Advances of nanofluid in food processing: Preparation, thermophysical properties, and applications.

Nanofluids (NFs) are homogenous mixes of solid nanoparticles as well as base fluid in which the size of the solid nanoparticles (NPs) is smaller than 100 nm. These solid NPs are intended to enhance the thermophysical characteristics and heat transmission attributes of the base fluid. The thermophysical characteristics of nanofluids are influenced by their density, viscosity, thermal conductivity and specific heat. These colloidal solutions of nanofluids include condensed nanomaterials such as nanoparticles, nanotubes, nanofibers, nanowires, nanosheets, and nanorods. The effectiveness of NF is significantly influenced by temperature, shape, size, type, as well as the concentration of NPs or the thermal characteristics of the base fluid. Compared to oxide NPs, metal NPs have superior thermal conductivity. Many of these investigations revealed that hybrid NFs had enhanced thermal conductivity than traditional ones. Thermal conductivity values are reduced by the formation of clusters in nanofluid. When compared to spherically formed nanoparticles, cylindrically shaped nanoparticles produced superior outcomes. In food industries, NFs could be used in various unit operations where heat needs to be transported from a heating or cooling medium to food product using a heat exchanger, as in freezing, pasteurization, refrigeration, drying, thawing, sterilization, and evaporation. The objective of this review is to analyze the recent developments in the research of nanofluids including innovative production methods, stability assessment, enhancement approaches, and thermophysical properties of nanofluids.

Purification and characterization of Taxol and 10-Deacetyl baccatin III from the bark, needles, and endophytes of Taxus baccata by preparative high-performance liquid chromatography, ultra-high-performance liquid chromatography-mass spectrometry, and nuclear magnetic resonance.

Taxol and 10-Deacetyl baccatin III are major taxanes in the bark, needles, and endophytes of Taxus baccata. The current study aimed to develop a process for their separation from different matrices. Crude taxoid was prepared by extraction of samples with methanol, followed by partitioning with dichloromethane and precipitation with hexane. Analytical high-performance liquid chromatography involved isocratic elution on C18 column (4.6 × 250 mm, 5 µm) with methanol-water (70:30 v/v) at a flow rate of 1 ml/min. Injection volume was 20 µl and detection was carried out at 227 nm. The content of Taxol and 10-Deacetyl baccatin III in bark, needles and endophytic culture broth was 11.19 and 1.75 µg/mg; 11.19 and 1.75 µg/mg; and 2.80 and 0.22 µg/L, respectively. Preparative high-performance liquid chromatography was done on C18 column (10 × 250 mm, 5 µm) at a flow rate of 10 ml/min. About 20 g crude taxoid was processed in < 3 h with a recovery of about 90% for both the analytes. The purity of recovered Taxol and 10-Deacetyl baccatin III determined by ultra-high-performance liquid chromatography-mass spectrometry was found to be 95.78 ± 3.63% and 99.72 ± 0.18%, respectively. The structure of recovered Taxol was confirmed by nuclear magnetic resonance. The method can find use in biotransformation studies.