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Physical Stability and Antimicrobial Activity of Encapsulated Cinnamaldehyde by Self‐Emulsifying Nanoemulsion
Author(s) -
Tian WeiLu,
Lei LingLing,
Zhang Qi,
Li Yan
Publication year - 2016
Publication title -
journal of food process engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 45
eISSN - 1745-4530
pISSN - 0145-8876
DOI - 10.1111/jfpe.12237
Subject(s) - cinnamaldehyde , emulsion , antimicrobial , chemistry , preservative , pulmonary surfactant , essential oil , chromatography , limonene , food science , organic chemistry , biochemistry , catalysis
In the present study, natural cinnamaldehyde was encapsulated in self‐emulsifying emulsion systems. After optimization, the stability of encapsulated cinnamaldehyde was evaluated by dynamic light‐scattering and electronic nose. The antimicrobial activity of cinnamaldehyde was investigated by minimum inhibition concentration and time‐kill assay. The results showed that pure cinnamaldehyde as oil phase could not form stable emulsion under different oil‐to‐surfactant ratio. Stable cinnamaldehyde nanoemulsions were achieved with the addition of medium‐chain triglyceride. With the exception of temperature, the obtained nanoemulsions were stable against pH and NaCl . Phase separation was observed after 12 days of storage under 37C. Encapsulation efficiency of cinnamaldehyde in nanoemulsions was maintained around 80% within 1 week. Radar plots from electronic nose indicated that encapsulation could slow the release of cinnamaldehyde from nanoemulsion. Hence, the antimicrobial activity of cinnamaldehyde encapsulated in nanoemulsion could provide a long‐term inhibition on the bacterial growth of E scherichia coli compared with pure cinnamaldehyde. Practical Applications The applications of natural essential oils with their excellent antibacterial activities, such as cinnamon essential oils, as a food additive and green preservative are limited in the food systems, due to their highly instability against environmental conditions including temperature, light, air and others. The emulsification technique has been successfully utilized to overcome this drawback. However, it is known that emulsions with essential oils as oil phase will be highly unstable due to O stwald ripening. Although the evaluation of the stability and bioactivities of encapsulated essential oil is an important and critical issue during the practical application, hence, studies of the physical properties such as environmental stability, volatility and antibacterial activity can explore the ideal formulation and applications of natural essential oils.