Modeling engineering characteristics of hazelnut kernel during infrared fluidized bed drying

In this study, a laboratory scale infrared fluidized bed dryer was used to dry the hazelnut kernels. The drying experiments were performed under the following drying conditions: air temperatures of 45, 65 and 85?°C, air velocities of 1.30, 3.09 and 4.87 m/s and infrared powers of 500, 1000 and 1500 W. Maximum and minimum values of effective moisture diffusivity for hazelnut kernels were obtained 1.87?×?10^?9 and 1.75?×?10^?10 m²/s, respectively. Activation energy was obtained between 33.02 and 50.22 kJ/mol. Specific energy consumption of hazelnut kernels was obtained between 1.72?×?10³ and 2.23?×?10⁴ MJ/kg. Six mathematical models were used to predict the drying behavior of hazelnut samples. Among these models, the Midilli model sufficiently fitted the experimental drying data. The shrinkage values were obtained within the range of 0.10 and 0.24. The results obtained showed that the \({{L}^{*}},\) \({{a}^{*}},\) \({{b}^{*}}\) and \(\Delta E\) color values of the kernels were significantly affected (P?<?0.05) by air temperature. The highest color changes were related to the air temperature of 85?°C at all air velocities and infrared powers. Maximum values of energy (103.57 N mm) and force (129.84 N) at initial rupture point was related to air temperatures of 85?°C and infrared powers of 1500 W. Minimum values of energy (16.47 N mm) and force (31.74 N) at initial rupture point was related to air temperatures of 45?°C and infrared powers of 500 W.     

Effects of inlet air temperature and spray rate of coating solution on quality attributes of turmeric extract coated rice using top-spray fluidized bed coating technique

The addition of natural antioxidants onto white rice kernel can improve its functionality. Curcuminoids that present in turmeric rhizomes possess high antioxidant activity and heat stability. The objective of this study was to investigate the effects of inlet air temperatures and spray rates of turmeric extract solution on quality attributes of the turmeric extract coated rice (TCR) using the top-spray fluidized bed coating technique. The experimental results have shown that inlet air temperature and spray rate of coating solution strongly affected the final moisture content and percentage of fissured kernel of TCR. Almost all of TCR kernels in the bed cracked when their final moisture content was lower than 11.8% wet basis. However, the head coated rice yield of fissured TCR slightly decreased from that of white rice. The color of TCR was uniform over the entire surface. Texture of cooked TCR insignificantly changed from that of uncoated sample. Increasing spray rate provided higher both total phenolic content (TPC) and total antioxidant capacity (TAC) whilst increasing inlet temperature yielded lower TPC but it did not affect TAC. Retentions of TPC and TAC of TCR after cooking remained higher than 90%.     

Fluidized bed coating in food technology

Originally developed as a pharmaceutical technique, fluidized bed coating is now increasingly being applied in the food industry to tune the effect of functional ingredients and additives. Main benefits of such miniature packages, called microcapsules, include increased shelf life, taste masking, ease of handling, controlled release, improved aesthetics, taste and color. However, compared with a pharmaceutical technologist, a food technologist is more obliged to cut production costs and, therefore, should adopt a somewhat different approach to this rather expensive technology. As a consequence, conventional top-spray film coating of food ingredients seems the most feasible. Moreover, the barrier characteristics of a top-spray coating serve most food applications. Nevertheless, numerous variables are involved in film coating and a thorough insight into their action is essential for establishing an appropriate thermodynamic operation point that provides the required process and product quality. Finally, the development of continuous fluidized bed coaters will offer new possibilities.     

基于CFD方法优化离心式中浓浆泵湍流发生器结构的研究

基于CFD方法在FLUENT 6.0软件平台上模拟了湍流发生器作用下中浓纸浆悬浮液的三维流场,并根据模拟结果对离心式中浓浆泵湍流发生器的结构进行了优化设计。实验表明,优化结构的湍流发生器在较低能量消耗的前提下对中浓纸浆悬浮液的湍流流动、气体分离都有更好的贡献。因此在工程实际中,CFD方法对缩短设计周期、降低资金消耗具有重要作用。     

Modeling some thermal and physical characteristics of terebinth fruit under semi industrial continuous drying

