In vitro and in vivo antifungal activity of a water-dilutable cassia oil microemulsion against Geotrichum citri-aurantii.
BACKGROUND
Recently, food-grade microemulsions have been of increasing interest to researchers and have shown great potential in industrial applications. In this study a food-grade water-dilutable microemulsion system with cassia oil as oil, ethanol as cosurfactant, Tween 20 as surfactant and water was developed and its antifungal activity in vitro and in vivo against Geotrichum citri-aurantii was assessed.


RESULTS
The phase diagram results confirmed the feasibility of forming a water-dilutable microemulsion based on cassia oil. One microemulsion formulation, cassia oil/ethanol/Tween 20 = 1:3:6 (w/w/w), was selected with the capability to undergo full dilution with water. The average particle size was 6.3 nm. The in vitro antifungal experiments showed that the microemulsion inhibited fungal growth on solid medium and prevented arthroconidium germination in liquid medium and that cassia oil had stronger activity when encapsulated in the microemulsion. The in vivo antifungal experiments indicated that the water-dilutable microemulsion was effective in preventing postharvest diseases of citrus fruits caused by G. citri-aurantii.


CONCLUSIONS
The results of this study suggest a promising utilisation of water-dilutable microemulsions based on essential oils for the control of postharvest diseases.
Department of Food Science and Nutrition, Zijingang Campus, Zhejiang University, Hangzhou 310058, China.
Shi-Xiang
SX
Xu
Yi-Chen
YC
Li
Xia
X
Liu
Li-Juan
LJ
Mao
Hui
H
Zhang
Xiao-Dong
XD
Zheng
D000935:Antifungal Agents / Q000494:pharmacology*; D002366:Cassia / Q000737:chemistry*; D002957:Citrus / Q000382:microbiology*; D004032:Diet; D004655:Emulsions; D000431:Ethanol; D005638:Fruit / Q000382:microbiology*; D005848:Geotrichum / Q000187:drug effects* / Q000254:growth & development; D010316:Particle Size; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D010938:Plant Oils / Q000494:pharmacology*; D011136:Polysorbates; D013501:Surface-Active Agents; D014867:Water
D000935:Antifungal Agents; D004655:Emulsions; D010938:Plant Oils; D011136:Polysorbates; D013501:Surface-Active Agents; D014867:Water; D000431:Ethanol