EXPERIMENT 3 PREPARATION OF ______MISHTI DAHI ______

Structure

3.1 Introduction 3.2 Objectives 3.3 Experiments Principle Requirements Procedure Observation Results 3.4 Precautions

3.1 INTRODUCTION

Mishti dahi or is a popular traditional sweetened fermented milk product. In Eastern part of , especially in West , , Bihar and Orissa, the sweetened variety of dahi known as Mishti dahi, Lal dahi or Payodhi is quite popular. The product is prepared by the Halwais on a small scale. It is a delicacy of choice during religious festivities and is considered an auspicious item to serve while starting journey or any important work. The product is commonly sold in earthen pots of varying sizes.

3.2 OBJECTIVES

The students should be able to: a) Prepare good quality mishti dahi. b) Evaluate the quality of mishti dahi.

3.3 EXPERIMENT i. Principle

Mishti dahi is a fermented milk product, having creamish to light brown colour, firm body, smooth texture, sweet-sour taste and pleasant aroma. The milk is heated to desired consistency, sugar is added during heating of milk and thereafter desired starter culture is added to set the dahi at proper temperature of incubation. ii. Requirements

i) Multipurpose vat

ii) Plate heat exchanger/ HTST pasteurizer.

iii) Homogenizer. 11 Practical iv) Incubation room/ incubator Manual— Dairy Products-III v) Plunger. vi) Polystyrene cups. vii) P a ckaging machine. viii) Milk and sugar. ix) Dahi starter culture. x) Thermometer (0-100oC). xi) Heating and cooling medium (steam and chilled water). xii) Fat and acidity testing kit. x i i i ) Muslin cloth. xiv) Refractrometer for total solids.

iii. Procedure

i) Take good quality cow/ buffalo milk (selected on the basis of acidity and organoleptic quality) and standardize it to 3.5 per cent fat and 9.0 per cent SNF.

ii) Filter the standardized milk through a muslin cloth and then pre heat at a temperature of 75-80oC either in a plate heat exchanger or a multipurpose vat.

iii) Homogenize this milk at single stage at a pressure of 800 psi.

iv) Take this milk in a heating kettle/ vat, add sugar at the rate of 12-13 per cent of milk and heat at 85oC with continuous stirring. The heating should be continued till the milk is concentrated up to about 1.5 times and this normally takes 40 minutes. A caramelized flavour also develops during this period.

v) Cool the milk to about 30oC. Add lactic acid culture (LF-40) at the rate of 1.0 – 1.5 per cent and mix well.

vi) Fill the cultured milk into polystyrene cups under aseptic condition. Incubate the cups at 30oC till the is properly set and the desired acidity develops (about six to seven hours).

vii) Finally, store the cups under refrigerated condition (below 5oC).

iv. Observations

i) Particulars of Milk

Type of milk ______Fat ______%

Solid-not-fat ______% Acidity ______%

12 Quantity ______kg. ii) Standardization Preparation of Mishti Dahi

Desired fat % in standardized milk ______%

Amount of skim milk/ cream/ SMP added ______kg.

Quantity of standardized milk made ______kg.

Fat of standardized milk ______%.

SNF of standardized milk ______% i i i ) Homogenization of Milk ______.

Mode of pre-heating ______.

Temperature of pre-heating ______OC

Pressure of homogenization ______. iv) Processing of Milk

Rate of sugar ______%

Amount of sugar added ______kg.

Methods of heating mixture ______.

Temperature of heating ______oC.

Duration of heating ______min

Temperature of cooling ______oC. v) Inoculation and Incubation of Milk

Type of starter culture ______.

Acidity ______%

General characteristics ______.

Amount of inoculum ______gm.

Temperature of milk at the time of inoculation ______oC.

Period of setting ______hrs. vi) Particulars of Mishti Dahi

Amount obtained ______% Out-turn ______%

Chemical quality

Acidity ______% Total solids ______% Fat ______% Sugar ______% 13 Practical Manual— Dairy Organoleptic quality Products-III Flavour Body and Texture ______

Colour Appearance ______

v. Results

Write your observations in a tabular form and compare the quality of mishti dahi prepared from cow, buffalo and mixed milk. Record organoleptic quality of the product

3.4 PRECAUTIONS

i) Use fresh and good quality milk.

ii) Milk should be free from antibiotics and other inhibitory substances.

iii) S tir milk continuously while heating with sugar.

iv) Use fresh and good quality culture.

v) Maintain aseptic conditions during the processing, transfer of the starter culture and packaging.

vi) Store set mishti dahi at refrigeration temperature.

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