Synthesis of Functionalized High‐Oleic Soybean Oil Wax Coatings and Emulsions for Postharvest Treatment of Fresh Citrus Fruit

High‐oleic soybean oil is chemically functionalized in order to mimic the structure and physical properties of hydrogenated castor oil (HCO). The resulting wax‐like material is evaluated for use as an alternative to other commercial wax coatings for the postharvest treatment of fresh citrus fruit. The racemic nature of the material inhibits ordered crystalline arrangement and negatively affects its relative crystallinity (17.7%), hardness (0.59 ± 0.04 mm^?1), and melting profile (44–46 °C), with respect to HCO oil (37.7%, 5.33 ± 0.01 mm^?1, 83–87 °C). Nevertheless, compounding the new material with carnauba wax (CAR) imparts a very attractive gloss and prevents moisture loss significantly better than polyethylene, shellac, and CAR‐based coatings. Compounding the hydroxy‐functionalized high‐oleic soybean wax may potentially reduce dependence on imported CAR and other ingredients used in citrus coating emulsion formulations. Practical Applications: The soybean oil‐derived material described in this contribution provides two key performance characteristics desired by citrus growers and packing houses: an efficient barrier to moisture loss and an attractive shine. The synthesis of the hydroxy‐wax is facile and mild, and the materials can be readily formulated into emulsions as required for fruit coating applications. Use of the formulated coating can be extended to other agricultural commodities such as avocados, melons, and stone fruit.     

An aging theory-based mathematic model for estimating the wax content of wax deposits using the Fick's second law

In this study, a mathematic model is proposed for estimating the wax content of wax deposits. The proposed model was built based on the diffusion of wax molecules and counter-diffusion of oil molecules and described using the Fick's second law, allowing for the stacking fraction and orientational order of precipitated wax crystals and the tortuosity of diffusion path of de-waxed oil molecules during the counter-diffusion. The calculated results were verified by comparing with the flow-loop wax deposition experimental results. Dependence of radial position, deposition duration, bulk temperature, and wall temperature were investigated. These factors significantly affected the wax content during wax deposition. Good agreements were observed between the predictions and experimental results. The variation trends of wax content affected by various aspects are consistent with the existing studies.     

对《原油析蜡点的测定 旋转黏计法》的改进意见

通过对流变仪温控原理的研究,分析了行业标准《原油析蜡点的测定旋转黏计法》中采用连续降温方式的不合理性,建议采用分段降温的方式。在低温段曲线呈非线性关系的情况下,若按照标准推荐的计算析蜡点软件计算,会造成析蜡点偏小或偏大。为此,提出了按照低温段曲线偏离高温段拟合直线的程度,判断析蜡点的改进意见。     

Use of High-Intensity Ultrasound to Change the Physical Properties of Oleogels and Emulsion Gels

The objective of this work was to evaluate the effect of high-intensity ultrasound (HIU) on the physical properties of a soft oleogel (2% of candelilla wax, 2% of monoacylglycerol, and 2% of hardfat) and of water-in-oil (W/O) emulsion gels (EG) with various amounts of water (0%, 5%, and 25%). Physical properties of these systems such as thermoresistance, microstructure, melting profile, hardness, rheology, and oil loss were measured. When HIU was applied to the oleogel for 3 min using a 3.2 mm-diameter tip at an amplitude of vibration of 216 μm, a reduction in crystal size and crystal area (P < 0.05) was observed with an increase in hardness and no change in G′ nor in oil loss compared to the nonsonicated oleogel. Other sonication conditions (lower power levels, shorter durations, and bigger tips) tested in this study reduced the hardness and elasticity of the sample and increased oil loss. When HIU (3.2 mm-diameter tip, 216 μm, 3 min) was used in emulsions, harder and more elastic (P < 0.05) samples were obtained only in the samples with 25% water. This study shows that the texture of oleogels and EG with 25% of water can be improved by using HIU. The impact of these results is that the fat content of an EG can be reduced by 25% by adding water and HIU can be used to recover the structure lost due to water addition.     

