Production and evaluation of Physicochemical, Mechanical and Antimicrobial Properties of Chia (Salvia hispanica L.) mucilage-gelatin based Edible Films Incorporated with Chitosan Nanoparticles

Edible films and coatings are edible thin layers used as food coatings or barriers between foods and the environment. Biopolymers including polysaccharides, proteins or their mixture which used to produce edible films, are high potential as carriers of additives such as anti-microbial agents and antioxidants. Generally, the use of edible and biodegradable films has been limited due to their sensitivity to moisture and poor mechanical properties. On the other side, the use of a combination of polymers for film forming considered as an effective method to overcome mentioned limitations, so, the best functional properties of each compound can be used.This paper intended to investigate the ability of the mucilage from chia seeds in combination with gelatin to form a suitable composite film and produce a new type of biodegradable biopolymers used in food packaging. Chitosan nanoparticles used in four different levels (0, 2, 4 and 6%) as antimicrobial agent in the production of the films. Physicochemical and antimicrobial properties of the produced films were evaluated. Results shown that adding chitosan nanoparticles in different percentages caused significant changes in water vapor permeability (0.129- 256), opacity (0.656-6.185), Delta E colorimetric factor (5.570-4.736) and antimicrobial properties against gram-positive microorganisms (S. aureus) (1-21.666 mm) (p < 0.05). Furthermore, the microbial tests indicated a greater inhibitory effect of chitosan nanoparticles against gram-positive bacteria (max for gram positive = 21.666 mm vs. max for gram negative = 12.333 mm). In conclusion, development of the environmental friendly food packaging such as bio-composite or nanobiocomposite ones reduces the negative impacts of packaging on the environment. Although nanocomposites are an improved form of biopolymers, they still have some deficiencies compared to synthetic polymers that limit their use. To overcome these drawbacks, various agricultural and food-based materials should be considered and evaluated for their potential application in the packaging industry.