Chemical composition of the seed and ‘milk’ of three common bean (Phaseolus vulgaris L) varieties

摘要

Beans are a good source of nutrients and a variety of phytochemicals such as flavonoids, tannins and phytates. On the one hand, these non-nutrient phytochemicals reduce nutrient bio availability, but on the other hand they have some health benefits including reducing the risks for aging-related diseases. This study investigated the content of nutrients and non-nutrient phytochemicals in three varieties of common beans, namely red haricot, pinto and yellow kidney beans, and their corresponding milk extracts. Carbohydrates were the most abundant nutrient in the beans (63–66%), followed by proteins (21–24%), crude fiber (5–7%), crude ash (4–5%), and crude fat (2–3%). The beans were also rich in non-nutrient phytochemicals. The protein, carbohydrate and fat contents of the milk (18–26%, 63–67%, and 3–4%, respectively) did not differ much from the beans. Unlike the beans, the milk lacked crude fiber, and had greatly reduced ash (2%) and phytochemicals. Consistent with the reduction in ash, therewas a reduction in minerals; calcium, iron, zinc and magnesium in the milk. The reduction in minerals was less than the reduction of phytates, indicating that the milk may have higher bioavailability of minerals than the beans. The milk also had higherprotein digestibility. Thus, consumption of bean milk may be encouraged as an alternative way of bean consumption, especially by individuals whose greater needs are for nutrients rather than phytochemicals. The bean varieties had significant differencesin the retention of nutrients and phytochemicals, and such differences should be considered during bean milk production.