Development and characterization of an antimicrobial edible film from basil seed (Ocimum basilicum L.) mucilage and sodium alginate

Abstract

Edible films are a recent trend in the field of packaging which are economic and biodegradable. The biodegradability of edible films can sufficiently reduce the use of plastics around the globe. The study fabricated an antimicrobial edible film based on basil seed gum and alginate which was characterized for its mechanical, barrier, and antimicrobial properties. The essential oil from clove (4%) was added to provide antimicrobial properties to film. The thickness of the films was observed in the range of 0.10–0.12 mm. The values for opacity of the edible films were 8.50–10.50. X-ray diffraction (XRD) showed crystalline behavior of films. Thermal stability of the film was measured using differential scanning calorimetry (DSC) and peak temperatures were observed in the range of 112.6–114.1 °C. Tensile strength was obtained in the range of 2.30–2.86 MPa. The water vapor permeability (WVP) of the films was 6.71–7.89 g mm/h mm2 kPa × 10−3. Oxygen barrier properties were found to decrease with the addition of essential oil. Results for water solubility were obtained in the range of 56.33–65.26%. A significant loss in weight of edible film was recorded for five days. The loss in weight was 2.12 to 0.0311 g for control sample and 2.28 to 0.0280 g for sample containing essential oil. The loss of weight illustrated biodegradable nature of the developed edible film. The antimicrobial activity of the edible films was evaluated against gram-positive (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli) through disc diffusion agar method and results indicated remarkable anti-bacterial properties for edible films incorporated with clove oil.