Physical, mechanical, optical, barrier, and antioxidant properties of sodium alginate–aloe vera biocomposite film

Abstract

Plastics are being used as effective packaging material for food preservation, but their diminishing resources and damaging impact on the environment are important factors driving the need for the development of food packaging from renewable and biodegradable natural polymers. Many naturally occurring hydrocolloids were utilized for the development of edible coatings and films. One of the most important among such hydrocolloids is sodium alginate (Tavassoli-Kafrani et al., 2016) which is extracted from brown seaweed and is used as a thickening and stabilizing agent in various food and non-food products (Benavides et al., 2012;Liakos et al., 2013;Nair et al., 2018). Chemical structure of alginate generally comprises (1 → 4)-linked α-l-guluronic acid(G)and β-d-mannuronic acid(M). Depending on the species of brown algae, guluronic and mannuronic acids are arranged in homogeneous blocks (GG or MM)

Sustainable alginate/aloe vera composite biodegradable films reinforced with carboxymethyl cellulose and hydroxypropyl methylcellulose

“…Alginate/aloe vera (AA) composite films were prepared by the method described previously. [ 30 ] A total of 3% (w/w) sodium alginate dissolved in distilled water at 60–70°C on a hot plate for 30 min under stirring. Aloe vera gel 10% (wet basis) of the mass of alginate was then added to the alginate solution and was again homogenized using magnetic stirrer.…”

“…Sodium alginate was extracted by following the method of Calumpong et al [30] Dried brown algae (25 g) was immersed in 800 ml of formaldehyde (2%) for 24 h at room temperature. After washing with distilled water it was left in 800 ml HCl (0.2 M) solution for 24 h. The sample was again washed with distilled water and then blended with 2% sodium carbonate for 3 h at 50 C. The slurry was centrifuged at 950 Â g for 20 min and the supernatant was mixed with 95% ethanol to precipitate the sodium alginate.…”

Alginate/aloe vera films reinforced with tragacanth gum

“…Then 10% aloe vera extract (w/w of sodium alginate db) was added to the alginate solution, and homogenized again using magnetic stirrer. 50% sorbitol (w/w of sodium alginate db) was used as plasticizer and it was added after complete dissolution ( Hadi, Nawab, Alam, & Zehra, 2021 ). Film based on sodium alginate alone was taken as control.…”

“…The mechanical tests were performed according to the method described by Hadi et al ( Hadi et al, 2021 ).…”

Sustainable food packaging films based on alginate and aloe vera

“…This study is a continuation of a previous work in which sorbitol was used as a plasticizer and the effect of various concentrations of aloe vera on enhancing the antioxidant and mechanical properties of the composite films was investigated. [ 27 ] It is expected that these films would bring a promising alternative to conventional synthetic plastics being used in food packaging. The study would be useful to explore innovative modern packaging material which can effectively preserve food and also enhance its functional and nutritive value.…”