EFFECTS OF PHYSIOLOGICAL MATURITY OF BEEF AND MARBLING OF RIB STEAKS ON EATING QUALITY

SUMMARY— Selected characteristics of beef rib steaks representing three physiological maturity levels and two marbling levels were investigated. Paired steaks at the 1lth thoracic vertebra were used to obtain cooking time and losses, palatability scores, Warner-Bratzter shear values, and selected histological data. In addition, steaks from the left 7th and right 8th thoracic vertebrae positions were used to measure cooking time and losses, Warner-Bratzfer shear values, waterholding capacity, pH, color-difference, and total moisture. Ether extract was obtained for raw longissimus dorsi at the 12th thoracic vertebra. Maturity and marbling affected told moisture (P < 0.001), quantity of fat in raw muscle (histological measurement, P < 0.01). ether extract (P < 0.001). and dripping losses (7th and 8th thoracic vertebrae P < 0.001). Other factors were not affected significantly. Maturity and marbling, at levels represented, had little effect on palatability of the steaks, although generally, measurements for fat content were higher and those for moisture lower at the higher marbling level. Most correlation coefficients for overall acceptability and histological measurements were low. Tenderness had more influence on the overall acceptability of the meat than flavor or juiciness. Moderate to high relationships occurred between cooking time and both initial weight of steaks and cooking losses. Generally, waterholding capacity was not related to pH, total moisture, or cooking losses. Correlation coefficients for pH vs. shear value and pH vs. color-difference were low.     

High-Temperature Reactions of Clay Mineral Mixtures and Their Ceramic Properties: III, Shrinkage and Porosity in Relation to Initial Mineralogy

Little exact information exists on the relation of mineralogical composition of clay materials to their properties after firing. Property-composition diagrams are constructed for linear shrinkage and apparent porosity of quartz-kaolinitemica mixtures fired at 1100° and 1200°C.; contours of equal shrinkage and equal porosity are derived. Sixty natural clays and shales are analyzed semiquantitatively for mineral content, and their shrinkage and porosity values are obtained after firing to 1100° and 1200°C. The ceramic properties of the natural materials are compared with those of the prepared mixtures. Conclusions are drawn regarding the influence of mineralogical composition on the ceramic properties. The mica content is shown to be particularly important because of its role in the for mation of a glassy component.     

Nutrient Content and Edible Yield of Selected Cuts of Cooked Pork

Analysis of lean-type pork cooked by standard methods showed that cooking to a final internal temperature of 77°C for fresh cuts, and 71°C for cured meats resulted in increased amounts of several essential nutrients. Edible yield was similar to that reported from earlier studies, while amounts of internal fat were somewhat lower. Levels of thiamin, riboflavin and niacin and of several minerals were found to be slightly higher than Handbook 8 values. Cobalamin and zinc from 100g of edible lean would provide approximately 10% and 20–35% of the respective recommended daily allowances. Iron contents were lower than previously reported for pork.