Determination of Total Anthocyanin Content in Raspberry (Rubus rosifolius Sm.) Fruit Extract and Its Physical Evaluation in Lip Cream Formulations

Abstract

Background: Natural colorants are increasingly investigated for lip cosmetics. Raspberry (Rubus rosifolius Sm.) contains anthocyanins with potential as natural pigments, although their stability is influenced by environmental and processing conditions. Objective: To determine the total anthocyanin content of raspberry fruit extract and evaluate the physical characteristics and short-term stability of lip cream containing 4%, 6%, and 8% extract. Methods: An experimental laboratory study was conducted from January to May 2026. Raspberry fruit was extracted by maceration using 96% ethanol. Total anthocyanin content was determined by UV-Vis spectrophotometry using the pH differential method. Four formulations were prepared: F0 (0%), F1 (4%), F2 (6%), and F3 (8%). Physical properties and stability were evaluated for four weeks at 25–30°C. Data were analyzed using appropriate parametric tests. Results: Extract yield was 23.2%, with total anthocyanin content of 9.40 mg/L, equivalent to 0.094 mg/g extract. All formulations were homogeneous and water-in-oil emulsions. F1–F3 maintained pH 4.5–6.5, whereas F0 remained above this range. Mean adhesion increased from 7.299 ± 0.173 s (F0) to 10.458 ± 0.096 s (F3) (p<0.001Conclusion: Raspberry extract contained measurable anthocyanins and could be incorporated into physically stable lip cream. However, its effectiveness and anthocyanin stability as a colorant after formulation remain unconfirmed. F2 provided the most balanced physical characteristics among the extract-containing formulations tested in this study