Background: The fruits acerola and red plum are known to be good sources of antioxidants, particularly vitamin C. Antioxidants are compounds that protect organisms from biomolecular damage, such as accelerated aging, caused by free radicals.
Objective: The objective of this study was to extract vitamin C from acerola and red plum, incorporate these extracts into different topical formulations, and evaluate the physicochemical stabilities of these formulations under stress conditions.
Methods: Vitamin C was extracted from acerola and red plum via dynamic maceration for 2 h at 50 ± 2°C and was quantified via HPLC. In vitro antioxidant activities were evaluated using DPPH assays. The extracts were then incorporated into emulsion and gel formulations in two types of packaging, and stability studies were carried out.
Results: Red plum and acerola extracts were orange and red and contained vitamin C concentrations of 2732.70 ± 93.01 mg/100 g and 2.60 ± 1.2 mg/100 g, respectively. In vitro antioxidant activity resulted in over 90.0% inhibition of free radicals at 0.01 mL/mL acerola extract and 0.1 mL/mL red plum extract. In the stability study, pH values decreased for both acerola formulations when stored in the oven or in transparent glass containers. Formulations containing red plum extract were stable under all conditions. Acerola extracts contained a higher concentration of vitamin C than red plum extracts. Both extracts possessed antioxidant activity, although the acerola-based formulation was unstable when stored at high temperatures or in transparent glass containers.
Highlights: Extracts from red plum and acerola contained vitamin C; antioxidant activity of the extracts resulted in over 90.0% inhibition of free radicals. Formulations containing red plum were stable under all tested conditions, and formulations containing acerola were unstable when stored in the oven or in transparent glass containers.