Characterizations of high purity starches isolated from five different jackfruit cultivars

Microstructure and physicochemical properties of starches isolated from five jackfruit cultivars (M1, M5, M6, M11, and BD) were investigated. The five jackfruit cultivars could become the origin of high purity starches which could reach above 99%. The amylose content, microstructure and particle size varied significantly in five cultivars starches (p < 0.05). The five starches should be medium (BD), small (M11, M6, M5), and very small (M1) with average particle size of 12.59, 10.12–6.62 and 4.28 μm, respectively. With the lowest amylose content, the BD starch showed higher swelling power, solubility, peak viscosity, breakdown, gelatinization enthalpy and crystallinity, but lower peak, setback, pasting and gelatinization temperature compared to the other starches. Pearson's correlation analysis indicated that there were significant positive correlations between swelling power (SP) and solubility (0.90, p < 0.01) based on amylose content and particle size. In addition, peak viscosity, breakdown showed positive correlation with SP (0.86, 0.86, p < 0.01) while final viscosity, setback and pasting temperature (Ptem) showed significant negative with SP (−0.87, −0.87, −0.90, p < 0.01). The DSC results were also consistent with the results obtained from the RVA data based on amylose content and particle size. All starches showed a typical A-type X-ray diffraction pattern. The analysis of crystal structure confirmed the DSC results that starch with medium particle size but the lowest amylose content showed a lower gelatinization temperature but higher enthalpy. All results showed the amylose content, microstructure and particle size had significant effect on the physicochemical properties of the starches.