The objective was to design a feasible drying method to increase the retention rates of phytoene (PT), phytofluene (PTF) and lycopene (LYC) in tomato powder. The method was to compare the effects of vacuum freeze-drying (FD), vacuum drying (VD) and hot-air drying (HAD) technologies on tomato pulp rich in PT, PTF and LYC. When dried by HAD, the retention rates of PT, PTF and LYC decreased significantly (p< 0.05) only when the water content decreased from 30% to 3.5%. When dried by VD, the temperatures had no significant effect on the retention rates, and only alkaline conditions (pH = 9), Fe3+and Al3+could significantly reduce the retention rates (p< 0.05). Therefore, a combined drying process (CDP) was designed: before the water content decreased to 50%, HD (60 °C) technology was used; then, the paste was dried via VD (80 °C, 0.08 MPa) technology till the water content reached 5 ± 2%; loading weight was 40 g (thinkness 5.70 mm) for each batch. Compared with VD alone, the CDP technology improved the retention rates of PT and LYC by 12% and 36%, respectively, while PTF decreased by only 6%.Keywords:phytoene (PT);phytofluene (PTF);lycopene (LYC);drying technology;retention rate
Biomass-based poly (trimethylene 2,5-furandicarboxylate) (PTF) was synthesized by the simple and low-cost direct esterification method. The high number-average molecular weight (M n ) of about 39.6 kDa was achieved for PTF with a polydispersity index (PDI) of 2.0, which was suitable for spinning. The electrospun PTF nanofiber membranes were fabricated firstly and displayed adjustable diameters, excellent mechanical properties (lifting 550 g weight, foldability) and large-scale preparation potential (area of 100 cm × 50 cm). More impressively, high initial surface potential (13.5 kV) was found for the electrospun in-suit electret membranes, which facilitated the capture of ultrafine PM particles. Subsequently, the PTF membrane showed exceptional particle capture capability with a filtration performance of 99.96 %, low pressure drops of 78 Pa, and a satisfactory quality factor of 0.1 Pa −1 . PTF filters also demonstrated long-term service capability for purifying high PM 2.5 concentration smoke (15 cycles, 55 min), and could be flexibly introduced into various practical scenarios. Additionally, based on the selective oil/water wettability of PTF membranes, which showed outstanding separation effects of oily wastewater(>99.88 %, 15 cycles). Therefore, the development and application of the PTF nanofibers provided a sustainable alternative for separation/purification and various fields in the future.