Search results for "pasteur"

Please, do not forget Pasteurella multocida!

2007

Quality evaluation of cheese from raw or pasteurized milk of ewes grazing sulla forage (Hedysarum coronarium L.) for different daily time

2009

Pasteurization is the more effective method for eliminating pathogens contaminating milk. However, the high temperature of pasteurization destroys either pathogens or lactic endemic flora, this latter involved in cheese ripening, thus impairing the development of sensory properties of cheese. It was previously observed that longer permanence at pasture allows the ewes to spend more time for eating; accordingly, ewes increase feed intake and milk yield. Aim of this experiment was to evaluate the effect of the prolongation of ewes daily grazing from 8 to 24 h and the effect of the milk pasteurization process on milk and cheese quality, with particular regard on fatty acid (FA) composition. In…

Inhibition of tumor lactate oxidation: consequences for the tumor microenvironment.

2011

Abstract Background and purpose Tumor cells are recognized as being highly glycolytic. However, recently it was suggested that lactate produced in hypoxic tumor areas may be taken up by the monocarboxylate transporter MCT1 and oxidized in well-oxygenated tumor parts. Furthermore, it was shown that inhibition of lactate oxidation using the MCT1 inhibitor α-cyano-hydroxycinnamate (CHC) can radio-sensitize tumors possibly by forcing a switch from lactate oxidization to glycolysis in oxygenated cells, which in turn improves tumor oxygenation and indirectly kills radio-resistant hypoxic tumor cells from glucose starvation. Material and methods To provide direct evidence for the existence of a ta…

2018

Tiger nut (Cyperus esculentus) is a tuber that can be consumed raw or processed into beverages. Its nutritional composition shows a high content of lipid and dietary fiber, close to those of nuts, and a high content of starch, like in other tubers. Tiger nuts also contain high levels of phosphorus, calcium, and phenolic compounds, which contribute to their antioxidant activity. From those characteristics, tiger nuts and derived beverages are particularly relevant to limit food insecurity in regions where the plant can grow. In Europe and United States, the tiger nut derived beverages are of high interest as alternatives to milk and for gluten-free diets. Fermentation or addition of probioti…

Ascorbic acid stability during refrigerated storage of orange–carrot juice treated by high pulsed electric field and comparison with pasteurized juice

2006

Abstract The degradation kinetics of ascorbic acid was determined in orange–carrot juice treated by PEF in order to establish its shelf life. Different electric field intensities (25, 30, 35, and 40 kV/cm) and different treatment times (from 30 to 340 μs) were studied. The ascorbic acid degradation rate (k) obtained was −0.009 ± 0.0008 μs−1, −0.0140 ± 0.0009 μs−1, −0.0220 ± 0.0023 μs−1 and −0.0187 ± 0.0049 μs−1 for fields of 25, 30, 35, and 40 kV/cm, respectively. The treatment selected was 25 kV/cm. The shelf life of the orange–carrot juice treated by pulses at 25 kV/cm for two times (280 μs and 330 μs) was compared with a heat-treated juice (98 °C, 21 s) kept in refrigerated storage at 2 …

Ascorbic acid in orange juice–milk beverage treated by high intensity pulsed electric fields and its stability during storage

2010

Abstract The degradation of ascorbic acid was determined in a ready-to-drink orange juice–milk beverage treated by high intensity pulsed electric fields (PEF). The effects of PEF treatment were compared to those of heat pasteurization (90 oC, 20 s). Four electric field strengths (15, 25, 35, 40 kV/cm) and six treatment times for each field (from 40 µs to 700 µs) were studied. Ascorbic acid degradation was adjusted to an exponential model. The obtained ascorbic acid degradation rate constants (kE) were − 0.11·10− 3 ± 0.03·10− 3 μs− 1, − 0.23·10− 3 ± 0.07·10− 3 μs− 1, − 0.42·10− 3 ± 0.09·10− 3 μs− 1 and − 0.60·10− 3 ± 0.06·10− 3 μs− 1 for field strengths of 15, 25, 35 and 40 kV/cm, respective…

PCR-fingerprinting and RAPD approaches for tracing the source of yeast contamination in a carbonated orange juice production chain.

2005

Aims: To investigate the sort and the origin of the contamination of a packed fruit juice. Methods and Results: Fifty-eight yeast isolates were collected in a survey of two different visits to a carbonated orange juice factory. In each visit, samples were collected, six times, from seven points in the production chain. For each visit, no significant differences were observed among the yeast average values obtained in the control points considered. The random amplified polymorphic DNA (RAPD) with primer P24 and the PCR-fingerprinting with the microsatellites primers (GTG)5 and (GAC)5 were used, in order to discriminate the isolates, rendering 29 composite profiles; the most frequent one (24/…

Color of orange juice treated by High Intensity Pulsed Electric Fields during refrigerated storage and comparison with pasteurized juice

2008

Abstract High Intensity Pulsed Electric Field (HIPEF) is one of the nonthermal minimal processing technologies interesting for scientists and food industry as a new, alternative (preservation) process for liquid food. We have evaluated the effect on color, browning and hydroxymethylfurfural (HMF) of a pasteurized orange juice and the same orange juice treated by HIPEF, during 7 weeks stored in refrigeration at 2 °C and 10 °C. Pasteurized orange juice presents greater yellow tendency ( b ∗ ) and less red tendency ( a ∗ ) than the untreated orange juice, while HIPEF orange juice presents a coloration more similar to the untreated orange juice. Color variations (Δ E ) during storage are greate…

Effects of thermal treatments on pectinesterase activity determined in blood oranges juices

2005

Abstract The citrus processing industry aims to maintain turbidity and attractive colour of the juice obtained from Sicilian blood oranges. Nevertheless, the presence of pectinesterase (PE, E.C. 3.1.1.11) causes the loss of these peculiar characteristics, due to precipitation of colloids and very fine pieces of pulp in suspension, with negative effects on colour and clarification of the juices. This study compares total PE activity of Sicilian blood oranges ( Sanguinello , Moro , Tarocco ) with the blonde cultivar Navel , checking enzyme stability with various pasteurisation times and temperatures conditions. Decimal reduction time and temperature ( D and z ) as well as the kinetic constant…

Anteroxanthin concentration during refrigerated storage in orange juice treated by PEF

2009

Pulsed Electric Field (PEF) processing inactivates microorganisms without significant adverse effects on flavor and nutrients. In this work was studied the transformations of antheraxanthin and mutatoxanthin when natural orange juice is treated by pasteurisation (90°C, 20 s) or PEF (30 kV/cm, 100 µs), and also its evolution during seven weeks of storage in refrigeration at two different temperatures (2°C and 10°C). The results showed that antheraxanthin concentration decreased during the storage. The decrease was greater in the untreated, pasteurised and PEF-treated orange juices stored at 10°C and this carotenoid was not detected from the 6 th week onwards. The same result was observed in …