Effect of candelilla wax edible coatings combined with biocontrol bacteria on strawberry quality during the shelf-life

Abstract

The effect of edible films of candelilla wax alone or in combination with a Bacillus subtilis HFC103 strain on shelf life of strawberry, has been assayed. Treatments were: control, film (edible coating), bacteria (inoculated with B. subtilis HFC103) and film+bacteria (edible coating+B. subtilis HFC103). Fruits were treated and stored at 25°C for six d. Decay percentage and weight loss were assayed daily, while pH and total soluble solids (TSS) were determined at the end of the assay. The film, bacteria and film+bacteria treatments significantly reduced the decay percentage and weight loss with respect to control since day 3. Film+bacteria treatment reduced decay around 100% with respect to control on day 6. Film treatment kept a low weight loss during the assay. There were no changes of pH and TSS as effect of the treatments. Additionally, the effects of the treatments described on the severity of the damage caused by Rhizopus stolonifer were assayed. All the treatments were inoculated with a spore suspension of such pathogen, stored at 25°C for 6 d, and the severity index was recorded every 24h. Film, bacteria and film+bacteria treatments significantly reduced the severity index with respect to control since day 2. The Bacteria treatment was the most effective to control R. stolonifer. However, it did not show the same efficacy to control weight loss or to prolong shelf life of strawberry. Results showed that the combination of candelilla wax edible films and the inoculation with B. subtilis HFC103 is an innovative strategy with the potential to prolong shelf life of strawberry.