MATERIALS&METHODSA method has been developed to measure the texture of raw and soaked cowpeas (Vigna unguicuiata) using a wedge-type blade mounted in an Instron testing machine to cut across the cotyledons. It was found that soaking raw cowpeas in water prior to cooking produced a softer bean and the decrease in hardness was proportional to the soaking time. Texture of cooked beans could be predicted from the texture of the corresponding soaked bean. The influence of cooking temperature and time on bean texture was studied using the shear-compression cell of -the Texture Test System and the Ottawa Texture Measuring System cell with a wire extrusion grid. It was found that the rate of cooking relative to texture followed first order kinetics. Scanning electron microscopy was used to study changes in microstructure during the cooking process. The major effect observed was a breakdown of the middle lamella; cell walls remained intact.

Techniques used to measure the eggshell strength and associated parameters are reviewed. Much of the early research was based on crude instruments that did not adequately control test conditions, particularly the rate of applying force to the shell. Better instruments have been used recently to obtain precise readings. A significant advance has been the development of techniques to describe the physical properties of the shell material. This is potentially more meaningful than the empirical comparisons of egg behaviour, and is leading to a better understanding of the shell fracture mechanism. Two practical tests are currently available to the biologist for non‐destructive measurements: specific gravity of the egg and shell deformation under a non‐destructive force. Both predict ‐ with acceptable precision ‐ the shell fracture force. Eggshell strength has been investigated for over 70 years, but an ideal test method has yet to be found, and research is still required.

A review of the methods used to measure meat texture indicates considerable confusion in terminology, test conditions, and interpretation of the readings that makes evaluation of the results a complex task. Standardization of the methods appears premature and until this is accomplished, the applied methodology must be reported fully. Errors due to instrument design can no longer be accepted since modern instruments that overcome this are readily available. A common error in terminology or interpretation is the use of the term shear to describe the rupture imposed on meat samples in popular tests. It is shown that meat generally ruptures in tension which is also the case during mastication; this explains why empirical measurements often relate to sensory readings. It is concluded that there is room for improvement in existing methods, particularly in the interpretation of the results using common sense, close observation and theoretical analysis.

Storage under unfavorable conditions is known to adversely affect the cooking quality of legumes by leading to the "hard--to-cook" defect. This phenomenon was studied by examining the texture and microstructure of Ghanainan cowpeas, variety "Adua ayera," following storage at 0°C 80% RH; 21°C 35% RH and 29'C, 85% RH for up to 12 months. Scanning electron microscopy revealed no changes in raw beans after 12 months storage but soaking in water produced a loss of some protein bodies in seeds stored at 29°C. Texture measurements indicated that the rate of cooking of the beans decreased with increasing storage temperature and that storage at 29°C introduced the formation of the "hard-to-cook" defect. The microstructure of the defective beans showed an incomplete breakdown of the middle lamella which may partially explain this defect.

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