Shrinkage in canned mushrooms treated with xanthan gum as a pre-blanch soak treatment

Vacuum treating freshly harvested mushrooms with a 1% xanthan gum solution (XVT) containing 0.25% sodium metabisulphite (SMBS) prior to blanching and canning gave a lower shrinkage value than for corresponding samples vacuum treated with water, or those canned by conventional means or the 3S process. A combination of chill storage (2-4°C) for 1-3 days coupled with 1% XVT was found best and gave even lower total canning losses (chill storage loss + blanch loss + retort loss); these were 6% lower than in the 3S process and 11.5% lower than for mushrooms canned by the conventional procedure. These data suggest that xanthan gum has considerable potential for reducing shrinkage in canned mushrooms. The XVT canned samples had an excellent colour and an acceptable texture. Further storage tests over a 9 month period with xanthan treated canned mushrooms showed than an SMBS level of 0.1% in the pre-blanch soak solution maintained an excellent colour in the canned product. No in-can mushroom shrinkage took place during the 9 month storage test.     

Development of a Colorimetric, Second Generation Nucleic Acid Hybridization Method For Detection of Salmonella in Foods and a Comparison With Conventional Culture Procedure

A new, highly specific colorimetric DNA hybridization method (cDNAH) for detection of Salmonella in foods was developed. It detected 355/362 strains representing 206/213 serovars of Salmonella, and showed no cross-reactivity with 32 different non-Salmonella species, including a variety of Enterobacter and Citrobacter species. The cDNAH method was compared with the BAM/AOAC culture method in two studies: (1) with 20 different inoculated and uninoculated foods overall agreement between the two methods was 99%. (2) with naturally contaminated foods at two independent sites agreement with culture was 99.8% where 9/404 samples were positive for Salmonella.     

Trade Effluent Control: Prospects for the 1990s

The proposed privatization of the ten regional water authorities together with the accompanying reorganization of water pollution control responsibilities between the new National Rivers Authority and Her Majesty's Pollution Inspectorate, as well as the ever tightening environmental standards for the aquatic environment emanating from Brussels and from general environmental pressures, means that dischargers of industrial effluents can expect major changes both in the cost of disposing of their effluents and in terms of the legislative controls which will restrict their content.
The paper examines the various factors which will influence the management of trade effluents in the 1990s and endeavours to give some indication of what the future holds both in terms of disposal costs and environmental regulation from the point of view of the discharger.     

Kinetics and Mechanisms of High-Temperature Creep in Silicon Carbide: III, Sintered α-Silicon Carbide

The operative and controlling mechanisms of steady-state creep in sintered α-SiC have been determined both from kinetic data within the ranges of temperature and constant compressive stress of 1670 to 2073 K and 138 to 414 MPa, respectively, and from the results of extensive TEM and other analytical analyses. Dislocations in glide bands, B₄C precipitates, and the interaction of these two entities were the dominant microstructural features of the crept material. The stress exponent increased from 1.44 to 1.71 with temperature; it was not a function of stress at a given temperature. The curves of In ɛ vs 1/ T showed a change in slope at 1920 ± 20 K. The respective activation energies below and above this temperature interval were 338 to 434 and 802 to 914 kJ/mol. A synthesis of all this information leads to the conclusion that the controlling creep mechanism at low temperatures is grain-boundary sliding accommodated by grain-boundary self-diffusion; at high temperatures, the controlling mechanism becomes grain-boundary sliding accommodated by lattice diffusion. The parallel mechanism of dislocation glide contributes increasingly to the total strain as the number/volume of precipitates declines as a result of progressive coalescence with increasing temperature.     

Selenium Content of Chicken Meat as Affected by Cooking

Twelve dressed chickens of the same flock were quartered and prepared by four cooking treatments: microwaving, conventional oven cooking, broiling, and panfrying. The mean value of selenium (fluorometic method) in raw chicken was 0.38 μg/g dry weight, with no significant differences between white and dark meat. There was insignificant loss of selenium due to cooking. Cooked chicken breast had a significantly higher level of dialysable selenium compounds (MW < 2000 daltons) than raw chicken.     

VISCOSITY AND PICKUP OF A FISH AND CHIP BATTER: DETERMINANTS OF VARIATION

Relationship between viscosity and pickup (percent coating weight) of a fish and chip batter was examined with respect to the following parameters: (1) protein content of wheat flour used, (2) batter temperature, and (3) batter holding time. Results obtained indicated that a statistically significant (P 0.001) correlation existed between viscosity and: (1) wheat flour protein content (r= 0.96), (2) percent pickup (r= 0.90), and (3) batter temperature (r=?0.62). Results also indicated that protein content of the wheat flour ingredient and batter temperature may be used as indicators of batter viscosity and, subsequently, percent pickup in the operation of battering portion-controlled codfish fillets.     

FIELDS FOR RESEARCH IN DROP FORGING

This article is somewhat different from most of those appearing in this journal. Usually the papers printed here describe the result or an investigation into some aspect of production engineering, or at the least they describe work in progress. The present article will do neither of these things, but is intended to introduce some of the problems which would repay scientific study in one particular industry. The problems discussed and the manner of describing them are purely personal and, hence, I shall be writing in the first person singular and not in the third person normally adopted by scientists writing reports.