Activated-hydrochar (AHC) derived from sugarcane bagasse was synthesized by hydrothermal carbonization (HTC) using phosphoric acid and sodium hydroxide (NaOH) as activators. The properties of AHC were systematically characterized by elemental analysis, BET, SEM, FTIR, XPS and zeta potential, and applied to evaluate the adsorption ability of methylene blue (MB) by batch adsorption tests. The MB adsorption isotherm and kinetics of AHC were well described by the Langmuir model and pseudo-second-order kinetic model. Characteristic analysis suggested electrostatic attraction, hydrogen bonding and π–π interactions were the main contributors to MB adsorption. Analysis of mass transfer mechanisms demonstrated the adsorption process towards MB by AHC involved intra-particle diffusion to some extent. Thermodynamic studies indicated MB adsorption was an endothermic, spontaneous process associated with a disorder increase at the solid–liquid interface. The maximum adsorption capacity of AHC for MB was 357.14 mg g⁻¹ at 303 K. Thus, the combination of HTC in phosphoric acid and NaOH activation offered a facile, green and economical alternative for conversion of sugarcane bagasse into efficient adsorbents used in wastewater treatment.

In this study, a novel polyethyleneimine (PEI) modified MOF-derived carbon adsorbent (PEI@MDC) was proposed, which exhibited significant adsorption capacity for Congo Red (CR) in aqueous solutions. FT-IR and XPS results showed that PEI was successfully grafted onto MDC, increasing the content of amine groups on the surface of MDC. The adsorption process conformed to the Langmuir isotherm adsorption model and pseudo-second-order kinetic equation, indicating that the adsorption of CR on PEI@MDC was covered by a single layer, and the adsorption process was controlled by chemical processes. According to the Langmuir model, the maximum adsorption capacity at 30 °C was 1723.86 mg g⁻¹. Hydrogen bonding and electrostatic interactions between CR and PEI@MDC surface functional groups were the main mechanisms controlling the adsorption process. After five adsorption–desorption cycles, PEI@MDC still showed a high adsorption capacity for CR, indicating that the adsorbent had an excellent regeneration ability.

The aim of this study is to produce activated-carbon materials from sugarcane tips (ST) via two-step pre-carbonization and evaluate the electrochemical performance.

This study identified and tested fruit-isolated Metschnikowia yeasts against three major postharvest citrus pathogens, namely, Penicillium digitatum, Penicillium italicum, and Geotrichum citri-aurantii, and further evaluated the impact of FeCl₃ on the biocontrol efficiency of pulcherrimin-producing M. pulcherrima strains. Based on the characterization of the pigmented halo surrounding the colonies and the analysis of the D1/D2 domain of 26S rDNA, a total of 46 Metschnikowia sp. were screened and identified. All 46 Metschnikowia strains significantly inhibited the hyphal growth of Penicillium digitatum, Penicillium italicum, and Geotrichum citri-aurantii, and effectively controlled the development of green mold, blue mold and sour rot of citrus fruit. The introduction of exogenous FeCl₃ at certain concentrations did not significantly impact the pulcherriminic acid (PA) production of pigmented M. pulcherrima strains, but notably diminished the size of pigmented zones and the biocontrol efficacy against the three pathogens. Iron deficiency sensitivity experiments revealed that P. digitatum and P. italicum exhibited higher sensitivity compared to G. citri-aurantii, indicating that iron dependence varied among the three pathogens. These results suggested that M. pulcherrima strains, capable of producing high yields of PA, possessed great potential for use as biocontrol agents against postharvest citrus diseases. The biocontrol efficacy of these yeasts is mainly attributed to their ability to competitively deplete iron ions in a shared environment, with the magnitude of their pigmented halo directly correlating to their antagonistic capability. It is worth noting that the level of sensitivity of pathogens to iron deficiency might also affect the biocontrol effect of pulcherrimin-producing M. pulcherrima.

The development of volatile compounds and their precursors during the dehydration process of membrane-clarified sugarcane juice to non-centrifugal sugar (NCS) was investigated. Head-space solid phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC–MS) coupled with chemometrics was employed to assess the differences at the various stages of the dehydration process. A total of 111 volatile compounds were identified, among which 57 were endogenous compounds from sugarcane juice and displayed an attenuated abundance in the first 30 min. Typical oxygen and nitrogen heterocyclic compounds, including furans and pyrazines, and aldehydes derived were found to be the main volatiles contributing to the formation of NCS characteristic aroma, with phenols, alcohols, esters, acids, and sulfur compounds as supplementary odor. Free amino acids and reducing sugars were identified as important precursors for the aroma development process. The low temperature (90–108 °C) and micro vacuum condition (−0.03 MPa) approach used in this study could be an alternative option for the manufacture of NCS.

Bagasse is one of major by-product of sugar mills, but its utilization is limited by the high concentration of lignin. In this study, the optimal alkaline hydrogen peroxide (AHP) treatment conditions were determined by the response surface optimization method. The results showed that the lignin removal rate was 62.23% and the solid recovery rate was 53.76% when bagasse was prepared under optimal conditions (1.2% H₂O₂, 0.9% NaOH, and 46°C for 12.3 h), while higher purity of bagasse insoluble dietary fiber (BIDF) was obtained. To further investigate the modification effect, AHP assisted with high-temperature-pressure cooking (A–H) and enzymatic hydrolysis (A–E) were used to modify bagasse, respectively. The results showed that the water holding capacity (WHC), oil holding capacity (OHC), bile salt adsorption capacity (BSAC), and nitrite ion adsorption capacity (NIAC) were significantly improved after A-H treatment. With the A–E treatment, cation exchange capacity (CEC) and BSAC were significantly increased, while WHC, OHC, and glucose adsorption capacity (GAC) were decreased. Especially, the highest WHC, OHC, BSAC and NIAC were gained by A–H treatment compared to the A–E treatment. These changes in the physicochemical and functional properties of bagasse fiber were in agreement with the microscopic surface wrinkles and pore structure, crystallinity and functional groups. In summary, the A–H modification can effectively improve the functional properties of bagasse fiber, which potentially can be applied further in the food industry.