Effect of yoghurt processing and ice cream manufacture on viability of some foodborne bacteria

Abstract EN

-Food borne bacterial gastrointestinal infections are important causes o morbidity and mortality worldwide.

Despite of successful control programs in some developing countries, these infections continue to have major impacts on public health and economy.

The present study was planned t spotlight on the effect of processing, as well as storage of yoghurt and ice cream on survival of enter hemorrhagic e.

Coli 0157: h7 and yersinia enterocolitica.

Yoghurt and ice cream that were manufactured in the laboratory inoculated with the organisms being tested.

In case of yoghurt raw milk inoculated with enter hemorrhagic e.

Coli 0157:h7 and yersinia enterocolitica at density of 5.13 x 104 and 8.1 x 104 (CFU/ml), respectively and stored at 4°c.

Samples of milk, curd and finished product were examined up to 12th day of storage for growth of tested organisms and ph value.

While, ice cream samples inoculated with enter hemorrhagic e.

Coli and yersinia enterocolitica at density of 1.55 xlo5 and 8.2 × 105(cfu/ml), respectively and stored at (-4°c) and (-18°c).

The effect of freezing on growth and survival of both organisms examined daily up to 35th day of storage.

Enter hemorrhagic e.

Coli and yersinia enterocolitica could survive in yoghurt before completely reduced at the 10th and 4th day of storage, respectively.

The results of ice cream obtained by the end of storage indicated that enter hemorrhagic e.

Coli and yersinia enterocolitica count reduced at -4°c by 86.25 and 99.4% respectively.

Also, at -18°c by., 99.4 and 99.9 %, respectively.

So, the concerned health authorities should, impose regulations and bacteriological standards on the manufacturers also,, tacking an active part by monitoring the health of dairy used to ensure the best possible protection for the consumer.

In addition to the enforcement of GMP and HACCP system inside dairy plants is of critical.