To elucidate ozone action mechanism, cell suspensions of E. coli 8099 and S. faecalis ATCC29212 were initially exposed to ozone for 5 min, and then treated with sodium dodecyl sulfate, sodium hydroxide, and proteinase K. Results showed that, after ozone treatment, OD600 reduction rates of E. coli cells were 6.11±1.29%–7.06±1.23%. And those of S. faecalis were 7.95±2.81%–55.85±1.43%. After ozone pretreatment, OD600 value of E. coli cells, sequently treated with SDS, NaOH, and PK, decreased by 8.83±1.86%, 34.72±0.42%, and 10.42±2.08%, respectively. And that of S. feacalis decreased by2.85±3.63%, 71.30±1.08%, and 7.00±2.47%, respectively. Therefore, ozone pretreatment made E. coli cells be sensitive to SDS and NaOH, not susceptible to PK. It was confirmed by transmission electron microscopy of E. coli cells. To S. faecalis, ozone pretreatment activated the effects of SDS, NaOH, and PK on cells. ATP loss from S. faecalis cells indicated that ozone damaged cell membrane and increased membrane permeability. Because SDS-, NaOH-, and PK-induced cell lyses were respectively due to protein denaturation, cell membrane damage, and the reactions between PK and proteins or conjugated proteins, it was concluded that protein changes and cell membrane damage generated by ozone are responsible for E. coli and S. faecalis inactivation.

In the present study, we investigated the effect of ripening stage on the physicochemical characteristics, phenolic profile, and antioxidant activity of carob (Ceratonia siliqua L.) pulp. Total soluble solids, maturity index, and sugar content of carob pulp increased at the ripe stage, whereas titratable acidity, protein, total phenolic contents, and antioxidant activity decreased. Analysis of phenolic compounds of three carob varieties (Wild, Sisam, and Fleshy) has been carried out by HPLC-DAD-MS. Gallic acid and its derivatives including monogalloylglucoside, digalloylglucoside, trigalloylglucoside, and tetragalloylglucoside were the main identified phenolic compounds in the studied carob varieties. Gallotannin contents were higher in the extract of green carob pulp than in the ripe one.

Ready To Eat (RTE) meat products may be able to support the growth of Listeria monocytogenes during their shelf life. In agreement with the European Commission (EC) Regulation N. 2073/2005 on microbiological criteria for foodstuff, the products with pH ? 4.4 or aw ? 0.92, those with pH ? 5.0 and aw ? 0.94 and those with a shelf-life of less than five days are automatically included in the category of RTE foods that doesn’t able to support the growth of L. monocytogenes. Otherwise, the manufacturers must demonstrate whether their products not allow the growth of L. monocytogenes by use of different approaches based on: i) physical-chemical analyses of product, ii) predictive microbiology and iii) Microbial Challenge Test (MCT), as suggested by EC Regulation 2073/2005. The present study evaluated the three above mentioned approaches on Speck, a traditional smoked dry cured ham produced in South Tyrol (Italy). Both the variability of the physical-chemical properties of Speck (aw ranging from 0.890 to 0.940 and pH from 5.37 to 6.24) and the use of prediction models did not allow to state whether the product supports the growth of the pathogen and a reliable classification of the product. On the contrary, the MCT carried out showed the L. monocytogenes inactivation during shelf life of sliced vacuum-packed or modified atmosphere-packed Speck stored at different temperatures 4°, 8° and 20°C.

Umami is an important taste element in natural products like wine. The umami taste has characteristic qualities that differentiate it from other tastes, including a taste-enhancing synergism between two umami compounds, L-glutamate and 5’-ribonulceotides, and a prolonged aftertaste. In human taste cells, taste buds transduce the chemicals that elicit the umami tastes into membrane depolarization, which triggers release of transmitter to activate gustatory afferent nerve fibers. Umami taste stimuli is primarily received by type II receptor cells which contain the T1R and T2R families of G protein-coupled taste receptors. The taste sensation of umami requires protein hydrolysis which renders free glutamic acid. The main components of the nitrogen fraction of musts and wines are amino acids, peptides, proteins and ammonium ion. Their presence in wine is from amino acids of grapes, enzymatic degradation of grape proteins, excretion by living yeasts at the end of fermentation and to proteolysis during yeast autolysis. Thus, amino acids are important contributors of the wine savory taste and flavor.

Azoxystrobin, boscalid, cyprodinil, fludioxonil and pyraclostrobin are fungicides commonly used in Argentina against different fungus contaminations in the blueberry field. The presence of these fungicides was investigated in 50 samples of blueberry fruit and 15 samples of blueberry juice purchased in Argentina. Fungicide residues were determined by solid-phase microextraction (SPME) coupled to gas chromatography with micro-electron capture and nitrogen phosphorous detector. The average concentrations of azoxystrobin were 48 ?g/kg in blueberry fruit. Average of boscalid were 43 and 239 ?g/kg, of cyprodinil 1581 and 852 ?g/kg, of fludioxonil 1077 and 2842 ?g/kg, and of pyraclostrobin 578 and 3414 ?g/kg, in fruits and juice respectively. The higher concentrations of fungicides were found in those cases where the time between the application of the compound and the fruit’s commercialization was shorter than the fungicide’s half-life.