Different drying methods of Pistacia Atlantica seeds: Impact on drying kinetics and selected quality properties

The Quality of Infrared Rotary Dried Terebinth (Pistacia atlantica L.)-Optimization and Prediction Approach Using Response Surface Methodology

Most agricultural products are harvested with a moisture content that is not suitable for storage. Therefore, the products are subjected to a drying process to prevent spoilage. This study evaluates an infrared rotary dryer (IRRD) with three levels of infrared power (250, 500, and 750 W) and three levels of rotation speed (5, 10, and 15 rpm) to dry terebinth. Response surface methodology (RSM) was used to illustrate and optimize the interaction between the independent variables (infrared power and rotation speed) and the response variables (drying time, moisture diffusivity, shrinkage, color change, rehydration rate, total phenolic content, and antioxidant activity). As infrared power and rotation speed increased, drying time, rehydration rate, antioxidant activity, and total phenolic content decreased, while the other parameters were increased. According to the results, the optimum drying conditions of terebinth were determined in the IRRD at an infrared power of 250 W and drum rotation speed of 5 rpm. The optimum values of the response variables were 49.5 min for drying time, 8.27 × 10⁻⁹ m²/s for effective moisture diffusivity, 2.26 for lightness, 21.60 for total color changes, 34.75% for shrinkage, 2.4 for rehydration rate, 124.76 mg GAE/g d.m. for total phenolic content and 81% for antioxidant activity.

Optimization of fortified sponge cake by nettle leaves and milk thistle seed powder using mixture design approach

Powdered nettle leaf and milk thistle (MT) seed were added to the cake batter with certain percentages selected by the Design-Expert v. 10 software (0-25, 25-0, 18.75-6.25, 6.25-18.75, and 12.5-12.5). Addition of nettle and MT seeds to the cake reduced the moisture content, volume, and springiness and increased hardness of the samples. 12.5% nettle-12.5% MT seed had the least hardness and the highest amount of springiness and cohesiveness. The highest BI, WI, SI, L*, a*, and b* and the lowest ΔE were observed in 12.5% nettle-12.5% MT seed and 25% MT seed samples, respectively. Antioxidant activity and antimicrobial properties were increased in all samples compared to the control sample, so that 6.25% nettle-18.75% MT exhibited the highest antioxidant activity and antimicrobial properties. The highest levels of quercetin and silymarin were observed in 25% nettle and 25% MT seeds, respectively. In the sensory evaluation, 12.5% nettle-12.5% MT seed took the best scores regarding flavor, texture, color, and overall acceptance. Based on the lowest hardness, 13.65% nettle-11.34% MT seed was determined as optimized points by the software, which was equivalent to desirability of 0.72. The optimum sample contained 62.90 mg quercetin and 886.70 mg silymarin. According to the HPLC analysis results, consumption of 10 optimal cakes daily could theoretically decrease the blood sugar level, which requires further studies. The remaining amount of quercetin and silymarin in 2.5 g of nettle leaves and 2.5 g of MT seeds after heating was 11 and 19 mg, respectively. In other words, heat did not have much effect on the destruction of quercetin and silymarin.