Waleed Aboshora

Highly efficient trans–cis isomerization of lycopene catalyzed by iodine-doped TiO2 nanoparticles

Highly efficient trans–cis isomerization of lycopene was achieved in the presence of a novel iodine-doped titanium dioxide (I-TiO2) catalyst. The catalyst was prepared via a hydrothermal route and subsequent vacuum calcination and was characterized with thermogravimetric analysis, X-ray diffraction, nitrogen adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy techniques. Factors that affected the reaction parameters, such as the reaction temperature, the concentration of substrate, the weight of the catalyst and the reaction time, were investigated in detail. Application tests showed that the catalyst was highly active in the isomerization of lycopene in a heterogeneous reaction, and the conversion of all-trans-lycopene exceeded 80% after 2 h of reaction at 75 °C in ethyl acetate. Moreover, the catalyst displayed no significant loss of activity after five cycles of reuse.

Triacylglycerol composition, melting and crystallization profiles of lipase catalysed anhydrous milk fats hydrolysed

ABSTRACT Dairy products remain valuable components of human diet due to their balanced nutritive value and pleasant flavour. In this study, triacylglycerols (TAGs) from anhydrous milk fats were hydrolysed by Lipozyme-435 and Novozyme-435 and later on analysed by using ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Results revealed that the percentages of TAGs (CN 28–34) and TAGs (CN 36–42) with at least two short-chain fatty acids and with short- and medium-chain fatty acids were respectively decreased after 24 h of enzymatic hydrolysis. On the other hand, TAGs (CN 44–54) with at least two long-chain fatty acids were found to increase in both Lipozyme-435- and Novozyme-435-treated anhydrous milk fat (AMF). Meanwhile, the melting and crystallization profiles of both Lipozyme-435- and Novozyme-435-treated AMF were modified and significantly different when compared with the untreated AMF.

Influence of lipase under ultrasonic microwave assisted extraction on changes of triacylglycerol distribution and melting profiles during lipolysis of milk fat

In this study, the use of low irradiation ultrasonic microwave assisted extraction (UMAE) on lipases mixed with anhydrous milk fat (AMF) or anhydrous buffalo milk fat (ABF), with the aim of hydrolyzing triacylglycerols (TAGs), especially those containing short chain fatty acids, is reported. Lipozyme-435, Novozyme-435 and Thermomyces lanuginosus were mixed with phosphate buffer and either AMF or ABF in a jacketed flask. The reaction mixtures were exposed to low irradiation UMAE under temperature control (50 °C ± 2 °C) for 45 minutes. An ultra-performance liquid chromatography (UPLC) system coupled with quadrupole time-of-flight mass spectrometry (Qu-ToF-MS) was used to analyze TAG in AMF and ABF after lipolysis. The re-distribution was evidenced by the presence of a higher percentage of TAGs with at least two medium-chain fatty acids and one long-chain fatty acid, and a high percentage of TAGs with long-chain fatty acids as a consequence of a decreased percentage of TAGs with short-chain fatty acids. Furthermore, the melting and crystallization profiles were modified in both AMF and ABF treated with lipases in comparison to just AMF or ABF.

Health benefits of milk and functional dairy products

1School of Food Science and Technology, Jiangnan University, China 2Department of Nutrition & Food technology, Faculty of Science and Technology, Omdurman Islamic University, Sudan 3Departmentof Food process Engineering, Addis Ababa Science and Technology University, Ethiopia 4Department of Animal Science, Faculty of Agricultural Sciences, University of Gezira, Sudan 5Department of Food Processing Engineering, Faculty of Engineering, Al Imam Almahdi University, Sudan