Tween 80 polysorbate

Breadfruit starch was extracted from the local breadfruits cultivated in the Aceh Province, Indonesia. 2-octen-1-ylsuccinic anhydride was purchased from Sigma-Aldrich (Singapore). Tween 80 (polysorbate) was purchased from Merck, Darmstadt, Germany. The dispersed phase contained palm oil (purchased from a local supermarket in Banda Aceh, Indonesia) and Class A lemon oil (purchased from CV Karunia, Atsiri Harapan, Surabaya, Indonesia). Other chemicals were of analytical grade. Further, double-distilled water was used to prepare all the emulsions in this study.

SLN were produced according to the method previously described.6 (link),7 The waxes used were Witepsol H15 (Sasol, Hamburg, Germany) and Carnauba wax yellow number 1 (Sigma-Aldrich, St Louis, MO, USA). Surfactant polysorbate (Tween 80) and RA were purchased from Sigma-Aldrich. Briefly, SLN were prepared by hot-melt ultrasonication, loading the RA and herbal aqueous extracts at the final concentration of 0.15 mg RA/mL. The lipid at 0.5% (w/v) was warmed to a temperature of 5°C above the melting point (36°C for Witepsol and 86°C for Carnauba), then the melted matrix was added with RA or herbal extracts and subjected to ultrasonication (VCX 130, Sonics & Materials, Newtown, CT, USA) for 1 minute at 70% of intensity. Finally, the aqueous surfactant solution of polysorbate 80 was added to obtain a final concentration of 2% (v/v) and mixed for a few seconds, for completely homogenization of the O/W emulsion. The resulting fluid solutions were left to cool at room temperature (20°C). The SLN emulsions were stored at 5°C for 28 days until further use. When dried SLN were used, the emulsions were freeze-dried upon production using a vacuum freeze drier (Model FT33), under a vacuum pressure of 100 mTorr; the temperature in the freezing chamber was −46°C, and the temperature in the sample chamber was 15°C.