Thermal treatments affected to quality attributes of Solanum procumbens Lour.

Abstract

Solanum procumbens Lour. plant has been distributed in many places of Vietnam and tropical regions. Its extract includes numerous therapeutic properties in pharmacopeia. This research evaluates the possibility of dried herbal tea production from this valuable phytochemical source. Different variables of vapor steaming, convective drying, roasting are verified to monitor the degradation of total phenolic content, total flavonoid content, diphenylpicrylhydrazyl (DPPH) free radical scavenging, ferric reducing antioxidant power (FRAP) and overall acceptance in Solanum procumbens. Results show that Solanum procumbens should be blanched by steaming within 45 s as primary treatment, dehydrated at 45/7.0 ºC/hrs, roasted at 150/20 ºC/min to preserve the most antioxidant constituents with total phenolic content, total flavonoid content, half inhibitory concentration (IC50) of DPPH, FRAP as well as the highest organoleptic value. High retention of total phenolic content, total flavonoid content, antioxidant power as well as high sensory score of the dried Solanum procumbens herbal tea plays an important decision in consumer preference and acceptance. All these processing steps can be performed in simple handling with universal available equipments like steaming oven, convective drier and roasting oven. Findings in this study will be useful data for house-hold scale production.