Study of hydrolysis and production of instant ginger (Zingiber officinale) tea

Abstract

The aim of this study is to determine the suitable conditions for enzyme-assisted hydrolysis and the production of instant tea from hydrolysed ginger. Several parameters of ginger hydrolysis were investigated, such as the enzyme concentration from 0.1 to 0.4 g/100 g ginger powder (w/w), material/water ratios of 1/10; 1/15; 1/20; and 1/25 (w/w), pH from 3.5 to 5.0; temperature of hydrolysis process from 45 to 60°C, and time of hydrolysis process from 90 to 150 min. Subsequently, the hydrolysed ginger was spray-dried to produce instant products with surveyed parameters, including the maltodextrin concentration from 15 to 35 g/100 g ginger extraction, feed flow rates from 120 to 600 mL/h, and the temperatures of spray drying from 120 to 150°C. The suitable parameters for enzyme-assisted hydrolysis and production of instant tea were determined, including enzyme concentration as 0.2 g/100 g ginger powder (w/w), material/water ratio as 1/10 (w/w), pH at 5.0, temperature process as 55°C, the time of hydrolysis process as 120 min, the maltodextrin concentration as 15 g/100 g extraction (w/w), feed flow rate as 240 mL h-1, and the inlet temperature as 140°C. Furthermore, the physicochemical properties of the product were identified with moisture content as 2.36 ± 0.09%, total phenolic content as 98.34 ± 0.59 mg gallic acid equivalent/g DW, and IC50 value as 1,082 μgAA/mL.