Inhibitory effect of salicylic acid and Aloe vera gel edible coating on microbial load and chilling injury of orange fruit

Abstract

Effects of salicylic acid (SA) and Aloe vera gel (AV) on microbial load, quality and chilling injury of ‘Thomson Navel’ oranges (Citrus sinensis L. Osbeck) stored at 4 ± 1 °C and 80 ± 5% RH were evaluated. Fruit were treated by immersion in distilled water (control), SA 2 mM, AV 30% and the combination of SA + AV. Decay index, microbiological analysis, weight loss, firmness, soluble solids content, titratable acidity, vitamin C, total phenol, chilling injury, electrolyte leakage, malondialdehyde and sensory evaluation were measured at 0, 20, 40, 60 and 80 days of storage. Results showed that treated fruit had lower decay index, total yeasts + molds count, total aerobic mesophilic bacteria, weight loss and higher firmness, soluble solids content, titratable acidity, vitamin C, and total phenol content. The treatment with SA and AV gel coating reduced malondialdehyde, electrolyte leakage and chilling injury. Fruit odor attributes was not affected by treatments but skin appearance, sweetness, juiciness and intention to buy in treated fruit were higher than control. SA + AV was more effective than SA and AV solely in maintaining fruit quality and reducing microbial load and chilling injury. It could be concluded that the combination of SA with AV might leads to increased oranges fruit shelf-life.