Development of a process for the manufacture of shelf stable dhal and its physico-chemical properties

Thermally processed, ready-to consume dhal with natural sensory attributes was developed. Product optimization was done using two variables, retort process time and ratio of water to dhal. Dhal were packed in retortable pouches and processed in a stationary air-steam retort. The product was characterized by a short lag period for the heating curve, j h (0.52-0.64), small heating rate index, f h (3.9-6.5 min) and a short lag factor for the cooling curve, j c (0.53-0.73) implying essentially convective heating regime. The total process time (B') was 11.56-40.25 min for F o value of 2.30-27.30 min. Process time of 25 min at 121 °C and ratio of water to dhal of 2.5 yielded a product that was microbiologically safe as well as sensorily acceptable. During storage, chemical parameters like thiobarbituric acid and free fatty acid increased, while pH decreased with concomitant decrease in sensory scores. Textural properties like, consistency, cohesiveness and index of viscosity underwent a significant (P < 0.05) increase during the storage.