Physicochemical, nutritional and microbiological characteristics of traditional table olives from Southern Portugal

Abstract

Table olives (Olea europaea) are an important fermented product of the Mediterranean diet food pattern and Portugal is one of the biggest producers in Europe. Three different cultivars produced traditionally in Southern Portugal were studied, Maçanilha Algarvia, Cobrançosa and Galega, which were all processed through natural fermentations, although prepared differently. Maçanilha green were cracked, Cobrançosa turning color split, and Galega black prepared as a whole. At the end of the fermentation, the microbiological, physicochemical and nutritional characteristics were studied following standard methodologies. All the fruits showed a good pulp/stone ratio, confirming their aptitude to produce table olives, though their color and texture were statistically different. The three table olives showed suitable acidity and pH values, in addition to a high water content, followed by fat, low-sugar content and fairly low dietary fiber, resulting in a valuable energy food product. Nutritionally, the olives were not significantly different, however Galega had the highest total phenolic content. Statistical differences were observed among their fatty acid composition, with Galega and Maçanilha having the highest oleic and linoleic contents, respectively. The mesophilic microorganisms, the fungi and the LAB were 5.3, 4.7, 4.0 Log CFU/g, 5.9, 5.0, 4.4 Log CFU/g and 5.6, 3.7, 3.7 Log CFU/g for Maçanilha, Cobrançosa and Galega, respectively. No E. coli, staphylococci, Salmonella sp. and Listeria monocytogenes were detected in the samples.  The table olives studied revealed an excellent microbial quality and are a good source of phenolics and total unsaturated fatty acids, namely linoleic and oleic acids.