In this research, the effect of different drying conditions on thermal and physical properties of terebinth fruit was studied. Experiments were conducted with a semi industrial continuous dryer in air temperature levels of 45, 60, 75 °C, air velocity levels of 1, 1.5 and 2 m/s and belt linear speeds of 2.5, 6.5, 10.5 mm/s. Results showed that the Midilli model had the best performance in predicting the moisture ratio. Effective moisture diffusivity of terebinth fruit during experiments was 6.48 × 10^?11–2.34 × 10^?10 m²/s achieved. Activation energy of the samples between 25.45 and 35.16 kJ/mol was obtained. The highest and lowest values of specific energy consumption 65.2 and 10.5 GJ/kg were calculated. Maximum value of shrinkage (16.70 %) was calculated at air temperatures of 75 °C and minimum value (12.34 %) was achieved at air temperature of 45 °C. After drying, total color difference was increased, and hue angle and chroma were decreased. Rupture force for dried terebinth between 80.15 and 112.68 N mm were calculated.     

Effect of Osmotic Dehydration and High Temperature Fluidized Bed Drying on Properties of Dehydrated Rabbiteye Blueberries

Rabbiteye blueberries were dried using an experimental high temperature fluidized bed (HTFB) dehydrator and the properties of the dried product were evaluated. 15 m/sec air velocity was required for fluidization and at 170°C the moisture content (MC in kg water/kg dry matter) of thawed blueberries was reduced from 5.8 to 0.7 after 8 min. After osmotic dehydration in sucrose, MC was 1.3, and 4 min in the HTFB drier at 150°C reduced MC to 0.28. Reduction of water activity to 0.5 after HTFB required cabinet drying at 60°C and 4 m/ set for 2.13 and 2.75 hr for the untreated and osmotically dehydrated berries, respectively. HTFB simultaneously dried and puffed the berries, resulting in reduced bulk density compared to berries produced using conventional drying. Osmotic dehydration prior to HTFB imparted a raisin-like texture to the product.     

Temperature- and Moisture-Dependent Dielectric Properties of Macadamia Nut Kernels

Conventional hot air drying for macadamia nuts takes several weeks, generating great interest in developing advanced drying technologies. Radio frequency (RF) and microwave (MW) heating hold potential for providing fast and uniform drying with acceptable product quality. To clearly understand the interaction between electromagnetic energy and macadamia nuts, information on dielectric properties of the kernels is needed for designing a practical and effective drying process. In this study, dielectric properties of the macadamia nut kernels were measured between 10 and 1,800 MHz using an open-ended coaxial-line probe technique at temperatures between 25 and 100 °C and moisture contents between 3 % and 24 % on a wet basis (w.b.). The results showed that both dielectric constant and loss factor of the kernels decreased sharply with increasing frequency over the RF range (10 to 300 MHz), but gradually over the measured MW range (300–1,800 MHz), which were largely enhanced by increasing moisture content and temperature. Penetration depth decreased with increasing frequency, moisture content, and temperature. Based on this study, uniform drying of macadamia nut kernels in thick layers could be effectively developed using RF energy.     

Determination of 6-Benzylaminopurine in Bean Sprouts by Capillary Electrophoresis Compared with HPLC

A simple capillary electrophoresis (CE) method based on solid-phase extraction (SPE) for the analysis of 6-Benzylaminopurine (6-BAP) was developed. Separation conditions were obtained in the sodium phosphate buffer solution (20 mM and pH 2.0), with 25 kV applied voltage and UV detection at 274 nm. Amiloride hydrochloride (AM) was used as an internal standard. Under the selected conditions, electrophoretic analysis was completed in less than 7 min, with LOD and LOQ of 19 and 65 ng mL^?1 for 6-BAP. The method was successfully applied to determine 6-BAP in bean sprouts with RSD lower than 3.6 % and the recoveries from 95.0 to 103.4 % for the spiked samples. Comparative experiments were also carried out with HPLC-UV method described in National Standards of People’s Republic of China. The validation results of the two methods are comparable, but the proposed CE method was found to be simple, rapid, allowing separation and analyte quantification in shorter time, and the reagent consumption was reduced.     

