J. Bandekar et al., MICROBIOLOGICAL QUALITY OF THE DAIRY PRODUCT PEDHA AND ITS IMPROVEMENT USING GAMMA-RADIATION, Journal of food safety, 18(3), 1998, pp. 221-230
Eighteen pedha samples procured from A and B grade retail shops were e
xamined for their overall microbiological quality and for the presence
of foodborne pathogens viz. Staphylococcus aureus, Salmonella sp., Co
liforms, Listeria monocytogenes, Yersinia enterocolitica and Bacillus
cereus. The microbiological quality of pedha samples from B grade shop
s was very poor as compared to pedha from A grade shop as evidenced by
the very high total bacterial counts (6 x 10(7) cfu/g), high counts o
f S. aureus (as high as 7 x 10(6) cfu/g) and presence of coliforms and
Listeria and Yersinia sp, in 33% of the samples. All the samples from
A grade shops were also positive for S, aureus though negative for co
liforms, Yersinia, Salmonella, Listeria and B, cereus. Gamma irradiati
on of pedha at a dose of 3kGy at 0C reduced overall bacterial load by
five log cycles and S. aureus and coliforms could be totally eliminate
d. However, 5 kGy dose was necessary to eliminate S. aureus if the ini
tial number exceed I x 10(5) cfu/g. Inoculated pack studies confirmed
that 3 kGy dose was sufficient for the complete elimination of up to I
x 10(5) cfu/g of S. aureus. A dose of 3 kGy had minimal effect on the
sensory quality of pedha and even pedha samples irradiated at 5 kGy d
ose were acceptable. Treatment with 3 kGy dose of gamma radiation tota
lly eliminated S. aureus and coliforms in pedha, thereby ensuring thei
r microbial safety.