Physicochemical properties and in vitro digestive properties of amylose and amylopectin isolated from tigernut (Cyperus esculentus L.) starch

This work systematically analyzed the microstructure and physicochemical properties of amylose (AM) and amylopectin (AP) isolated from tigernut starch (TS). The yields of AM and AP were 66.50% and 72.80%, respectively. Scanning electron micrographs showed that AM and AP were, structurally, very different from TS. Granules of AM and AP had rough surfaces and irregular shapes. AM had a V-type crystalline structure, while AP was believed to be amorphous. These structural differences influence their functional properties. AM had superior thermal stability and swelling characteristics, as well as high resistance to digestion. Meanwhile, AM gel had superior springiness and high chewability. While AP had good solubility and its paste was a liquid showing high fluidity. Collectively, these results are expected to provide new information valuable for future developments in the industrial application of AM and AP derived from TS.