Thuong Thi Nguyen

This study investigated the effects of lotus leaf extract (LLE) at different concentrations (30%, 40%, and 50%, w/w) on the physicochemical and functional properties of purple passion fruit mesocarp pectin (PPMP)/agarose (PPMP‐A) films and their effectiveness as coatings for preserving King mandarins. The films were evaluated for their mechanical behavior, surface hydrophilicity, water vapor permeability (WVP), solubility, swelling capacity, moisture content, UV‐shielding ability, oxygen permeability, shape‐memory performance, and radical‐scavenging activity. FTIR analysis suggested the formation of intermolecular hydrogen bonds among the components, consistent with improved mechanical performance. The incorporation of LLE significantly improved DPPH radical‐scavenging activity, reduced moisture content (19.76%–11.07%), and increased the water contact angle (27.2°–48.3°). When applied to King mandarins stored for 18 days, the LLE‐containing coatings exhibited different preservation advantages. The PPMP‐A coating containing 30% (w/w) LLE resulted in the slowest increase in the ripening index. The coating containing 50% (w/w) LLE provided the best visual quality and decay control, while retarding weight loss and changes in fruit firmness, total soluble solids, and titratable acidity. Overall, this formulation was selected as the most suitable for maintaining the marketable quality of mandarins, highlighting its potential as a bio‐based active coating for postharvest preservation applications.

This work aimed to extract pectin from purple passion fruit mesocarp (PPMP) and then blend it with agarose to obtain an eco-friendly material with desirable properties suitable for banana preservation. The PPMP exhibits a high methyl esterification degree (66.79%) and yield (29.83%) under optimal conditions consisting of a dry peel powder particle size of 0.25 mm, a mesocarp powder-to-citric acid solution ratio of 1 : 25 (g mL⁻¹), extraction at 90 °C for 60 min, followed by precipitation with 96% ethanol. To overcome the hydrophilicity and limited mechanical strength of neat PPMP films, agarose (A) is blended at varying concentrations of 0.5%, 1%, and 1.5% (w/v). Among the tested formulations, PPMP-A1.5 exhibited the best overall performance, exhibiting increased tensile strength (from 1.15 MPa for neat PPMP to 1.71 MPa), enhanced oxygen-barrier performance (OP reduced from 32.93 × 10⁻¹² to 21.60 × 10⁻¹² mol m⁻¹ s⁻¹ Pa⁻¹), and improved surface hydrophobicity (contact angle increased from 26.1° to 77.2°), despite certain trade-offs in flexibility and water vapor permeability. Preservation tests further confirm that the PPMP-A1.5 coating effectively prolonged the shelf life of bananas by up to 8 days at 25 °C, minimizing changes in peel browning, firmness, ripening rate, and pH. Notably, the weight loss of bananas coated with PPMP-A1.5 on day 6 is 11.69%, which is significantly lower than that of the uncoated samples (18.04%). These findings underscore the potential of PPMP/agarose coatings as safe, biodegradable, and sustainable packaging materials, serving as an alternative to conventional plastics and aligning with the principles of the circular economy.

In this work, the composite membrane based on chitosan (CS) and agarose (AG) is developed for removing methyl orange dye (MO). The morphology and physical properties of membranes in various compositions of CS/AG as 100:0, 80:20, 60:40, 40:60, and 20:80 are investigated. The AG addition significantly increases the film stiffness and fracture resistance but causes a notable reduction in flexibility. The swelling of the CS membrane significantly increases upon blending with AG, facilitating efficient dye adsorption. The 6C4A membrane containing 60% CS and 40% AG effectively adsorbs anionic MO, while it shows trivial adsorption toward cationic dye. The effects of various conditions, including pH of the solution, shaking time, initial MO concentration, and solution temperature, are explored. Maximum adsorption capacity of 229.546 mg g ⁻¹ is recorded at 270 min, pH 6, 200 mg L ⁻¹ MO concentration, and room temperature. The thermodynamic study reveals the spontaneous, favorable, and exothermic behaviors of the adsorption process. The experimental data fit well with the nonlinear pseudo‐first‐order and pseudo‐second‐order kinetic models and the Temkin and Langmuir isotherm models. The composite membrane can be recycled four times, as an ideal option to remove anionic azo dyes from real wastewater efficiently.

This work is the first to optimize hCeO ₂ concentration within chitosan matrices and its application to prolong the shelf life of bananas.

The Solanaceae family includes many species of plants with high nutritional and medicinal value. Plants in this family have evolved towards diversifying specialized (secondary) metabolism to adapt to adverse conditions, and a few of them have been used as model plants in the study of plant defense. 2-Methylketones are insecticidal compounds that accumulate in certain plants, particularly in wild tomato Solanum habrochaites f. glabratum – a Solanaceae member. 2-Methylketones are the decarboxylated products of 3-ketoacids generated through the hydrolysis of 3-ketoacyl-ACPs by methylketone synthase 2 (MKS2). In this study, we isolated one of the four MKS2 homolog genes from the cultivated potato Solanum tuberosum and designated it as StMKS2-3. A combined in silico approach including sequence alignment, phylogenetic assessment, 3D structural modeling and RNA-sequencing data analysis was performed to exploit the functional properties of this gene. The encoded protein possesses the conserved Aspartate and functional domain characteristic of single Hotdog-fold thioesterases, and it shares high similarity in sequence and structure with SlMKS2a of the cultivated tomato (S. lycopersicum). This suggests that, like SlMKS2a, StMKS2-3 could act as a 3-ketoacyl-ACP thioesterase. According to RNA-seq data, StMKS2-3 exhibited higher expression than the other three StMKS2 genes in most tissues across different potato S. tuberosum cultivars. The quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that StMKS2-3 was expressed in multiple potato tissues, both aerial and root parts, but the highest expression was in tubers and sprouts. Furthermore, this gene appeared to be transcriptionally induced in response to salinity, drought, and Phytophthora infestans infection, supporting a possible role for StMKS2-3 in the response of potato S. tuberosum to such stress.

The increasing demand for fresh tropical fruits and vegetables from importing countries has promoted constant supply from Vietnam. However, the perishable nature of fresh commodities causes major postharvest losses upon long‐distance transport and international export. Recently, the application of biopolymers as innovative, environmentally friendly packaging materials in the preservation industry has garnered significant scientific interest. This approach aims to maintain the quality and safety of fruits and vegetables while mitigating the environmental impacts associated with conventional nondegradable plastics. Several biopolymer‐based films and coatings have been reported to prevent moisture, extend the shelf life, and maintain the desirable nutrient quality and sensory characteristics of the fresh produce. The preservation effectiveness is further enhanced by the synergistic effect derived from the combinations between biopolymers or between biopolymers and essential oils, natural extracts, or nanoparticles. These combinatory coatings improve mechanical strength, flexibility, and durability and exhibit potential biological activities while extending the shelf life of tested fruits and vegetables. The emergence of biopolymers in packaging technology in Vietnam has shown promising results for future improvements. This article reviews the recent use and underlying mechanisms of different biopolymer‐based materials in the preservation of Vietnamese tropical fruits and vegetables such as banana, mango, and citrus fruits, followed by proposing possible composite materials and influencing factors for optimization and international safety regulations of biopolymer application in packaging technologies with the focus on Vietnam.