PHYSICAL CHARACTERISTICS OF BEEF ROASTS PREPARED WITH DIFFERENT FOODSERVICE COOKING METHODS

Effects of cooking rate, fat trim level, aging period, endpoint temperature and oven type (conventional, forced air convection and forced air/steam combination) on yield, composition and cooking parameters for eight types of beef roasts were investigated. Generally, fast cooking, higher endpoint temperatures, complete removal of external fat and the use of forced air/steam combination ovens increased cooking losses. Fast cooking rates and forced air/steam combination ovens increased moisture loss in some roasts. Reduced levels of external fat did not dramatically affect yields or relative changes in composition due to cooking, but did increase cooking time per unit weight. Forced air/steam combination ovens may reduce the required length of preparation per unit raw weight while conventional ovens may increase cooking time. Rapid cooking of larger roasts with moist heat increased postcooking temperature rise. These results should aid in the revision of foodservice beef cookery guidelines.     

EFFECTS OF HETEROTROPHIC AND AUTOTROPHIC GROWTH CONDITIONS ON THE COMPOSITION OF Chlorella sorokiniana

SUMMARY –The effects of heterotrophic and autotrophic growth conditions on the composition of Chlorella are discussed in relation to the potential food value of algae. Cells from the two culture modes differ appreciably in proximate analysis and elemental composition; however, fiber content and vitamin andamino acid composition are essentially unchanged. On this basis it appears that heterotrophic algae, which are less expensive to produce, can be used to examine the acute toxicity problem with bacteria-free cells. In addition, heterotrophic algae may also be used to predict results that would be obtained with autotrophic material in studies of processing techniques designed to improve protein quality and digestibility.     

Effectiveness of Chlortetracycline in Combination with Potassium Sorbate or Tetrasodium Ethylenediaminetetraacetate for Preservation of Vacuum Packed Rockfish Fillets

Rockfish fillets were dipped in either distilled deionized water (DDW), a solution of 1% Na₄EDTA plus 5 ppm chlortetracycline (CTC) or 1% K-sorbate plus 5 ppm CTC. After dipping, fliets were vacuum packed and stored at 2°C. Samples were evaluated after 0, 3, 7, 10, 14, and 21 days. The sorbate/CTC group differed less from fresh Filets than did the control (fillets dipped in DDW) for all indices measured (plate count, pH, redox potential, and TMA and NH₃ concentrations). Fillets treated with EDTA/CTC differed to a greater extent from fresh fillets than the sorbate/CTC group but less than the controls. Results were corroborated by sensory analyses which tested for color, flavor and odor. Fish fillets dipped in a solution of 1% K-sorbate plus 5 ppm CTC retained odor and flavor properties of fresh fillets better than the EDTA/CTC treated fillets after 14 days of storage.     

Effects of Phosphate in Combination with Nitrite or Maillard Reaction Products upon Warmed-Over Flavor in Precooked, Restructured Beef Chuck Roasts

The effectiveness of a phosphate compound alone in combination with other antioxidants in preventing warmed-over flavor (WOF) in precooked recombined beef roasts was investigated. Treatments without phosphate had significantly different proximate composition due to lower yields and higher cooking losses and received lower tenderness and juiciness scores from the sensory panel. WOF scores and thiobarbituric acid (TBA) values were lower (P < 0.05) for the phosphate treatments. A correlation coefficient of 0.96 was obtained between panel scores and TBA numbers. The panel threshold for WOF was 1.6 TBA value. Results indicate phosphate alone was effective in preventing WOF in vacuum packaged precooked roast beef.     

Physical and Sensory Characteristics of Low-Fat Fresh Pork Sausage Processed with Various Levels of Added Water

The acceptability of low-fat pork sausage, formulated by replacing fat with added water, was studied. Six sausage blends, consisting of three fat levels (15, 25 and 35%) and two levels of added water (3 and 13%) were stratified across two packaging treatments, chubpacks or mechanically formed patties. Increased amounts of added water in low-fat sausage resulted in cooking losses, color and textural characteristics similar to control sausage. Sensory panel ratings did not differ between sausage formulated to contain 35% fat (3% added water) and those containing 15% fat. Acceptable lower fat pork sausage may be produced with 15% fat if water is used for the replacement of fat.     

