EMULSION COATING TO EXTEND POSTHARVEST LIFE OF MANGO (MANGIFERA INDICA CV. MANILA)

A coating emulsion was prepared using maltodextrins, carboxymethylcellulose, propileneglycol and a mixture of s orbit an fatty acid esters with an HLB of 6. The emulsion was sprayed on fully mature, unripened manila mangoes, which were the stored at 15 and 25C and 80–85% R.H. At 25C it was observed that rate CO² production increased and lost in control fruits after 12 days of storage. Coated mangoes kept their rate CO² production and suffered only 8% weight loss after 21 days of storage. After storage, the coating was washed out and fruits were allowed to ripen naturally, which occurred in 3–4 days. The results obtained from this study indicate that application of the hydrophobic coating extended the postharvest storage of mangoes for at least 20 days more than uncoated fruits.     

Behavior of Multicomponent Gas Bubbles in Glass Melts

A mathematical model is proposed to study the behavior of multicomponent gas bubbles in glass melts. The effects of the melt temperature on bubble radius, trajectory, and composition were studied as a function of time, both accounting for and disregarding bubble boundary motion. It is shown that accounting for the boundary motion results in shorter refining times, smaller bubbles, and larger concentrations of the gaseous species than if this motion is disregarded. It is also shown that the bubble trajectory is almost a linear function of time and that mass transfer has a very small effect on bubble trajectory and refining times; however, it has a strong influence on the bubble radius, which, in the absence of mass transfeir, increases linearly with the temperature.     

An application of satellite-derived sea surface temperature data to the skipjack (Katsuwonus pelamis Linnaeus, 1758) and albacore tuna (Thunnus alalunga Bonaterre, 1788) fisheries in the north-east Atlantic

In April-December 1989, June 1990 and July-October (1990-92), AVHRR/NOAA scenes from the north-east Atlantic (10-50° N and 0-30° W) and Mediterranean Alboran Sea were processed. The objective was to study the relationships between the upper ocean dynamics (synoptic and mesoscale fronts and vorticity) with skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) and albacore tuna (Thunnus alalunga Bonaterre, 1788) fishing ground locations by satellite-derived sea surface temperature (SST) maps and in situ data sets. Results show an analogy between the bioecological responses of both species to the large (SST seasonal drifts) and small-scale oceanographic events (eddy fields, as a consequence of their similar physiological response to all the anomalies at sea.     

Preparation of Low Free Gossypol and High Available Lysine Cottonseed/Soybean Blends

Cottonseed/soybean blends (50/50) were ground in an Alpine pin mill with or without previous cooking in a Brady low-cost extruder. Free gossypol decreased with increasing amount of water added prior to extrusion and number of passes through the extruder. Available lysine increased with decreasing amount of added water but was unaffected by number of passes through the extruder. Type of soybean raw material utilized had no effect on free gossypol. Blends prepared from defatted cottonseed meal, however, had lower free gossypol than those made from cottonseed kernels. A blend similar to full-fat soy flour but of lower cost was prepared from unextruded 50% defatted cotton-seed meal/50% extruded soybean flakes, without added water, and ground in the Alpine mill.     

THIXOTROPY OF ORANGE CONCENTRATE AND QUINCE PUREE

Orange juice with pulp and pectins is thixotropic at soluble solids concentrations of 55 and 60 Brix in the range of temperatures from 0 to 20C and shear rate from 7.2 to 57.6 s⁻¹. Quince purée is thixotropic at soluble solids concentrations of 12.3 to 28 °Brix in the range of temperatures between 0 to 20C and shear rate from 7.2 to 57.6 s⁻¹. The thixotropic behaviour of orange juice and quince purée increases with increasing concentration and decreasing temperature and they can be described by the kinetic model proposed by Figoni and Shoemaker (1983):

The thixotropic structure of orange juice was destroyed by applying a shear rate of 57.6 s⁻¹ for 5 min, and for quince purée for 10 min. Quince purée shows a greater thixotropic character than orange juice, because it has a higher content of fiber, pulp and pectins and also because it shows a microscopic structure consisting of long particles and heterogeneous fibers.     

Optimum Measure of Cap Color in Agaricus bisporus Wild and Cultivated Strains

Cap color was characterized on a wide range of Agaricus bisporus strains. L, a and b tristimulus coordinates were tested by linear model analysis to determine color information related to each parameter. One model was retained: log(L/(100-L)) =α* H +β. Visual cap color variation was continuous and well described by log(L/(100-L)) or H parameters. In the wild, the range of color varied from white to dark brown which would enable mushroom breeding for cap color adapted to the market.     

Effect of single and multiple overloading on the residual fatigue life of a structural steel

This work was carried out to determine the effect of overload cycles on the fatigue life of a structural steel used for offshore applications. Single and multiple overloads were adopted and the corresponding fatigue crack growth retardation was evaluated. Residual stress fields were measured in the vicinity of the crack tip using an X‐ray diffraction technique and their size compared with that of the overload cyclic plastic zone. In regard to crack growth retardation, the results indicated that the extension in fatigue life increases with an increase in overload, as a consequence of the generation of higher compressive residual stress levels over a larger distance ahead of the crack tip. The effect of two equal and consecutive overloads, with the second one applied at different intervals of crack propagation from the first, was also considered. Larger intervals were shown to lead to a longer residual fatigue life.