Preparation of Instant Dhokla Mix (Flour) using fermentation technology.

 Introduction :

Dhokla is a vegetarian culinary dish that is found mainly in the Indian state of Gujarat and parts of adjacent states. It is made with a fermented batter derived from rice and split chickpeas. Dhokla can be eaten for breakfast, as a main course, as a side dish, or as a snack. 

Alternative names :	Dhokla
Course :	Breakfast, side dish, main course
Place of origin :	India
Region or state :	Gujarat, Maharashtra
Serving temperature :	room temp
Main ingredients :	Besan (chickpea flour) and rice flour
Variations :	Khaman

Science Behind Dhokla :

Dhoklas are made of besan (roasted Bengal gram flour), sour curd/buttermilk, and eno fruit salt / baking soda. Each ingredient contributes itself to play a role in making the final dhokla that we see as an end result. 

1. Besan : besan is the protein source in the dhokla. Proteins when heated along with water (in this case buttermilk contains the required water content) starts to swell and therefore increases the mobility of dry protein content. This is why we get the texture and the mouthfeel that we get in the dhokla. Besan also has a binding property because of which it binds to the flavours and gives a characteristic flavour and aroma of dhokla. 

2. Sour Buttermilk : The catch here is the word sour, which indicates that the curd from which the buttermilk is made has already undergone enough fermention to release carbon dioxide by the lactobacillus bulgaricus and streptococcus thermophilus bacteria. This leads to aeration or leavening resulting in a fluffy, well risen dhokla. Secondly, buttermilk has some portions of the lipids / fats which act like an emulsifying agent and emulsifies the besan molecules to make a homogeneous mixture, thereby giving a smooth mouthfeel. 

3. Eno fruit salt or Baking soda : either of these ingredients may be used but both if these contain sodium carbonate, which when combined with the acidic components present in curd or buttermilk and reacts with some acids such as (cream of tartar) tartaric acids. On heating, these two components react together to produce carbon dioxide molecules which is trapped between the besan molecules and causes the dhokla to rise and give a volume to it. 

Tartaric acid + sodium bicarbonate → sodium tartrate + carbon dioxide + water 

C4H6O6 + 2 NaHCO3 → Na2C4H4O6 + 2 CO2 + 2 H2O

Need:

At present in the market, instant  Dhokla flour is available, but it is mostly not   fermented. Our plan is to prepare instant Dhokla flour/mix which is naturally fermented and  hence expected to have better glycemic index.

Objectives:

1) To prepare naturally fermented Idli and dhokla flour

2) Shelf life of 3 months

3) No or low preservatives

4) No need of refrigerator storage

Idea or Technology to Achieve Objectives :

1) Fermentation technology

2) Drying methods :

• Sun drying
• Oven dry
• Electrical dryer

Literature :

1. Formulation of Nutritious Mixes for Development of Dhokla and their Quality Evaluation 

Dhokla is a popular fermented food of India. It is steam cooked

fermented Indian breakfast food prepared from bengal gram flour. The

popularity of Dhokla is due to its delicate spongy texture and its digestibility.

• Chickpea

• Soybean

• Rice

• Kodo millet

• Kutki millet

Raw materials & methods used for preparation of fermented products :

• Proximate composition of Bengal gram: The various constituents in the bengal gram viz., moisture ranged from 5.34 to 12.7, protein 16.7 to 24.6, fat 4.9 to 6.85, total ash by 2.04 to 3.3, crude fibre 1.7 to 10.79 and carbohydrates from 56.8 to 70.9%

• .Proximate composition of Soybean :   Soybean (Glycine max.) with 40% protein and 20% oil. Mineral analysis of soybean seeds revealed that they are rich in sodium (0.48 to 0.61%). potassium (1.56 tol .92%) and phosphorous (0.352 to 80.753%). The calcium (0.024 to 0.063%) and iron (0.0044 to 0.0163%) were found at low level.

• Proximate composition of full fat Soy flour :
• Proximate composition of rice flour : contain crude protein 12.6 g crude fibre 0.19 g and phytate phosphorus 0.06 g per 100 g of the material. 

Material and method : 

• Food commodities
• Cleaning
• Preparation of chickpea flour
• Preparation of rice flour
• Preparation of full fat soy flour

Nutritional evaluation of instant mixes : 

• Determination of Moisture content (method described in AOAC )
• Determination of Fat content (method described in AOAC )
• Determination of Protein content  (method described in AOAC )
• Determination of Ash content (method described in AOAC )
• Determination of Crude Fibre (method described in AOAC )
• Determination of Total Carbohydrates (method described in AOAC )

Sensory quality characteristics of rice based instant mixes : 

•  overall acceptability ranged in between 6.9 to 8.5.

