Evidence for Vacancy Injection during the Oxidation of Iron

Iron discs have been oxidised at 890 ℃ on one side only, with the other side protected by an inert gas. The scale-metal adhesion was very good. Initially, scale-metal adhesion was maintained by the scale relaxing towards the metal but after a time which depended upon the initial metal thickness, oxide relaxation ceased and the inert face moved towards the scale-metal interface. When the face which was normally inert was covered with a non-growing oxide layer, the scale-metal adhesion deteriorated. The results show that vacancies which were produced by oxidation were annihilated within the metal, that the inert face played a part and that the scale-metal interface is not a good sink for vacancies.     

DEEP-FAT FRYING OF YAM SLICES: OPTIMIZATION OF PROCESSING CONDITIONS USING RESPONSE SURFACE METHODOLOGY

The deep-fat frying of yam slices was investigated with the aim of optimizing the processing conditions. During frying, frying temperature, initial dry matter and frying time have a significant effect on moisture loss and oil uptake. Response surface methodology central composite rotatable design was used to study the effects of the independent variables on quality attributes of yam chips. Breaking force, oil content, moisture content and color parameters were determined. Statistical analysis with response surface regression showed that breaking force, oil and moisture contents and color parameters ( L* and a* ) were significantly ( P <  0.05) correlated with frying temperature, initial dry matter and frying time. The optimum conditions were a frying temperature of 175–180C, using tubers of initial dry matter of 0.179–0.214 kg/kg with a frying time of 4–5 min. It was suggested that the regression equation can be used to estimate the dependent variables for fried yam chips except b* (yellowness) parameter.

PRACTICAL APPLICATIONS

It is expected that the optimized processing conditions highlighted in this work will be useful in obtaining fried yam chips of acceptable quality attributes. This optimized condition would be a good prospect for commercialization in small-scale industries.     

Detection of Enocyanin in Cranberry Juice Cocktail by HPLC Anthocyanin Profile

Adulteration of cranberry juice products by enocyanin, a colorant from grapes, was detected by comparing HPLC chromatographic profiles of cranberry anthocyanins with those from enocyanin. Two peaks present in all enocyanin samples but not in cranberries were identified as delphinidin-3-glucoside and petunidin-3-glucoside. A group of unidentified pigments which eluted after the cranberry pigments was also present in enocyanin. It was possible by considering differences in the chromatograms to detect replacement of 5% or more of the expected amount of cranberry juice in cranberry juice cocktail by a solution of enocyanin. A CG-50 column was used to concentrate the pigments followed by chromatography on a polymer styrene column at pH 1.6. The method gives reliable results even on samples 18 months of age.     

A 'Mouth-feel Wheel': terminology for communicating the mouth-feel characteristics of red wine

A hierarchically structured vocabulary of mouth-feel sensations elicited by red wines has been produced. Represented as a wheel, this structured vocabulary should assist tasters in their interpretation and use of terminology relating to 'in mouth' sensations produced by red wines. These terms and their definitions were generated by consulting the opinions of experienced wine tasters following exposure to an extensive range of commercial red wines. Logical relationships among the derived terms were formulated by analysis of 'sorting data' provided by a combined group of experienced winemakers and wine-tasters.     

Phase Relationships in the System Zirconia—Ceria

The phase relationships in the system zirconia-ceria were investigated by X-ray diffraction and dilatometric methods. The specimens were prepared by mixing and compacting the oxide powders and firing at 2000°C. At 2000°C. zirconia and ceria are miscible in each other from about 24 to 100 mole % ceria. The range of solid solubility decreases markedly with temperature, so that near 1000°C. the solubility of zirconia in ceria is only about 10 mole %. The addition of 0 to 1.5 mole % ceria lowers the temperature at which zirconia transforms from the tetragonal to the monoclinic form. Near 15%, therefore, this temperature is below room temperature and zirconia is stabilized. On the basis of these results, a tentative phase diagram of the system zirconia-ceria is presented. Experiments also have been conducted with zirconia containing 13.8 mole % magnesia (stabilized zirconia). In this case the solubility between stabilized zirconia and ceria is complete at high temperature (2000°C.). At lower temperature, however, the solid solution breaks down and a two-phase region appears in the center of the diagram.     

QUANTITATIVE METHODS FOR ANTHOCYANINS

SUMMARY –A qualitative technique for the determination of the individual flavonol pigments of cranberries was developed, based on cellulose thin-layer chromatography. The method was such that it was suitable for quantitative use by removing the pigment spots and measurement of the selected pigments by spectrophotometry. A quantitative technique for total flavonols, expressed as quercetin, based on spectrophotometry at 374 nm was developed. Total flavonols and total anthocyanins can be determined on the same extract.