Physicochemical properties and microstructure of the pregelatinized tannia flour prepared by a simple parboiling method

Abstract

The flour of tannia tuber has the potential to be used as raw material for various flour-based food products. However, some of its functional properties are still limited, so it needs to be improved. This study aimed to determine the effect of parboiling treatment on the physicochemical properties of pregelatinized tannia flour (PTF). PTF preparation was carried out by boiling the tannia tuber slices at varying temperatures and times, before drying in an oven dryer at 70°C, milling, and sieving through a 60 mesh sieve. The native tannia flour (without parboiling) was also prepared as a control sample. The results showed that the parboiling treatment significantly improved the flour water absorption capacity (WAC) and swelling power (SP), and also it remarkably decreased the flour pasting temperature and pasting time, so it enhanced pasting characteristics of the flour. Parboiling treatment at 95oC for 10 minutes generated the fine PTF with WAC (2.76 g/g), water soluble index (6.7%), SP (9.08 g/g), water content (7.00%), amylose level (24.68%), amylopectin level (29.53%), pasting time (11 minutes), pasting temperature (68.27°C), final paste viscosity (1,773.33 cP), and type C pasting profile. Based on its characteristics, PTF is possible to be used as a partial substitute for wheat flour in the production of flour-based foods such as simulated chips, noodles, biscuits, and cakes.