CHEMICAL CHARACTERIZATION AND PREPARATION OF SALTED MINCES FROM BIGEYE GRUNT AND LONGFIN BONEFISH

The proximate chemical composition, amino add and fatty add profile of bigeye grunt (Brachydeuterus auritus) and longfin bonefish (Pterothrissus belloci) minces were determined. Both minces contained a low fat content. Polyunsatu‐rated fatty adds represented more than 50% of the fatty adds in bigeye grunt but in the case of longfin bonefish the percentages of saturated, mono‐, and polyunsaturated were similar. The amino add profile of minces from these species was very similar. The preparation of salted minces using different drying methods is described. The chemical and physical characteristics of raw and dried salted minces as well as cooked products were measured. Dried salted minces from these species had high water uptake and cooked products presented a low salt content (1 %). Cooked rehydrated salted minces from longfin bonefish were lighter in color than those from bigeye grunt and color values were not significantly influenced by the salt level used in the preparation.     

RHEOLOGY OF SUCROSE-CMC MODEL SOLUTION

The rheological behavior of an aqueous solution composed of 65% sucrose and 0.1% CMC was experimentally determined from -10C to 50C using a rotational viscometer equipped with coaxial cylinders. The model solution behaved as pseudoplastic fluid, represented by the power-law model. Flow behavior and consistency indices determined at -10.1, 0.5, 9.8, 19.0, 30.1 and 50. OC, showed values between 0.79 to 0.86 and 0.15 to 10.22 Pa. sⁿ, respectively. The effect of temperature on the rheological parameters was represented by Arrhenius-type relationships, with R²≥ 0.97. They were compared to the rheological behavior of a concentrated orange juice with 65° Brix and 7% pulp content. The comparison of separate rheograms for both fluids showed that the model solution can be used to represent concentrated orange juice.     

GREEN COLOR DEGRADATION of BLANCHED BROCCOLI (BRASSICA OLERACEA) DUE to ACID and MICROBIAL GROWTH

Effect of acid and microbial growth on green color degradation of blanched broccoli (Brassica oleracea) during storage at 7C was studied. When broccoli was submerged in McIlvaine's buffer at pH 3–8, color degradation accelerated as pH decreased, as expected. High Performance Liquid Chromatography (HPLC) was used to show that the color degradation was due to the conversion of chlorophyll to pheophytin only. Pheophytinization followed a first order reaction. the logarithm of the reaction rate constants were linearly correlated to the environmental pH, up to pH 7. Acids containing a benzene ring caused a faster color change than acids with a simple carbon chain due to their hydrophobicity. Microbial growth accelerated color change by producing acid and produced what appear to be holes in the surface of the broccoli, as shown by Environmental Scanning Electron Microscopy (ESEM).     

Polyphenoloxidase Activity, Polyphenols Concentration and Browning Intensity during Soursop (Annona muricata, L.) Maturation

Values for polyphenoloxidase (PPO), total phenols and ascorbic acid, browning intensity and pH in soursops (Annona muricata, L.) decreased during maturation. Optimum pH was 7.5 (fully developed immature, mature unripe and ripe fruits) or 7.0 (fully ripe fruits). High correlation was found between PPO activity and phenolic compounds. The enzymic browning of soursops occurred during maturation. The least browning intensity was in fully ripe fruits.     

Effect of Processing on Proximate Composition and Mineral Content of Sea Cucumbers (Parastichopus spp.)

The nutrient content, texture and holothurin content of two sea cucumber species were determined for fresh, dried and canned products. Fresh sea cucumber contained 89–91% moisture, 5–6% protein, 0.3% fat, 3% ash and 0.3% carbohydrate; dried sea cucumber contained 2–6% moisture, 61–70% protein, 2–3% fat, 16–24% ash, and 2–3% carbohydrate. Fresh sea cucumber contained 90 mg of holothurin per 100g of tissue. Canned sea cucumber contained moisture and protein levels similar to those generally found in marine finfish. Processing methods for canned sea cucumber resulted in a significant (P<0.01) decrease in potassium and increase in sodium. No significant differences (P<0.01) were found in the texture of canned products made from fresh-cooked, salted-cooked and cooked-dried raw material.     

False topography perception phenomena and its correction

The remote sensing data of a rugged terrain always suffer from topographic effects and, in such cases people frequently perceive valleys as ridges, and vice versa in the optical imagery of Sun-synchronous satellite. The appearance of inverse topography can be termed as false topography perception ( FTP) FTP has been observed in various satellites images such as Landsat, IRS, and SPOT The problem of FTP becomes more severe in high altitude areas of hilly terrain, such as Himalayan terrain. FTP is usually caused by the combination of various interrelated factors; among them are topographic relief, Sun elevation, the azimuth angle, viewing angle, and hatching or engraving features present on the slopes. Once satellite data of rugged terrain are acquired, then all FTP-influencing factors are fixed, except for the viewing angle of the observer. Hence, the correction of FTP becomes straightforward. There are two ways to correct satellite dala for FTP effects: ( a) rotate the image by between 135° -180° i.e changing the viewing angle of the observer; or (b) inverse the image data by making a negative of the whole image (255-image) which will bring change in the Sun' s illumination by 1807deg; The present paper discusses the FTP phenomena and its causes, and suggests methods of correction.     

Effect of zinc on the electrocrystallization of cobalt

The effects of zinc on the current efficiency, power consumption, deposit quality and contamination of cathode deposit during electrocrystallization of cobalt were studied. The presence of zinc affected current efficiency at all temperatures and the effect was intensified at lower temperature. Increase in power consumption was significant at lower temperature. The quantity of zinc in the electrodeposited cobalt invariably increased with increase in zinc concentration in the electrolyte, however, the zinc content of the deposit was significantly low at higher temperature. The tolerance limit of zinc in the electrolyte with respect to deposit quality was also greater at higher temperature. Increase in current density decreased the current efficiency, increased the power consumption and lowered the cathode contamination.     

VHF propagation characterization during atmospheric disturbances

Abstract

The propagation of a television (TV) signal is usually perturbed during periods of atmospheric disturbance such as in thunderstorms. The region under investigation here is situated in the coastal area of the Bay of Bengal and has experienced frequent thunderstorm activities. An investigation to study their effects on VHF signal propagation transmitted from Satkhira in Bangladesh and received at the Indian Statistical Institute, Calcutta, has been undertaken. The depths of the atmospheric disturbances within a 1?km range have been recorded and measured by acoustic sounder (sodar) operated continuously at the receiving station. The inset of the storm is marked by the enhanced signal level with deep fluctuations characteristic during the periods of thunderstorms.