Effect of Cooking on Moisture Sorption Isotherms of Shea Nut (Vitellaria paradoxa Gaertn.) Kernels Part II: Modelling and Properties of Sorbed Water

An investigation was undertaken in this work to model the sorption isotherms of cooked and raw shea nut kernels determined by the standard static gravimetric method. The GAB, Halsey and Caurie models were validated and used in describing the sorption behaviour of the kernels. The monolayer moisture contents derived from Caurie’s equation for the desorption of cooked and raw kernels at 40, 50 and 60 °C were 5.49, 4.40 and 2.65 % and 5.22, 3.68 and 2.47 %, respectively. Monolayer moisture contents obtained from the GAB model showed a similar variation. As the temperature of sorption increased from 40 to 60 °C, the number of adsorbed monolayers (N), the surface area of adsorbent (A) and the percent bound water decreased significantly (p?<?0.05). It is suggested that the sorption process at all temperatures is multilayered. Desorption isosteric heats were lower for cooked kernels than the raw ones, while the reverse phenomenon was obtained for the adsorption process. It was established that, during storage, cooked kernels adsorbed moisture more slowly, suggesting that they could be stored for a longer period compared to the raw ones.     

Investigating shrinkage and moisture diffusivity of melon seed in a microwave assisted thin layer fluidized bed dryer

This work aimed to investigate the drying behavior of melon seed during combined fluidized bed-microwave drying system. Three drying air temperatures (40, 55 and 70 °C), three microwave powers (270, 450 and 630 W) and three air velocities (0.8, 1.5 and 2.3 m/s) were tested. Five mathematical models were selected to fit the experimental data for drying kinetics, and the results revealed that the Aghbashloo et al. model exhibited, in all cases, the best performance in fitting the experimental data (R² varying from 0.99088 to 0.99998; χ² from 0.00000 to 0.00185 and RMSE from 0.02289 to 0.82316). Calculated values of moisture diffusivity for dried melon seed varied from a minimum of 6.51 × 10?10 to a maximum of 6.59 × 10?9 m²/s under the tested drying conditions. Moisture diffusivity values increased as air temperature and microwave power was increased. Shrinkage values were calculated and found to vary in the range from 46.99 to 15.09 %.     

制备条件对玉米醇溶蛋白包衣性能的影响

本试验研究了玉米醇溶蛋白（Zein)溶液的浓度、pH值、干燥温度及增塑剂种类与数量等条件对Zein包衣抗张强度（TS）和透气性（Ap)的影响,结果发现,当Zein浓度为10%、pH=5、干燥温度为45℃、添加2%的甘油时所制得的包衣具有良好的外观、TS与Ap,其中TS达1.47kN/m,Ap为1.54um/Pa.s。为Zein包衣的实际应用提供了基础依据。     

Coating quality as affected by core particle segregation in fluidized bed processing

Fluidized bed coating is an important technique in the food powder industry, where often particles of a wide size distribution are dealt with. In this paper, glass beads of different particle size distribution were coated with sodium caseinate in a top-spray fluid bed unit. Positron Emission Particle Tracking (PEPT) was used to visualize and quantify the particle motion in the fluidized bed. Confocal Laser Scanning Microscopy combined with image analysis were used to investigate the effect of core particle size and its distribution on the thickness and quality of the coating. Particle size significantly affected the thickness and quality of the coating, due to differences in the corresponding fluidization patterns, as corroborated by PEPT observations. As the particle size distribution becomes narrower, segregation is less likely to occur. This results in a thicker coating which is, however, less uniform compared to when cores of a wider particle size distribution are spray coated.     

The Effect of Methylcellulose,Temperature, and Microwave Pretreatment on Kinetic of Mass Transfer During Deep Fat Frying of Chicken Nuggets

The aim of this study was to determine the effect of microwave pretreatment, usage of methylcellulose, oil temperature, and frying time on mass transfer during deep fat frying of chicken nuggets. Methylcellulose was used in batter and as a coating on product. Microwave with two power densities namely 3.7 and 7.4 W/g was used for reduction of initial moisture content of samples before frying. Frying was performed at three temperatures (150 °C, 170 °C, and 190 °C) and five intervals (0.5, 1, 2, 3, and 4 min) in the sunflower oil. The least oil content was observed when MC was used as a coating layer on non-precooked samples fried at 190 °C. Oil absorption of samples with MC in batter was partially higher compared to control samples. This could be attributed to the rheology of batters. The first-order kinetic model was fitted to moisture and oil content. For determining the correlation between temperature and moisture diffusivity, Arrhenius equation was used. The constant rate for moisture and oil transfer was in the range of 2.2–5 and 0.023–2.67 s^?1, respectively. Effective moisture diffusivity values were between 1.43?×?10^?8 and 3.24?×?10^?8 m²/s. Activation energy ranged between 0.71 and 1.71 kJ/mol.     

