MICROBIOLOGICAL QUALITY OF COLD PRESSED PUMPKIN AND WALNUT OILS

Abstract

The aim of this study was to determine the content of crude oil in seeds and the microbiological quality of cold pressed oils of eight genotypes of pumpkin and walnut from Central and Western Serbia. The oil content in pumpkin seeds of different genotypes ranged from 16.44% to 35.13% per dry matter of whole seed, in the walnut kernel was between 50.17% and 60.41% per weight of the walnut kernel. Genotypes of pumpkin seeds differ significantly in oil content - genotype with the lowest oil content contains only 47% crude oil compared to the genotype with the highest oil content. Among the walnut samples, there is less deviation in the oil content of different genotypes. The number of total bacteria in walnut oil was less than 100 cfu/g. The number of yeasts and mold in walnut oil was very low, even in 3 samples the presence of this microorganisms were not detected, in 4 samples the number was lower than 10 and in the 1 sample the number was between 10 and 100 cfu/g. Two samples of pumpkin oil had a number of bacteria more than 100, but in other samples the number of bacteria less than 100 cfu/g. The number of bacteria, yeasts and molds in the oils of all genotypes was lower than the limit values prescribed in the "Guide to the application of microbiological criteria for food" Sulfite-reducing clostridia were not detected in any oil sample.