Distributions of Polycyclic Aromatic Hydrocarbons and Phthalic Acid Esters in Gums and Soapstocks Obtained from Soybean Oil Refinery

Soybean oil gums and soapstocks are important by-products that may potentially be contaminated by persistent organic pollutants (POP) such as polycyclic aromatic hydrocarbons (PAH) and phthalic acid esters (PAE), thus lowering the value when using them as starting materials to produce animal feed additives, food industry ingredients, and pharmaceutical products. In the present work, PAH and PAE distributions in these two types of by-products were detected using solvent extraction–solid phase extraction purification coupled with gas chromatography–mass spectrometry. Total PAH and PAE amounts in the soapstocks were significantly higher than those in the gums, thus indicating that neutralization showed much higher removal efficiency than degumming in terms of PAH and PAE eliminations. Meanwhile, the results proved that the concentrations of these two kinds of contaminants in the soybean oil gums and soapstocks were much higher than those in the soybean oils, suggesting that further investigations were needed and that the contents of PAH and PAE in soybean oil refining by-products should be carefully monitored and regulated.     

基于体积温度系数法测量进口精炼棕榈硬脂体积

为了估算拟卸液油到罐体积,使储油罐区有效配置罐容,避免加热液油卸入岸罐时发生溢冒事故,以进口精炼棕榈硬脂(熔点52.6℃)为例,研究了其在液态下温度变化和体积相对变化的关系,并基于体积温度系数对其在60～75℃范围内的体积进行了估算,同时实测液位和液温,求取体积和密度,计算液货质量,并采用常规密度推算法对精炼棕榈硬脂在60～75℃范围内的体积进行估算,对两种方法估算的体积进行t检验。结果表明：在60～75℃范围内,运用体积温度系数法求得的体积与常规密度推算法求得的体积没有显著差异。因此,可以采用体积温度系数法估算精炼棕榈硬脂的体积。     

The effects of oil,egg and salt content on some physical properties of canned moinmoin

Samples of canned moinmoin were prepared containing different quantities of oil, egg and salt. A uniaxial compression test was carried out on these samples using an Instron UTM. Three measurements were taken from the force-deformation traces, i.e. rupture force (F_R), deformation to rupture (D_R) and stress at yield point (Y_S). Variations in the oil content significantly influenced the values of F_R and D_R obtained. Variations in egg content influenced the values of F_R and Y_S. The salt content had no significant influence on the three measurements. The conclusions were that an increase in oil content softened the moinmoin whereas an increase in egg content resulted in a firmer product.     

Preparation of Docosahexaenoic Acid-Rich Diacylglycerol-Rich Oil by Lipase-Catalyzed Glycerolysis of Microbial Oil from Schizochytrium sp. in a Solvent-Free System

Docosahexaenoic acid (DHA)-rich diacylglycerol (DAG)-rich oil was prepared by lipase-catalyzed glycerolysis of microbial oil from Schizochytrium sp. in a solvent-free system. The reaction parameters including lipase type, substrate molar ratio, temperature, lipase concentration, and reaction time were screened. The selected conditions were determined as follows: Novozym® 435 (Novozymes A/S, Bagsvaerd, Denmark) as biocatalyst at 8 wt%, substrate ratio (DHA-rich microbial TAG/glycerol) of 1:1 mol/mol, temperature of 50 °C, and reaction time of 12 hours. Under these conditions, the triacylglycerol (TAG), DAG, and monoacylglycerol (MAG) contents in the product were 36.4%, 48.2%, and 15.4%, respectively. The lipase was reused successively for 18 cycles without significant loss of activity under the conditions given above. Fatty acid composition analysis of the final product showed that the contents of DHA in TAG, DAG, and MAG were 53.9%, 44.9%, and 34.8%, respectively. DHA-rich DAG has the potential to be used as an ingredient in infant formula to increase the bioavailability of DHA.     

Microwaves to control Callosobruchus maculatus in stored mung bean (Vigna radiata)

Disinfestation of stored grains using microwaves can be an alternative to chemical methods for controlling insects in grains and pulses. Mung bean of 12% moisture content (m.c.) was infested with different life stages of the cowpea weevil (Callosobruchus maculatus) and exposed to 200, 300 or 400 W microwave power levels for 14, 28 and 42 s. One hundred percent insect mortality for all life stages (egg, young larva, old larva, pupa and adult) was achieved with exposure to 400 W power level for 28 s, which caused a surface temperature of mung bean of 68.1 °C. Eggs were the most susceptible and adults were the least susceptible life stages to microwave treatments. No significant difference was observed between mortality of larvae and pupae stages and their mortality was between eggs and adults. Mung bean temperatures increased and germination decreased with increased power level or exposure time.     

