Time Dependence of the Induced Charge in Closed Ended HP Ge Detectors

Starting from energy balance considerations, the time dependence of the induced charge in closed ended HPGe gamma detectors is numerically determined as a function of detectors geometry, applied voltage and coordinates of created e-h pairs. These data can support the choice of geometry and applied voltage for the optimal use of closed ended detectors.     

Phenolic compounds in olive oil and olive pomace from Cilento (Campania,Italy) and their antioxidant activity

Virgin olive oil (VOO) has nutritional and sensory characteristics that make it unique and a basic component of the Mediterranean diet. Its importance is mainly attributed to its richness in polyphenols, which act as natural antioxidants and may contribute to the prevention of several human diseases. In this paper we report the determination and quantification of oleocanthal, one of the main substances responsible for the bitter taste of olive oil, together with a quali-quantitative analysis by HPLC analytical methods of phenolics from Cilento VOO and olive oil pomace. The total phenolic content was also determined and the in vitro antioxidant and free-radical scavenging activities by DPPH test was evaluated. A superoxide anion enzymatic assay was also carried out and the results were confirmed by the inhibition of xanthine oxidase activity assay. The possible protective role played by VOO secoiridoids on injurious effects of reactive oxygen metabolites on the intestinal epithelium, using Caco-2 human cell line, was investigated.     

Seasonal chemical–physical changes of PGI Pachino cherry tomatoes detected by magnetic resonance imaging (MRI)

Magnetic resonance imaging (MRI) has been used to study the variations of internal structure and chemical–physical characteristics of cherry tomatoes (Lycopersicon esculentum cv. Shiren), one the most economically valuable horticultural crops, in different harvesting seasons. In particular, the study focused on PGI (Protected Geographical Indication) Pachino cherry tomatoes, characterised by taste and nutritional value, notably in the winter production, amounting about 500 ton/year.     

Shelf life of ready to use peeled shrimps as affected by thymol essential oil and modified atmosphere packaging

In this work the influence of different packaging strategies on the shelf life of ready to use peeled shrimps was investigated. First, the effectiveness of the coating (Coat) and the active coating loaded with different concentrations of thymol (Coat-500, Coat-1000, and Coat-1500) on the quality loss of the investigated food product packaged in air was addressed; afterwards, the thymol concentration that had shown the best performance was used in combination with MAP (5% O₂; 95% CO₂). Microbial cell load of main spoilage microorganisms, pH and sensorial quality were monitored during the refrigerated storage. Results of the first step suggested that the sole coating did not affect the microbial growth. A slight antimicrobial effect was obtained when the coating was loaded with thymol and a concentration dependence was also observed. Moreover, the active coating was effective in minimizing the sensory quality loss of the investigated product, it was particularly true at the lowest thymol concentration. In the second step, the thymol concentration (1000 ppm) that showed the strike balance between microbial and sensorial quality was chosen in combination with MAP. As expected, MAP significantly affected the growth of the mesophilic bacteria. In particular, a cell load reduction of about 2 log cycle for the samples under MAP respect to that in air was obtained. Moreover, the MAP packaging inhibited the growth of the Pseudomonas spp. and hydrogen sulphide-producing bacteria. The MAP alone was not able to improve the shelf life of the uncoated samples. In fact, no significant difference between the control samples packaged in air and MAP was observed. Whilst, the use of coating under MAP condition prolonged the shelf life of about 6 days with respect to the same samples packaged in air. Moreover, when the MAP was used in combination with thymol, a further shelf life prolongation with respect to the samples packaged in air was observed. In particular, a shelf life of about 14 days for the active coating under MAP compared to the same samples in air (5 days) was obtained.     

Predicting odour emissions from wastewater treatment plants by means of odour emission factors

In this study, the results of odour concentration measurements on different wastewater treatment plants are presented and used in order to estimate the odour emission factors relevant to single odour sources. An odour emission factor is a representative value that relates the quantity of odour released to the atmosphere to a specific activity index, which in this case was the plant treatment capacity, resulting in an odour emission factor expressed in odour units per cubic metre of treated sewage. The results show that the major odour source of a wastewater treatment plant is represented by the primary sedimentation (with an OEF equal to 1.9 × 10⁵ ou_E m⁻³). In general, the highest OEFs are observed in correspondence of the first steps of the wastewater depuration cycle (OEF between 1.1 × 10⁴ ou_E m⁻³ and 1.9 × 10⁵ ou_E m⁻³) and tend to decrease along the depuration process (OEF between 7.4 × 10³ ou_E m⁻³ and 4.3 × 10⁴ ou_E m⁻³). In general, the OEFs calculated according to this approach represent a model for a rough prediction of odour emissions independently from the specific characteristics of the different plants.     

