Development and antifungal evaluation of a food-grade U-type microemulsion

Abstract

Aims: Food‐grade microemulsions have been of increasing interest to researchers as potential delivery systems for bioactive compounds. However, food‐grade microemulsions are difficult to formulate and no microemulsion has been documented for antifungal purpose. The physicochemical characterization of a food‐grade glycerol monolaurate (GML)/ethanol (EtOH)/Tween 80/potassium sorbate (PS)/water microemulsion system and the antifungal activities against Aspergillus niger and Penicillium italicum have been studied in this paper. Methods and Results: The influence of EtOH and PS on oil solubilization capability was clearly reflected in the phase behaviour of U‐type microemulsion systems. One dilution‐stable formulation ME (GML/EtOH/Tween 80/PS/water = 3 : 3 : 3·5 : 10·5 : 16) was selected. After 4 days of incubation, ME showed 80%A. niger growth inhibition at 0·2% and 72%P. italicum growth inhibition at 0·1%, respectively, and a delay of conidiation of 2 days compared with the control. In the antifungal activities of the microemulsion, GML and PS made major contributions with similar antifungal activities at a GML/PS weight ratio of 1: 3·5. Conclusions: Food‐grade dilution‐stable microemulsions prepared with GML as oil phase for antifungal purpose are feasible and solubilization of a hydrotrope contributes to the formation of microemulsions and enhanced antifungal activities. Significance and Impact of the Study: The present report represents the first to develop a food‐grade microemulsion system for antifugal purpose.

Influence of monoacylglycerols on growth inhibition of micromycetes in vitro and on bread

“…Similar results were also published by Zhang et al [25], Mansour et al [27] and Altieri et al [28]. They found out that effect of fatty acids and MAG against micromycetes growth is specific for individual strains or species.…”

“…Inhibition of growth of this species was observed using 164 mg/L monolaurin and spore inhibition using 300 mg/L monolaurin. According Zhang et al [25,26] microemulsions containing monolaurin can modify the morphology of A. niger. The microemulsions inhibited growth and conidiation both of aspergilli and penicillia.…”

Characterization and antimicrobial activity of a pharmaceutical microemulsion

“…Our previous GML-loaded microemulsion with solubilization of potassium sorbate showed 80% A. niger growth inhibition at 0.2% and 72% P. italicum growth inhibition at 0.1%, and a delay of conidiation of 2 days compared with the control (Zhang et al, 2008a). The GML- loaded microemulsion prepared by Fu et al (2006) inhibited 78% A. niger growth at 0.05% after 5 days of incubation.…”

“…Sodium diacetate (SD), the sodium salt of the acetic acid, is an economical GRAS ingredient by the US FDA (Shelef and Addala, 1994). Our previous work (Zhang et al, 2008a) showed that the solubilization of water-soluble salts with antimicrobial properties in microemulsions could enhance the antimicrobial effects.…”

Antibacterial Activities of a Food‐grade Dilution‐stable Microemulsion

“…Our group has studied food‐grade microemulsions stabilized by short‐chain alcohols for antimicrobial purpose (Zhang et al . 2008a,b).…”