Abstract
Safe and shelf-stable natural casing were prepared using a combination of hurdles viz. reduced water activity, packaging and
gamma irradiation. Washed lamb intestines were treated with common salt to reduce water activity to 0.80 ± 0.02, packed in polyethylene
bags and subjected to gamma-irradiation (5 and 10kGy). Control non-irradiated samples had high total viable counts
(106CFU/g), aerobic spores (103CFU/g), spores of sulphite reducing clostridia (103CFU/g), potentially pathogenic bacteria such
as staphylococci (104CFU/g) and coliforms (102CFU/g). Treatment with gamma radiation resulted in a dose dependent reduction
in counts of these microbes. A dose of 5kGy was sufficient to reduce total viable counts by three log cycles; spore counts by two log
cycles and completely eliminate staphylococci and coliforms. Samples subjected to a 10kGy dose were devoid of any viable
microbes. The reduced water activity of the product prevented growth of the microbes in natural casings during storage at room
temperature. Sausages prepared using hurdle processed natural casing were examined for sensory and textural properties. It was
observed that product acceptability and mechanical strength was not affected by radiation processing. Our studies indicated that
shelf-stable and safe natural casing could be prepared using a combination of hurdles.