STUDY OF ENGINEERING PROPERTIES OF MISTI DAHI DURING THE PROCESS OF FERMENTATION USING BATCH FERMENTATION UNIT
Loading...
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ICAR-NDRI, KARNAL
Abstract
Mistidahi is the traditional indigenous fermented milk product produced from partially concentrated sweetened milk. It is popular fermented product of eastern region of India. Mistidahi is analogues to sweetened yoghurt having pleasant caramel colour and flavour. For better taste and acidity its fermentation process must be monitored. Mostly syneresis is the property which affects the body and texture of mistidahi, so proper total solid content is very import while production. Slightly brown colour and caramelized flavour are also very important properties, hence to be monitored continuously. During incubation period of mistidahi the study of pH variation is also necessary. The industrial pH measurement is performed in a discontinuous way, that is because the pH probe is sensitive to both drift and protein deposit. Continuous pH measurement during yogurt fermentation was studied by (Brabandere and Baerdemaeker 1999). During mistidahi preparation both the processes of heating and cooling are involved. The effect of different heating methods on various quality parameters of Misti Dahi was studied. The research is conducted in order to check the fermentation level in a developed batch fermentation unit and to maximise heat transfer and to ensure uniform fermentation level in different zones of batch fermentation unit. Determination of initial and final acidity, pH and viscosity during fermentation was done by continuous pH monitoring system. In convection heater viscosity up to 180 minutes increased very slowly then rapidly increases up to 240 minutes. After that viscosity increases till incubation period of 360 minutes. Convection heater having method have shown the viscosity of 0.35 Pa.s. For proper fermentation and to improve the efficiency of batch fermented unit the acidity was checked for every 30 min. till the incubation is completed. By using web cam and auto mouse clicker applications, images of product were captured at every 10 min. of interval and these images were used for measuring changes in the colour values of product during fermentation process. In convection heater the CIE b* value increased up to 120 minutes then after incubation its value decreased. In halogen and quartz heater CIE b* value continuously increased till incubation. Temperature scanning with the help of PT 100 temperature sensor was continuously done. Sensory analysis (using 9 point hedonic scale) was conducted. Wheying off is the major problem in mistidahi which was controlled in this system. The texture of mistidahi made by different heaters were studied.