Stable auto-tuning of hybrid adaptive fuzzy/neural controllers for nonlinear systems

In direct adaptive control, the adaptation mechanism attempts to adjust a parameterized nonlinear controller to approximate an ideal controller. In the indirect case, however, we approximate parts of the plant dynamics that are used by a feedback controller to cancel the system nonlinearities. In both cases, “approximators” such as linear mappings, polynomials, fuzzy systems, or neural networks can be used as either the parameterized nonlinear controller or identifier model. In this paper, we present an algorithm to tune the adaptation gain for a gradient-based hybrid update law used for a class of nonlinear continuous-time systems in both direct and indirect cases. In our proposed algorithm, the adaptation gain is obtained by minimizing the instantaneous control energy. Finally, we will demonstrate the performance of the algorithm via a wing rock regulation example.     

Detecting and measuring rings in banknote images

Various intelligent systems show a rapidly growing potential use of visual information processing technologies. This paper presents an example of employing visual information processing technologies for detecting and measuring rings in banknote images. The size of the rings is one of parameters used to inspect the banknote printing quality. The approach developed consists of two phases. In the first phase, based on histogram processing and data clustering, image areas containing rings are localized and edges of the rings are detected. Then, in the second phase, applying the hard and possibilistic spherical shell clustering to the extracted edge pixels the ring centre and radii are estimated. The experimental investigations performed have shown that even highly occluded rings are robustly detected. Several prototypes of the system developed have been installed in two banknote printing shops in Europe.     

Effect of medium temperature setting on gelling characteristics of surimi from some tropical fish

Effects of setting at 25 °C on textural properties and cross-linking of myofibrillar proteins in surimi produced from threadfin bream (Nemipterus bleekeri), bigeye snapper (Priacanthus tayenus), barracuda (Sphyraena jello) and bigeye croaker (Pennahai macrophthalmus) were investigated. Increase in setting time (0–8 h) resulted in a higher breaking force and deformation for all surimi gels tested (P<0.05). Increased gel strength was associated with increase in non-disulfide bond formation and decreased heavy chain myosin. Proteins underwent degradation during setting; however polymerization occurred to a much higher extent, leading to a strengthened gel matrix. Therefore, setting at 25 °C, for an appropriate time, should be a promising means to improve gelling properties of surimi produced from tropical fish.     

Dielectric properties of α-d-glucose aqueous solutions at 2450 MHz

Using a cavity perturbation technique, dielectric properties of α-d-glucose aqueous solution at 2450 MHz were measured at concentrations ranging from 10 to 60% in the temperature range of 0–70 °C. Dielectric constant increases with temperature in a quadratic manner while linearly decreasing with glucose concentration. Dielectric loss factor decreases with temperature in a quadratic way. The loss factor–concentration relationship depends on the temperature. At lower temperature, loss factor increases linearly with concentration up to a certain concentration then decreases. At temperatures higher than 40 °C, loss factor linearly increases with concentration at all concentration ranges studied. The results are useful for studying volumetric heating of these solutions by microwave energy, and chemical changes such as Maillard reaction and mutarotation involving glucose aqueous solutions in microwave field.     

Microwave-assisted catalytic synthesis of phytosterol esters

A low-temperature reaction is of considerable importance in avoiding the degradation of phytosterol esters caused by high temperatures. In this study, an efficient method under mild conditions was developed to synthesise phytosterol esters by using microwave-assisted catalyst dodecyl benzene sulphonic acid (DBSA). The phytosterol conversion reached 94.27% under the optimal conditions: oleic acid to phytosterol molar ratio of 2.5:1, catalyst dosage of 20% (mol%) and reaction temperature of 60°C for 60 min. Fourier transform infrared (FTIR) spectroscopy was applied to determine the structure of phytosterol oleates. Moreover, a second-order kinetic model describing phytosterols esterification exhibited an adequate agreement with the experimental data. Microwave irradiation achieved the reduction of energy barrier (Ea = 29.17 kJ mol⁻¹) in comparison with conventional heating (Ea = 49.22 kJ mol⁻¹). This study suggests that microwave-assisted catalyst DBSA is a reliable and efficient method for the production of high-quality phytosterol esters.