Bernardo Junior Quispe-Ciudad’s scientific contributions

Global food demand is rising, leading to increased food waste, which contains underutilized bioactive compounds. The Pressurized Liquid Extraction (PLE) method employs high temperature and pressure to maintain the solvent in a liquid state above its boiling point, thereby minimizing extraction time and solvent usage. Ginger waste is known to contain bioactive compounds with significant antioxidant activity. We aimed to assess the effect of temperature, time, and particle size on the total phenolic content (TPC) and antioxidant activity (AA) of ginger (Zingiber officinale R.) waste aqueous extract using the PLE method. A Box–Behnken design with 16 runs was employed. Each extraction utilized 40 g of the sample and was conducted at a constant pressure of 20 bar with a solvent ratio of 27:1 mL/g. Data analysis was performed with Minitab® 19.1 (64-bit). TPC ranged from 10.42 to 14.1 mg GAE/g, and AA ranged from 72.9 to 111.9 μmol TE/g. The model explained 81.07% of AA’s total variability. Positive correlation was found between TPC and AA (Pearson’s ρ = 0.58, p < 0.05). The optimized extraction conditions were a temperature of 126 °C, an extraction time of 38 min, and a particle size between 355 and 500 μm. Temperature significantly influenced AA (p < 0.05), while time and particle size were not significant factors. To enhance future research, conducting nutritional and functional studies on the extracted compounds would provide valuable insights. Lastly, evaluating the economic feasibility of using PLE for ginger waste valorization should be considered to support its commercial application.

Global demand for food shows an increasing trend, which implies that volumes of food waste also increase. These wastes contain bioactive compounds that are not properly utilized or valorized. It was reported that ginger waste contains phenolic compounds with high antioxidant activity. Thus, this study aimed to evaluate the effect of temperature, time, and particle size on the total phenolic content (TPC) and antioxidant activity (AA) of ginger (Zingiber officinale R.) waste aqueous extract using the Pressurized Liquid Extraction (PLE) method with water as the sole solvent. Box-Behnken design was used. The sample was 1.60 kg of dried ginger peel powder. Data analysis was performed with Minitab ® 19.1 (64-bit). TPC ranged from 10.42 to 14.1 mg GAE/g, and AA (DPPH method) ranged from 72.9 to 111.9 μmol TE/g. The model explained 81.07% of AA’s total variability. Positive correlation was found between TPC and AA (Pearson's ρ = 0.58, p < 0.05). Response optimization values were 126 °C and 38 min. Temperature was a significant factor (p < 0.05) influencing AA, while time and particle size were not significant. Higher temperatures, longer extraction times and smaller particle sizes increase TPC and AA of the ginger waste aqueous extract.