Gelatinization and Retrogradation Characteristics of Hydroxypropylated and Cross-linked Rices

Chemically modified rices were prepared by treating with propylene oxide and epichlorohydrin. Gelatinization and retrogradation characteristics of these modified rices were investigated by using DSC and amylograph. Hydroxypropylation of rice caused an extreme decrease in gelatinization temperature from 62°C to 50°C and reduced the retrogradation rate of cooked rice. In rice treated by both hydroxypropylation and cross-linking the retrogradation was reduced more than for hydroxypropylated rice.     

TEM microstructure of mechanically alloyed Ti-12Mg powders

The microstructures of mechanical alloyed（MA） Ti-12%Mg alloy powders were examined using a high resolution TEM （HRTEM）. The effect of MA atmospheres such as argon gas and liquid isopropyl alcohol on the resultant microstructure was investigated. Both the MA powders form a homogeneous Ti-Mg solid solution, but the oxidation behavior is distinguished. The phase change was studied as a function of milling conditions and annealing temperatures.     

Potential of Near Infrared Reflectance (NIR) Spectroscopy for Estimating Nutrient Content of Dehydrated Vegetables

A near infrared reflectance (NIR) spectrophotometric procedure was evaluated for potential use in assaying nutrient contents of vegetables. Dried ground samples of cauliflower, broccoli, Brussels sprouts, spinach, asparagus, peas, green beans, and squash were analyzed chemically for crude protein, crude fat, ash, and neutral detergent fiber (NDF) and then scanned to develop NIR prediction equations. For the 75 calibration foods samples, the respective correlation coefficients between actual and NIR predicted values of these food components were 0.97, 0.77, 0.91, 0.81. Predictions for 26 unknown samples, which included cabbage, carrots, chard, corn, onions and rhubarb, were based on NIR equations developed from the first 75 samples. The resultant correlations were 0.95, 0.49, 0.85, and 0.78, respectively, for crude protein, crude fat, ash and NDF. NIR prediction detected incorrect chemical values of crude protein in several samples.     

Increased Aflatoxin Production by Aspergillus parasiticus Under Conditions of Cycling Temperatures

The effects of cycling temperatures (5°C for 12 hr and 25°C for 12 hr) on aflatoxin production by Aspergillus parasiticus NRRL 2999 in yeast extract sucrose (YES) medium were studied. Cycling temperatures, after preincubation at 25°C for various times, resulted in more aflatoxin B₁, G₁, and total aflatoxin production than did constant incubation at either 25°C, which is generally considered to be the optimum for aflatoxin production, or 15°C, which is the same total thermal input as the 5-25°C temperature cycling. With increased preincubation time at 25°C, toxin production increased and the lag phase of growth was shortened or not evident. Cultures that were preincubated at 25°C for 1, 2, and 3 days prior to onset of temperature cycling showed the greatest increase in maximum aflatoxin production over the 25°C and 15°C constant temperatures. Cultures that were not preincubated at 25°C but subjected to constantly fluctuating temperatures produced maximum amounts of aflatoxin equivalent to cultures incubated at a constant 25°C. The maximum aflatoxin production at all temperatures studied occurred during the late log phase of growth and at pH minimums. Aflatoxins were found in higher concentrations in the broth than the mycelia under temperature cycling conditions, at 15°C, and at 25°C during the first 21 days of incubation, whereas greater amounts of toxin were retained in mycelium at 25°C in the later incubation period (28-42 days).     

Carbonising of Woollen Fabric

Investigations on the carbonising of wool are reviewed. Anomalous results have been obtained by a number of workers. The moisture content of wool material as it enters the dryer after the acid treatment can greatly affect the extent of damage. There are arguments in favour of carbonising at different points in the processing sequence. These are considered in detail, and form the basis of the work reported in Part II.