Simultaneous extraction and pasteurization of a drink from 'Blood Root' (Justicia secunda) leaves stabilized with a natural preservative: Optimization and storage

摘要

Simultaneous extraction and pasteurization (SEPA) has recently been presented as an appealing process in juice processing because of significant reduction in time, energy consumptions, and production cost resulting from the combination of unit operations. However, the optimum SEPA operating conditions and their effects on the quality and shelf-life of juice are still unmastered. The Doehlert experimental design was used to optimize the SEPA process of juice from Justicia secunda leaves. Optimum conditions for vitamin C retention were temperature (80 degrees C), quantity of ginger (2.6 g/100 ml) and time (20 min) which gave a vitamin C concentration of 4.61 mg/100 ml. The second part of the study evaluated the stability of juice using ginger powder as a natural stabilizer. Results showed that juice produced with and without ginger (WOG) retained 81.27 and 51.18% of their initial vitamin C contents on Day 9 of storage, respectively. Vitamin C content, pH, and acidity showed that addition of ginger preserved the quality of the juice better than that WOG throughout the storage period. Ginger is a natural source of preservative that contributes to the vitamin C content of the juice and extends its shelf-life from 3 to 9 days for storage at room temperature.Practical applicationsThis work describes simple procedures that can be used to extract and pasteurize juice from plant material with simple equipment simultaneously. The optimum conditions that retain more than 90% of the initial vitamin C content of the juice are defined and the use of ginger as a natural preservative that prolongs the shelf-life of the drink at room temperature makes the process very appealing. The process can be easily adapted and used at both laboratory, local and industrial levels to produce juice of good quality.