Physicochemical and functional properties of native starch from seeds of Pterocarpus santalinoides

Abstract

In order to enhance the value of the seeds of P. santalinoides, consumed like peanut seeds by certain populations of Côte d'Ivoire, studies on a few physicochemical and functional properties have been carried out on the starch extracted from these seeds. Indeed, the humidity rate, the percentage of amylose and amylopectin as well as the non-carbohydrate composition (proteins, lipids, ash) were evaluated. In addition to these parameters, the shape and size of the grains, the water absorption capacity, the clarity, the swelling and solubility power as well as the percentage of syneresis were investigated at -15 and 4 °C for 4 weeks. The results obtained indicate that the starch grains exhibited spherical shapes for some and polyhedral shapes with a smooth outline for others. Also, the average starch grain diameter was 10.30 µm. The rate of amyloidosis was 27.40% and 65.01% for amylopectin. The low humidity rate (6.72%) observed gave the starch long-lasting preservation. The non-carbohydrate composition for its part gave 0.87%. In addition, the in vitro digestibility study revealed that the starch of P. santalinoides was digestible. The recorded water absorption capacity was 117.34% with a percentage clarity that ranged from 5.84 to 0.62% transmittance in four weeks. The swelling ranged from 1.33 at 50 °C to 19.22 ge / gms at 90 °C. In contrast, the solubility was 0.50 at 50 °C and then intensified to reach 20.14% at 90 °C. These values for swelling and solubility reflect a possible use of this starch in food technology. The syneresis study indicated a value of 59.41% for storage at -15 °C compared to 52.72% at 4 °C. This study, which revealed interesting properties of the native starch of the seeds of P. santalinoides, thus suggests some areas of use of these seeds.