that coliforms, yeasts and molds as well as pathogenic bacteria; Salmonella, Escherichia coli, and Staphylococcus aureus, were below detection limit. In addition, TVC and LAB were found to be 1.87 ± 1.09 and 1.25 ± 0.75 Log 10 CFU g-1, respectively. The results of accuracy analysis showed that both the Baranyi and modified Gompertz models were adequate in representing the bacterial growth in beef rounds injected with curing brines containing gum arabic. The predicted shelf life was found to be between 84.3 – 88.1 h and 158.0 – 173.1 h at 15 oC and 7 oC, respectively.

Evaluating the Predictive Ability of a Path-Dependent Thermal Inactivation Model for Salmonella Subjected to Prior Sublethal Heating in Ground Turkey, Beef, and Pork

Pathogen thermal inactivation models currently available to and used by industry consider only the present state of the product when predicting inactivation rates. However, bacteria subjected to sublethal thermal injury can develop partial protection against lethal temperatures. The objective of this study was to extend the capabilities of a previously published path-dependent Salmonella inactivation model by accounting for longer sublethal heating periods and different substrates and to test this new model against independent data. Ground samples of irradiated (&gt;10 kGy) turkey breast, beef round, and pork loin were inoculated with an eight-serovar Salmonella cocktail and subjected to 53 nonisothermal treatments (in triplicate) that combined a linear heating rate (1, 2, 3, 4, or 7 K/min), a variable length sublethal holding period (at 40, 45, or 50°C), a lethal holding temperature (55, 58, 61, or 64°C), and a nominal target kill (3- or 5-log reductions) (n = 159 for each meat species). When validated against nonisothermal data from similar treatments, traditional state-dependent model predictions resulted in root mean squared errors (RMSEs) of 2.9, 2.2, and 4.6 log CFU/g for turkey, beef, and pork, respectively. RMSEs for the new path-dependent model were 0.90, 0.81, and 0.82 log CFU/g for the same species, respectively, with reductions in error of 63 to 82% relative to the state-dependent model. This new path-dependent model can significantly reduce error from the state-dependent model and could become a useful tool for assuring product safety, particularly relative to slow heating processes.