An NMR pulsed field gradient study of the electrical and conventional heating of carrot

Experiments have been carried out using pulsed field gradient NMR to characterize the self-diffusion of water within samples of carrot, both uncooked and cooked by either volumetric electrical or conventional heating. The method detected the presence of structure within uncooked carrot, and the disappearance of the structure on cooking. The NMR data were fitted to two models: (i) an analytical solution for diffusion between impermeable barriers and (ii) a numerical solution to the more physically realistic situation of diffusion between permeable barriers. The barrier spacings obtained with raw carrot data using both methods (i) and (ii) were consistent with cell sizes found in carrots. The effect of cooking on the model fit was either an increase in barrier spacing (method i), or an increase in barrier permeability (method ii). There was a statistically significant difference between samples cooked electrically and conventionally, but this was much less than the difference between cooked and uncooked material.     

EFFECT OF SONIC ENERGY ON THE AIR DRYING OF APPLE AND SWEET POTATO CUBES

Cubes (2 cc) of apple and sweet potato were dried with and without sound energy in air at velocities of 5 – 20 fps and temperatures of 125 – 175°F. A stem jet or electronic whistle provided sound energy at 9,800 and 13,000 Hz with an intensity up to 135 dB. Results indicated that sonic energy had no effect on drying rate under all experimental conditions.     

EFFECTS OF LIQUID SMOKE ON LIPID OXIDATION IN A BEEF MODEL SYSTEM AND RESTRUCTURED ROASTS

Commercially available liquid smokes were added to a meat model system and to a restructured beef product to assess their ability to suppress lipid oxidation. Aqueous hickory smoke was the most effective smoke in suppressing oxidation as reflected in 2-thiobarbituric acid reactive substances (TBARS) of microsomal lipids. Phenol was not antioxidative in the model system. Addition of liquid smoke had no significant effect on "stale, cardboardy, painty" flavor or aroma of restructured beef roast slices stored at 4C. The aroma and flavor of sliced beef deteriorated over the 7-day storage regardless of liquid smoke addition. Hexanal in the control roasts increased during storage from ∼0 to >3 ppm; those containing aqueous liquid smoke contained little (< 0.5 ppm) hexanal. Smokes, but not the phenol mix, kept TBARS near day zero (0.2 mg/kg) levels through 7 days.     

Effect of TiO2 on Initial Sintering of Al2O3

Alpha alumina with additions of TiO₂ sintered more rapidly than "pure" alumina. The rate of initial sintering increased approximately exponentially with titania concentration up to a percentage beyond which the rate of sintering remained approximately constant or decreased slightly with additional titania. The concentration which produces the maximum rate of sintering is thought to be the solubility limit of TiO₂ in Al₂O₃. For alumina particles larger than about 2 μm, the kinetic process was mainly grain-boundary diffusion. With smaller particles, volume diffusion increased. The "solubility limit" increased with decreasing particle size, indicating an excess surface concentration of TiO₂. The data may be interpreted in terms of a region of enhanced diffusion at the grain boundary that increases with TiO₂ concentration. With small alumina particles, this region is large enough to become a significant portion of the volume of the particle, and the small particles appear to sinter by volume diffusion kinetics, but the diffusion coefficient corresponds to an enhanced diffusion coefficient.     

FREQUENCY OF SALMONELLA, CAMPYLOBACTER, LISTERIA AND ENTEROBACTERIACEAE DETECTION IN COMMERCIALLY COOL WATER-WASHED SHELL EGGS

The effect of cool water washing on shell egg temperature and pathogen detection was examined. Three temperature schemes were utilized in commercial dual washer systems: (1) HH = 48.9C, 48.9C; (2) HC = 48.9C, 23.9C; and (3) CC = 23.9C, 23.9C. HH eggsmaintainedthe highest surface temperature (26.25C in‐line, 20.25C off‐line and 23.25C combined, P < 0.05). The lowest temperatures were found in the CC eggs (21.25C in‐line, 17.25C off‐line and 19.25C combined). The frequency of Enterobacteriaceae detection in shell and membrane emulsions was greatest for the CC eggs (P < 0.05 for in‐line and combined). There was no difference in Enterobacteriaceae detection for the off‐line facility. Salmonella was detected in three of 384 samples from the in‐line facility. They were found in HC (2) and CC (1) shell emulsions. Two of 384 samples were positive for Campylobacter from the in‐line facility (CC). Three wash water samples were positive for Listeria in the off‐line facility (1 HC, 2 CC). No pathogens were detected in the egg contents during this study. The results of this study indicate that warm followed by cool water washing has the potential of decreasing egg temperature while maintaining surface microbiology at an acceptable level.     

Some Physical Parameters Involved in the Addition of Inorganic Phosphates to Reduced-Sodium Meat Emulsions

The effects of preblending, order of addition and the physical state of alkaline phosphates on the stability of reduced sodium chloride (0.75%) meat emulsions were determined. Preblending meat batches with reduced sodium chloride for 16 hr resulted in no significant effect upon the stability of meat emulsions, with or without the presence of alkaline phosphates. However, the addition of sodium tripolyphosphate (STPP) and tetrasodium pyrophosphate (TSPP) significantly improved emulsion stability. Neither the order of TSPP addition in relation to that of sodium chloride nor the physical state of its addition (dry or in solution) affected emulsion stability or the soluble protein level.     

Lot sizing problems with strong set-up interactions

We address the problem of coordinated replenishment of products when the products can be produced only in fixed proportion to each other. Such problems commonly arise in the manufacture of sheet/plate metal parts or die-cast parts. The problem is a variant of the well-known Joint Replenishment Problem. We call this problem the Strong Interaction Problem (SIP). After giving a mathematical formulation of the problem, we show that the general problem is NP-hard. An important variant of the problem, in which products are unique to a family, is shown to be polynomially solvable. We present several lower bounds, an exact algorithm and a heuristic for the problem. Computational testing on randomly generated problems suggests that our exact algorithm performs very well when compared with a commercially available integer programming solver. The heuristic method also gives good solutions.     

Properties of Yttrium Oxide Ceramics

The cubic structure of yttrium oxide is stable to 1800°C. in air as indicated by petrographic, X-ray, and differential thermal analyses. A change in lattice parameter of less than ±0.007 a.u. was observed on heating the oxide to 1800°C. The mean specific heat of Y₂O₃ to 1600°C. was 0.13 cal. per gm. per °C. The coefficient of linear expansion to 1400°C. was 9.3 × 10⁻⁶ in. per in. per °C. Compacts of Y₂O₃ required a temperature of 1800°C. for vitrification. In equimolecular binary mixtures heated in the powdered state at 1500°C., Y₂O₃ formed compounds with Al₂O₃ and Fe₂O₃ and solid solutions with ZrO₂ and HfO₂. Y₂O₃ did not react with CaO, MgO, or ThO₂. Crystal types and unit-cell sizes of the reaction products are included.