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Bamboo is a renewable and fast-growing biomass resource with limited utilization and service life owing to its susceptibility to mold. Conventional nano-modification methods, particularly two-step approaches, are limited by weak interfacial bonding between nanoparticles and the bamboo substrate, complex processing, and an inability to simultaneously enhance antimildew performance and dimensional stability. To address these limitations, we developed a one-step hydrothermal method involving the use of tannic acid (TA) for in situ fabrication of ZnO/TA/Ag composite particles on bamboo surfaces. Process parameters were optimized to 100 °C, 10 h, and a zinc acetate-to-tannic acid molar ratio of 20:1. The modified bamboo was characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and thermogravimetric analysis. We demonstrated that ZnO/TA/Ag composite particles were successfully loaded onto the bamboo surface, thus improving the all-around performance of the bamboo simultaneously. Antimildew activity against Aspergillus niger and Penicillium citrinum increased from grade 4 in untreated bamboo to grades 1 and 0, respectively; water absorption decreased by 52.85%, and anti-swelling efficiency reached 30.41%, indicating improved mold resistance and dimensional stability. Thus, our technique could serve as a green and efficient one-step in situ modification strategy for high-performance functionalization of bamboo, making it suitable for applications in humid outdoor and indoor environments.

Gallic acid (GA) exhibits excellent antioxidant properties but suffers from chemical instability due to its carboxyl group, which limits practical application. To address this, we designed and investigated 14 distinct ester derivatives of GA, which were categorized into two major groups based on their substituents: chain alkyl and hydroxyl-substituted alkyl groups. Systematic evaluation revealed a striking decline in the DPPH radical scavenging activity of alkyl esters with increasing carbon chain length, from 91.9% for GA-C3 to 55.6% for GA-C30. The hydroxyl-functionalized GA esters GA-EG, GA-GL, and GA-PT maintain high antioxidant activity (>90%) while improving applicability through carboxyl substitution. In the oil system, all derivatives significantly prolong the oxidation induction time, with GA-C3 exhibiting the highest performance by extending the induction time by 2.15 h. Hydroxyl-functionalized esters such as GA-EG, GA-GL, and GA-PT also demonstrated significant efficacy, prolonging oxidation induction by 1.92 to 2.03 h. The results suggest how the structure of GA esters affects their antioxidant behavior, providing a direction for designing antioxidants suitable for specific systems.

Aurantiochytrium sp., a heterotrophic microorganism, has received increasing attention for its high production of polyunsaturated fatty acids and has been widely applied in various industries. This study intended to optimize the carotenoid synthesis pathway in Aurantiochytrium sp. by metabolic engineering to increase the carotenoid content. Multi-sourced key enzyme genes involved in lipid synthesis (LPAAT and DGAT) and astaxanthin synthesis (crtZ and crtW) were selected to construct single-gene expression vectors and transformed into Aurantiochytrium sp. The results showed that the overexpression of LPAAT of Phaeodactylum tricornutum in Aurantiochytrium sp. caused an increase of 39.3% in astaxanthin, 424.7% in β-carotene, 901.8% in canthaxanthin, and 575.9% in lutein, as well as a down-regulation of 15.3% in the fatty acid content. Transcriptomics analysis revealed enhanced expression of genes involved in purine and amino acid metabolism in the transformed strains, and the down-regulation of the citric acid cycle led to an increase in the source of acetyl coenzyme A for the production of fatty acids. This study provides strong experimental evidence to support the application of increasing carotenoid levels in Aurantiochytrium sp.

