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Abstract: Starch is a highly hydrophilic biomaterial with weak mechanical properties rendering it useless for commercial applications. A fully ‘green’ water based process is presented to crosslink corn (cereal) and potato (tuber) starch to enhance mechanical properties as well as lower hydrophilicity. In addition, malonic acid, a green, plant based water soluble and relatively inexpensive polycarboxylic acid, was used as the crosslinker. The reactivity of potato starch toward esterification and crosslinking was found to be higher than that of corn starch owing to the inherent differences in the granule morphology and internal structure of the two starches. It was observed that potato starch granules had a higher degree of substitution (DS) of 0.19 than corn starch granules (DS=0.1) under similar reaction conditions. Chemical, thermal and mechanical test results confirmed the crosslinking as well as reduced moisture sensitivity. [Copyright &y& Elsevier]

• Chitosan/pullulan nanofibers were crosslinked by Maillard and Schiff base reaction. • Crosslinked films showed good water resistance, mechanical and thermal properties. • The enhancing effects of the two crosslinking methods were compared. In this study, electrospun chitosan/pullulan composite nanofiber films were crosslinked by two green methods (heating and cinnamaldehyde). With the increase of chitosan content, the morphology results indicated that the nanostructures of thermal crosslinking chitosan/pullulan (TCP) and cinnamaldehyde crosslinking chitosan/pullulan (CCP) nanofiber films became more stable. The decreases in weight loss (83.65 % to 43.85 % for TCP and 23.42 % to 15.58 % for CCP) and the increases in water contact angle (31.8° to 54.1° for TCP and 83.65 % to 43.85 % for CCP) confirmed the improved water stability. The decreases in water vapor permeability indicated that the crosslinking processes significantly improved the barrier properties of the films. Mechanical and thermal properties of TCP and CCP films were enhanced respectively. Furthermore, the corresponding properties of CCP films were more excellent than TCP films. FTIR results indicated the occurrence of Maillard reaction during the thermal crosslinking process and Schiff base reaction during the cinnamaldehyde crosslinking process. [ABSTRACT FROM AUTHOR]