Stability of the Key Substances in Isaria tenuipes Extracts in Cosmetic Products

Abstract

This paper quantified key bioactive substances in Isaria tenuipes extracts on a dry weight basis, including cordycepin (0.32 mg/g), adenosine (5.62 mg/g), and polysaccharides (65.8 mg/g). Antioxidant activity was evaluated using DPPH and ABTS assays, yielding IC₅₀ values of 0.27 mg/g and 0.04 mg/g, respectively. Stability testing demonstrated that polysaccharides and adenosine remained relatively stable (less than 10% degradation) after 12 weeks of storage at both 4°C and 30°C, whereas cordycepin exhibited a greater reduction. The optimal formulation for incorporating I. tenuipes extract into a serum product was identified as 2.0% (w/w). After 12 weeks of storage at 30°C, the primary active compounds in the serum showed minimal degradation (<10%), while the pH, viscosity, and color remained stable at 4°C. Microbiological analysis confirmed compliance with industrial safety standards. Consumer evaluation using a 5-point hedonic scale (n = 100) indicated high satisfaction with moisturization (4.02), texture (3.93), absorption (4.10), and overall preference (4.06), outperforming a commercial reference product. These findings highlight the stability and cosmetic potential of I. tenuipes extract-based formulations.