Ultrasonic-Assisted Preparation, Characterization and Antibacterial Activity of β-Chitosan from Squid Pens

Abstract

β-chitosan preparation from squid pens was carried out using aqueous NaOH with the ultrasonic assistance. Single factor experiments and L9(34) orthogonal experiments were used to investigate the effect of three parameters (reaction time, concentration of NaOH and reaction temperature) on deacetylation of β-chitin. The optimal conditions for deacetylation of chitin were reaction temperature 80°C, reaction time 2 h and concentration of NaOH 50%. The optimal conditions allowed deacetylation degree of β-chitin from 71.32% to 92.91%. The β-chitosan from squid pens was confirmed by Fourier transform infrared spectroscopy. The antibacterial activities of the prepared β-chitosans againstaphylococcus aureus(S. aureus) andEscherchia coli(E.coli) were then determined and compared by the MIC (minimum inhibitory concentration). Results indicate that β-chitosans with different degrees of deacetylation (DD) possess different antibacterial activity. The growth ofS. aureuscan be easily inhibited by prepared β-chitosan thanE.coli.

Impact of the Structural Differences between α- and β-Chitosan on Their Depolymerizing Reaction and Antibacterial Activity

“…So far, the antibacterial studies on chitosan have been focused on readily accessible α-chitosan extracted from crustacean shells, − but little was reported on β-chitosan from squid pens. , No previous study has compared the antibacterial activity between α- and β-chitosan based on their polymeric structural differences. In addition, it is unclear how α- and β-chitosan respond differently to the enzymatic depolymerization in association with their polymorphic structures.…”

β‐Chitin and chitosan from waste shells of edible mollusks as a functional ingredient

“…It improves mass balance, shortens extraction time, reduces energy input and environmental impact compared to conventional extraction methods (Tiwari, 2015). Most importantly, very few studies evidenced the effectiveness of ultrasound based approaches to remove β‐chitin and chitosan from the shells of mollusks (Delezuk et al., 2011; Fiamingo et al., 2016; Huang et al., 2011; Singh et al., 2019). Most importantly, chitosan extracted from squid pens using high‐intensity ultrasonic signals reduced the extraction time, temperature, power consumption, and operation frequency of 20 kHz ± 50 Hz (Huang et al., 2011; Singh et al., 2019).…”

“…Most importantly, very few studies evidenced the effectiveness of ultrasound based approaches to remove β‐chitin and chitosan from the shells of mollusks (Delezuk et al., 2011; Fiamingo et al., 2016; Huang et al., 2011; Singh et al., 2019). Most importantly, chitosan extracted from squid pens using high‐intensity ultrasonic signals reduced the extraction time, temperature, power consumption, and operation frequency of 20 kHz ± 50 Hz (Huang et al., 2011; Singh et al., 2019). On the other hand, β‐chitin particles showed remarkable morphological changes as a result of ultrasound cavitation, that is, small particle size and enhanced N ‐deacetylation efficiency (Delezuk et al., 2011).…”