Boondi and laadu – Traditional Foods of India

Traditional Food of India

4.1.Boondi and laadu

Boondi (fried chickpea batter droplets) is a popular traditional snack in India and neighboring countries (Figure 4.1.1). It is consumed as (a) a crispy fried snack after adding salt and a spice like chilli powder, (b) the less fried sample is soaked in sugar syrup and consumed as sweet boondi, and (c) the sugar syrup-soaked sweet boondis are formed into balls to be called laadu. Small-sized laadus are also known as darbesh.

Different varieties of laadu
Besan (Bengal gram or chickpea) laadu is the most common product that is prepared from flour. Motichur, popular in North India, is a laadu (Figure 4.1.2) variety prepared with very small sizes of sweet boondi. The usual colour is light orange, yellow or pink. Laadu is also made from roasted wheat flour, fine semolina (sooji), flour or grits of other cereals, millets or pulses like ragi (finger millet), besan (Figure 4.1.2) and green gram (moong). Mawa or khoa (semi-solid mass of concentrated milk) laadu is also available in North India. Mihidana from Bardhaman district of West Bengal is sweet small boondis of 1-2 mm in diameter.

Raw materials
Chickpea (channa, chole or Bengal gram) flour or besan and frying oil are the main raw materials required for the preparation of boondi. In the case of ready-to-eat salty boondi snacks, the additional ingredients are salt and spice powder like chilli while sugar is used for sweet boondi and laadu. The optional ingredients are rice flour, raisin, baking soda, khoa, pieces of sugar candy and nuts like cashew nuts and almonds, while cardamom and clove may be used for flavouring.

Method of preparation
Fine flour of chickpea or Bengal gram (besan) is mixed with water, containing a small amount of salt, to obtain a smooth batter having about 40% solids. The batter is then allowed to fall under gravity (for a batter having less consistency/viscosity) through a perforated ladle having several circular openings. The diameter of these openings is between 3 and 6 mm. In the case of small-sized boondi like mihidana and a product like motichur laadu, the openings are small (about 1 mm in diameter or less). In some practices, the batter is gently pressed/rubbed against the perforated ladle when the consistency/viscosity of the batter is high. These droplets fall directly on hot oil, maintained at a temperature of 170-1800C. The time of frying varies between 90 and 240 seconds; the time varies with the size of batter droplets to be fried and the extent of frying required or the texture of the finished product to be obtained. In the case of a crispy ready-to-eat product like savoury snack, the frying time is long; the finished product is marginally hard and crispy. On the other hand, less frying time is needed for confectionery products like sugar syrup-soaked boondi and laadu (Figure 4.1.3) where the frying is limited to obtain a semi-soft and cooked product.

The fried samples are immediately soaked with the minimum quantity of warm sugar syrup to obtain sweet boondis. These sugar syrup-soaked boondis are usually formed into a spherical product called laadu. The diameter of laadu usually varies from 25 mm to 100 mm, and the process of ball making is manual in sweetmeat shops and small production units. In some cases, the frying process and ball-making step are mechanised. A forming extruder or pasta press makes small-size cylindrical pieces that are finally given a round shape while moving in an open-barrel co-rotating twin-screw device or placed between the reciprocating parallel plates. The formation of laadu is easy when the boondis are warm and a significant portion of boondis is crushed. The extent of crushed boondi in laadu may be 20% and above; the crushed item helps in the formation of the spherical and cohesive samples called laadu. The sugar syrup coming out during crushing/ball formation also helps in the formation of cohesive laadus.

The fried boondi has a shelf-life of about 3 months when crispness, the key feature of acceptance, starts decreasing. The sweet boondi and laadu can be stored for 20 to 30 days; the absorption of moisture and fungal infection could be the possibilities that can happen in these products like other sugar-rich semi-moist foods.