Photo-grafting is a gentle, simple, and precise approach to incorporating specific functional molecules for the surface functionalization of substrates. In this work, ultraviolet (UV)-induced tannic acid (TA) grafting onto the surface of bamboo was proposed as a viable strategy for functionalizing bamboo. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) clearly indicated that TA was successfully introduced to the bamboo’s surface. The optimal conditions for the grafting reaction were determined to be 15 mM Methyl-2-benzoylbenzoate (BB), 30 mM TA, 20 min, and a pH = 8. Under these conditions, the amount of TA grafted onto the bamboo’s surface was measured to be 19.98 μg/cm2. Results from Inductively Coupled Plasma (ICP) and Energy Dispersive Spectrometer (EDS) analyses showed that the silver ion loading capacity of tannic acid-grafted bamboo was significantly improved compared to that of raw bamboo and tannic acid-impregnated bamboo. Furthermore, the presence of TA grafted on the bamboo’s surface exhibited a positive correlation with the loading of silver ions, indicating that grafted TA plays an important role in the surface functionalization of bamboo. We believe that photo-grafted TA may help generate multifunctional bamboo with diverse properties.

A degradable flocculant was prepared by natural renewable products (starch) and a cationic polymer. A cationic polyamine polymer was prepared by reaction of bis(hexamethylene)triamine with epichlorohydrin. The influence of substrate ratio and molecular weight of cationic polymer on flocculation was investigated and the optimum molecular weight was about 4000. Polyamine-modified starch flocculant was prepared by etherification reaction of cationic polyamine polymer and corn starch. The influence of substitution degree (DS) of starch on flocculation was investigated and the maximum DS was 0.18. The structure of starch-modified flocculant was characterized by XRD and the results confirmed that the plasticized samples contained some crystalline structures that were not destroyed by the etherification reaction process and some newly formed V-type crystalline structures were mainly induced by processing. Flocculation performance was evaluated in simulated kaolin suspension and was compared with that of commercial cationic polyacrylamide (CPAM) and polyaluminium chloride (PAC) flocculants. The flocculation effects of polyamine-modified starch flocculants and commercial flocculants under different dosages and pH values were compared. The results showed that the starch-modified flocculant had the best effect and the cationic starch derivatives flocculation performance increased with increasing DS, and exhibited steady flocculation performance to kaolin suspension in the broad pH range from 4 to 10. The preparation method of starch-modified flocculant is simple in preparation process, low in production cost and pollution-free, and facilitates industrial production.

Rapid economic growth and changing consumer patterns have made fresh-cut fruits and vegetables household staples because of their high nutritional value, their role in reducing the risk of illnesses and other health problems, and convenience. However, fresh-cut produce is susceptible to the rapid deterioration of sensory quality, nutrient loss, foodborne pathogens contamination, and spoilage caused by microbial growth, which can lead to consumer health risks. Thus, there is an urgent need to improve preservation methods, to increase the shelf life of fresh-cut produce. This review examines the primary mechanisms underlying quality deterioration in fresh-cut produce and critically evaluates emerging preservation technologies including physical, chemical, and biopreservation for their efficacy in reducing microbial growth while maintaining product quality. This paper also discusses key gaps and proposes future research directions to improve preservation methods, extend shelf life, and ensure the safety of fresh-cut produce.

Insect wax is a famous biological resource for the role in economic production in China. Insect wax is a good source of policosanol, which may is a candidate supplement in foodstuff and pharmaceuticals that has important physiological activities. Therefore, this work aims to investigate a high-yield and rapid method for policosanol fabrication from insect wax. The conditions for policosanol fabrication were optimized as follows: an oil bath temperature of 112.7°C and reductant dosage of 0.97 g (used for the reduction of 10.00 g of insect wax). The yield of policosanol reached 83.20%, which was 4 times greater than that of existing methods, such as saponification. The total content of policosanol obtained under the optimal conditions reached 87%. In other words, a high yield of policosanol was obtained from insect wax (723.84 mg/g), that was 55 times higher than that generated from beeswax-brown via saponification. The concentrations of metal residues in policosanol were within the limits of the European Union regulations and EFSA stipulation. The LD50 values for oral doses of insect wax and policosanol were both > 5 g/kg. Policosanol was fabricated via solvent-free reduction from insect wax using LiAlH4 at a high yield. The fabrication conditions were optimized. Policosanol and insect wax showed high security, which made them potential candidates as supplements in foods, pharmaceuticals and cosmetics. The rapid and high-yield method has great potential for commercial manufacturing of policosanol.