Developing treatment protocols for disinfesting pine wood product using radio frequency energy

Numerous non-native insect pests are moved around the world via international trade and have caused major forestry losses, especially for pine trees. The purpose of this research was to study a potential application of radio frequency (RF) heating for disinfesting pine wood products to reduce forestry damage caused by exotic pests. A pilot-scale 6 kW, 27.12 MHz RF system was used to develop a treatment protocol for disinfesting pine wood products based on the heating uniformity studies. The results showed that the heating time needed was only 6.7 min to heat the wood blocks (250?×?400?×?60 mm³) with moisture content of 13.3% d.b. from 25 to 60?°C using RF energy, but 320 min to reach 56.2?°C using hot air at 60?°C with 1.6 m/s. Based on the heating uniformity study, the best condition occurred when the lower wood moisture content was used and the wood width approached the RF electrode one. The RF treatment protocol was finally developed to combine RF energy with forced hot air at 60?°C, movement of conveyor at 7.4 m/h and holding at 60?°C hot air for 1 min. Wood quality was not affected significantly by the RF treatments because quality parameters of treated wood samples were similar to those of controls. The RF treatment may provide a rapid, effective and environmentally friendly method to disinfest wood products.     

Cutting forces in bandsaw processing of oak and beech wood as affected by wood moisture content and cutting directions

Cutting forces in bandsaw processing of oak and beech wood were measured at two levels of wood moisture content (about 12 % and FSP) for four cutting directions (90°–90°, 90°–0°, 0°–90° and 90°–45°). A constant cutting speed of 40 m/s and a feed rate of 20 m/min were applied. A piezoelectric dynamometer (KISTLER type 9257A) mounted on the carriage of the vertical bandsaw machine (ESTERER model EB 1400) was used to measure the parallel, normal and lateral cutting forces. Results revealed that all cutting forces depend on the wood moisture content and cutting direction. The greatest parallel force was observed for oak wood at 12 % MC for 90°–90° cutting direction (44 N/mm) whereas the lowest one was for beech wood at 30 % MC for 0°–90° cutting direction (20 N/mm). In contrast to the little change of lateral force at various cutting directions, the change in parallel force was significant.     

Nutritional Composition of Shea Products and Chemical Properties of Shea Butter: A Review

Increasing demand of shea products (kernels and butter) has led to the assessment of the state-of-the-art of these products. In this review, attention has been focused on macronutrients and micronutrients of pulp, kernels, and butter of shea tree and also the physicochemical properties of shea butter. Surveying the literature revealed that the pulp is rich in vitamin C (196.1 mg/100 g); consumption of 50 g covers 332% and 98% of the recommended daily intake (RDI) of children (4–8 years old) and pregnant women, respectively. The kernels contain a high level of fat (17.4–59.1 g/100 g dry weight). Fat extraction is mainly done by traditional methods that involve roasting and pressing of the kernels, churning the obtained liquid with water, boiling, sieving, and cooling. The fat (butter) is used in food preparation and medicinal and cosmetics industries. Its biochemical properties indicate some antioxidant and anti-inflammatory activities. Large variations are observed in the reported values for the composition of shea products. Recommendations for future research are presented to improve the quality and the shelf-life of the butter. In addition, more attention should be given to the accuracy and precision in experimental analyses to obtain more reliable information about biological variation.     

Heat transfer through glassfiber fabrics coated with silicone resin

Coatings can improve the performance of textiles, including flame retardants, water repellents and for heat resistance and weather resistance. Experimental methods are used normally to prepare heat insulation fabrics using coating technology. But there are many problems such as long processing time, high energy consumption, and the production of fumes. As computer technology develops, it is important to use numerical methods to predict the heat transfer performance of the coated fabrics. In this work, based on the yarn paths and their cross-sectional shapes, geometry models of the coated fabrics have been established. The finite element method was used to solve the heat transfer equations, and the numerical model was established to predict heat transfer performance. It was found that: (1) when comparing with the SEM images, the geometry model can represent well the structure and appearance of the coated fabric; (2) validation of the experimental data indicates that the numerical simulation model of heat transfer through the coated fabric is reliable and useful to predict the heat transfer performance, and the average relative deviation between the numerical data and experimental data was less than 7.0%; (3) when the thickness of the silicone coating layer is less than 0.50 mm, the temperature of the back face of fabric rapidly increased between 1 and 10 s, and it remained more than 510 °C as the heating time was extended. When the coating thickness is between 0.75 and 2 mm, the rising tendency of the temperature becomes gradually slower, and their temperatures remained 489, 455, 369 and 281 °C when the thickness of the coating layer is 0.75, 1.00, 1.50 and 2.00 mm, respectively.     