Technical data

The process of boondi preparation is a traditional process in India where frying of a high moisture-containing batter in the form of droplets is done to develop ready-to-eat snacks. It may be worth mentioning that products based on the frying of batter droplets are rare though frying of batter-coated snacks is practiced.
Chickpea batter was reported to exhibit non-Newtonian shear-thinning characteristics, time-dependent (thixotrpic) behaviour and possessed yield stress. Yield stress was affected by the particle size of the flour as well as the concentration of solids in the batter.
The development of sugar-free boondi and laadu has been reported. Sorbitol, a mixture of sorbitol and mannitol along with a permitted intense sweetener could be used to replace sucrose.
A sharp temperature drop of up to 15oC was reported when the batter droplets were put into the hot oil, which might take about 20 seconds to regain the desired frying temperature.
The frying characteristics of small and large boondis indicated that the rate of moisture loss during frying was much higher than that of oil uptake. Large-sized fried boondis had less oil content (about 52%, dry basis) compared to smaller samples (about 57%, dry basis).
The fried product (crisp boondi) had a moisture content of about 3% (dry basis). The use of a higher concentration of chickpea flour and/or the addition of gum Arabic in the batter decreased the oil content up to 20% in the fried boondi.
The shape of the sample also varied with the type and level of ingredients used for batter making. An increase in the concentration of chickpea flour and/or gum Arabic changed the desired spherical shape of the fried boondi to an ovoid/oblong shape. The use of 37% chickpea flour containing 0-2% of gum Arabic or 40% chickpea flour containing 0-1% gum Arabic in the batter has been reported to produce a near-spherical product.
The fried crisp product showed a porous microstructure possessing small cavities and large vacuoles. The detailed textural characteristics of the product were also reported.
The concentration of sugar in the syrup used for soaking fried boondi is around 50%. The moisture and fat contents of sweet boondi and laadu are 15-25% and 10-15%, respectively.

Machinery
The processing of boondi and laadu requires a batter mixing unit like a planetary mixer, batter dispensing unit, continuous/batch fryer, deoiling unit, laadu forming gadget and packaging machinery.

Requirements

There is a need to increase the shelf-life of fried crisp savoury boondi from the existing 3 months to 6 months through research efforts that will help industries to manufacture and market the product for internal consumption and export purposes.
Less fat-containing fried savoury boondi is needed. The use of gum Arabic or other hydrocolloids in the batter formulation, and deoiling after frying is possible. The other alternative technology is the use of an extrusion cooking process to develop expanded snacks that are finally seasoned with a small quantity of oil, salt and spice powder.
The sugar syrup-soaked boondi and laadu have a low shelf-life at ambient temperature. Attaining a shelf-life of 3 months will be highly useful.
The mechanisation of the whole process may lead to large-scale manufacture of the product with improved hygienic status and consistent product quality.
Specification of the product with an emphasis on moisture and fat contents, and microbial status is desired.

Further reading
Bhat, K.K. and Bhattacharya, S. (2001). Deep fat frying characteristics of chickpea flour suspensions. International Journal of Food Science and Technology 35, 499-507.

Bhattacharya, S., Bhat, K.K. and Raghuveer, K.G. (1992). Rheology of Bengal gram (Cicer arietinum) flour suspensions. Journal of Food Engineering. 17, 83-96.

Chetana, R., Srinivasa, P.C. and Yella Reddy, S. (2006). Effect of sugar substitutes on moisture sorption characteristics of laddu, an Indian traditional sweet. Journal of Food Science and Technology 43, 634-638.

Ravi, R., Roopa, B.S. and Bhattacharya, S. (2007). Texture evaluation by uniaxial compression of some snack foods. Journal Texture Studies 38, 135-152.

Ravi, R. and Susheelamma, N.S. (2005). Simultaneous optimization of a multi-response system by desirability function analysis of boondi-making: a case study. Journal of Food Science 70, S539-S547.

Shanthilal, J., Babylatha, R., Navya, M.C., Chakkaravarthi, A. and Bhattacharya, S. (2018). Frying of the dispersion droplets with varying contents of chickpea flour and gum arabic: Product characterization and modeling. Journal of Food Science 83, E648-E660.

Shanthilal, J. and Bhattacharya, S. (2016). Time-independent and time-dependent rheological characterization of dispersions with varying contents of chickpea flour and gum Arabic employing the multiple loop experiments. Journal of Food Science 81, E1938-E1948.

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