New functional fibre in milk puddings: Effect on sensory properties and consumers' acceptability

The effect of the addition of a new functional fibre (high-amylose maize starch, HAMS, as a source of resistant starch), recently available in the market, on sensory characteristics and consumers' acceptability of milk puddings was studied. Milk puddings containing modified waxy maize starch and κ-carrageenan were produced with different HAMS concentrations (0, 1, 2, 3 and 4%). Higher HAMS concentration caused changes in the sensory characteristics of milk puddings. Particularly, sensory attributes such as some roughness, rough afterfeel and floury taste appeared. Besides, the addition of HAMS caused an increase in manual and oral thickness and a decrease in creaminess, melting, and sweetness. A HAMS enrichment level of 1.4% in this product was estimated as the maximum concentration that does not significantly modify consumers' overall acceptability. Using survival analysis the proportion of consumers who would buy milk desserts containing 1.4 % HAMS was estimated as 71%. Consumers more interested in consuming functional foods enriched with fibre were more tolerant to the sensory changes caused by the addition of HAMS to the milk puddings.     

Polyacrylamide-gelatin polymeric networks: effect of pH and gelatin concentration on the swelling kinetics and mechanical properties

This work presents the synthesis of polyacrylamide-gelatin (PAM-G) semi-interpenetrating hydrogels, as well as the study of the swelling capacity of this material at different pH’s, and we report its Young modulus. The hydrogels were crosslinked with N,N′-methylenebisacrylamide and synthesized at different acrylamide/gelatin weight relationship. It was observed that the swelling capacity of the hydrogels increases when the gelatin concentration is increased; while the Young modulus (at the swelling equilibrium) decreases lightly. Therefore, the gelatin has a small effect in the Young modulus, unlike its influence in the swelling ability. The swelling experiments reveal that the PAM-G hydrogels increase its swelling capacity in alkaline mediums because the presence of the hydrophobic functional groups (mainly COO⁻) in the gelatin structure.     

Stability during storage of LC-PUFA-supplemented infant formula containing single cell oil or egg yolk

The medical community recommends that infant formulae should mimic human milk as far as possible, particularly in regards to long-chain polyunsaturated fatty acids (LC-PUFA). These include arachidonic acid (AA) and docosahexaenoic acid (DHA), both of which provide biochemical and functional benefits to neonates. However, LC-PUFAs are highly susceptible to oxidation and the composition of formulae must be carefully controlled. In this study, the stability of two types of LC-PUFA-supplemented milk-based powdered infant formula was evaluated over the course of 18 months storage at 25 °C and 40 °C. One contained egg yolk phospholipids (IF-EPL) and the other contained triacylglycerides (DHA and AA) synthesized by single cell oils (IF-SCO). The following parameters were monitored: peroxide values, volatile content (propanal, pentanal and hexanal), fatty acid profiles, and potential and free furfural content (5-hydroxymethyl-2-furaldehyde and 2-furaldehyde). In addition, these formulae were subjected to sensory evaluations by a panel of experts. The parameters studied revealed acceptable lipid stability in both types of formula, with better results for IF-EPL. At the end of the study period, significant deficits (p < 0.05) in linoleic acid were noted in both formulae. However, no significant decreases were observed in the other fatty acids, including AA and DHA. In regards to furfural content, both formulae exhibited a similar increase, indicative of the typical Maillard reaction characteristic of products stored for long periods.     

Cross-linked soy protein as material for biodegradable films: Synthesis, characterization and biodegradation

The modification of soy protein isolate (SPI) with different amounts of a naturally occurring cross-linking agent (genipin, Gen) and glycerol used as plasticizer was carried out in this work. The films yielded were cast from heated and alkaline aqueous solution of SPI, glycerol and Gen and then dried in an oven. Total soluble matter, water vapor permeability and mechanical properties were improved by adding small amounts of Gen. These properties were not significantly affected (P ? 0.05) by additions exceeding 2.5% (w/w of SPI). The opacity and cross-linking degree were linearly increased with the addition of Gen, whereas the swelling ratios in water were decreased. All the films were submitted to degradation under indoor soil burial conditions and the weight loss of the films was measured at different times. This study revealed that the film biodegradation time can be controlled or modified from at least 14 to 33 days. The tests performed showed the potential of Gen to improve the SPI film properties, in which the possibility of employing such new films as biodegradable food packaging was raised.     

Application of centralised DEA approach to capital budgeting in Spanish ports

In this paper, we propose a number of non-radial, output-oriented, centralised DEA models to determine individual and collective output target levels, input slacks and input reallocations as well as additional inputs acquisitions under a capital budget constraint. The application of the proposed approach to the Spanish Port Agency is presented. The overall amount of inefficiency currently found in the system allows for the determination of potential total output increases ranging from 24% to 114% without additional resources. Considering inputs reallocation would allow for an additional 20% output expansion. The acquisition of additional input resources would make feasible to expand outputs further, to levels whose exact values monotonously depend on the capital budget considered.     

