Effect of chitosan beads incorporated with lavender or red thyme essential oils in inhibiting Botrytis cinerea and their application in strawberry packaging system

• Chitosan beads containing lavender or red thyme essential oils (EOs) can inhibit Botrytis cinerea.
• The beads containing EOs can extend strawberry shelf life.
• Overall qualities of strawberry treated with both types of EOs were maintained.
• Consumer preferred strawberry packed with lavender beads.

Chitosan beads (C), those containing lavender (L) or red thyme (RT) essential oils at 2 levels: low or high (0.125 or 0.25 g/plate or sachet) were used to inhibit Botrytis cinerea on potato dextrose agar (PDA) and in strawberry clamshell. The system without beads served as control. L-high, RT-low and RT-high can effectively inhibit B. cinerea on PDA. The efficiency of beads was also tested with strawberry packed in clamshell by attaching a bag containing beads under clamshell lid and stored at 7 °C for 10 days. On Day10, decay of control strawberry, strawberry with C-low, C-high, L-low, L-high, RT-low and RT-high were 40%, 30%, 30%, 5%, 5%, 10% and 0%, respectively. The quality of strawberry during storage was evaluated. On Day10, weight loss of strawberry packed with C-high, L-high, RT-low and RT-high were significantly lower than control. Also these treatments had higher CO2 and lower O2 concentration in the clamshell. From sensory evaluation using 9-point hedonic scale, essential oils did not affect appearance, colour and firmness of strawberry but lowered odour, flavour and overall acceptability scores. However, on Day10, the control strawberry, strawberry with C-high, L-high and RT-high were acceptable with the score of 7.0, 7.2, 5.8 and 5.1, respectively.