Pasting properties of teff, maize, and potato starches with added microcrystalline cellulose and cellulose nanofiber

Abstract

An increase in health concerns from consumers towards the use of synthetic chemicals in starchy food formulation has led to a significant preference for “clean” label starches. Hydrocolloids are organically-sourced food additives. This study utilized microcrystalline cellulose (MCC) and cellulose nanofiber (CNF), a group of cellulose-derivative hydrocolloids that have not yet been extensively in starch modification to investigate the effect of CNF (a nano-polymer) and MCC (a micro-polymer) on the pasting properties of teff, maize, and potato starches. Starch suspensions with MCC and CNF at different concentrations (0%, 0.2%, 0.5%, 2% and 5% w/w) underwent short and extended pasting cycles for 30 and 120 minutes respectively. MCC and CNF significantly increased the peak and final viscosities of the starch pastes. Hydrocolloids when added to a water-rich continuous phase form viscous networks via hydrogen bonding that increase the overall viscosity of the starch hydrocolloid system. However, a decrease in the starch gel strength was observed with an increase in MCC and CNF concentration. Hydrocolloid and leached amylose interactions limit junction zone formation which results in the formation of weaker gels. Overall, starches treated with CNF had higher paste viscosities and lower gel strength than those with MCC. This results from the nanostructure of CNF which gives it a high surface area and hydrodynamic volume to form more associations. Modified starch produced by the addition of MCC and CNF to starch is a possible “clean” replacement for chemically modified starches in the food industry because of their increased viscosity and non-gelling properties