Date Published: May 18, 2020
Publisher: Springer International Publishing
Author(s): Victor Oloruntoba Bankole, Michael Oluwole Osungunna, Claudia Regina Fernandes Souza, Sergio Luiz Salvador, Wanderley Pereira Oliveira.
This work aims to improve the functionality of Rosmarinus officinalis L. (rosemary) polyphenols by encapsulation in an optimized proliposome formulation. A 23 Box-Wilson central composite design (CCD) was employed to determine lone and interaction effects of composition variables on moisture content (Xp); water activity (Aw); concentration and retention of rosemary polyphenols—rosmarinic acid (ROA), carnosol (CAR), and carnosic acid (CNA); and recovery of spray-dried proliposomes (SDP). Processing conditions which generate proliposomes with optimum physicochemical properties were determined by multi-response analysis (desirability approach). Antioxidant and antifungal activities were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH•) sequestering and minimum inhibitory concentration (MIC)/minimum fungicidal concentration (MFC) assays, respectively. SDP exhibited high polyphenol retention, ranging from 62.0 to 100.0% w/w, showing dependence on composition variables and polyphenol lipophilicity. SDP recovery ranged from 20.1 to 45.8%, with Xp and Aw of 1.7 ± 0.14–2.5 ± 0.23% w/w and 0.30 ± 0.004–0.47 ± 0.003, respectively, evidencing product with good chemical and microbiological stability. Optimum liposomal composition was determined, namely, lipid concentration (4.26% w/w), lyophilized extract (LE) concentration (4.48% w/w), and drying aid:(lipid+extract) ratio (7.55% w/w) on wet basis. Relative errors between experimental and predicted values for SDP properties showed concurrence for all responses except CAR retention, being 22% lower. SDP showed high antioxidant activity with IC50 of 9.2 ± 0.2 μg/mL, superior to results obtained for LE (10.8 μg/mL) and butylated hydroxytoluene (BHT), a synthetic antioxidant (12.5 μg/mL). MIC and MFC against Candida albicans (ATCC1023) were 312.5 μg/mL and 1250 μg/mL, respectively, a moderate antimicrobial activity for phytochemical-based products. SDP is shown as a veritable tool to encapsulate hydrophilic and lipophilic rosemary polyphenols generating a product with optimal physicochemical and biological properties.
Currently, plant polyphenols have received high attention of the pharmaceutical, nutraceutical, cosmetic, and food sectors mainly due to their attributed biological activities. Rosmarinus officinalis L., commonly called rosemary, is an aromatic herbaceous plant from the Lamiaceae family, native to the Mediterranean region, but cultivated all over the world. It is widely used as food flavoring and preservative and as herbal drug in folk medicine (1–3).
In this study, proliposome was shown as a viable system for the encapsulation of rosemary polyphenols through a systematic study of the relationships between composition variables and their effects on desirable responses, guided by experimental design. It was shown that relative concentration and retention of each rosemary polyphenol in SDP is a function of its own polarity and composition variables. Whereas ROA retention is largely dependent on concentration of the extract, values for CAR and CNA are influenced by lipid, extract, and drying aid concentrations. Aw depends on the drying aid (lactose) concentration while Xp is only slightly influenced by both lipid and extract concentrations.