Opuntia ficus-indica Mucilage and Edible Chitosan Biofilms Including Brassica olearacea Extract for Extending the Shell-life of Capsicum annuum var Serrano

Aims: This work describes the manufacture of biofilms using a mixture of Opuntia ficus-indica (nopal) mucilage, chitosan and active ingredients extracted from plants. In this case, ethanolic extractions of white cabbage (Brassica olearacea) were performed, since it has been demonstrated in previous studies that these present antioxidant and antibiotic properties. Chilies (Capsicum annuum) were covered with only chitosan, chitosan+nopal mucilage, or the chitosan-mucilage mixture added with white cabbage extract. Triplicates or quintuplicates of the covered chilies and a control group were administered without any application.

Place and Duration of Study: Assessments were carried out at Unidad Profesional Interdisciplinaria de Biotecnologia-IPN (Mexico) facilities during the end of 2016-2017.

Methodology: Covered and no-covered fruits were stored under two conditions: a) ambient temperature (24 to 28°C) and b) refrigeration at 4°C. They were observed day by day, photographed, and maturation was evaluated in all groups. Also, the weight loss, hardness and content of some metabolites (flavonoids and phenols), acidity and °Brix were determined every third day and the respiration rate of the chilies every five days.

Results: Results indicated that the addition of edible mucilage and chitosan films, added with the white cabbage extract, lengthened the shelf life of the chilies, reducing weight loss and improving the hardness of the fruits. There was also a delay in the maturation process measured as the colour changes from green to mixed green-orange, to yellow and orange and a decrease in the respiration rate of covered chilies compared to those that were not covered. Acidity, °Brix, phenol and flavonoids analyze also provided evidence of the improvement in the final quality of the mucilage-covered chilies, and even more those covered with mucilage + white cabbage extract.

Conclusion: The use of Opuntia ficus/chitosan biofilms amended with white cabbage extract resulted very useful in extending the shelf life of Capsicum annuum var Serrano fruits under refrigeration or environmental conditions, prolonging their shelf life with a better quality.