Abstract
To evaluate the bioavailability of β-carotene in foods, we examined the effects of the drying process for spinach on retinol accumulation in rats. We prepared 4 types of dried spinach powders (hot-air dried powder, maximum particle size 1.0mm; vacuum dehydrated powder, maximum particle size 1.0mm; freeze and vacuum dehydrated powder, maximum particle size 1.0mm; hot-air dried powder, maximum particle size 0.5mm.), and individually administrated the powders to SD rats. The retinol accumulation rate of 2 vacuum dehydrated powders (freeze or not) were about 1.3 or 1.5-fold higher than that of hot-air dried powder (1.0mm). These findings suggest that retinol accumulation is affected by the drying process for spinach. We suppose that the differences are caused by the rehydration and the digestibility of dried powder in the digestive organ.
