Postharvest shelf life enhancement of peach fruit treated with glucose oxidase immobilized on ZnO nanoparticles

Enhancing Postharvest Quality of Fresh-Cut Changgen Mushrooms by Exogenous L-Cysteine Treatment: Aspects of Accumulating Amino Acids, Triggering Energy Metabolism and Enhancing Endogenous H2S Regulation

As a rare and functional edible mushroom, the market potential of ready-to-eat fresh-cut Changgen mushrooms (Oudemansiella raphanipes) is booming in developing countries. However, fresh-cut mushrooms preservation is challenging in distribution and consumption. The present study discovered that exogenous L-cysteine (L-Cys) treatment delayed the weight loss, browning degree, nutrition depletion and microbial contamination of fresh-cut Changgen mushrooms at 4 °C. Based on transcriptomic data, exogenous L-Cys significantly activated the metabolism of 17 amino acids, including L-Cys and methionine, a prerequisite for hydrogen sulfide (H2S) synthesis. Exogenous L-Cys also stimulated the activities and gene expressions of cystathionine beta-synthase and cystathionine gamma-lyase, thereby increasing H2S levels. Furthermore, exogenous L-Cys enhanced the energy metabolism by improving cytochrome c oxidase, H+-ATPase and Ca2+-ATPase enzymes activity. Exogenous L-Cys treatment reduced the reactive oxygen species by regulating enzyme activities such as polyphenol oxidase, catalase and superoxide dismutase. This study contributes valuable insights into the physiological function of L-Cys and the role of H2S on the fresh-cut Changgen mushroom.

Metal-anchored oxidized starch-pullulan nanofiber films enhance ethylene adsorption and banana preservation

The development of novel strategies to control ethylene accumulation of fruit is crucial for improving food preservation and reducing spoilage-related losses. In this study, an oxidized starch-pullulan (OS-PUL) nanofiber films were prepared with silver, copper, and iron to control ethylene accumulation. The starch nanofiber film exhibited an average diameter of 96 nm at an OS-PUL concentration of 25 % (wt/wt). Adsorption test showed the maximum ethylene adsorption capacity (21.86 mg·m-2) of metal-nanofiber film with typical hierarchical microporous and mesoporous structure. Oxidized starch-pullulan-metal-nanofiber film extended the shelf life of bananas from 8 to 15 days by efficiently absorbing ethylene. This work will contribute to the development of innovative packaging materials with ethylene adsorption properties, which can help reduce food waste.

Modularization of Immobilized Multienzyme Cascades for Continuous-Flow Enantioselective C-H Amination

Multienzyme cascades (MECs) have gained much attention in synthetic chemistry but remain far from being a reliable synthetic tool. Here we report a four-enzyme cascade comprising a cofactor-independent and a cofactor self-sustaining bienzymatic modules for the enantioselective benzylic C-H amination of arylalkanes, a challenging transformation from bulk chemicals to high value-added chiral amines. The two modules were subsequently optimized by enzyme co-immobilization with microenvironmental tuning, and finally integrated in a gas-liquid segmented flow system, resulting in simultaneous improvements in enzyme performance, mass transfer, system compatibility, and productivity. The flow system enabled continuous C-H amination of arylalkanes (up to 100 mM) utilizing the sole cofactor NADH (0.5 mM) in >90 % conversion, achieving a high space-time yield (STY) of 3.6 g ⋅ L-1 ⋅ h-1, which is a 90-fold increase over the highest value previously reported.

The potential of glucosidase and glucose oxidase for aroma improvement in concentrated peach puree based on volatilomics and metabolomics

Cooked off-flavor was produced during the processing of concentrated peach puree (CPP), which led to aroma deterioration. Enzymatic treatment was beneficial in eliminating off-flavors and improving the aroma quality. Herein, the efficacy of glycosidase (AR2000), glucose oxidation (GOD), and their combination on the inhibition of off-flavors and aroma enhancement were evaluated. Compared with CPP, contents of benzaldehyde, benzyl alcohol, nonanal, and linalool increased by 198%, 1222%, 781%, and 71% after AR2000 treatment via the metabolisms of shikimate, glucose, linoleic acid, and linolenic acid, leading to the strengthening of floral and grassy. Due to the removal of 1-octen-3-one via linolenic acid metabolism, cooked off-flavor could be significantly weakened by GOD. Furthermore, Furthermore, the combination of AR2000 and GOD could not only inhibit the production of 1-octen-3-one to weaken the cooked note but also enhance grassy and floral attributes via the increase of aldehydes and alcohols.

Bridging agro-science and human nutrition: zinc nanoparticles and biochar as catalysts for enhanced crop productivity and biofortification

The integration of zinc nanoparticles (Zn NPs) with biochar offers a transformative approach to sustainable agriculture by enhancing plant productivity and human nutrition. This combination improves soil health, optimizes nutrient uptake, and increases resilience to environmental stressors, leading to superior crop performance. Our literature review shows that combining Zn NPs with biochar significantly boosts the crop nutrient composition, including proteins, vitamins, sugars, and secondary metabolites. This enhancement improves the plant tolerance to environmental challenges, crop quality, and shelf life. This technique addresses the global issue of Zn deficiency by biofortifying food crops with increased Zn levels, such as mung beans, lettuce, tomatoes, wheat, maize, rice, citrus, apples, and microgreens. Additionally, Zn NPs and biochar improve soil properties by enhancing water retention, cation exchange capacity (CEC), and microbial activity, making soils more fertile and productive. The porous structure of biochar facilitates the slow and sustained release of Zn, ensuring its bioavailability over extended periods and reducing the need for frequent fertilizer applications. This synergy promotes sustainable agricultural practices and reduces the environmental footprint of the traditional farming methods. However, potential ecological risks such as biomagnification, nanoparticle accumulation, and toxicity require careful consideration. Comprehensive risk assessments and management strategies are essential to ensure that agricultural benefits do not compromise the environmental or human health. Future research should focus on sustainable practices for deploying Zn NPs in agriculture, balancing food security and ecological integrity and positioning this approach as a viable solution for nutrient-efficient and sustainable agriculture.

