Application of hurdle technology for the development of Caprine keema and its stability at ambient temperature

The study was envisaged to develop and extend the shelf life of the highly perishable Indian traditional meat product, chevon (capine) keema, through the application of hurdle technology.The hurdles used were water activity (a(w)) and pH as variable hurdles as well as vacuum packaging, preservatives and heat treatment as constant hurdles. The water activity of the product was adjusted to 2 levels viz., 0.90 and 0.88 by the addition of humectants. The product with 0.90 was preferred for sensory quality. The pH of the keema was adjusted with lactic acid to 3 desired levels viz. 5.50, 5.65 and 5.80. The product with pH 5.8 was the most acceptable and with pH 5.50 was the least acceptable. Standardised keema with a(w) 0.90 and pH 5.80 was stored at ambient temperature (36.2±1.2°C) and evaluated for physico-chemical, microbiological and sensory characteristics. A gradual increase in moisture, a(w), thiobarbituric acid reactive substances (TBARS) number and tyrosine value were observed throughout the storage period. There was a decrease in the growth rate of aerobic and anaerobic counts and complete inhibition of Staphylococcus aureus. Although sensory scores for hurdle treated keema declined upon storage, the product was well accepted up to the 3rd day and fairly accepted up to 5th day whereas the keema prepared by the traditional method was acceptable only on the first day. Hurdle technology significantly improved the shelf life of keema.