Material and Compression Properties of Native and Co-Processed Breadfruit Starches

Abstract

Background: Inadequacies observed in the physicochemical properties of native starches suggest the need to co-process them with standard excipients in order to improve their material and packing properties.
Objectives: This work was therefore aimed at characterizing starch obtained from local bread fruit tree, Artocarpus atilis (Moraceae) and assessing the effects of co-processing with sodium starch glycolate (SSG) and hydroxypropylmethylcellulose (HPMC). The effect of different co-processing methods was also investigated.
Materials and Methods: Bread fruit starch (BF) was extracted and two methods of co-processing; physical mixing and kneading, were used to prepare starches with BF and either SSG or HPMC in the ratios 1:1, 1:2, 1:4 and 1:5. Flow properties and compressibility of the co-processed materials were evaluated using Hausner’s ratio, angle of repose and Carr’s compressibility index. Packing properties were determined by tapping experiment, while viscosity and solubility profiles were determined. Data were analysed with ANOVA and t-test at p≤0.05.
Results: Improved flow and compressibility of BF starch were observed on co-processing with either excipient. The angle of repose of BF (63.330) decreased to 36.260 with SSG and to 58.250 with HPMC at the ratio of 1:2. There was a significant increase (p<0.05) in the swelling index (from 1.73 to 2.67) when BF was co-processed with SSG at ratio of 1:4. Co-processing with either HPMC or SSG enhanced volume reduction of BF starch, the highest volume reduction of 0.285 was obtained at the ratio of 1:1. Solubility of the product decreased with both SSG and HPMC at all ratios. Viscosity of BF starch increased when co-processed with HPMC at all ratios except 1:2. There was no significant change in viscosity when the starch was co-processed with SSG.
Conclusion: Co-processing Breadfruit starch with either Sodium starch glycolate or HPMC yielded products with improved flow and compression properties; the properties of BF:SSG were better than BF:HPMC. The method used in the co-processing had no significant effect on the starch material properties.

Keywords: Co-processing, Bread fruit starch, Compressibility, Material properties