Propolis is a Natural Food Preservative

Propolis as a Natural Decontaminant and Antioxidant in Fresh Oriental Sausage
Vet Ital, 2010 Apr-Jun;46(2):167-72

The authors evaluate the effect of propolis on the shelf-life and different quality criteria of fresh oriental sausage. Experimentally processed fresh oriental sausage treated with 0.6% ethanolic extract of propolis and control samples were kept in a refrigerator at 5 degrees C and examined every 3 days until signs of spoilage were observed. Both groups were investigated for sensory, chemical and microbiological deteriorative criteria.

The results revealed that control samples decomposed after 12 days, while treated samples had longer shelf-life as they decomposed after 21 days.

In general, the thiobarbituric acid (TBA) value (mg malondialdehyde/kg) and total volatile bases nitrogen (TVB-N) mg/100 g increased gradually in all samples examined, with a significantly lower level for treated samples than for controls. In addition, a gradual increase in the microbiological load of control samples throughout the storage time was observed, whereas proteolytic, lipolytic and total mould and yeast counts were 6.39 +/- 0.41, 6.0 +/- 0.57 and 6.6 +/- 0.53 log(10) cfu/g, respectively, at day 12 and were rejected. Such counts were slightly lower in treated samples up to day 15 of storage, followed by a gradual increase until the end of storage.

Propolis is recommended as a preservative in fresh oriental sausage processing.