SAFETY OF FOODS AND SWEETS
Sweets are an integral part of any ritual in India - birth, wedding, festivals, success celebrations, auspicious visits to the temple, et cetera. While some sweet preparations are made at home, a majority of the sweets we indulge in are purchased from vendors or stores. Most milk based sweets such as pedha, kheer and burfi are made from milk that is heated treated for long durations. The process will destroy any micro flora that may be present. But post-preparation, there are chances of microbial contamination through improper handling and through the handlers (packers) themselves.
A customer walked into Ramaiah Advanced Testing Laboratory (RATL) with a box of pedhas that he had purchased during his visit to Shirdi Sai Baba temple near Ahmednagar in Maharashtra. The customer claimed to have purchased the pedhas from a store and that he had fallen ill after consuming the pedha with severe bouts of diarrhea, vomiting, stomach cramps and nausea. He also asserted that the pedha contained a piece of plastic.
At RATL, based on the customer's description of symptoms and our understanding of food poisoning, our team decided on a microbiological analysis of the pedha, a fatty acid profiling by GC-FID as well as an FTIR analysis of the ingredient in the pedha, presumed to be plastic.
Our microbial analysis was carried out to test for the presence of Escherichia coli, Salmonella spp, Shigella spp, Pseudomonas aeruginosa, Staphylococcus aureus along with an enumeration for Total Bacterial Count (TBC) and Total Fungal Count (TFC or Yeast & Mold Count).
Surprisingly, the pedha was found to have
- A relatively high total bacterial count (TBC) in the magnitude of 103
- Presence of Staphylococcus aureus and Pseudomonas aeruginosa
- Presence of higher than expected levels of palmitic acid
None of the enterics were found to be present in the pedha sample tested. Cases of food poisoning due to S. aureus and P. aeruginosa have been reported and symptoms include vomiting, stomach cramps, headache and diarrhea. Contamination occurs post-production during handling of the prepared food by handlers who carry the bacteria on their skin or mucosal membrane (hands, face, nose). P. aeruginosa can be present in biofilms formed due to unhygienic conditions and poor maintenance of utensils used in food preparation. Food poisoning due to S. aureus and P. aeruginosa, however, is not life-threatening and is self-limiting, only in rare cases being severe and requiring hospitalization.
FTIR analysis of the ingredient in the pedha presumed to be plastic indicated that it was not. GC-FID analysis, however, showed that palmitic acid was present at levels not typical of products made from milk (animal fat only). Since palmitic acid is found to a larger extent in vegetable fat, we infer that vegetable fat (vanaspati) may have also been added during the manufacture of the sweet.
Proper handling of prepared food and educating handlers about safe and hygienic approaches to food and food preparation, and the consequences of the lack of the same, would go a long way in preventing such occurrences.
Sample submitted by Mr. V G Parshuram on June 21, 2017. Contact information: 461, 11th Cross, 5th Main, Sadashivnagar, Bengaluru 560 080. Cell: +91 948 323 1591