Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment

This is the peer reviewed version of the following article: García Martínez, Eva María, Andújar Pérez, Isabel, Yuste Del Carmen, Alberto, Prohens Tomás, Jaime, Martínez Navarrete, Nuria. (2018). Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment..Journal of the Science of Food and Agriculture, 98, 8, 3076-3083. , which has been published in final form at http://doi.org/10.1002/jsfa.8807. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] BACKGROUND: Recent epidemiological studies have suggested that phenolic compounds present in grapefruit play an important role in the bioactive properties of this fruit. However, the consumption of fresh grapefruit is low. Freeze dried powdered grapefruit can be an alternative to promote this fruit consumption. To improve the quality and stability of the powdered fruit, the addition of encapsulating and anticaking agents can be used. In this work, different grapefruit powders obtained by freeze drying with addition of gum arabic (1.27 g/100 g), and bamboo fibre (0.76 g/100 g) with and without a pre-drying microwave treatment were compared with the fresh and freeze-dried fruit with no carriers added in order to evaluate the effect of these preservation processes on phenolics content and on its antioxidant (DPPH, ABTS and FRAP) and anti-inflamatory (evaluated in RAW 264.7 macrophages) capacities. RESULTS: Freeze drying and gum arabic and bamboo fibre addition significantly increased the total phenolics, and antioxidant and anti-inflammatory activities (by inhibiting NO production of LPS activated RAW 264.7 macrophages) of grapefruit. An additional increase in these parameters was obtained with a microwave pretreatment before freeze-drying. CONCLUSIONS: The combined addition of gum arabic and bamboo fibre to the grapefruit puree and the application of a microwave pretreatment improve the functional properties of the fruit without showing cytotoxicity in vitro.We thank the Ministerio de Economia y Competitividad and FEDER for financial support given through the Project AGL 2012-39103.García Martínez, EM.; Andújar Pérez, I.; Yuste Del Carmen, A.; Prohens Tomás, J.; Martínez Navarrete, N. (2018). Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment. Journal of the Science of Food and Agriculture. 98(8):3076-3083. https://doi.org/10.1002/jsfa.8807S3076308398

The thermal analysis of the fin usage in the natural circulation indirect hot water preparing systems by solar energy

Bu çalışmada, güneş enerjili tabii sirkülasyonla endirekt sıcak su hazırlama sistemlerinde kanatçık kullanmanın ısıl analizi teorik olarak yapılmıştır. Bu nedenden dolayı aynı özelliklere sahip kanatçıklı bir sistem ve kanatçıksız bir sistem ısıl verim açısından karşılaştırılmıştır. Karşılaştırma sonucunda kanatçıklı sistemin kanatçıksız sistemden % 10,5 daha iyi performansa sahip olduğu belirlenmiştir.In this study the thermal analysis of the fin usage has been done theorically in the natural circulation indirect hot water preparing systems by solar energy. Because of the this reason a finned system and without fin system that have the same properties have been compared in terms of thermal performance. The result of comparing a finned system has better performance 10,5 % than without fin system has been determined

Derivation of empirical equations for thermodynamic properties of a ozone safe refrigerant (R404a) using artificial neural network

ARCAKLIOGLU, Erol/0000-0001-8073-5207WOS: 000272432300031This study, deals with the potential application of the artificial neural networks (ANNs) to represent PVTx (pressure-specific volume-temperature-vapor quality) data in the range of temperature of 173-498 K and pressure of 10-3600 kPa. Generally, numerical equations of thermodynamic properties are used in the computer simulation analysis instead of analytical differential equations. And also analytical computer codes usually require a large amount of computer power and need a considerable amount of time to give accurate predictions Instead of complex rules and mathematical routines, this study proposes an alternative approach based on ANN to determine the thermodynamic properties of an environmentally friendly refrigerant (R404a) for both saturated liquid-vapor region (wet vapor) and superheated vapor region as numerical equations. Therefore, reducing the risk of experimental uncertainties and also removing the need for complex analytic equations requiring long computational time and effort. R-2 values which are errors known as absolute fraction of variance - in wet vapor region are 0.999401, 0 999982 and 0.999993 for specific volume. enthalpy and entropy for training data, respectively. For testing data, these values are 0.998808. 0.999988, and 0 999993 Similarly, for superheated vapor region, they are 0.999967, 0.999999 and 0.999999 for training data, 0.999978, 0.999997 and 0.999999 for testing data. As seen from the results of mathematical modeling, the calculated thermodynamic properties are obviously within acceptable uncertainties. (C) 2009 Elsevier Ltd. All rights reserved

The determinig of collector heat load for swimming pool heating systems with solar energy

Günümüzde yaygın olarak kullanılmaya başlanan yüzme havuzlarının ısıtılmasında katı, sıvı, gaz yakıtlı ve elektrikli ısıtma sistemlerine yüksek maliyetlerinden dolayı alternatif olarak güneş enerjili ısıtma sistemleri geliştirilmektedir. Bu çalışmada, güneş enerjisi ile ısıtılan havuzlardaki havuz ısıtma yükü hesabında kullanılan; buharlaşma,ışınım, taşınım ve ilave edilen sudan meydana gelen ısı kayıpları ile ısı kazanç parametreleri ayrıntılı olarak incelenmiştir. Son bölümde 50 m x 15 m boyutlarında bir yüzme havuzunun ısıtılmasında kullanılan kollektör net ısı yükü örnek olarak hesaplanmıştır.Nowadays, to swimming pools being used widespreadly, solar energy heating systems are being developed as alternative to solid, liquid, gas fuel and electricity heating systems due to the high costs. In this study, using parameters (etc. evaporation, radiation, convection heat losses and heat losses is taken from added water and heat gains) in the calculation of the heat load of pools, heated by solar energy, were examined in details. In the last part, as an example, heat load has been calculated for collector used for heating a swimming pool dimension of that 50 m x 15 m