Synthesis and Conformational Analysis of Cyclotetrapeptide Mimetic β‐Turn Templates and Validation as 3D Scaffolds

The conformations of all stereoisomers of PMRI cyclotetrapeptide mimetics 1 – 8 are essentially determined by the predisposition of the diamine to stabilize β‐turns. The peptide mimetics can be regarded as 3D scaffolds for designing molecules with a predictable display of the pharmacophores. We used the models for testing novel RGD analogues as α_vβ₃‐integrin receptor antagonists.

     

Treatment of petroleum refinery sourwater by advanced oxidation processes

The performance of several oxidation processes to remove organic pollutants from sourwater was investigated. Sourwater is a specific stream of petroleum refineries, which contains slowly biodegradable compounds and toxic substances that impair the industrial biological wastewater treatment system. Preliminary experiments were conducted, using the following processes: H2O2, H2O2/UV, UV, photocatalysis, ozonation, Fenton and photo-Fenton. All processes, except Fenton and photo-Fenton, did not lead to satisfactory results, reducing at most 35% of the sourwater dissolved organic carbon (DOC). Thus, further experiments were performed with these two techniques to evaluate process conditions and organic matter removal kinetics. Batch experiments revealed that the Fenton reaction is very fast and reaches, in a few minutes, an ultimate DOC removal of 13-27%, due to the formation of iron complexes. Radiation for an additional period of 60 min can increase DOC removal up to 87%. Experiments were also conducted in a continuous mode, operating one 0.4L Fenton stirred reactor and one 1.6L photo-Fenton reactor in series. DOC removals above 75% were reached, when the reaction system was operated with hydraulic retention times (HRT) higher than 85 min. An empirical mathematical model was proposed to represent the DOC removal kinetics, allowing predicting process performance quite satisfactorily.     

Effect of vacuum impregnation on the phenolic content of Granny Smith and Stark Delicious frozen apple <Emphasis Type="Italic">cvv</Emphasis>

ABTS•+ test, o-diphenols (spectrophotometric) and HPLC-DAD phenolic content in vacuum impregnated apple slices from Stark Delicious and Granny Smith cvv. were studied. Vacuum impregnation (VI) was carried out in a pilot plant using an aqueous solution containing 37.9% dextrose, 15.2% sucrose, 1.0% ascorbic acid, 0.25% calcium chloride and 0.25% sodium chloride. The impregnation time was 30 min and the vacuum pressure was 100 mbar; the temperature was 25 °C during all processing steps and the solution/fruit ratio was 11:1. At the end of VI, samples were left 5 min in syrup. They were then rinsed with water, drained in a vibrating screen and quickly frozen. A significant decrease (p < 0.05) of the o-diphenol content was seen (17.84 and 12.32% of the initial content in Stark and Granny varieties, respectively). The same trend was confirmed by HPLC-DAD where reductions in total phenols were 21.57 and 26.86% in Stark and Granny, respectively. Individual phenolic compounds showed different rates of depletion, although in some cases there was no reduction. The ABTS•+ test was strongly affected by the presence of ascorbic acid (AA), which was much higher in treated samples. Sensory evaluation showed higher values of hardness, crispness, juiciness and sourness in VI Granny Smith than VI Stark delicious, with a higher retention of texture parameters in the former. Finally, sweetness was slightly higher in VI Stark. An erratum to this article can be found at     

Influence of microorganisms on retinol isomerization in milk

In order to have a deeper insight into the retinol isomerization phenomenon, in this work different milk samples have been analysed for their content of trans retinol and its cis-isomers, by means of reliable HPLC techniques. Levels of the different isomers and the degree of retinol isomerization (13-cis/all-trans ratio, %) have been monitored during milk storage at different temperatures and after addition of specific microorganisms. In raw milk stored at 4 degrees C for 96 h the degree of retinol isomerization shifted from 1.1 to 2.3%, while in raw milk stored at 22 degrees C for 24 h it increased from 1.1 to 12.7%. Among microorganisms tested in pasteurized milk, the most active in causing an increment in the 13-cis/all-trans ratio (%), from 3.4 to 33.4% in 8 h, was Streptococcus thermophilus. The results obtained demonstrated a relationship between microbial evolution and retinol isomerization. Therefore, the determination of retinol isomers is of importance not only for a more precise evaluation of vitamin A activity but also for the evaluation of the microbiological quality of milk.