Thermal Model in ANSYS for a Comparison Between two Configurations of a Concentrating Photovoltaic System

The theoretical analysis of different concentrating photovoltaic and thermal systems (CPV/T) is presented in this paper; it allows to evaluate the cooling fluid temperature in different working conditions. In particular, two CPV/T systems with different optics, line-focus and point-focus, are studied and compared theoretically by means of a model developed in ANSYS-CFX able to evaluate the theoretical temperature values of the fluid that flows in the cooling circuit, designed with the Solidworks software. The comparison in terms of the thermal performances between the point-focus and line-focus configurations of a CPV/T system has been realized considering different working conditions. As model input the uniform cell temperature has been set to different values, included between 323 K and 363 K, or determined experimentally referring to the point-focus configuration. In particular, the outlet temperatures of the cooling fluid, the fluid and cells temperatures difference at the outlet section, the time necessary to reach a steady-state condition, the fluid temperature trend in different parts of the tube and along the circuit, have been evaluated. Moreover, the fluid temperature trend has been studied varying the fluid velocity, its mass flow rate, and the insulation thickness. Finally, the point-focus CPV/T system thermal performances have been also evaluated adopting some experimental measurements as input data; the fluid temperature trend has been tested under a variable cell temperature during different hours of a sunny and a cloudy day.     

The detection of the presence of hazelnut oil in olive oil by free and esterified sterols

Genuine olive and hazelnut oils from diverse geographical origins, as single varieties and blends, were mixed at different percentages and analysed by the method based on the quantification of free and esterified sterols. Two formulas based on three sterols (Campesterol, Δ⁷-stigmastenol and Δ⁷-avenasterol) together with empirical decision rules were able to detect the presence of hazelnut oil in olive oil when the percentage of the former was more than 6–8%, although this figure was much lower in the most of the adulterations. Results of univariate and multivariate statistical procedures based on the analysis of 116 samples are presented in support of the method efficiency.     

Manufacture and characterization of functional emmer beverages fermented by selected lactic acid bacteria

Autochthonous lactic acid bacteria from emmer flour were screened based on the kinetic of acidification and used to ferment beverages containing emmer flour, emmer gelatinized flour, and emmer malt at percentages ranging 5-30% (wt/wt). Preliminarily, the concentration of raw flour and malt was selected based on sensory analysis. Different protocols were set up for the manufacture of four different beverages which used Lactobacillus plantarum 6E as the starter. Emmer beverages were mainly differentiated based on the concentration of organic acids, carbohydrates, amino acids, dietary fibers, vitamins, antioxidant and phytase activities, and volatiles and sensory profiles. Wheat flour bread was used as the control to determine the hydrolysis index (HI = 100), as an indirect estimation of the glycemic index. The beverage made with 30% (wt/wt) of gelatinized flour showed an HI of 56%, its viscosity was improved by using an EPS-producing strain and it allowed the survival of the potential probiotic Lactobacillus rhamnosus SP1 at cell density of ca. 5 × 10⁸ cfu/ml throughout storage at 4 °C. Among the exploited biotechnological options, this latter beverage could be considered as a promising novel functional food.     

Determination of Major Isoflavones in Soy Drinks by Solid-Phase Micro Extraction Coupled to Liquid Chromatography

A simple method for determination of major isoflavones (daidzein, genestein, genistin) and equol, a daidzein metabolite, has been developed using solid-phase micro extraction coupled to liquid chromatography with diode array UV detection. All the aspects influencing adsorption (fibre coating, extraction time, temperature, pH and salt addition) and desorption of the analytes (desorption and injection time and minimize carryover) were carefully investigated. The limits of detection obtained using a polydimethylsiloxane /divinylbenzene fiber coating were in the range 4 (genistein) to 38 (genistin) nM. The method proved to be useful for determination of analytes in soy-based products. Daidzein, genistein, and genistin were found in all samples (three soy milks and two blended rice/soy beverages) at concentrations ranging from 0.8?±?0.2 (daidzein) to 180.4?±?12.1 (genistin) μM, while glycitein and equol were found in three and in one of the drinks at levels between 1.7?±?0.1 and 5.0?±?0.2 μM and at 2.7?±?0.2 μM, respectively. The procedure was used to define the binding constants of isoflavones with serum albumin bovine that were found from 2.5?×?10⁴ (daidzein) to 2.9?×?10⁵ (genistein) L mol^?1. The method proposed restricts the use of organic solvents and can be used widely in most laboratories with standard equipment. In addition, it is suitable for easily studying the isoflavone interaction with the main constituents in plants, e.g., proteins and lipids, to evaluate their bioavailability and to clarify the controversial question on benefits for or damage to human health resulting from soy intake.     

