Physicochemical properties and in vitro digestibility of starches from field peas grown in China

The physicochemical and in vitro digestibility properties of starches isolated from four varieties of field peas grown in China were determined. Field pea starch granules were oval, round, even though there were many irregularly shaped granules with sizes between 21.5 and 23.9 μm. Zhongwan-6 showed the highest amylose content (36.0%), whereas Baofeng-3 showed the lowest amylose content (33.2%). All starches exhibited a C-type X-ray diffraction pattern, with relative crystallinity ranging between 27.0 and 30.2%. Zhongwan-6 had the highest relative crystallinity and the value of 1047/1022 cm−1. Baofeng-3 exhibited the highest swelling power (10.30 g/g) and Cai exhibited the lowest swelling power (8.45 g/g). Ma had the highest To and Tp, but the lowest ΔH and narrowest R, whereas Zhongwan-6 showed the lowest To and Tp, but the highest ΔH. Zhongwan-6 and Ma starches showed the lowest and highest pasting viscosities. The gel of Zhongwan-6 was the hardest and Baofeng-3 was the softest. The in vitro digestibility studies showed that Baofeng-3 starch may be more effective than other starches in moderating post-prandial blood glucose levels.