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Introduction: Coffee silver skin (CSS) is a thin covering over green coffee seeds inside coffee cherry. It is a good source of bioactive compounds like chlorogenic acid and caffeine. It is produced as a by‐product of the roasting process. Objective: The goal of this study is to apply spray drying method to encapsulate 5‐O‐caffeoylquinic acid (chlorogenic acid) and caffeine extracted from CSS. Methods: The main‐plots for optimisation were feed solid concentration (2.5, 5, 10°Bx), and the sub‐plots of the whole‐plot were carrier material type (maltodextrin, modified starch, arabic gum) and inlet air temperature (130, 160, 190°C). Responses included were drying yield, chlorogenic acid concentration, caffeine content, Carr index, and solubility values. Results: Suitable conditions were spray drying inlet temperature of 190°C, extract concentration of 10°Bx, and wall material composition [modified starch/arabic gum (MS:AG)] 10.5:9.5. As the feeding CSS extract concentration increased, the amount of chlorogenic acid and caffeine in the final powder increased, while the powder's flow characteristics improved. Conclusions: The concentration stage might be used to produce free‐flowing powdered particles with good bioactive retention for use in the food processing industry. The CSS extract can be successfully transformed into soluble powder using the spray drying process, based on product yield results (>50%). The optimum conditions are found as inlet temperature of 190°C, extract concentration of 10°Bx, and wall material composition (MN:AG) 10.5:9.5. The concentration treatment has a greater impact on the caffeine and chlorogenic acid content than the carrier material type. The findings reveal that the starting concentration has an impact on the final product's physical qualities. [ABSTRACT FROM AUTHOR]

Bitter gourd (Momordica charantia L.) is a plant species belonging to the Cucurbitaceae family, growing in tropical regions and containing health-promoting beneficial compounds. In the current study, bitter gourds prepared for drying were sliced in three different thicknesses (6, 8 and 10 mm) and dried in a hot-air dryer at three different temperatures (60, 70 and 80 °C) to preserve their medicinal efficacy. In the experiments, the samples were subjected to blanching at 93.5 °C and 2% salt water for 0, 2.5 and 5 min, and drying processes were conducted. After the drying process, drying time, total color change (∆E), total phenolic content (TPC), total antioxidant activity (TAA), and vitamin C properties were examined. The highest levels of TPC and TAA were found at lower drying air temperatures (DATs), and while these values increased with longer blanching times at lower DATs, they decreased with longer blanching times at higher DATs. According to the different drying temperatures used, it was discovered that the total color change peaked at 70 °C and that vitamin C levels declined as DAT rose. The optimal drying conditions for the 3D response surface methodology include 60 °C DAT, a slice thickness of 10 mm, and without blanching to maximize TPC, TAA and vitamin C content and minimize drying time and ∆E. [ABSTRACT FROM AUTHOR]