Effect of an Edible Pectin Coating and Blanching Pretreatments on the Air-Drying Kinetics of Pumpkin (<Emphasis Type="Italic">Cucurbita moschata</Emphasis>)

With the aim of making food drying processing data and their evaluation available, this work entails evaluating the air-drying kinetics of fresh pumpkin slices and those pre-treated by applying an edible pectin coating or blanching. The drying kinetics of the fresh, blanched, and pectin-coated pumpkin slices were evaluated at 60 and 70 °C with air velocities of 0.85 and 1.70 m?s^?1. The effects of the pre-treatments and drying parameters on moisture diffusivity were investigated. Under the drying conditions studied, a constant-rate period was found and the falling-rate period was described by the diffusion equation. In order to take shrinkage into account, shrinkage coefficients were incorporated in an approximate way, using the analytical solution of Fick’s equation. The highest constant drying rate values were obtained for the blanched samples, followed by the coated samples and finally the fresh samples. Constant drying rates demonstrated that this period did not significantly influence the estimate of the effective diffusion coefficients. It was shown that the water diffusivity of the coating was high, but only slightly increased the drying time, thus not affecting drying efficiency. Conversely, blanching promoted more water transfer and enhanced drying efficiency. It was concluded that coating and blanching at the temperatures and velocities studied were promising for use as pre-treatments in the drying of pumpkins.     

Energy drink consumption and impact on caffeine risk

The impact of caffeine from energy drinks occurs against a background exposure from naturally occurring caffeine (coffee, tea, cocoa and foods containing these ingredients) and caffeinated beverages (kola-type soft drinks). Background caffeine exposure, excluding energy drinks, was assessed for six New Zealand population groups aged 15 years and over (n = 4503) by combining concentration data for 53 caffeine-containing foods with consumption information from the 2008/09 New Zealand Adult Nutrition Survey (ANS). Caffeine exposure for those who consumed energy drinks (n = 138) was similarly assessed, with inclusion of energy drinks. Forty-seven energy drink products were identified on the New Zealand market in 2010. Product volumes ranged from 30 to 600 ml per unit, resulting in exposures of 10–300 mg caffeine per retail unit consumed. A small percentage, 3.1%, of New Zealanders reported consuming energy drinks, with most energy drink consumers (110/138) drinking one serving per 24 h. The maximum number of energy drinks consumed per 24 h was 14 (total caffeine of 390 mg). A high degree of brand loyalty was evident. Since only a minor proportion of New Zealanders reported consuming energy drinks, a greater number of New Zealanders exceeded a potentially adverse effect level (AEL) of 3 mg kg^?1 bw day^?1 for caffeine from caffeine-containing foods than from energy drinks. Energy drink consumption is not a risk at a population level because of the low prevalence of consumption. At an individual level, however, teenagers, adults (20–64 years) and females (16–44 years) were more likely to exceed the AEL by consuming energy drinks in combination with caffeine-containing foods.     

Use of Experimental Design and Artificial Neural Network in Optimization of Capillary Electrophoresis for the Determination of Nicotinic Acid and Nicotinamide in Food Compared with High-Performance Liquid Chromatography

A simple capillary electrophoresis (CE) method for the analysis of nicotinic acid (NA) and nicotinamide (NAM) was developed. Important experimental factors were optimized with response surface approach. Statistical models were constructed by Box–Behnken design as well as artificial neural network using the three selected variables (buffer concentration, sodium dodecyl sulfate (SDS) concentration, and voltage). Optimum separation conditions obtained were 10 mM sodium borate/10 mM SDS buffer, pH 9.0, 25 kV applied voltage, and UV detection at 210 nm. Linear relationships between peak-area and the content of the analytes were obtained in the concentration range (1.0–100 μg mL^?1), and the detection limit was less than 0.15 μg mL^?1. The method was applied to the determination of NA and NAM in different kinds of samples with satisfactory separation in less than 5 min. In addition, a comparison with high-performance liquid chromatography demonstrated that the developed CE method was comparable with regard to linearity, sensitivity, precision, and accuracy, but the analysis time and reagent consumption for CE were decreased significantly.