Extraction and process optimization of East Indian red wood (Caesalpinia sappan) in stirred yoghurt Geetha P.1,*, Sharon M. Esther Magdalene2 1Department of Food Processing Technology, College of Food and Dairy Technology, TANUVAS, Koduveli, Chennai-600052 2Department of Dairy Chemistry, College of Food and Dairy Technology, TANUVAS, Koduveli, Chennai-600052 *Corresponding author’s e-mail: drgeethaprincy@gmail.com
Online published on 31 March, 2025. Abstract Yoghurt is a fermented dairy product, having several health benefits. Redwood sappan wood (Caesalpinia sappan) is a plant yielding bark and stem with water soluble red pigment. Two methods of colour extraction were carried out, namely, Heat Extraction (extraction by aqueous & alcohol) and Cold Extraction (Ambient temperature & Refrigerated temperature) using five different medium such as distilled water, potable water, sodium carbonate solution, sodium hydroxide solution and ethyl alcohol. Among the mediums tried, potable water was found to be the best medium for extraction. The bark was heated in potable water for 2.5 h. The heat extracts had a pleasing pink to red colour. The colour of the extract was pH dependent, it was yellowish to brown at below neutral and pink to dark red at above neutral pH. Stirred type of yoghurt was prepared by standard method using cow milk. Redwood extract level was optimized at three levels viz. 10 mL, 20 mL and 30 mL with skim milk powder @ 40 gm and sugar 20 gm per 100 mL of yoghurt. Redwood extract 20 mL optimized based on 9-point Hedonic scale, textural parameter and storage stability of colour extraction up to 7 days. Physico- chemical analysis of the redwood added stirred yoghurt product such as pH, acidity(%), Lactose (%),Sucrose (%), Protein (%), Ash (%), Fat (%) values are 4.6±0.01, 1.02±0.00, 5.76±0.01, 20.44±0.02, 3.89±0.01, 1.10±0.01 and 2.49±0.10. respectively. Top Keywords Yoghurt, Redwood, Extraction, Syneresis, Texture, Colour, Storage. Top |