Effects of aging treatment and freezing/thawing methods on the quality attributes of beef from Limousin×Holstein-Friesian and Hereford×Holstein-Friesian crossbreeds.

The objective was to investigate combined effects of aging-, freezing-, thawing- treatments on the water-holding capacity, Warner-Bratzler shear force (WBSF) and sensory properties of beef. Semitendinosus muscles from two crossbreeds were analysed. Carcasses were conventionally aged (4days post mortem), muscles were separated and divided into samples. Part of the samples were frozen without wet-aging and the others were wet-aged for 3 or 6days (and then also frozen). Two freezing methods (conventional and cryogenic) and two thawing methods (at 4°C and 20°C) were applied. Stepwise conventional/wet-aging just as thawing at 20°C, decreased the WBSF (P<0.05) and increased the scores for tenderness (P<0.05). Moreover, wet-aging for 3days gave an equal effect on tenderness (P>0.05) as the 6-days period. Meat from Hereford-crosses scored significantly higher for juiciness, compared with Limousin-crosses. These tips may be applied in the meat industry to reduce time of aging process and ensure a consistent high quality of frozen beef.

The effect of muscle, cooking method and final internal temperature on quality parameters of beef roast.

The aim of the study was to evaluate the influence of cooking conditions (dry air and steam) and final internal temperature (75, 85, 95°C) on the physico-chemical properties of beef infraspinatus (INF) and semimembranosus (SEM) muscles as well as their tenderness and juiciness. Cooking method and temperature influenced moisture, total collagen content in cooked meat and cooking loss, whereas muscle type affected fat, total collagen content and cooking loss. Warner-Bratzler shear force values were affected by cooking method, which also influenced juiciness of roasts. Temperature affected tenderness and juiciness, whereas muscle type influenced juiciness. The most desirable tenderness had INF heated in steam and dry air to 95°C. Processing SEM in dry air to 85 and 95°C lowered the juiciness of the roasts. There were significant correlations between physico-chemical, sensorial and image attributes, however high accuracy of prediction (r(2)>0.8) was achieved only for SEM muscle.

The influence of carrageenan on the properties of low-fat frankfurters.

Research was undertaken to study the technological properties of six carrageenan fractions and their usefulness as fat substitutes in frankfurter type sausages. In the first stage of the experiment hardness of gels made of 3% solutions of carrageenan preparations with different pH (5.5, 6.0 and 6.5) was evaluated. The highest F(max.) values were noted in gels obtained from G-WG carrageenan (kappa I fraction). In the second stage of the study frankfurter type sausages were produced, containing 20% and 10% of fat in meat batter with or without (control) kappa I carrageenan (G-WG). Carrageenan as a fat substitute caused a reduction in cooking and storage weight losses, increased hardness, gumminess and chewiness. All frankfurters produced with carrageenan, irrespective of fat content, were characterized by significantly higher sensory evaluation scores for texture, color and taste in comparison to control sausages.

Effect of calcium ions on the solubility of muscular collagen and tenderness of beef meat.

The aim of the present study was to determine the effect of aqueous solutions of calcium chloride and calcium lactate on the solubility of beef collagen in raw and cooked meat. The content of total collagen, water- and acetic acid-soluble collagen and insoluble collagen was determined in beef samples. Shearing force was measured after heat treatment. It was found that calcium ions had no significant effect on the solubility of muscular collagen. An improvement in beef tenderness (27%-34%) caused by calcium ions did not result from breaking of the native structure of muscular collagen.