NDRI scientists develop technology for low-cal lassi with fizz of cola

A team of scientists from the National Dairy Research Institute in Karnal, Haryana - comprising Falguni Patra, Sudhir Kumar Tomar, A K Singh and Rameshwar Singh - has developed the technology for a reduced-calorie, naturally carbonated, sweetened, fermented dairy beverage, which they believe is not just inexpensive to produce (at Rs 7 per 100g), but also has distinct sensory attributes and moreover, is commercially viable.

A team of scientists from the National Dairy Research Institute in Karnal, Haryana - comprising Falguni Patra, Sudhir Kumar Tomar, A K Singh and Rameshwar Singh - has developed the technology for a reduced-calorie, naturally carbonated, sweetened, fermented dairy beverage, which they believe is not just inexpensive to produce (at Rs 7 per 100g), but also has distinct sensory attributes and moreover, is commercially viable.

Diabetics and weight-watchers (who have to control their sugar and calorie intake respectively) can also enjoy this sweet, flavourful and nutritious lassi, which carries all the virtues of milk. The fizzy characteristic of the product is likely to appeal to children who prefer carbonated drinks (which are otherwise junk foods). This way this product is suitable for consumers of all age groups.

The scientists, who are currently in the process for patenting the technology to manufacture the lassi, claim that it was developed by co-culturing Leuconostoc Ln27, a mannitol-producing native strain of Leuconostoc mesenteroides subsp. mesenteroides isolated and characterised from indigenous fermented milk products, and L. lactis subsp. lactis NCDC 90 under a set of optimised growth conditions.

The final composition of the product so developed was as follows: fat - 1.55 ± 0.05 per cent; protein - 4.73 ± 0.25 per cent; lactose - 4.25 ± 0.25 per cent; sucrose - 5.7 ± 0.3 per cent; mannitol - 3.1 ± 0.17 per cent; pH - 4.43 ± 0.02 per cent; titratable acidity - 0.93 ± 0.026 per cent, and viscosity, 0.395 ± 0.004 centipoises. 

The calorific value of control product was 106kcal/100g where as the developed product had 78 kcal/100g. During product formation there is a 35 per cent reduction in calorific value and 50 per cent reduction in sugar. 

Besides, the product has a novel characteristic effervescent and tingling flavour owing to natural biofortification of product with carbon dioxide produced during fermentation of milk. The product has a storage life of five days under refrigerated conditions.

It produces mannitol, a white crystalline polyol (sugar alcohol with six carbon atoms) found in animals and plants, and in small quantities in fruit and vegetables. 

Applications of mannitol
Mannitol is widely used in the food, pharmaceutical, medicine, and chemical industries. It is only half as sweet as sucrose. Mannitol and other sugar alcohols exhibit lower calorific values than the respective value of most sugars (the calorific values of mannitol and sucrose are 1.6 kcal/g and 4 kcal/g respectively). This makes them applicable as sweeteners in so-called 'light' foods.

At present, mannitol is mainly used in the food industry as a sweetener in sugar-free chewing gums and for dusting chewing gum sticks. Mannitol is also widely used in hard and soft candies, flavored jam and jelly spreads, confections and frostings and cough drops. In addition, mannitol is used as a bodying and texturizing agent, anticaking agent, and humectant. 

Starter cultures of LAB are often prepared by drying which impose stress conditions on the cells. Mannitol has been shown to exhibit osmoprotecting effect during drying of LAB. Mannitol is also known to be endowed with an antioxidant effect by scavenging off free hydroxyl radicals has the potential to extend the shelf life of various foodstuffs.

Some microorganisms can specifically produce mannitol from sucrose or fructose without making a sorbitol byproduct. Several heterofermentative lactic acid bacteria (LAB) belonging to the genera Lactobacillus and Leuconostoc have been studied for production of mannitol from fructose and sucrose. 

Out of these bacteria, Leuconostoc has been recognised to be endowed with enormous technological, functional, and economic applications. They play an important role in several industrial and food fermentation processes. In dairy and food technology, Leuconostoc plays vital multifunctional roles, manifested especially through the production of gas and aroma compounds.

Source: National Dairy Research Institute