Heme, as an essential cofactor and source of iron for cells, holds great promise in various areas, e.g., food and medicine. In this study, the model cyanobacteria Synechocystis sp. PCC6803 was used as a host for heme synthesis. The heme synthesis pathway and its competitive pathway were modified to obtain an engineered cyanobacteria with high heme production, and the total heme production of Synechocystis sp. PCC6803 was further enhanced by the optimization of the culture conditions and the enhancement of mixotrophic ability. The co-expression of hemC, hemF, hemH, and the knockout of pcyA, a key gene in the heme catabolic pathway, resulted in a 3.83-fold increase in the heme production of the wild type, while the knockout of chlH, a gene encoding a Mg-chelatase subunit and the key enzyme of the chlorophyll synthesis pathway, resulted in a 7.96-fold increase in the heme production of the wild type; further increased to 2.05 mg/L, its heme production was 10.25-fold that of the wild type under optimized mixotrophic culture conditions. Synechocystis sp. PCC6803 has shown great potential as a cell factory for photosynthetic carbon sequestration for heme production. This study provides novel engineering targets and research directions for constructing microbial cell factories for efficient heme production.

Insect wax is secreted by Ericerus pela Chavanness. It has been traditionally used to treat hair loss in China, but few reports have been published on the hair growth-promoting effect of insect wax. In this work, we examined the hair growth-promoting effects of insect wax on model animals. Different concentrations of insect wax were topically applied to the denuded backs of mice, and 5% minoxidil was applied topically as a positive control. We found that insect wax significantly promoted hair growth in a dose-dependent manner, 45% and 30% insect wax both induced hair to regrow, while less visible hair growth was observed in blank controls on the 16th day. The experimental areas treated with 45% and 30% insect wax exhibited significant differences in hair scores compared to blank controls, and hair lengths in the 45% and 30% insect wax group was significantly longer than in blank controls on the 16th and 20th days. There were no new hair follicles forming in the treated areas, and the hair follicles were prematurely converted to the anagen phase from the telogen phase in experimental areas treated with 45% and 30% insect wax. Both 45% and 30% insect wax upregulated vascular endothelial growth factor expression. The results indicated that 45% and 30% insect wax showed hair growth-promoting potential approximately as potent as 5% minoxidil by inducing the premature conversion of telogen-to-anagen and by prolonging the mature anagen phase rather than increasing the number of hair follicles, which was likely related to the upregulation of VEGF expression. The dissociative policosanol in insect wax was considered the key ingredient most likely responsible for the hair growth promoting potential.

In this study, we addressed various challenges associated with the consumption of functional lipids from the Ericerus pela (Chavannes), including unfavorable taste, insolubility in water, difficulty in oral intake, low bioavailability, and low psychological acceptance. Our study focused on the microencapsulation of policosanol, the key active component of insect wax, which is a mixture of functional lipids secreted by the Ericerus pela (Chavannes). We developed two innovative policosanol products, microcapsules, and effervescent tablets, and optimized their preparation conditions. We successfully prepared microcapsules containing insect wax–derived policosanol using the spray-drying method. We achieved 92.09% microencapsulation efficiency and 61.67% powder yield under the following conditions: maltodextrin, starch sodium octenyl succinate, and (2-hydroxy)propyl-β-cyclodextrin (HPβCD) at a ratio of 1:1:1, core-to-wall materials at a ratio of 1:10, 15% solid content, spray dryer feed temperature at 60 °C, inlet air temperature at 140 °C, and hot-air flow rate at 0.5 m3/min. The microcapsules exhibited a regular spherical shape with a minimal water content (1.82%) and rapid dispersion in water (within 143.5 s). These microcapsules released policosanol rapidly in simulated stomach fluid. Moreover, effervescent tablets were prepared using the policosanol-containing microcapsules. The tablets showed low friability (0.32%), quick disintegration in water (within 99.5 s), and high bubble volume. The microcapsules and effervescent tablets developed in this study presented effective solutions to the insolubility of policosanol in water. These products were portable and offered customizable tastes to address the psychological discomfort related to insect-based foods, thus providing a novel strategy for the consumption and secondary processing of insect lipids.