Effects of Flotation Deinking on Environmentally Friendly Offset Paper Printing Ink

Waste paper has become a promising raw material for the pulp and paper industry due to its low cost and because it is conducive to sustainable development. Unfortunately, waste paper contains a high volume of printed paper that is difficult to deink, which restricts its applications. Flotation deinking plays an essential role in the product quality and process cost of wastepaper recycling. This study was performed to evaluate the deinkability of environmentally friendly offset inks by flotation deinking. For this purpose, three series of four-color inks, namely, hybrid light emitting diode ultraviolet (LED‒UV), LED‒UV, and vegetable oil‒based inks, were printed on white lightweight coated papers under laboratory conditions. The deinking methodology involves repulping, deinking agent treatment, flotation, hand sheet making, and evaluation of the produced hand sheets. The obtained results indicated that the hybrid LED‒UV prints had the best deinkability. After flotation deinking, the deinking efficiency and the whiteness of the hybrid LED‒UV ink increased by 58.1% and 47.6%, respectively. LED‒UV ink had a 46.9% increase in the deinking efficiency and a 37.0% increase in the whiteness of the hand sheet. The deinking efficiency of the vegetable oil‒based ink was the lowest, at 42.1%, and the whiteness of the hand sheet increased only by 23.8%. The particle size distribution analysis demonstrated that the hybrid LED‒UV four-color ink exhibited a larger value of the average particle size than the two other. Scanning electron microscopy revealed that the hybrid LED‒UV ink particles on the surface of the fibers were the least abundant after deinking. The physical strength properties of the hand sheets, including tensile index, folding resistance, and cohesion of the hybrid LED‒UV, LED‒UV inks, and vegetable oil‒based inks, increased.

Development of a Web-App for the Ecological Momentary Assessment of Dietary Habits among College Students: The HEALTHY-UNICT Project

The transition from adolescence to adulthood is a critical period for the development of healthy behaviors. Yet, it is often characterized by unhealthy food choices. Considering the current pandemic scenario, it is also essential to assess the effects of coronavirus disease-19 (COVID-19) on lifestyles and diet, especially among young people. However, the assessment of dietary habits and their determinants is a complex issue that requires innovative approaches and tools, such as those based on the ecological momentary assessment (EMA). Here, we describe the first phases of the “HEALTHY-UNICT” project, which aimed to develop and validate a web-app for the EMA of dietary data among students from the University of Catania, Italy. The pilot study included 138 students (mean age 24 years, SD = 4.2; 75.4% women), who used the web-app for a week before filling out a food frequency questionnaire with validation purposes. Dietary data obtained through the two tools showed moderate correlations, with the lowest value for butter and margarine and the highest for pizza (Spearman’s correlation coefficients of 0.202 and 0.699, respectively). According to the cross-classification analysis, the percentage of students classified into the same quartile ranged from 36.9% for vegetable oil to 58.1% for pizza. In line with these findings, the weighted-kappa values ranged from 0.15 for vegetable oil to 0.67 for pizza, and most food categories showed values above 0.4. This web-app showed good usability among students, assessed through a 19-item usability scale. Moreover, the web-app also had the potential to evaluate the effect of the COVID-19 pandemic on students’ behaviors and emotions, showing a moderate impact on sedentary activities, level of stress, and depression. These findings, although interesting, might be confirmed by the next phases of the HEALTHY-UNICT project, which aims to characterize lifestyles, dietary habits, and their relationship with anthropometric measures and emotions in a larger sample of students.

Physical and Chemical Parameters of Emulsifiers and Their Effect on the Process of Food Emulsion Formation