Physical Properties of Candelilla Wax,Monoacylglycerols, and Fully Hydrogenated Oil Oleogels

Oleogels have been studied in the past decade due to their potential to replace saturated fat in foods. Oleogelators have been mostly studied alone or in binary systems. Sometimes a single oleogelator cannot achieve all the technological properties necessary for a specific food application. Thus, the aim of this work was to investigate the interaction between candelilla wax (CLX), monoacylglycerols (MAG), and a fully hydrogenated oil (hardfat [HF]) in soybean and high‐oleic sunflower oils and to evaluate their physical properties. The concentration of the total oleogelator was between 5% and 10%, from pure CLX (5%), sample OP, up to many combinations of MAG, HF, and CLX samples O1, O2, O3, O4, O5, and O6. Samples were evaluated according to their microstructure, melting properties, rheological behavior, hardness, oil‐binding capacity (OBC), and thermal stability. Results showed that the addition of MAG and HF to CLX created a softer gel but improved its rheological properties. Changes in the physical properties were related to the various proportions of CLX, MAG, and HF rather than the overall concentration of structuring agents. For example, for a total concentration of 5% of the structuring agent, a decrease in the CLX concentration from 5% to 3% and the addition of HF and MAG resulted in a softer crystalline network. Increasing the overall concentration of oleogelators by increasing the amount of HF and/or MAG and maintaining the concentration of the CLX constant did not improve the hardness of the gel. This study showed that at least 3% of CLX must be added to the system to obtain a semisolid material independently of the amount of MAG and/or HF added.     

Exploitation of high-intensity ultrasound to modify the structure of olive oil organogel containing propolis wax

In this research, the effect of high-intensity ultrasound (HIU) on physico-chemical properties of olive oil organogel containing propolis wax was studied. The experiment was accomplished by response surface method (RSM) in different ultrasonic power levels, ultrasonic times and cooling temperatures. Regarding to maximum firmness and minimum oil migration, 300 W ultrasonic power, 5 °C cooling temperature and 120 s ultrasonic time were introduced as the optimum HIU condition. Optimised HIU-organogel was characterised in comparison to control. Results showed that HIU induced nucleation by creating small crystals led to form a strong network with high oil binding capacity. DSC analysis confirmed nucleation by high enthalpy for HIU-organogel. XRD pattern revealed no polymorphism transformation. However, a slight increasing of peroxide value was observed for HIU-modified organogel. These findings indicated that HIU could be a possible modification tool to produce appropriate organogel for food application such as margarine and shortening.     

An experimental study on solar evaporation of sugarcane juice

In this study, an attempt is made to obtain concentrated sugarcane juice and distilled water using solar radiations that would save energy as well as environment. In this study work, the experimental performance of a sugarcane juice solar evaporation system (SJSES) is investigated for the evaporation of water from sugarcane juice. To check the influence of flow rate on the performance of SJSES units, experiments are carried out at 20, 25, 30, and 35 ml/min. The flow of sugarcane juice at 25 ml/min in SJSES unit is found optimum that resulted in highest energy saving, distilled water, and relatively more brix content of final product. The performance of SJSES unit loaded with paraffin wax at optimum flow rate (unit IV) resulted in maximum distilled water (605.1 g) which is 82.4%, 14.8%, and 39.4% higher than other units. Paraffin wax loading in SJSES increased its distillate output, brix of juice, and working time by 78.3 g, 7.9%, and 1 h, respectively. Thermal and exergy efficiencies are found maximum for unit IV having values 58.56% and 4.53%, respectively. The amount of energy saved is observed maximum for this unit along with least distillate cost and payback period.     

Nano-composite pour point depressants in improving the rheology of waxy crude oil

This article mainly describes the advantages of nano-pour point depressants on the low-temperature fluidity of crude oil compared with traditional pour point depressants. The common nano-pour point depressants are mainly divided blend type and polymerization type. It can effectively improve wax crystal structure and strength, thereby improving the low-temperature fluidity of crude oil. Nano-particles have better application prospects in improving rheological properties of waxy crude oil.     

输油管道蜡沉积试验新技术及装备

介绍了输油管道蜡沉积试验的一些新技术和装备。在析蜡点测量方面,主要介绍了旋转黏度计法、偏光显微镜法和差示扫描量热法;在蜡沉积量测定方面,主要介绍了清管法、拆管法、压降法、传热法、液体置换与检测法、超声波法和激光测厚法;在蜡沉积物组分测定方面,主要介绍了气相色谱法和气相色谱-质谱联用技术。这些新技术和装备为解决蜡沉积试验和工程中的问题提供有效手段。