Optimizing the Use of Garlic Oil as Antimicrobial Agent on Fresh‐Cut Tomato through a Controlled Release System

Abstract

Encapsulation of garlic oil (GO) in β-cyclodextrin (β-CD) was undertaken to generate a release system of antimicrobial volatiles and tested on microbial growth and sensory quality of fresh-cut tomato. GO volatile profile was characterized by gas chromatography mass spectrometry and to demonstrate the disadvantages of applying free GO to fresh-cut tomato, the effect of different free oil treatments (0, 50, 100, and 200 μg/100 g) on microbial growth and sensorial quality was tested. The effect of GO capsules (0, 0.25, 0.5, and 1 g/100 g) on microbial growth and sensory quality of tomato was also investigated. Allyl disulfide was the most abundant GO compound identified. The release of volatiles from GO: β-CD capsules (12: 88 [w/w] ratio) was evaluated at 100% relative humidity (RH). Close to 70% of GO volatiles were released from capsules when exposed to 100% RH during 5 wk. The most effective antimicrobial concentrations of free oil (100 and 200 μg/100 g) applied to tomatoes did not present acceptable sensory quality for panelists. Tomato was affected by the highest concentration of GO capsules applied, showing the lowest microbial growth and the highest sensory quality. In this context, successful encapsulation in β-CD could stimulate further interest in the use of GO for the control of microbial growth in fresh-cut tomato. The present study demonstrated that relative humidity in-package of fresh-cut tomatoes can be used as a trigger to release antimicrobial garlic oil volatiles from β-cyclodextrin capsules, reducing microbial growth and the sensory effect of the treatment caused by the free garlic oil. In this context, successful encapsulation in β-cyclodextrin could stimulate further interest in the use of garlic oil for the control of microbial growth in fresh-cut tomatoes.