Abstract: Kidney bean (Phaseolus vulgaris L.) is a featured crop grown in Qianjiang district, southeast Chongqing, China. The plant is commercially exploited due to its pleasant sensory characteristics and plentiful nutrients. In the present study, the chemical composition of Qianjiang grown kidney beans were determined. Moreover, the digestion rate of carbonhydrates from Qianjiang grown kidney beans was also explored by Englyst method. The results indicated that Qianjiang grown kidney beans contained protein (23.08 ± 0.97)%, starch (43.44 ± 0.69)%, crude fat (2.72 ± 0.09)%, crude fiber (3.90 ± 0.04)%, ash (3.19 ± 0.06)%, reducing sugar (1.38 ± 0.03)% and non-reducing sugar (0.29 ± 0.05)%. Meanwhile, high content of potassium and magnesium as well as low content of sodium were observed. The essential amino acid index (EAAI) was 0.87 and the ratio coefficient of amino acids (RC) was 0.91. These results suggest that kidney bean is a high-quality food source, and rich in slowly digestible starch (SDS) ((41.46 ± 0.64)%, relative to dry basic starch). Heat gelatinization can result in a reduction in the SDS content.

Key words: Qianjiang grown kidney bean, nutritional quality, slowly digestible starch (SDS)