Influences of Different Soil Types for Azuki Planting on the Organic Composition in the Beans

Abstract

In the previous paper, the present authors reported the influences exerted by different soil types for Azuki planting on the inorganic composition in beans (cv. Erimo-Shouzu) in Tokachi region of Hokkaido. This study dealt with the influences exerted by different soil types on the organic composition of the beans, using the same materials as the previous paper. The results obtained were summarized as follows;
1) The content of crude fat and oil was higher in the beans produced from brown volcanic soils and black volcanic soils, compared with the beans produced from alluvial soils.
2) Seven kinds of sugars, namely, fructose, glucose, sucrose, gentiobiose, raffinose, stachyose and verbascose were identified in the Azuki beans by means of thin layer chromatography. The total sugar content was lower in the beans produced from black volcanic soils and peat soils, compared with those produced from alluvial soils and brown volcanic soils.
3) The starch content was higher in the beans produced from alluvial soils, however, there was no difference among the beans produced from other soil types.
4) The soluble nitrogen content was less than 1% of the total nitrogen. The protein content was lower in the beans produced from alluvial soils, compared with those produced other soil types.
5) From above data, we conclude that the organic composition in Azuki beans, as well as their inorganic composition, was affected by the different soil types used for planting.