Introduction. Modern food science needs new research of food emulsifiers, their composition, properties and effect on the structural characteristics of emulsions. It looks for modern technological solutions on how to select proper emulsifiers and their mixes to produce emulsions with different mass fractions of fat. The research objective was to study the effect of physical and chemical indicators of surfactants on the properties of food emulsions, as well as to develop practical recommendations for the selection of surfactants for various types of products. Study objects and methods. The research featured model dairy fat emulsions and laboratory-made vegetable oil, as well as hard and soft mono- and diglycerides of fatty acids and lecithins. The emulsifiers were used to determine the melting point, fatty acid composition, iodine number, and solid triglyceride content at various temperatures. The melting point of emulsifiers was determined by fixing the melting temperature in a capillary oven. To identify the fatty acid composition, the methyl esters of fatty acids were subjected to the chromatogram method. After that, the separated components and their quantity were determined by the area of the peaks. The content of solid triglycerides in the emulsifiers was determined by the method of nuclear magnetic resonance. The hydrophilic-lipophilic balance was obtained from the manufacturer's specifications. Results and discussion. The solid mono- and diglycerides appeared to have a high content of stearic and palmitic acids. Oleic acid predominated in soft monoglycerides; unsaturated fatty acids (linolenic and oleic) also predominated in the monoglycerides/lecithin complex emulsifier. Solid monoglycerides had a high content of solid triglycerides at 35°C (82.93%), which correlated with the high melting point (80°C) and the lowest iodine number (3 mg I2/100 g) of all the samples. The optimal ratio of vegetable oil and the emulsifier was defined empirically. The emulsifiers were dissolved in refined deodorized vegetable oil at 5–7°C above the melting point of the emulsifier. The resulting ratios were between 6:1 and 10:1. The samples of creamy vegetable spreads were obtained using the studied emulsifiers and their compositions in different doses and ratios. The crystallization temperature and phase transition time were determined when studying the process of emulsion overcooling. The article introduces a list of technological and physicochemical indicators of emulsifiers: the fatty acid composition, the degree of saturation, the melting point, and the content of solid triglycerides. By finding out the physicochemical parameters of emulsifiers, producers can vary the ratio of the components of emulsifying compositions to achieve the desired properties of food emulsions. The hydrophilic-lipophilic balance also proved to be an important index since the proportion of hydrophilic and hydrophobic groups in surfactants affects the type of emulsions and makes it possible to adjust the fat content of the finished product. Conclusion. The research results can expand the theoretical foundations of food emulsions. The article contains scientifically grounded recommendations on how to select optimal surfactants. The research opens up prospects for further studies of emulsifiers and their effect on the quality of finished products.

Influence of the Mixtures of Vegetable Oil and Vitamin E over the Microstructure and Rheology of Organogels

Candelilla wax (CW) and 12-hydroxystearic acid (12HSA) are classic solid-fiber-matrix organogelators. Despite the high number of studies using those ingredients in oily systems, there is scarce literature using a mixture of oil and antioxidants. Vitamin E (VE) is an important candidate for its lipophilicity and several applications on pharmaceutical, cosmetics, and food industries. In this work, we investigated the influences of mixtures between vegetable oil (VO) and VE on the microstructures and rheological properties of CW and 12HSA organogels. A weak gel (G′′/G′ > 0.1) with a shear-thinning behavior was observed for all samples. The presence of VE impacted the gel strength and the phase transition temperatures in a dose-dependent pattern. Larger and denser packed crystals were seen for 12HSA samples, while smaller and more dispersed structures were obtained for CW organogels. The results obtained in this work allowed the correlation of the structural and mechanical properties of the organogels, which plays an important role in the physical-chemical characteristics of these materials.

EXPERIMENTAL STUDY ON THE INJECTION CHARACTERISTICS OF HYDROTREATED VEGETABLE OIL IN A DIESEL ENGINE COMMON RAIL SYSTEM

The diesel combustion is primarily controlled by the fuel injection process. The start of injection therefore has a significant effect in the engine, which relates large amount of injected fuel at the beginning of injection to produces a strong burst of combustion with a high local temperature and high NOx formation. This paper investigated the impact of Hydrotreated Vegetable Oil (HVO) and blends of 10%, 20%, 30%, 50%, 80% by mass of HVO with commercial diesel fuel (mixed 7% FAME-B7) to injection process under the Zeuch’s method and compared to that of B7. The focus was on the injection flow rate in the variation of injection pressures, back pressures, and energizing times. The experimental results indicated that injection delay was inversely correlated to HVO fraction in the blend as well as injection pressure. At different injection pressures, HVO revealed a slightly lower injection rate than diesel that resulted in smaller injection quantity. Discharge coefficient was recognized larger with HVO and its blends. At 0.5ms of energizing time, injection rate profile displayed the incompletely opening of needle. Insignificant difference in injection rate was observed as increasing of back pressure.