Chitosan-coated paper packaging for specialty coffee beans: Coating characterization, bean and beverage analysis

Abstract

Cellulose-based packaging has received great attention due to its characteristics of biodegradability, sustainability, and recyclability. Natural polymer coatings are usually applied to the paper surface to enhance the barriers to water vapour and improve the mechanical properties. A chitosan-based coating for paper packaging was developed in this work to store specialty roasted coffee beans, evaluating two samples of chitosan (Sigma® and molasses chitosan), and following the physico-chemical and microbiological characteristics of coffee beans along a period of 60 days. Sensory tests (Ranking Descriptive Analysis and Preference Test) were applied to the beverage prepared with the roasted and ground coffee beans stored in each packaging. Thin chitosan films provided good coverage and adhesion on the paper. Improved mechanical properties and lower water permeability were observed in the chitosan-coated papers. The physicochemical and microbiological characteristics of the coffee beans were not influenced by the packaging along 60 days of storage. The molasses chitosan coating resulted in slightly darker roasted beans. In sensory evaluation, there is a clear difference between the chitosan samples, so that molasses chitosan-coated packaging had higher scores compared to Sigma® chitosan treatment for flavor and global impression in the preference analysis of the beverage. The molasses chitosan-coated packaging had three to four more consumers attributing the highest scores for the beverage prepared with the roasted beans stored in this type of packaging.