Influence of Different Degradation Techniques on the Molecular Weight Distribution of κ -Carrageenan

Abstract

Carrageenan as an abundant natural carbohydrate could be used as a representative material instead of synthetic polymers. In this work, the degradation of κ-Carrageenan by means of ultrasound irradiation at a frequency of 24 kHz and its combination with heterogeneous Titanium dioxide, followed by a photocatalytic process was investigated. The scission of carrageenan chains induced by a high intensity field of ultrasonic irradiation; result in various molecular weights of carrageenan. The low molecular weight species of carrageenan have biological and pharmaceutical uses that only should be obtained from the degradation method. The ultrasound power not only led to enhanced turbulence and liquid streaming, but also increased the active surface area. Therefore, TiO 2 sonophotocatalysis was carried out faster than sonolysis and sonocatalysis processes. The influence of the basic operational parameters such as, ultrasound power and amount of TiO 2 on the degradation rate of carrageenan was also studied. The results revealed that the extent of sonolytic degradation was increased with increasing of ultrasound power (in the range 30-80 W) and at higher catalyst concentration, the degradation rate in the solution soared. The degraded carrageenans were characterized by gel permeation chromatography (GPC).

Effect of ultrasound on the physical properties and processing of major biopolymers—a review

“…120 The depolymerization of k-carrageenan at temperatures below 72.2 1C is reported to be faster than thermal depolymerization by Ratnawati et al 44 In many cases, an external metal catalyst is used to intensify the degradation, providing a high surface area of interaction and greater turbulence in the solution. 121 Moreover, US, along with ozone treatment, resulted in increased depolymerization by 88.36%, as reported by Prasetyaningrum et al 122 Gelation is another crucial physical phenomenon of carrageenan forming a cold gel in the presence of ultrasound. The carrageenan hydrocolloid has higher water solubility with ultrasound.…”

The Impact of Combination of Ozonation and Ultrasonication Process on Morphological and Chemical Properties of κ-Carrageenan

“…LMW of κ-carrageenan has been produced by several different techniques. There are thermal depolymerization (Qiet al, 2005), acid hydrolysis (Prajapati et al, 2014), enzymatic hydrolysis (Yao et al, 2014), microwave assisted depolymerization (Zhou et al,2006), sonication (Ratnawati et al, 2016;Taghizadeh & Abdollahi, 2015) irradiation (Chiu et al, 2012) and oxidation using H2O2 (Lai et al, 2010). To produce a series of the carrageenan oligomers, acidic hydrolysis has been considered as a common and rapid method.…”