Synergistic effect of hemiacetal crosslinking and crystallinity on wet strength of cellulose nanofiber-reinforced starch films

• Published in: Food hydrocolloids Vol. 120; p. 106956
• Main Authors: Soni, Raghav, Hsu, Yu-I, Asoh, Taka-Aki, Uyama, Hiroshi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2021
• Subjects: Cellulose nanofiber; Cellulose/starch composite films; Crystallinity; Hemiacetal crosslinking; Modified tapioca starch; Wet strength; Modified tapioca starch; Crystallinity; Hemiacetal crosslinking; Cellulose/starch composite films; Cellulose nanofiber; Wet strength
• ISSN: 0268-005X; 1873-7137
• DOI: 10.1016/j.foodhyd.2021.106956

Starch is the most abundant biomass and potential replacement of single-use packaging; however, the lack of water durability and wet strength restrict the applicability of starches. Hemiacetal/acetals cross-linked starch film have water stability, however, the film possess poor wet strength owing to lack of crystallinity. In this study, we prepared TEMPO-oxidized cellulose nanofiber (TCNF)/starch composite films by mixing different-storage-duration native tapioca starch (NTS), hydroxypropyl starch (HPS), and di-aldehyde starch (Di-aldS) with TCNF. We demonstrate that the films prepared with the stored starch pastes exhibit improved mechanical properties and wet strength owing to the synergistic effect of enhanced crystallinity and hemiacetal crosslinking. However, long-term storage of the starch pastes negatively affected their properties. Thus, improving the film properties by optimizing the starch paste storage time is an environmentally friendly and energy-conserving method. Moreover, our experimental results suggest that TCNF/HPS films prepared with the HPS paste stored for three days (~22 °C, ~25% RH) can be a potential alternative to single-use packaging films.
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•Effect of starch pastes storage time on wet strength of TCNF/starch films.•Synergistic effect of hemiacetal crosslinking and crystallinity enhanced water durability of the film.•TCNF/HPS film prepared with 3 days stored HPS paste is quite suitable for application.