ASHS 2024 Conference

The ripening and senescence of fresh fruit and vegetables are inevitable during storage, transportation, and sale, which will reduce their marketability and cause substantial economic losses. The infection of pathogenic microorganisms can also lead to food safety problems. Plant essential oils are considered a promising strategy to preserve fresh produce. However, their application is limited by several aspects, including high volatility, low solubility, off flavor, etc. Encapsulation technology has emerged as a promising solution to alleviate these limitations. Nanoencapsulation is a delivery system for bioactive compounds that is usually employed to support the stability of the agents, maximize their retention, and control the release of the compounds at the target locations. A nanoemulsion composed of carvacrol and β-cyclodextrin was prepared by an ultrasound-mediated method, and the encapsulation process was conducted using a Buchi® Nano Spray Dryer B-90. The inclusion complex powder was collected and filled to air-permeable sachets. The sachets were then fixed inside commercial clamshells containing limes to simulate shelf-life. Fruit quality and total microbial population were analyzed. The results showed that the dimensions of spray-dried powders were primarily at nanoscale. The encapsulation process did not affect the antimicrobial and antioxidant activities of carvacrol. The nanocapsules prolonged the release of carvacrol. It effectively delayed the rapid color deterioration of limes without causing phytotoxicity, and maintained lime quality with higher firmness and lower weight loss. Free carvacrol and carvacrol/β-cyclodextrin treatments significantly reduced the growth of P. digitatum and total bacteria on fruit peel and inside of the wounds. However, the GC-MS results showed carvacrol residue detected from free carvacrol-treated fruit, but not from the carvacrol/β-cyclodextrin-treated fruit. The results indicate that nano-encapsulated carvacrol/β-cyclodextrin inclusion complexes can be applied as an effective strategy to preserve postharvest produce. Keywords: Nanoencapsulation, nano spray drying, essential oil, postharvest quality, lime