Development of a process for shelf stable dairy dessert dalia and its physico-chemical properties

Dalia, is a traditional dairy food of Indian sub-continent. It is consumed as dessert by cooking cracked wheat (dalia grains) in milk along with addition of sugar. It is used as a breakfast food especially for growing children and also for old age people. It has a poor shelf life of 1-2 days. In order to enhance its shelf life, dalia was processed in tin-free steel cans at 121.1 °C in a rotary over pressure retort. Process lethality (Fo) was found to vary from 3.90 to 8.22 min for different formulations. The average composition of retort sterilized dalia dessert comprised of 29.60 g/100 g total solids (TS), 3.56 g/100 g protein, 0.84 g/100 g ash and 21.54 g/100 g total carbohydrates including 2.88 g/100 g amylose. The product had a short lag period for the heating curve, jh (0.40-0.85), small heating rate index, fh (3.2-5.5 min) and a short lag factor for the cooling curve, jc (0.91-1.10) implying essentially convective heating regime. The process time (B) was 10.20-15.78 min for Fo value of 3.90-8.22 min, whereas the cook value (Cg) was 28.95-54.03 min. Fo value of 4.15 min and nisin 376 IU/g yielded a product that was both safe and wholesome for 72 days at 37 °C.

► Retort process for manufacturing dalia dessert was standardized using different Fo and nisin levels. Dalia dessert had a composition of 29.6% TS, 3.66% fat, 3.56% protein, 0.84% ash, 2.88% amylase and 21.54% total carbohydrates. ► Process lethality values in terms of jh, fh, jc, B, and Cg were calculated. jh for dalia dessert was in the range of 0.40-0.85 indicating a convective heating regime. ► Studies on shelf life related parameters such as HMF, TBA and colour indices was conducted. ► Based on regression model, an optimum solution with Fo 4.15 min and nisin 376 IU/g having a shelf life of 72 days at 37 °C was arrived at, which is commercially useful.