Characterization and in vitro digestibility of non-conventional starches from guinea arrowroot and La Armuña lentils as potential food sources for special diet regimens

Abstract

Starches from guinea arrowroot (Calathea allouia) and La Armuña lentils (Lens culinaris var. La Armuña; certificate of origin La Armuña, Salamanca, Spain) were characterized and their in vitro digestibility investigated. This with the aim to compare the functional properties of starches from two different crops: Guinea arrowroot, which originated from the Amazon, and La Armuña lentils, an extremely well known species, but poorly studied as a starch source. To achieve this, proximate analysis, water activity, color parameters, microstructural analysis, X-ray diffraction, thermogravimetric analysis, rheological characterization, differential scanning calorimetry, resistant starch (RS), and in vitro digestibility assays were carried out. The study revealed that guinea arrowroot starch has some exceptional properties that ?could? be promising for the development of functional foods, especially for those suffering from obesity and diabetes. In addition, the high purity of the guinea arrowroot starch compared to the La Armuña lentil starch enabled the preparation of whiter and more thermally resistant starches that could be used in sauces, ice creams and pasteurized juices. Finally, the guinea arrowroot starch (higher amylose content, 17.97%) showed a higher percent crystallinity (25%) than the La Armuña lentil starch (lower amylose content 15.94%, and crystallinity 14%). This was attributed to the formation of an amylose-lipid complex in the guinea arrowroot starch.