Physicochemical Characterization of Starch from Unripe Artocarpus heterophyllus Lam Pulp as a Low-Cost Starch Source for Oilfield Applications

Starches serve as vital raw materials in many industrial applications especially in food, textile, pharmaceutical and petroleum industries. In petroleum industry, chemically modified starches are used in water based drilling mud to enhance fluid loss and viscosity in the formation during drilling. Most starches used for these applications are obtained from food sources such as corn, potato and cassava and this affects the overall production cost. Artocarpus heterophyllus Lam (AHL) is a tropical tree with large bulb (fruit) containing pulp and seed. In Nigeria, this tree grows in the wild or homes but its fruit is not seen as a food source and thus allowed to waste. Starch was extracted from the pulp of unripe but matured AHL using wet milling method, and the extracted starch was examined for its proximate composition and physicochemical properties. Starch extraction from the unripe pulp gave a starch yield of 44.12±1.13% and the physicochemical characterization shows that the starch has high amylose content (24.09±0.11%), water absorption capacity (116±0.18%), gelatinization temperature (71°C) and the swelling power increases with increase in temperature. The thermal behavior of the starch studied with differential scanning calorimeter (DSC) demonstrated a distinguished endothermic peak with distinct onset, peak and conclusion temperatures. The scanning electron microscope (SEM) result showed that the starch granules are small sized and aggregate together with high tendency of forming network of granules. The results obtained from the physicochemical characterization of unripe AHL pulp starch shows that it has high potential for oilfield applications.