Optimization of drying process for Rosa pimpinellifolia L. fruit (black rose hips) based on bioactive compounds and modeling of drying process

Abstract

Rosa pimpinellifolia, commonly known as the burnet rose, has shown huge functional properties and industrial potential. In this present study, the convective drying process was optimized to enhance the quality, antioxidant activity, and phenolic compounds. The influence of drying conditions on the drying and rehydration kinetics and mathematical modeling of the R. pimpinellifolia fruit (black rose hips) were investigated. Response surface methodology was used to detect the optimum drying conditions (i.e. temperature and air velocity). The optimum operating conditions were 67.21°C and 1.75 m s−1 providing maximum total phenolic compounds, total anthocyanin, DPPH radical scavenging and Ferric Reducing Antioxidant Power (FRAP) values of 1327 ± 5 mg GAE/100 g, 491 ± 2 mg c3g E/100 g, 110 ± 2 mmol TE/g and 698.00 ± 15 mmol ISE/g, respectively. The Page Model was the most fitted model to predict the drying kinetics. Vegas-gálves and Peleg models were the most effective to describe the rehydration kinetics. The rehydration was more efficient at 60°C compared to 20 and 40°C. The convective drying increased hardness, cohesiveness, gumminess, and chewiness while decreasing springiness and resilience. Catechin, epicatechin, quercetin-3-glucoside, protocatechuic acid, chlorogenic acid, quercetin, rutin, fumaric acid, and gallic acid were the major phenolic compounds identified. The drying process thus improved the quality, antioxidant activity, and overall phenolic compounds of R. pimpinellifolia.

Keywords

• black rose hip
• rosa pimpinellifolia l.
• drying
• antioxidant
• rehydration
• modeling
• response surface methodology