Deacetylation and pore generation of chitin submitted to explosive puffing
TSAI, MIN-LANG; LIN, YI SHENG（Department of Food Science, National Taiwan Ocean University）
TSAI, MIN-LANG; TAN, TOO SHEN; LIN, YI SHENG
The purpose of this study was to use an environmentally friendly explosive-puffing method to achieve deacetylation and porositization in chitin to enhance the degree of deacetylation (DD) in chitin and extend its applications. The deacetylation of chitin is produced industrially via the hot alkaline method. Attributes of the hot alkaline method include a rapid reaction rate, a higher DD in the chitosan derivatives and the feasibility of mass production. However, this method uses a large amount of NaOH and water, in turn producing huge volumes of wastewater, causing environmental pollution and high-energy consumption. The results show that the varying moisture contents of chitins were explosively puffed at a pressure of 9 kg/cm2 displayed a higher DD, lower density, less crystallinity and more porous structures compared to unpuffed chitin. After puffing, the β-chitin exhibited a greater expansion ratio, a higher proportion of small-sized particles and lower crystallinity than the α-chitin. The puffed α- and β-chitin had the highest DDs with 42.9% and 43.7% respectively at 75% moisture content. The puffed chitin with lower moisture content displayed lower DD, lower density, smaller particle size, lower crystallinity index, higher expansion ratio, and larger with more numerous pores than that of the chitin with higher moisture content. The eco-friendly explosive puffing method therefore represents a potential improvement with respect to current commercial chitosan production, which suffers from difficulties related to pollution and high energy consumption. In addition to porositization (pore size: 130-620 nm), this method can also enhance chemical reactions (derivative reactions) and broaden the application of explosive puffing to products such as absorbents and filters.