THE EFFECT OF VARIOUS LEVELS OF ADDED SODIUM CHLORIDE AND POTASSIUM CHLORIDE ON THE CHEMICAL,PHYSICAL AND SENSORY CHARACTERISTICS OF PRECOOKED,RECOMBINED BEEF CHUCK ROASTS1

Commercial beef chuck tenders were processed into recombined roasts utilizing salt or Morton's® Lite Salt (43% NaCl, 57% KCl) according to treatment (100% salt, 70% salt—30% lite salt, 30% salt—70% lite salt or 100% lite salt). Roasts were cooked to an internal temperature of 68°C. Percentages of water and protein were relatively constant across treatments and as fat percentages increased (P < 0.05) so did caloric content. As the level of lite salt increased, the percentage extractable potassium also increased. Cooking loss was not affected by treatment. Treatment 1 (100% salt) was harder and less tender (P < 0.05) than the other treatments; while juiciness, flavor and overall palatability were not affected by treatment. Results of this study suggest the feasibility of substituting lite salt for salt in these types of value added, precooked products.     

Liquid-Phase Sintering of TiC-Ni Composites

The sintering of TiC-Ni particle compacts was studied with specific attention to effects of processing conditions. Densification was progressively inhibited with the increasing additions of free carbon to the system. These results are explained on the basis of changes in the eutectic reactions in the system, reduced solubility of TiC in the Ni-rich liquid, and decreased wetting of the solid by the liquid. Presintering hydrogen heat treatment reduced the carbon content of the TiC-Ni compacts and led to reduction in sintering rates and elevated temperatures of liquid-phase formation. Wetting experiments with hydrogen-treated materials showed a time-dependent wetting angle. These results are discussed based on wetting theory and reactions predicted by the equilibrium ternary-phase diagram.     

Undergraduate Learning Portfolios for Institutional Assessment

Our objectives were to develop a model of student portfolios that simultaneously promotes student learning, provides useful outcomes assessment data, and is logistically feasible. From our pilot test of three portfolio models, we conclude that requiring students in selected courses to complete portfolio entries solves most of the logistics problems associated with a large‐scale portfolio plan. Such entries can promote learning by providing a focus for career and educational planning discussions between students and faculty academic advisors. Course faculty are probably in the best position to use the outcomes assessment data obtained from the entries.     

Effects of Feeding Elevated Levels of Monounsaturated Fats to Growing-finishing Swine on Acceptability of Low-fat Sausage

Sixty barrows and gilts were given one of five diets consisting of a control (corn and soybean meal), and four similar diets with a 10% replacement of animal fat, safflower oil, sunflower oil or canola oil. Pork trimmings, from carcasses of animals fed the five diets were used to formulate sausages at fat levels of 25 and 35% and water levels [4(% protein)+ 3% and 4(% protein)+ 11%]. Sensory panelists reported control sausages were springier than those from animal fat diets which were springier than those from all high oleate treatments. Sausages from high oleate treatments were more tender and less cohesive than the others. Sausage from canola oil treatment scored lowest flavor and palatability.     

Solubility of Oxygen in ZrC

Zirconium carbide specimens containing significant quantities of dissolved oxygen were synthesized using ZrO₂ and graphite as reactants in an atmosphere of CO. These specimens were studied by X-ray diffraction and analyzed chemically for C, O, and Zr. The data indicate that oxygen substitutes in the ZrC lattice, replacing more than 1 C atom/O atom, thus decreasing the lattice parameter. Under the conditions of the study, the reaction product is a solution of oxygen in the ZrC phase rather than a distinct oxycarbide phase.