Characterization of Semi-refined Carrageenan-Based Film for Primary Food Packaging Purposes

Abstract

Carrageenan-based films demonstrate good performance and the raw materials for their production are abundant in nature and can be sustainably sourced. Similar to other naturally-derived biopolymers, however, carrageenans are relatively expensive to purify and form into useful materials. In order to potentially lower the production costs compared to pure carrageenan, semirefined carrageenan (SRC) plasticized with 0-50% (w/w) glycerol was investigated using a solution casting method. The film color and opacity increased along with the moisture content, whereas the water vapor permeability decreased with increasing levels of glycerol. The tensile properties of the SRC films improved significantly, particularly at glycerol additions greater than 30% (w/w). Moreover, the addition of glycerol improved the thermal stability and altered the surface morphology of the films. In general, the properties of the SRC films were comparable with refined carrageenan films suggesting that SRC has potential to be furthered developed into more cost effective primary food packaging materials.

Reinforcement of Refined and Semi-Refined Carrageenan Film with Nanocellulose

“…It is expected that the range of loadings of NCF used and/or its dimensions and compatibility in relation to the polymer matrix are such that the additive will not affect the thickness of the resultant films prepared under the conditions used in this study. As shown in Figure 1, there are slight upward trends in the plots of film thickness versus moisture content for both the RC and SRC films, and a similar observation has also been found in the case of SRC films incorporated with glycerol [7]. For the RC/NCF film samples, the inherent moisture content is approximately equal to the average of the data, ca.…”

“…The SRC film preparation was performed following the method by Sedayu, Cran and Bigger [7] with some modifications. For the SRC control film, 5 g of SRC was dissolved in 250 mL of water and stirred vigorously for 15 min to dissolve the powder before heating to a temperature of 90 • C using a magnetic stirring hotplate.…”

“…Among the seaweed-derived polymers, carrageenan is one of the major polysaccharides that is extracted from red seaweed species and this polymer has been used for some time in a range of food applications [2]. Recently, the potential for the development of carrageenan films or composite materials has been demonstrated by several studies [3][4][5][6][7].…”

Improving the moisture barrier and mechanical properties of semi‐refined carrageenan films

“…A solvent casting method was used in the preparation of SRC films [11] whereby 5 g of SRC was dissolved in 250 ml of deionized water at 22 C with vigorous stirring for 15 min to remove SRC agglomerates. Afterward, the solution was heated and maintained under stirring at 90 C for 30 min before the plasticizing agent glycerol (2 g) was added.…”

“…[9,10] Nonetheless, the addition of plasticizers is also well known to exacerbate the moisture sensitivity of polysaccharide films. [11,12] To address this and other drawbacks, reinforcing nanoclays (NCs) and blending of hydrophobic materials into carrageenan-based film have been studied and have demonstrated positive outcomes. [13][14][15] The inclusion of natural NCs into bio-based polymers has been reported to successfully enhance the barrier and mechanical properties of the produced films.…”