Buhar sıkıştırmalı soğutma sisteminin performans iyileştirmesi: POE/Al2O3 uygulaması

In this experimental study, the results of utilizing a nano-lubricant in place of compressor work fluid in a refrigeration system wereexamined. R134a refrigerant was utilized in the refrigeration system. Polyol ester (POE) was used as a base fluid and a nanolubricant prepared from alumina oxide (Al2O3) nanoparticles was utilized. The experiments were carried out separately with nanolubricants created by mixing Al2O3 nanoparticles in the ratios of 0.5% and 1.0% into POE oil. Additionally, 0.5% triton X-100(TX-100) surfactant was utilized in the nano-lubricant in order to ensure a homogeneous dispersion in the suspension. As a resultof the experiments, the highest coefficient of performance (COP) value for the cooling system was obtained at the concentrationsof 0.5% Al2O3 and 0.5% TX-100. In the experiments with pure POE oil, the COP value was increased by 18.27%. The powervalue drawn by the compressor was reduced by 12.53% at the concentrations of 0.5% Al2O3 and 0.5% TX-100.Deneysel olarak gerçekleştirilen bu çalışmada bir soğutma sisteminde kompresör yağı yerine nanoyağlayıcı kullanımının sonuçları incelenmiştir. Çalışmada incelenen soğutma sisteminde, R134a soğutucu akışkanı kullanılmıştır. Kompresör yağı olarak polyol ester (POE) baz sıvısı ile birlikte, alüminyum oksit (Al2O3) nanopartiküllerinden hazırlanan nanoyağlayıcı değerlendirilmiştir. POE yağına %0,5 ve %1,0 oranlarında Al2O3nanopartikülleri karıştırılarak oluşturulan nanoyağlayıcılar ile deneyler gerçekleştirilmiştir. Ayrıca, oluşturulan nanoyağlayıcı içerisinde homojen bir dağılım sağlamak amacıyla süspansiyonda ağırlıkça %0,5 oranında triton X100 (TX-100) yüzey aktif malzemesi kullanılmıştır. Deneyler sonucunda soğutma sistemi için en yüksek soğutma tesir katsayısı (COP) değeri %0,5 Al2O3 ve %0,5 TX-100 konsantrasyonunda elde edilmiştir. Saf POE yağı ile yapılan deneylere göre COP değeri %18,27 kadar arttırılmıştır. Kompresörün çekmiş olduğu güç değeri de %0,5 Al2O3 ve %0,5 TX-100 konsantrasyonunda %12,53 kadar azaltılmıştır

The experimental analysis of the effect of the fin usage on the performance of solar energy systems

Bu çalışmada, güneş enerjili sistemlerde kanatçık kullanımının verime olan etkisi deneysel olarak incelenmiştir. Bu amaçla bütün özellikleri aynı, sadece kanatçık boyutları farklı, üç ayrı sistem ve karşılaştırma yapabilmek için bir kanatçıksız sistem tasarlanıp imal edilmiştir. Deney sonuçlarının kullanıldığı hesaplamalara göre; 30 mm x 310 mm boyutlarında dikdörtgen kanatçıklı sistemin diğer sistemlerden yaklaşık % 6 daha iyi performansa sahip olduğu görülmüştür.In this study, the effect of the fin usage on the performance has been examined experimentally in the solar energy systems. For this aim, three different systems whole properties are the same but only fin dimensions are different and the other one without fin have been designed and manufactured for comparing. According to calculations used experiment results, it was seen that the 30 mm x 310 mm dimensions finned rectangle system has better performance nearly 6 % than the others

Energy analysis of sic–si3n4 @ poe and sic–si3n4 @ r134a based cooling systems

WOS:000905667100001Passive methods are preferred in cooling systems and the development of these methods is one of the most important issues in terms of energy efficiency. Improving heat transfer in cooling systems by using solid–liquid and solid–gas suspensions instead of the base fluid is a crucial passive method. The compressor in the system was operated with nanolubricants in different mass fractions, and the cooling system was filled with a hybrid nanorefrigerant. The applications of nanolubricants and nanorefrigerants, the concentration of nanoparticles as an additive material in tribological tests, their compatibility with the particle type, base fluid, and surfactant are important parameters. In this context, silicon carbide (SiC) and silicon nitride (Si3N4) nanoparticles were preferred due to their compatibility and superior tribological properties in terms of contact area and wear mechanism. The results show that the addition of nanoparticles to the compressor oil and refrigerant has a positive effect on the system performance when nanolubricant with a mass fraction of 0.34% in polyol ester (POE) and hybrid nanorefrigerant with a mass fraction of 0.055% were used. With the use of nanoparticles, the coefficient of performance (COP) of the system increased by 21.82% compared to pure POE