Chemical and microbiological characterization of artisan inoculants used for the fermentation of traditional dairy products in Epirus area (Greece).

The artisan production of a variety of dairy products is a historical tradition since antiquity, which is still practiced nowadays, in the area of Epirus, (northwestern Greece). The common denominator of these products, regardless of the final form of the end product, is the fermentation of raw milk by the use of dried artisan inoculants made of the dehydrated rumen of small ruminants, mainly lambs. The aim of this research project is to study the microbiological parameters as well as certain technological parameters (chymosin activity and lipolytic activity) of these inoculants. The results revealed a wide biodiversity of microorganisms such as Lactobacilli, Lactococci, Leuconostoc, Pediococci, Streptococci, Bifidobacteria, Enterococci, Clostridia and coliforms. Chymosin activity and lipolytic activity were found to be higher in artisan inoculants than in the commercial ones.

Physical, chemical and microbiological quality of ice used to cool drinks and foods in Greece and its public health implications.

Ice used for direct human consumption or to preserve foods and cool down drinks can be contaminated with pathogenic microorganisms and may potentially become a vehicle for consumer's infection. To evaluate physical, chemical and microbiological quality of commercial ice and ice used for fish and seafood, 100 ice samples collected at 10 different retail points in the region of Epirus were studied. The following microbiological parameters were determined: Total coliforms, fecal coliforms, Salmonella spp., Shigella spp., Yersinia spp., Escherichia coli, Campylobacter sp., Vibrio cholerae, Aeromonas spp., Pseudomonas aeruginosa and Clostridium perfringens. E. coli was detected in 22% and coliforms were detected in 31% of samples. Samples in which coliforms were detected fail to meet the microbiological criteria specified by the drinking water legislation. Aeromonas spp., Shigella spp., Campylobacter sp. and V. cholerae were not detected. Spore forms of C. perfringens were prevalent at 35% and the psychotropic bacterium's P. aeruginosa and Yersinia spp. were found only at three samples each. The presence of large numbers of coliforms as well as of other pathogenic strains suggested that commercial ice and ice used to make cool drinks or in preservation of fish and seafood may represent a potential hazard to the consumer. In view of the results reported herein, it is highly recommended that national regulatory guidelines should be established for the production of ice as long as regular inspections.

Isolation of microbial pathogens of subclinical mastitis from raw sheep's milk of Epirus (Greece) and their role in its hygiene.

The natural raw milk microflora is a factor that expresses its sensorial characteristics. The microbial charge into the mammary gland of healthy animal is low and the application of right and healthy conditions during milking and cheese making procedure, prevents from contaminating as well as maintains the natural microflora in order to lend the particular characteristics of milk. The purpose of the present project was the study of the Total Viable Count (T.V.C.) and the count of total psychrotropic bacteria of raw sheep milk from Boutsiko and Karamaniko breeds, collected from healthy animals, as well as the isolation, identification and enumeration of pathogenic bacteria related with the hygiene and the quality of raw sheep milk (with a particular interest in bacteria that may cause human infection). During the experiment we examined two hundred forty (240) samples of raw sheep milk. In these samples a) Staphylococcus aureus, Salmonella sp., Escherichia coli, Clostridium perfringens (vegetative cells and spores) and Bacillus sp. were isolated and identified b) the Total Viable Count and the total number of psychrotropic bacteria were also specified. The sampling, the preparation of samples and decimal dilutions were based on international methods. The Total viable count was determined using the standard methods of the American Public Health Association, 2002. The total number of psychrotropic bacteria was determined using APHA 1976, 1978 rules. The identification of the bacteria was carried out according to the Bergey's manual. Microscopic examination of Gram stained cells, catalase, oxidase and biochemical tests were performed when necessary to further identify. From the 240 milk samples tested, only 5% were E. coli positive, with mean counts ranged from 2 × 10(3) to 2.4 × 10(4) cfu/ml. S. aureus was isolated from 24% of the samples and the mean count per ml was ranged from <10 to 3.4 × 10(2). Meanwhile, Bacillus spp. was also detected in 29% samples. Vegetative forms and spores of C. perfringens were detected in 13% and 63% of the samples respectively. However, microbiological analyses revealed the presence of a small number of selected pathogens in milk samples such as Salmonella, which was only detected in 5% of the samples. Listeria sp., Pseudomonas sp. and Vibrio cholerae were never found. From the experimental results, the Total Viable Count from raw sheep milk samples, fulfils the microbiological criteria of EU Legislation in a percentage of approximately 97%.

Determination of partition behavior of organic surrogates between paperboard packaging materials and air.

The suitability of recycled paperboard packaging materials for direct food contact applications is a major area of investigation. Chemical contaminants (surrogates) partitioning between recycled paper packaging and foods may affect the safety and health of the consumer. The partition behavior of all possible organic compounds between cardboards and individual foodstuffs is difficult and too time consuming for being fully investigated. Therefore it may be more efficient to determine these partition coefficients indirectly through experimental determination of the partitioning behavior between cardboard samples and air. In this work, the behavior of organic pollutants present in a set of two paper and board samples intended to be in contact with foods was studied. Adsorption isotherms have been plotted and partition coefficients between paper and air have been calculated as a basis for the estimation of their migration potential into food. Values of partition coefficients (Kpaper/air) from 47 to 1207 were obtained at different temperatures. For the less volatile surrogates such as dibutyl phthalate and methyl stearate higher Kpaper/air values were obtained. The adsorption curves showed that the more volatile substances are partitioning mainly in air phase and increasing the temperature from 70 to 100 degrees C their concentrations in air (Cair) have almost doubled. The analysis of surrogates was performed with a method based on solvent extraction and gas chromatographic-flame ionization detection (GC-FID) quantification.

pH and trace-elements content in raisin extract industrial-scale alcoholic fermentation.

The ability of all kinds of Greek raisins for the industrial-scale fermentation related to pH and trace-element contents is discussed. In the case of raisin extracts of pH 3.2 larger ethanol productivities, yields, and a continuous use of the same yeast culture at a level of 300 batches was obtained. Metals such as Co, Fe, Zn, Cu, Cd, and Pb in all kinds of raisins have been determined using atomic absorption spectroscopy. The raisin variety Trechumena contains the smallest amount of Cu, and the variety Psilla contains 7 times higher concentration than Trechumena. This is in agreement with the fact that Psilla is the worst kind of raisin and Trechumena the best for spirit production. This observation is related with experimental results obtained by alcoholic fermentation in a series of synthetic media containing sacharose and different concentrations of copper.