Studies on phenolase enzymes in prawns. Pt. 1. The distribution and physical properties of phenolases in Penaeid prawns

The distribution of phenolases in certain species of Penaeid prawns has been studied. Attempts were made to locate the regions of maximum enzyme activity in the prawns. The relative dopase activity has been examined in extracts from head, tail, shell with cuticles and muscle. The head juice and tail extracts were found to register very high order of enzyme activity. Metapenaeus affinis, Metapenaeus monoceros and Penaeus indicus record comparatively higher enzyme activity than Parapenaeopsis stylifera and Metapenaeus dobsoni, no definite relationship has been found between the relative activity of the enzyme and size grade at least in one species examined. Experiments were done to determine the pH optima of the enzyme and the influence of pH on its deactivation. Exposure to higher temperatures up to 55°c was shown to activate the crude enzyme considerably. The possible implications of the observations have been discussed.

Effect of frozen storage on the physical properties of corrugated fibre-board master cartons and waxed duplex cartons

Deteriorative changes in physical properties of corrugated fibre-board master cartons and waxed duplex cartons during frozen storage under commercial conditions were studied. Such changes due to prolonged exposure of these boards to moisture in the laboratory, effect of repeated wax-coating on the water resisting capacity of the boards and protection provided by increasing wax contents in the boards against water absorption and consequent deterioration in physical properties are reported.

Some physical properties of the muscle lipid of two freshwater teleosts, Ophicephalus striatus (Bloch.) and Clarias batrachus (Linn.)

Various physical properties (viscosity, fluidity, surface tension and specific gravity) have been determined for muscle lipids of Ophicephalus striatus and Clarias batrachus. Results are presented and the methods used in determination noted. The physical parameters studied are found to be species-specific.

Mineralogical variations and physical properties of deep sea sediments, northwest Arabian Sea

Charles Darwin the research ship undertook an Oceanographic Cruise in 1986, CD 86/17 of the North Arabian Sea. Sediment cores were collected between 15° and 25°N. In this study sediment cores collected from deep Indus and Oman basins (CD 1715, CD 1730, CD 1738) have been analyzed for mineralogy, water content and porosity. In general, the cores are mainly composed of clay to silt sized terrigenous and biogenic constituents. Quartz, Chlorite and Illite are the common minerals of Arabian Sea sediments. Porosity determined by water content of sediments has been correlated with quartz/chlorite and quartz/illite peak ratios to show a relationship between mineral composition and physical properties.