Health,Wellbeing and Social Sciences

For social interventions aimed at improving nutrition behavior evidence from randomized trials is essential but cannot be the only approach of research activities. Interventions on dietary habits require considerations on food security, economic and environmental sustainability, and a broad meaning of wellbeing which includes, but also goes beyond, health effects. The model of research in nutrition requires a new consideration of observational studies, mainly through different analytical models. Nutrition and food studies need research programs where medical (nutrition and health), psychology (how we behave), economics (how resources are used and their impact on wellbeing) and sociology (how social determinant shape behavior) collaborate.     

Ecology and characterization by molecular methods of Staphylococcus species isolated from fresh sausages

Staphylococcus spp. ecology in fresh sausages stored at 4 degrees C for a period of 10 days was investigated. Microbiological analyses to assess the quality and safety of the products studied were carried out, and strains on MSA agar were isolated. A total of 85 strains were identified, by traditional methods, as Staphylococcus spp. and a PCR-DGGE method, together with a S. xylosus-specific PCR, were used to determine the species of the strains isolated. Almost 50% of them were recognized as S. xylosus, but strains of S. pasteuri, S. warneri, S. equorum and S. succinus, were also found. Interesting population dynamics were observed, characterized by a succession of S. pasteuri and S. warneri at 0 day, with S. xylosus at 3 days and S. equorum at 6 and 10 days. Molecular characterization of S. xylosus strains and cluster analysis highlighted the presence of six main populations in the fresh sausages studied. However, the clusters were formed by strains isolated at different days of storage, implying a homogeneous distribution of the six subpopulations throughout the period in the products followed.     

Influence of chemical composition of olive oil on the development of volatile compounds during frying

In this study, 15 virgin olive oils from an industrial oil plant in the Abruzzo region were analyzed in terms of the volatile compounds responsible for the characteristic odor and olfactory perception of virgin olive oils and its modification upon frying (up to 60 min of heat treatment). Dynamic headspace–gas chromatography–mass spectrometry analysis was used to evaluate the volatile profile before and after each frying step and examine correlations with qualitative characteristic of oil (fatty acid composition, total phenolic compound content, tocopherols and pigments). The chemometric approach (genetic algorithms–partial least squares/multiple linear regression) developed for this study is a novel model for data treatment to select important variables in olive oil composition and understand their influence on spoilage during frying. An inverse correlation between oleic acid content and formation of toxic volatiles such as acrolein and crotonal during frying was demonstrated. Moreover, it was also observed that pigments such as chlorophylls, pheophytins, and carotenoids may prevent the formation of some aldehydes during frying.     

Post-17th-century changes of European lead emissions recorded in high-altitude alpine snow and ice

Lead concentrations and lead isotope ratios were analyzed in two firn/ice cores covering the period from 1650 to 1994, which were obtained from the 4450 m high glacier saddle Colle Gnifetti located in the Monte Rosa massif at the Swiss-Italian border. This study presents the first glaciochemical time series with annual resolution, spanning several centuries of lead concentrations and lead isotopic compositions in precipitation in Europe. Lead concentrations in firn dated from the 1970s are approximately 25 times higher than in ice dated from the 17th century, confirming the massive rise in lead pollution in Europe during the last few centuries. A decline of the lead concentration is then observed during the last two decades, i.e., from 1975 to 1994. The lead isotope ratio 206Pb/207Pb decreased from about 1.18 in the 17th and 18th centuries to about 1.12 in the 1970s. These variations are in good agreement with available information on variations in anthropogenic lead emissions from West European countries, especially from the use of lead additives in gasoline.     

Saponins in Ipomoeabatatas tubers: Isolation,characterization, quantification and antioxidant properties

Triterpene saponins are a class of plant natural products with a wide range of bioactivities, which makes them an interesting research subject. This work reports, for the first time, the isolation and characterization of saponins in Ipomoeabatatas tuber flour, their quantification and antioxidant properties. Their structures were characterized on the basis of UV, FAB–MS, ESI–MS, GC–MS, polarimetry and NMR data, as: oleanolic acid-3-O-[β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyl]-28-O-β-d-glucopyranoside (sandrosaponin IX) (1) and oleanolic acid-3-O-[β-d-galactopyranosyl-(1→3)-β-d-glucuronopyranosyl]-28-O-β-d-glucopyranoside (2). A new quantitative HPLC–DAD method for saponin content determination in this tuber was developed and validated. Their total content was 200.01 mg/100 g dry weight (RSD = 7.2%; p < 0.001). The single saponin contents were: 161.20 mg/100 g dry weight (RSD = 0.58%; p < 0.001) for saponin 1 and 14.67 mg/100 g dry weight (RSD = 0.41%; p < 0.001) for saponin 2. The antioxidant activities, tested by DPPH and FRAP assay, of total phytochemical fraction and of single saponins were moderate in relation to commercial standards.