Characterization of complexes of bergamot essential oil with b-cyclodextrin as antibiotic agents

MARAULO, GASTÓN EZEQUIEL; DOS SANTOS FERREIRA, CRISTINA; MAZZOBRE, M. FLORENCIA

Zhejiang

Simposio; 5th International Symposium on Phytochemicals in Medicine and Food; 2021

International Association of Dietetic Nutrition and Safety (IADNS); Phytochemical Society of Europe (PSE); Physiological Society of Japan; Phytochemical Society of Asia (PSA)

Bergamot essential oil (BEO) is an aromatic oil commonly used in pharmaceutical, cosmetic,and food industries. In addition to its pleasant aroma, it has noteworthy biological activitiessuch as digestive, antifungal, antibacterial, antioxidant [1] and anticancer [2]. This work aimed to study the antibacterial activity of bergamot essential oil encapsulated in β-cyclodextrin(BCD). These complexes were obtained by the ultrasound-assisted co-precipitation method.The encapsulation was performed by mixing 17.2 mL of AEB with 10 mL of 15mM of BCDaqueous solution. These AEB-BCD combined systems were sonicated (6 min), stirred (1 h at25 ºC) and subsequently cooled at 4 °C during 24 h, to promote the co-crystallisation andformation of the complexes. The precipitates were dried at 50°C, in order to obtain powderedsystems with AEB. Due to its importance in the food industry [3], Staphylococcus aureus wasselected to study the antimicrobial activity of the samples. This bioactivity was analysed bystudying the inhibition of S. aureus growth in broth test. BEO or BEO-BCD complexes wereadded to Peptone water (PWS, 0.1%) containing the S. aureus inoculum (103 UFC/mL), toobtain a 0.88 mg mL‒1 BEO concentration. The PWS with inoculum or with BCD were usedas controls. The systems were shaken at 35 °C for 2 h, and aliquots of 1 mL were taken atintervals of 1 h. Then, decimal dilutions of the systems were sown in Plate Count Agar Petridishes and stored at 35 °C for 24h. BEO and BEO-BCD complexes, presented antimicrobialactivity. Although the inhibition of S. aureus growth at 1 h was lower in the presence ofBEO-BCD complexes than with BEO, at 2 h it reached values with no significant differences,being 88.5 % and 96.6 % of inhibition compared with the control for BEO complexes andfree BEO respectively. Encapsulation in BCD allows obtaining an antimicrobial oil in powder,easy to handle and store. Results suggest that BEO-BCD complexes could be interesting andpractical to use as a natural antimicrobial agent in foods, favouring the controlled release ofthe oil.