1. Formulation of Nutritious Mixes for Development of Dhokla and their Quality Evaluation by Anand Agricultural University, Anand

Parameters: 

• Effect of fermentation time : 5.5-12.5 hrs
• Fermentation temperature : 26.5-35.5 C
• Moisture content of batter : 55-65 %
• Rice : Bengal ratio:- 1:2

Optimized condition for fermentation process was: 

• Total titratable acidity (TTA) : 0.64 g/mL
• Overall acceptability score (OAA) : 6.82 AT 12.5 hr
• Total lactic count : 221.62 cfu/g
• Firmness : 146.35 g

Protocol :

• Grains and splits were washed with clean water.
• Initial moisture content od sample was determined in hot air oven maintained at 100 C until the constant sample weight was obtained.
• Rice, bengal gram and black gram splits were weighed according to varying formula as per the experimental design and soaked in water for 125 min at ambient.
• After that grains and splits were ground in mixer to make batter
• After that batter was allowed to ferment in the incubator at different temperature for different time interval as per experimental design.
• After fermentation, 2% salt of total weight of batter was added for taste and mixed thoroughly.
• Fermented batter was steam cooked in dhokala vessel under atmospheric pressure for 10 min.

• Total titratable acidity (TTA), overall acceptability score (OAA), total lactic count, firmness were taken as response to optimized the fermentation process.

Protocol :

• Weigh 2 kg of chick pea and kept it for soaking in water for 6-8 hrs.
• Soaked chick peas kept for drying .
• After drying chick dal is prepared.

Trials :

1. Protocol :

• 75 gm chick pea flour.
• Salt + turmeric powder.
• Above ingredients mix water .
• Prepared batter kept for fermentation at temp  26°c and time 8 hrs.
• After 8 hrs, batter becomes sticky with unpleasant.

2. Protocol :

• 75 gm chick pea dal soaked in water for 6 hrs.
• Soaked chick pea dal grind in mixer for the preparation of batter.
• 60 gm curd in it + salt and turmeric powder. Mixed properly.
• Kept 8 hrs for fermentation.
• After 8 hrs, Steamed batter for 20 min on low flame.

3. Protocol :

• 75 gm chick pea flour
• 60 gm curd + Salt + turmeric powder.
• Mix above ingredients by adding water 
• Prepared batter kept for fermentation at temp  26°c and time 8 hrs
• After 8 hrs. Steamed batter for 20 min on low flame.

4. Protocol :

• 100 gm chick pea flour
• Add 80 gm curd + Salt + turmeric powder + sugar + semolina + lemon juice.
• Mix above ingredients by adding water 
• Prepared batter kept for fermentation at temp  27°c and time 8 hrs
• After 8 hrs. Steamed batter for 20 min on low flame.

5. Protocol :

• 100 gm chick pea dal soaked in water for 6 hrs.
• Soaked chick pea dal grind in mixer for the preparation of batter.
• Add 80 gm curd + Salt + turmeric powder + sugar + lemon juice.
• After 8 hrs, Steamed batter for 20 min on low flame

6. Protocol :

• 100 gm chick pea flour
• Add 80 gm curd + Salt + turmeric powder + sugar + semolina + lemon juice.
• Mix above ingredients by adding water 
• Prepared batter kept for fermentation at temp  27°c and time 10 hrs
• After 10 hrs, Steamed batter for 20 min on low flame.

7. Protocol :

• 100 gm chick pea flour
• Add 80 gm curd + Salt + turmeric powder + sugar + semolina + lemon juice.
• Mix above ingredients by adding water 
• Prepared batter kept for fermentation at temp  27°c and time 8hrs.
• After 8 hrs, Add 3/4 gm baking soda in it .
• Steamed batter for 20 min on low flame.

8. Protocol :

• 100 gm chick pea dal
• Add 80 gm curd + Salt + turmeric powder + sugar + semolina + lemon juice.
• Mix above ingredients by adding water 
• Prepared batter kept for fermentation at temp  27°c and time 8hrs.
• After 8 hrs, Add 3/4 gm baking soda in it .
• Steamed batter for 20 min on low flame.

Final Protocol :

Specification:

Technical specification:

1.	Effect of fermentation time :	5.5-12.5 hrs
2.	Fermentation temperature :	26.5-35.5 C
3.	Rice : Chick pea ratio:	1:4
4.	Total titratable acidity (TTA) :	0.64 g/mL
5.	pH :	4.6

Material and Quantity :

Sr.No.	Material	Quantity
1.	Chick pea	200 gm
2.	Rice	50 gm
3.	Water	750 ml
4.	salt	½ tbps
5.	Baking soda	½ tbps

Procedure:  

Step 01 : Take 200 gm of chick pea dal and 50 gm of rice.
Step 02 : Wash and soaked the chick pea nd rice for 10 hrs at room temperature.

Step 03 : After 10 hrs, grind in mixer by adding 200 ml of water.

Step 04 : Kept batter for 10 hrs fermentation at temp  29°c  .

Step 05 : After 10 hrs fermentation, batter oven dry at temp  55°C for 7 hrs.

Step 06 : Dhokla mix ready. Add water, salt and baking soda make batter.
Step 07 : Steam batter at low flame for 25 min.

Result:

 Fermented dhokla mix prepared which is easy to digest. And boost the immune system.

Advantages: 

1.  No or low preservatives.
2.  No need of refrigerator storage.
3. Less time to prepared.

Precautions: 

1. Batter should not ferment above 10 hrs.
2. Drying temperature should not be above 60 ºC.