Evaluation of the effect of pretreatment and preservation on macro- and microelements retention in flageolet (Phaseolus vulgaris L.) bean seeds.

BACKGROUND: Legume seeds, including beans, are a good source of mineral constituents. The level of these compounds depends among other factors, on the species, cultivar and the methods of processing applied. However, there are no studies in the literature which deal with the content of mineral constituents in physiologically immature bean seeds.

MATERIAL AND METHODS: The aim of this study was to evaluate the retention of ash and 13 mineral constituents in immature seeds of three bean cultivars. The investigation included raw, blanched and cooked seeds and three products prepared for consumption after 12-month storage: a frozen product obtained using the traditional method (blanching-freezing-frozen storage-cooking); a frozen product obtained using the modified method (cooking-freezing-frozen storage-defrosting and heating in a microwave oven); and a sterilized canned product.

RESULTS: The application of technological processes; the storage of frozen and sterilized products; and the preparation of frozen products for consumption had an effect on minerals content in finished products. The frozen product obtained using the modified method retained greater amounts of the investigated elements (apart from calcium, lead and cadmium) than the traditional frozen product. Canned bean seeds retained less ash, phosphorus, potassium, calcium, magnesium, sodium and iron than the products of the two ways of freezing, while the retention of the remaining constituents depended on the cultivar.

CONCLUSIONS: Modified method of freezing of immature bean seeds resulted in greater retention of the investigated components in products prepared for consumption than the traditional method of freezing or canning.