Abstract
Bioactive edible coatings were developed and applied to blueberries as a natural treatment. E. coli O157:H7, L. innocua, S. aureus, and P. aeruginosa were subjected to four bioactive compounds and to three film‐forming solutions (FFS). Vanillin and geraniol at low concentrations (1.2–1.8 mg/mL and 0.4–1 μL/mL) demonstrated significant inhibitory effects on all pathogens counts. Chitosan (Ch) showed a high antimicrobial activity (final counts below 2 log CFU/mL). The effectiveness of Ch plus vanillin (Ch‐Va) and geraniol (Ch‐Ge) in improving the safety were tested against pathogens inoculated on blueberries. Ch, Ch‐Va, and Ch‐Ge coatings exerted a bactericidal effect on all pathogens (from 1.24 to more than 2 log reductions). Significant reduction in yeast and mold counts was achieved with Ch (1.09 log) and Ch + Va (1.74 log). Sensory attributes of blueberries remained acceptable. Ch‐Va and Ch‐Ge were an alternative to improve the quality and safety and could be effective in extending the shelf life of ready‐to‐eat blueberries.
Practical applications
The present study proposes the use of natural coatings enriched with biopreservatives as a technological alternative to enhance the quality and safety of minimally processed fruits. According to the results obtained, the application of chitosan plus vanillin/geraniol coatings on fresh blueberries would allow to offer a safe product and respond the growing demand of consumers for fresh, environmentally friendly and chemical preservatives‐free foods. These findings and those obtained by the sensory evaluation support the practical application of this alternative in the minimally processed fruit industry.
