Nut and kernel traits and chemical composition of hazelnut (Corylus avellana L.) cultivars

BACKGROUND: Nut and kernel traits and chemical composition of 24 Italian and foreign hazelnut cultivars were analysed in 2002–2004 in order to study the effect of genotype and environment on nut quality. Nuts were sampled in a germplasm collection in the Italian province of Viterbo. RESULTS: Quantitative and qualitative determinations of sugars, organic acids and lipids revealed good nutritional and health potential of the nuts, with several differences among cultivars and years. The total contents of oil and sugars ranged from 563.69 to 656.36 g kg^?1 dry weight (DW) and from 39.80 to 59.51 g kg^?1 DW respectively. Fatty acid profile and sugar and total phenolic contents varied with the year. Significantly higher palmitic acid concentration (6.18%) was found in the hot summer year 2003; lower saturated fatty acid concentration (8.20%) and higher unsaturated/saturated acid ratio (11.27) were observed in the coolest year (2004). These differences among years were highlighted by discriminant analysis. CONCLUSION: The information relating to secondary components such as sugars, organic acids and phenolics was useful for discriminating among cultivars and years. Owing to the effect of these compounds on sensory attributes perceived by consumers, their concentration and the varietal differences can be considered primary determinants of nut quality and should be valued when planning the cultivar choice for new plantations. Copyright © 2008 Society of Chemical Industry     

Supercritical fluid extraction of bioactive lipids from the microalga Nannochloropsis sp.

Marine microalgae are recognised as an important renewable source of bioactive lipids with a high proportion of polyunsaturated fatty acids (PUFA), which have been shown to be effective in preventing or treating several diseases. For the extraction of oil from microalgae, supercritical CO₂ (ScCO₂) is regarded with interest, being safer than hexane and offering a negligible environmental impact, a short extraction time and a high‐quality final product. Whilst some experimental papers are available on the supercritical fluid extraction (SFE) of oil from microalgae, only limited information exists on the kinetics of the process. In such a contest, a mathematical model able to describe the kinetics of the SFE was applied to the recovery with ScCO₂ of lipids from Nannochloropsis sp., a marine microalga commonly used in aquaculture and characterised by a lipid fraction with a high PUFA content. The aim of this paper was to examine the effect of operating conditions on the kinetics of the SFE, on process yields and on the fatty acid composition of lipid extracts.     

A new algorithm for temperature and spectral emissivity retrieval over active fires in the TIR spectral range

The problem of temperature and spectral emissivity assessment from hyperspectral remotely sensed data is discussed with reference to monitoring of active fires and hot targets. A new algorithm, called similar pixel addition, was developed, which allows us to retrieve the temperature of burning areas by employing spectral data collected at thermal infrared (TIR) wavelengths. The new algorithm resolves the uncertainty connected with temperature-emissivity separation assuming a slow spatial variation of emissivity, hence reducing the number of unknowns involved in the inversion of a couple of similar pixels at once. Performance of this procedure is thoroughly discussed and compared with results from two other algorithms operating in the TIR and shortwave infrared spectral ranges. This paper shows results obtained applying the new algorithm to hyperspectral images gathered by the Multispectral Infrared and Visible Imaging Spectrometer in Northern Italy (Alps) over a natural fire that broke out in July 1999. This paper is completed with a theoretical discussion of the involved topics.     

Rheological study of the incorporation of grape seed extract in chitosan and gelatin coatings

This study aims to evaluate the incorporation, addition order and concentration of grape seed extract (Vitis vinifera L.) in chitosan and gelatin solutions, candidates as food coatings due to their excellent antioxidant and barrier properties. This study originally assesses how such variables can affect the rheological parameters of this particular combination of materials. Initially, 1% (w/w) solutions of chitosan (C) and gelatin (G) are mixed at a 1:1 ratio (CG). For grape seed extract addition, ethanolic solutions (50%, v/v) are prepared in different concentrations, with two incorporation orders: 1) addition to CG and 2) addition to the chitosan gel (C), followed by G mixing. The addition order reveals a direct influence on the rheological properties, and low extract concentrations leads to solutions with adequate viscosity for coating applications. The findings of this study confirm that it is essential to standardize the addition procedures during the preparation of the materials.     

Flow-based reactor design for the continuous production of polymeric nanoparticles

Polymeric nanoparticles (NPs) are versatile and effective drug delivery systems (DDS) that can be produced via nanoprecipitation of block copolymers. Yet, translation into clinical products has been limited. Thus, methods for NP production that enable rapid formulation screening and continuous production are needed. Toward this end, we engineered a coaxial jet mixer (CJM) for controlled and continuous nanoprecipitation in flow. The CJM enabled continuous assembly of poly(ethylene glycol)-block-polylactide NPs with various co-solvents and was compared to batch nanoprecipitation. Other fabricated microfluidic devices were suitable for small scale formulation screening but more limited in scalable and continuous processes. In contrast, the CJM was tolerant to all water-miscible solvents tested, enabled formulation screening, and scalable production of NPs and DDS. In total, the CJM provides a complementary approach to the process engineering of polymeric NP formation that can be used broadly for formulation screening and production.     

Composition profiling of inhomogeneous SiGe nanostructures by Raman spectroscopy

In this work, we present an experimental procedure to measure the composition distribution within inhomogeneous SiGe nanostructures. The method is based on the Raman spectra of the nanostructures, quantitatively analyzed through the knowledge of the scattering efficiency of SiGe as a function of composition and excitation wavelength. The accuracy of the method and its limitations are evidenced through the analysis of a multilayer and of self-assembled islands.     

Automotive reliability inference based on past data and technical knowledge

The constantly increasing market requirements of high quality vehicles ask for the automotive manufacturers to carry out—before starting mass production—reliability demonstration tests on new products. However, due to cost and time limitation, a small number of copies of the new product are available for testing, so that, when the classical approach is used, a very low level of confidence in reliability estimation results in. In this paper, a Bayes procedure is proposed for making inference on the reliability of a new upgraded version of a mechanical component, by using both failure data relative to a previous version of the component and prior information on the effectiveness of design modifications introduced in the new version. The proposed procedure is then applied to a case study and its feasibility in supporting reliability estimation is illustrated.     

Influence of varying porogen loads and different UV cures on low-kappa film characteristics

Nanoporous low-kappa films were manufactured by using a 3-step process: co-deposition of a skeleton and porogens by PECVD, porogen removal by remote plasma and UV cure. In this study, the influence of both the variation of the porogen load and the different types of UV-cures on several film characteristics were investigated. Improved kappa-values were observed for increased porogen to skeleton ratios and a broad band cure, where the wavelength of the photons is always higher than 200 nm. However the Young's modulus and hardness decreased correspondingly. These variations can be attributed to the changing density and chemical composition of the different films. A wide range of low-kappa films was obtained by tuning the porogen load and applying different types of UV cures.     

Experimental validation of a spectral direct solar radiation model

A model of spectral direct radiation of the sun at the ground compared with the spectral measurements performed by a monochromator has evidenced a satisfactory agreement. However, some discrepancies, mainly in the shorter wavelength range, have been evaluated. In order to point out the causes of these discrepancies, long series of data of direct integral radiation, water vapour content, aerosol turbidity together with standard meteorological data have been performed. These causes are defined by means of a statistical analysis.