RECENT ADVANCES IN PHARMACEUTICAL RHEOLOGY

Significant advances in rheology of pharmaceutical and allied materials since 1965 are covered in a review of 292 references. The subject matter is divided into considerations of powders, suspensions and suspending agents, semi-solids (creams and ointments), emulsions, suppositories and pessaries, foam aerosols and a general section. Material related to tablets, biorheology, and surface and interfacial films is not considered.     

Implication of Breeding Programs on Potato Quality

The effect of potato breeding on the tendency of tubers to bruise or discolor as well as the phenolic content of tubers was examined. A new cultivar, Lemhi Russet, was compared with two well established varieties, Katahdin and Russet Burbank. In addition, two new nematode-resistant cultivars, Hampton and Islander, were compared with a nematode-susceptible variety, Katahdin. Lemhi was found to discolor more and was higher in phenols than either Katahdin or Russet Burbank. The nematode-resistant varieties, Hampton and Islander, discolored less and were lower in phenols than Katahdin, a nematodesusceptible variety.     

Defect Characterization in and Precipitation from CaO:Yb2O3 Crystalline Solutions

The defects formed when trivalent rare earth ions are accepted into the sodium chloride structure of CaO were determined from precise measurement of lattice parameters and densities to be predominantly cation vacancies. The exsolution kinetics of Yb₂O₃ from CaO crystalline solutions were studied in situ using high-temperature X-ray methods. Kinetic plots for this reaction show that it is diffusion-controlled, at least in the initial stages. Quantitative information could not easily be extracted from the results of this study because of the appearance of a reaction intermediate. The appearance of this intermediate is rationalized by depicting the free energy-composition relations which exist at the decomposition temperatures used.     

A simulation comparison of group technology with traditional job shop manufacturing

A simulation model of an actual job shop was used to compare group technology with traditional job shop manufacturing. The experiment compared shops which had four different layouts, designed to emphasize different features of traditional job shops and group technology shops, and four distributions of demand for end items. The group technology shops exhibited superior performance in terms of average move time and average set-up time. The traditional job shops had superior performance in queue related variables (average queue length, average waiting time, work-in-process inventory, etc.). This was caused by group technology's dedication of machines. The effects of the queue related variables outweighed the effects of average move time and average set-up time: the average flow time was shorter in the traditional job shop than in the group technology shops.     

DILUTION AND SOLIDS ADULTERATION OF APPLE JUICE

The adulteration of apple juice with pear juice and corn drived syrups has been practiced in many countries. The sorbitol/sucrose ratios and the sorbitol/total sugar ratios were determined for the juices of 14 apple varieties and 3 pear varieties. A multivariate normal test was applied to develop an equation for the detection of apple juice adulteration with sugar solutions or pear juice. Adulteration of apple juice with more than 10% sugar solution or pear juice were detectable with this method.     

Properties of Frankfurters Made From Electrically Stimulated Beef

Frankfurters (3 replications of 4.54 kg meat batches) were conventionally made. Paired sides from beef were used for control (NES) and electrically stimulated (ES) meats (clods, flanks and plates). All-beef frankfurters (100% ES beef or 100% NES beef) and beef-pork frankfurters (80% ES beef-20% pork or 80% NES beef-20% pork) were made. The pork was not electrically stimulated. Proximate composition within cut of beef (plate, flank, clod) was not affected (P > 0.05) by ES. However, ES clods had (numerically) greater percentages of expressible juice loss, greater percentages of salt-soluble protein and lower percentages of juice loss during cooking than did NES clods (not statistically different). Use of ES beef alone or in combination with 20% pork did not affect external visual color, off-flavor, overall desirability or processing shrinkage of frankfurters. ES may affect certain properties (raw and cooked muscles) as measured in the laboratory, but when these ES muscles are used to make frankfurters, no real advantages or disadvantages were suggested by this study.     

EFFECT OF HIGH HYDROSTATIC PRESSURE ON SPORES OF GEOBACILLUS STEAROTHERMOPHILUS SUSPENDED IN SOYMILK

The inactivation of Geobacillus stearothermophilus spores (ATCC 7953) inoculated in soymilk was investigated using high hydrostatic pressure (550, 585 and 620 MPa) in combination with temperature (70, 80 and 90C) for selected times (2 s to 15 min). Inactivation of spores occurred at all selected treatments. Less than 10 CFU/mL of G. stearothermophilus were observed after 7 min of treatment at 620 MPa and 90C. An increase in the inactivation rate constant, at the highest pressure, was observed, resulting in a decrease in D values at all temperatures. D values were calculated as 10.6, 6.2 and 3.5 min for 70, 80 and 90C, respectively after pressurization at 620 MPa. z_p values decreased as temperature increased with values ranging from 142 to 238 MPa. The activation energy required for inactivation of G. stearothermophilus spores in soymilk, at the selected treatments, was in the range of 37.9–57.4 kJ/mol.     

INACTIVATION of E. COLI FOR FOOD PASTEURIZATION BY HIGH-STRENGTH PULSED ELECTRIC FIELDS

Pulsed electric fields of very high field strength and short duration are effective in the inactivation of E. coli. Nine log reduction in E. coli viability was achieved using a stepwise pulsed electric field treatment where E. coli suspensions were treated repeatedly in batches. It was demonstrated that high-strength pulsed electric field treatment is adequate for pasteurization of liquid foods.
A 40,000 volt pulse generator was constructed to supply high voltage electric pulses to a treatment chamber with two parallel plate stainless steel electrodes where fluid food was contained. the gap between electrodes was 0.51 cm and the chamber volume was 14 ml. Pulse electric field strength ranged from 35 to 70 kV/cm. Pulse width was selected at 2 μs. Number of pulses per treatment varied from 1 to 80.
E. coli were suspended in a simulated milk ultra-filtrate (SMUF) and treated with pulsed electric fields in a batch mode. the suspension fluid was maintained at constant temperatures of 7, 20, or 33C. Maximum temperature change occurring during each pulse was 0.3C measured by a fiber optics temperature probe. E. coli viability before and after treatment were assayed by counting colony forming units (cfu).     

INACTIVATION OF LISTERIA INNOCUA AND PSEUDOMONAS FLUORESCENS BY PULSED ELECTRIC FIELDS IN SKIM MILK: ENERGY REQUIREMENTS

Pulsed electric field energy applied over a short duration of time was effective in the inactivation of Listeria innocua and Pseudomonas fluorescens inoculated into 0.2% skim milk. Additionally, the energy consumption was reasonable for industry applications compared with the alternative of thermal pasteurization. The energy densities required to achieve three log reductions of the microorganisms were 120, 212 and 270 kJ/L for L. innocua corresponding to input voltages of 30, 35 and 40 kV, and 88, 105 and 128 kJ/L for P. fluorescens under the same input conditions. Treatment times were, respectively, 145 µs and 290 µs, and exponentially decaying wave pulses with time duration of 3 µs were selected. For L. innocua, the inactivation of viable cells was significantly different (P < 0.05) between energy inputs of 120, 212 and 270 kJ/L. Meanwhile, the inactivation of P. fluorescens exhibited significant differences (P < 0.05) between energy inputs of 88 and 128 kJ/L, but not between inputs of 105 and 128 kJ/L. These results consistently indicated that microbial inactivation in skim milk increased as the energy intensity and the treatment time increased.