Abstract:

【Objective】 Thirty-three Chinese chestnut varieties collected from three variety groups were used to test starch pasting properties, starch granule size and starch content to analyze the relationship between them and make cluster analysis according to amylose content and peak viscosity among these varieties. 【Method】 Pasting characteristics of defatted chestnut starches were determined using Rapid Viscosity Analyzer (RVA); Starch granule size was determined using S3500 Laser Granularity Analyzer; All statistical procedures were performed according to SPSS. 【Result】 Differences were found among RVA eigenvalues in different starch of chestnut. The average of peak viscosity, through viscosity, final viscosity and breakdown in north variety group (NVG) were higher than that of others; the setback, the peak time and the pasting temperature were significantly lower than that of mid-type variety group (MVG) and south variety group (SVG). There were differences between starch and amylose content among different chestnut varieties. The starch content of NVG was significantly lower than that of MVG and SVG while the amylose content of SVG was the highest. Significant differences were found in starch granule size among different chestnut varieties’ starch. The granule size has very close relationship with variety and with obvious character of location distributing. The average granule size has a significant correlation with peak viscosity, while other eigenvalues were based on the varieties to appear correlations with granule size. 【Conclusion】 The cluster analysis divided the 33 varieties to 4 parts: NVG were featured with low amylose content and high peak viscosity; SVG were featured with high amylose and low peak viscosity; some of MVG were similar with NVG and some similar with SVG. So, the amylose content and peak viscosity can be used as the index to measure the waxy quality of chestnut.

Key words: chestnut (Castanea mollissima Blume), amylose, pasting property, granule size