Effect of high-pressure/high-temperature processing on chemical pectin conversions in relation to fruit and vegetable texture

Heat sterilization of plant derived food products entails considerable organoleptic and nutritional quality losses. For instance, texture loss of fruits and vegetables occurs, next to turgor pressure losses, mainly due to chemical changes in the cell-wall pectic polysaccharides. High-pressure sterilization, i.e. the combination of high temperature (?90 °C) with high pressure (?500 MPa), could present a positive alternative assuring safety while minimizing quality losses. In this study, the potential of high-pressure sterilization in preserving fruit and vegetable texture was evaluated by investigating the effect of combined high-pressure/high-temperature (HP/HT) treatments on two texture related chemical pectin conversions in model sytems. First, a protocol was developed to perform reproducible kinetic studies at HP/HT under constant processing conditions. Subsequently, apple pectin solutions at pH 6.5 were subjected to different HP/HT combinations (500, 600 and 700 MPa/90, 110 and 115 °C) and the extent of chemical demethoxylation and β-eliminative depolymerization was determined. At atmospheric pressure, both zero-order reaction rate constants increased with increasing temperature. At all temperatures, demethoxylation showed a higher rate constant than β-elimination. However, a temperature rise resulted in a stronger acceleration of β-elimination than of demethoxylation. When combining high temperature with high pressure, β-elimination was retarded or even stopped, whereas demethoxylation was stimulated. These results are very promising in the context of the texture preservation of high-pressure sterilized fruits and vegetables, as β-elimination is accepted to be one of the main causes of thermal softening and low methoxylated pectin can enhance tissue strength by forming cross-links with calcium ions present.     

新型墙体材料的现状与展望

介绍了我国目前墙体材料的生产与应用状况，分析了新型墙体材料的技术应用政策和应用前景，评述了新型墙体材料的优越性，介绍生产新型墙体材料的原材料和设备，提出了新型墙体材料及其砌体结构存在和应解决的问题，为新型墙体材料在建筑业中的推广应用提供部分资料。     

A Report on the First IFIP/IEEE Workshop on Quality of Experience Centric Management (QCMan 2013)

The first IFIP/IEEE international workshop on quality of experience (QoE) centric management (QCMan 2013) was held on May 31, 2013 in Ghent, Belgium. This report summarizes the keynotes, presentations and discussions in QCMan 2013 and provides a high-level view of ideas, challenges, strategies and the current state of the research activities in the field of QoE management.     

The efficiency and comparison of novel techniques for cell wall disruption in astaxanthin extraction from Haematococcus pluvialis

The efficiency of various techniques pulsed electric field (PEF), ultrasound (US), high‐pressure microfluidisation (HPMF), hydrochloric acid (HCl) and ionic liquids (ILs) for cell wall disruption in astaxanthin extraction from Haematococcus pluvialis was compared. The results indicated that ILs, HCl and HPMF treatment were shown the most efficient for cell disruption with more than 80% astaxanthin recovery. While the cell wall integrity of H. pluvialis cyst cell was less affected by US and PEF treatment. It was found that imidazolium‐based ILs showed the greater potential for cell disruption than pyridinium‐based and ammonium‐based ILs. Among all the ILs examined, 1‐butyl‐3‐methylimidazolium chloride ([Bmim] Cl) exhibited efficient cell disruption and capability of astaxanthin recovery at mild condition (pretreatment with 40% IL aqueous solution at 40 °C, followed by extraction with methanol at 50 °C) without extensive energy consumption and special facility requirement. In addition, recyclability of ILs was excellent.     

Visually weighted neighbor voting for image tag relevance learning

Multimedia Tools and Applications - The presence of non-relevant tags in image folksonomies hampers the effective organization and retrieval of user-contributed images. In this paper, we propose to...     

A new method to deal with fuzzy classification problems by tuning membership functions for fuzzy classification systems

Abstract

This paper presents a new method to construct and tune membership functions and generate fuzzy classification rules from training instances for handling the Iris data classification problem. First, we find two attributes of the Iris data from the training instances that are suitable to serve as classification criteria. Then, we construct and tune the membership functions of these two attributes and generate fuzzy classification rules from the training instances. The proposed method generates the same number of fuzzy classification rules as the number of species of the training instances. It generates fewer fuzzy classification rules and can get a higher average classification accuracy rate than the existing methods.     

Palynological and physicochemical data characterisation of honeys produced in the Entre‐Douro e Minho region of Portugal

Honey legislation has been addressed to establish the minimum marketing level of the product and the need for consumer protection through correct denominations. Research oriented toward assessment of floral origin and physicochemical properties may increase the commercial value of these products. The characteristics of thirty‐one honeys produced in the Entre‐Douro e Minho region in Portugal were studied. Pollen features and some physicochemical parameters (moisture, ash, pH, free acidity, electrical conductivity, hydroxymethylfurfural contain, apparent sucrose, reducing sugars and diastase activity) were determined. The samples were found to meet international honey specifications. The present study found a linear regression between the ash content of honeys and their specific conductivity. Five samples are listed as Eucalyptus honey, one sample as Citrus honey, and twenty‐five samples as multifloral honeys. Of the total, 87.1% exceeded the quality parameters and should be labelled as ‘virgin’ honey.     

A method for comparison of 3D surfaces using pyramidal height maps and fussy masks

A method for comparison of 3D surfaces mutually displaced in space is developed. This method is based on the measure of distinction expressed by the volume between two optimally superimposed surfaces. The volume is determined from the height map calculated with respect to a specified plane. Pyramidal representation of height maps is used to reduce the amount of examination. In addition, the maps are calculated using graphic processors. This method can be used in the problem of superposition (and identification) of identically oriented, mutually displaced surfaces.     

A New Active Tilting-Pad Bearing: Nonlinear Modeling and Feedback Control

This article introduces a new type of active fluid film bearing and its feedback control. In particular, the active adjustment of the angular velocity of the pads of a tilting-pad bearing in response to changes in the operating conditions of the rotating machine is proposed. This is motivated by the observation that there is more control authority in the pad tilting motion than in its radial translation. To this end, a dynamic model for the bearing system is first developed, inclusive of the nonlinear hydrodynamic force for the infinitely short bearing case. A model-based controller is then constructed, based on measurements of the journal position and velocity and pad tilting angles, to ensure that the journal is asymptotically regulated to the bearing center. Numerical simulations illustrate the performance of the active bearing under the proposed control in comparison with the bearing's standard passive mode of operation.     

石炭二叠纪5~#煤层顶板支护技术的研究与应用

介绍了大同煤矿集团挖金湾煤业公司虎龙沟煤矿石炭二叠纪5#煤层顶板支护技术的改进研究与应用。