Arenga pinnata starch (APS) is separated into large and small size fractions. The large granules (APS-L) show a more elongated oval shape, while the small granules (APS-S) are roughly close to a round shape. The large and small granules exhibit a Maltese cross at one end of the APS granules. Both large and small fractions show C-type crystallinity, but the APS-L display a higher crystallinity and more ordered molecular structure. In addition, APS-L have higher helices content than that of APS-S. The APS-L have higher peak viscosity, trough, and final viscosity values, breakdown value, gelatinization enthalpy, and gelatinization temperatures than that of the APS-S, but the APS-L fraction displays a lower setback value. The APS-S gel is more elastic and more solid than APS-L gel. The results indicate that granule size is significantly related to pasting, rheological, and thermal properties of the APS.

This study aims to investigate chitosan (CS) with five different molecular weight (Mw) on freeze–thaw stability of Arenga pinnata starch (APS) gel subjected to five freeze–thaw cycles (FTC). The syneresis of APS gels was reduced by adding CS and the APS gel with high Mw CS had lower syneresis duo to a higher water holding capacity (P < 0.05). The addition of CS significantly decreased the hardness and molecular ordered structure of APS gel. In addition, CS could improve the microstructural stability. The results suggested that CS could effectively improve the freeze–thaw stability of APS gel, and CS with higher Mw might have more practical utility to improve stability of APS gel.

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