Protein content was used as an indicator of environmental conditions for a study on varietal and environmental variation in proximate composition, minerals, amino acids and certain antinutrients of field peas. Four field pea varieties, each with three levels of protein content, were selected. Crude protein content overall ranged from 20.2 to 26.7%. Analysis of variance showed that both variety and environmental conditions had a significant effect on starch, acid detergent fibre (ADF), neutral detergent fibre (NDF) and fat content, but ash content was only affected by variety. Significant varietal and environmental differences in potassium (K), manganese (Mn) and phosphorus (P) were noted. Calcium (Ca) and copper (Cu) showed significant varietal differences, while iron (Fe), magnesium (Mg) and zinc (Zn) had significant environmental differences. Environmental conditions showed significant effects on alanine, glycine, isoleucine, lysine and threonine content. Variety had a significant effect on sucrose, raffinose and phytic acid content, whereas environmental conditions had an influence on trypsin inhibitor activity (TIA). The major pea components protein and starch were inversely correlated. ADF, NDF, Fe, Mg, Zn and the amino acid arginine were positively correlated with protein content. The amino acids glycine, histidine, isoleucine, lysine and threonine were negatively correlated with protein content. It was found that tryptophan was the most deficient amino acid and the sulphur-containing amino acids were the second limiting amino acids in peas. Raffinose was positively correlated with sucrose but negatively correlated with verbascose. There were significant correlations between mineral contents and some of the proximate components.

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A Mattson bean cooker apparatus was modified to electronically register individual cooked seeds by automatically recording the time taken for each plunger to drop. Contact switches, interfaced with a computer via a digital input/output board, were activated when individual plungers dropped through the cooked seeds. It was found that at the time when 80% of the seeds had been penetrated the Mattson cooker method agreed with a tactile method for determining cooking times for yellow peas (Pisum sativum), lentils (Lens culinaris), chickpeas (Cicer arietinum) and navy beans (Phaseolus vulgaris). Compared with the tactile method, the automated Mattson cooker method was more objective, much easier to carry out and more resource-efficient. The automated Mattson cooker could provide plant breeders and the pulse industry with a reference testing method for evaluating the cookability of pulses.

The relationship between the physicochemical and cooking properties of yellow peas was examined in this study. A positive correlation was found between seed weight and water hydration capacity. The Peleg model, which was modified, could be used to describe the water absorption characteristics of peas and could be used to predict the rate of water absorption in the initial water absorption period. Cooking time could be measured objectively using the Mattson cooker. Cooking time was found to decrease with an increase in water hydration capacity. Hardness of cooked peas, measured using a texture analyser, was negatively correlated with both seed weight and water hydration capacity. Seed coats had a significant effect on water hydration and cooking quality of peas. Peas with relatively thin seed coats exhibited higher water hydration capacity, shorter cooking times and softer texture after cooking. The effects of soaking and cooking on trypsin inhibitor activity (TIA) and oligosaccharide levels in peas were also studied. Cooking was more effective than soaking in reducing TIA levels and oligosaccharides (raffinose, stachyose and verbascose) in peas.

Whole seed neal~infrared (NIR) analyzers are capable of high, speed compositional analysis of oilseed commodities. This study compared the PerCon Inframatic 8144 (Perten Instruments, North America Inc., Ren~ NV), the Tecator Infratec 1225 (Tecator AB, Hoganas, Sweden) and the NIR-Systems 6500 (NIR Systems, Inc, Silver Spring, MD) analyzers for measurement of oil, protein, chlorophyll and glucosinolates in intact canola seed of composite samples from the Grain Research Laboratory's (Winnipeg, Manitoba, Canada) 8nnual Western Canada Harvest Surveys (1985-1989) for assembly of calibration and prediction sets. No significant differences were found between the three instruments for oil [standard error of prediction (SEP 0.43-0.55%)], protein (SEP 0.35-0.42%) and gheosinolates (SEP 2.4-3.8 mM/g). Neither the Tecator nor the PerCon instruments were effective for determining chlorophylL By combining oil content and fatty acid composition data to give an estimate of the total level of each fatty acid in the sample, high correlations were obtained for total saturates, linolenic acid, and linoleic acid although the RPD (ratio of the S.E. of prediction to the S.D. of the original data) values were not high enough to enable routine use of the method to predict results.