Assessing the Assessments: Improving Methodologies for Impact Assessment in Transboundary Watercourses

Transboundary impact assessment (TIA) has become an important environmental management tool, particularly where a project may have transboundary impacts. With the growing practice of TIA, it becomes important to consider the accuracy of the transboundary impact assessments that are being conducted. If TIA is a planning tool designed to provide a basis for making an informed decision, does it actually provide the necessary information? This paper summarizes lessons learned in pilot testing a methodology to assess the accuracy of TIAs.     

Effect of Temperature on Collagen Extractability and Kramer Shear Force of Restructured Beef

Collagen extractability and Kramer shear force were measured for raw and heated restructured beef products made with trimmed (epimysium removed) and untrimmed clods (triceps brachii, infraspinatus, and supraspinatus). Collagen extractability was significantly (p < 0.001) higher for untrimmed samples heated at 50°C than for trimmed samples. Kramer shear forces were significantly higher (p < 0.01) for untrimmed than trimmed when raw or heated at 35°C, 45°C, WC, and 55°C. Collagen extractabilities showed no distinct changes with temperature for trimmed samples. Collagen extractability of untrimmed samples increased then decreased as heating temperature increased. Kramer shear forces decreased between 55°C and 60°C for both trimmed and untrimmed samples.     

Double Direct Shear Test for Potato Texture

A double direct shear device was developed to examine shear strength parameters of mealy and waxy potatoes. Cohesion and coefficients of friction were measured at peak and ultimate shear with two machine speeds. Coefficients of friction of potato types did not differ. However, mealy potatoes displayed greater cohesion than waxy potatoes and a greater difference between peak and ultimate cohesion values. Stem ends of mealy potatoes were the most firm. Shear strength was related to strain rate.     

Phytate × Calcium/Zinc Molar Ratios: Are They Predictive of Zinc Bioavailability?

The utility of the phytate/zinc and phytate × calcium/zinc molar ratios for predicting zinc bioavailability from processed soybean foods was investigated. Weight gain and bone zinc accumulation in rats fed various soy protein products were plotted against the calculated molar ratios. The phytate × calcium/zinc ratio was a better predictor of zinc bioavailability in similarly processed products than was the phytate/ zinc ratio. However, in some cases the phytate × calcium/zinc ratio was not effective since some processing procedures apparently altered binding of phytic acid to minerals and other food components.     

EFFECT OF CONTROLLED CONDITIONS DURING DEEP BED FERMENTATION AND DRYING ON ROOIBOS TEA (ASPALATHUS LINEARIS) QUALITY

Small-scale processing of rooibos tea was achieved under controlled conditions of bruising, fermentation and drying. The effects of aeration, fermentation time, fermentation temperature and drying method on rooibos quality were investigated, using plant material that was stored at −30C after harvesting and comminution. Adequate aeration significantly improved rooibos quality. Overall quality improved significantly with increasing fermentation time, mainly due to an improvement in taste. Fermentation temperature did not affect quality significantly. Freezing of the plant material before processing was detrimental to quality, resulting in some instances in a Standard grade infusion with a grassy aroma and an astringent taste that is indicative of under-fermented rooibos. Choice grade rooibos with a flat, "thin" taste and a poorly developed sweet aroma was obtained in a few cases. The drying method (deep bed versus thin layer) did not affect overall quality significantly.     

Apparent shear viscosity of native egg white

Temperature and shear dependency of the apparent viscosity of the thick and thin portions of egg white from fresh hen eggs, in their native state was investigated. The viscosity of the egg white was determined in the temperature range of 5–30°C and the shear rate range 34–600 sec^-1. The viscosity of both the thick and thin portions of the egg white decreased with increase in temperature. The thin portion showed no decrease in viscosity with shearing time at constant shear rates while the viscosity of the thick portion decreased within the first 6 min of shearing and then remained constant. The rate of decrease in viscosity with shearing time was more at higher temperatures. At 20°C and a shear rate of 34.2 sec^-1, the equilibrium-apparent viscosity of the thick portion was 160 cp, approximately forty times greater than that of the thin portion (4cp). This difference in viscometric properties may be due to the presence, in the thick portion, of high molecular weight complexes which are disrupted under shearing.