Salt in food processing; usage and reduction: a review

Salt is one of the most widely used additives in food industries because of its low cost and varied properties. It has a preservative and antimicrobial effect as a direct consequence of the capacity of sodium chloride to reduce water activity values. In addition, sodium chloride is a flavour enhancer as a consequence of its effect on different biochemical mechanisms. It also has flavour enhancing effects from reducing or enhancing the enzymatic activity of some enzymes responsible for the development of different organoleptic parameters. Trends in sodium chloride use in food industries point to salt replacement or reduction by means of the use of sodium chloride substitutes such as KCl or phosphates; flavour enhancers and the optimisation of the physical form of salt. This trend has arisen as a result of the greater awareness of the negative effects of excess dietary intake of sodium, which has been linked to hypertension and consequently an increased risk of cardiovascular disease. The average total daily sodium intake per individual in developed countries is 4–5 g of Na, which is up to 25 times greater than the minimum adult requirement.     

Spectrum of a frequency modulated pulse width modulation signal

In power electronics, the switching elements are controlled by pulse width modulated (PWM) signals making their currents on and off repeatedly. This might cause electromagnetic interference (EMI) problems especially in switched mode power supplies. One method for mitigating the EMI is to use the frequency modulation technique in the control signal of the switching metal–oxide–semiconductor field‐effect transistor. According to this approach, frequency of the PWM signal is modulated in order to spread its spectrum and hence reduce the EMI levels. This paper presents the theoretical analysis for the spectrum of a frequency modulated PWM signal. Copyright © 2013 John Wiley & Sons, Ltd.     

A novel magneto‐impedance sensor model based on the zeros of Bessel functions

Nowadays, the design of magneto‐impedance (MI) sensors requires the development of lumped circuit models that can be simulated through equivalent impedance circuits relied on Bessel functions. A new impedance model based on Senani's equivalent using the zeros of Bessel functions is developed in this paper. The model allows to describe the impedance as a transfer function that can be easily synthesized by means of current conveyor circuits and passive elements. The mathematical representation was verified under simulation of transfer functions involving different number of poles and zeros. Moreover, the model has been verified using SPICE simulations and measurement results from a fabricated prototype demonstrating its scope and validity. Finally, a study of finite tracking errors of CCIIs used in the implementation of magneto‐impedance sensor has been realized. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis of a PPV‐fluorene derivative: Applications in luminescent devices

Synthesis of a polyfluorene/poly(p‐phenylene vinylene) derivative, the Poly [(9,9′‐di‐hexylfluorenediylvinylene‐alt‐1,4‐phenylenevinylene)‐co‐((9,9′‐(3‐t‐butylpropanoate) fluorene‐1,4‐phenylene)] (LaPPS 42) was performed following Wittig and Suzuki routes. Polyfluorenes and derivatives have been used in electroluminescent devices, and the synthesis described here has the advantage in pave the way to get distinct structures having different emission spectra. An extensive study of its electrochemical, thermomechanical, optical, and structural properties was carried out, as well as its application in electroluminescent devices. Polymer light‐emitting diodes (PLEDs) and polymer light‐emitting electrochemical cells (PLECs) were built using LaPPS 42 as active layer, and their electric and optical characterizations confirm they have a potential as active element in electroluminescent devices. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42579.     

Optical and Structural Properties of ZnO and ZnO:Cd Particles Grown by the Hydrothermal Method

Here, we examine the structural, vibrational, optical, and morphological properties of ZnO particles synthesized by the hydrothermal method, incorporating cadmium at different concentrations through the molar ratio R_m = Cd⁺²/Zn⁺² and a thermal treatment at 500°C. The X‐ray diffraction results demonstrated the high crystallinity of the ZnO compound with a wurtzite‐type hexagonal structure. The Raman scattering spectra demonstrated that the ZnO vibrational modes occur in the region between 200 and 1300 cm^?1, which is associated with different vibrational configurations characteristic of the ZnO molecule: E₂(Low), E₂(M), A₁(TO) E₁(TO), 2B₁(High), E₂(High), and TA + LO. The modes that were most affected by the incorporation of Cd²⁺ were those assigned to 2E₂(Low), E₂(M), and 2B₁(High), and this effect was associated with a greater displacement of Zn²⁺ ions. The optical study showed a reduction in the band gap and a decrease in the crystalline quality due to the substitution of Cd²⁺ in the ZnO lattice. Cadmium incorporation affected the morphology of the ZnO:Cd particles, changing the lengths and diameters of the ZnO rods; when the Cd concentration was increased, the ZnO rods shortened, forming coin‐type hexagonal structures.