Impacts of Climate Change and Mitigation Strategies for Some Abiotic and Biotic Constraints Influencing Fruit Growth and Quality

Factors such as extreme temperatures, light radiation, and nutritional condition influence the physiological, biochemical, and molecular processes associated with fruit development and its quality. Besides abiotic stresses, biotic constraints can also affect fruit growth and quality. Moreover, there can be interactions between stressful conditions. However, it is challenging to predict and generalize the risks of climate change scenarios on seasonal patterns of growth, development, yield, and quality of fruit species because their responses are often highly complex and involve changes at multiple levels. Advancements in genetic editing technologies hold great potential for the agricultural sector, particularly in enhancing fruit crop traits. These improvements can be tailored to meet consumer preferences, which is crucial for commercial success. Canopy management and innovative training systems are also key factors that contribute to maximizing yield efficiency and improving fruit quality, which are essential for the competitiveness of orchards. Moreover, the creation of habitats that support pollinators is a critical aspect of sustainable agriculture, as they play a significant role in the production of many crops, including fruits. Incorporating these strategies allows fruit growers to adapt to changing climate conditions, which is increasingly important for the stability of food production. By investing in these areas, fruit growers can stay ahead of challenges and opportunities in the industry, ultimately leading to increased success and profitability. In this review, we aim to provide an updated overview of the current knowledge on this important topic. We also provide recommendations for future research.

Application of green synthesized magnesium oxide nanoparticles to prolong commercial availability of Vitis vinifera L

The objective of the study was to extend shelf life of Vitis vinifera (L.) by the application of green synthesized Magnesium oxide nanoparticles. Aqueous leaf extract of Azadirachta indica A. juss. and various concentrations of 20 mM, 30 mM, and 40 mM solutions of Magnesium nitrate hexa hydrate salt, were used to synthesize nanoparticles of different size. The characterization of nanoparticles was done by SEM, XRD, and UV. The antimicrobial activity of MgO NPs was evaluated for Azospirilum brasilense and Trichoderma viride, representative of microbes responsible for V. vinifera fruits spoilage. Nanoparticles with crystal size of 28.60 nm has more pronounced effect against microbes. The Shelf life of the Vitis vinifera L. was evaluated by application of 28.60 nm MgO NPs through T1 (nanoparticles coated on packaging), T2 (nanoparticles coated directly on fruit) at 4 °C and 25 °C. T1 at 4 °C was effective to extend the shelf life of Vitis vinifera (L) for an average of 20 days.

Shelf life enhancement technique of Musa acuminata in a controlled environment and optimization of process parameters affecting shelf life using genetic algorithm

An economical and effective storage solution has been designed in this work for the storage of postharvest fruits and vegetables. Musa acuminata or banana has a shelf life of 5-6 days in open uncontrolled environment. This article reports a storage solution of M. acuminata in a controlled enclosure containing titanium oxide (TiO2 )-coated inner walls and irradiated with ultraviolet ray of band "C," an air filtration unit, 5% by volume potassium permanganate (KMnO4 ) solution in a clay pot, grow lights, and activated charcoal granules. The same fruit was kept in an uncontrolled environment too. The percentages of dark spots on banana (M. acuminata) upon storage in controlled and uncontrolled environments have been estimated using an image-processing algorithm. The prediction of dark spots was conducted using multi-linear and multivariate polynomial regression. Experimentation with optimum process parameters obtained with genetic algorithm resulted in a shelf life extension of 6 days as compared to its storage in an uncontrolled environment. The setup can be used in vegetable and fruit markets for the extension of shelf life of postharvest perishable items in a compact and cost-effective manner. The setup does not use any refrigeration process thereby decreasing energy requirement.

Development of bio-based PLA/cellulose antibacterial packaging and its application for the storage of shiitake mushroom

This study presents the extraction of cellulose from water bamboo byproducts to prepare polylactic acid (PLA)/cellulose antibacterial packaging material. The cellulose was modified using a silane coupling agent, which improved the interfacial compatibility between cellulose and PLA. Upon coating the PLA onto the modified cellulose sheet, the water contact angle of the composite material increased from 11.42° to 132.12° and the water absorption rate decreased from 182.52% to 55.71%, which improved the water resistance performance of the material. The addition of cinnamaldehyde in the PLA layer imparted antibacterial activity to the PLA/cellulose packaging material. This packaging material effectively inhibited the mycelial growth and spore germination of Aspergillus niger and Trichoderma harzianum isolated from shiitake mushroom. Additionally, the study investigated the effects of the composite on the postharvest quality of shiitake mushroom. Overall, the packaging material contributed to shiitake mushroom storage and can be applied to other perishable food products.

Antimicrobial starch/poly(butylene adipate-co-terephthalate) nanocomposite films loaded with a combination of silver and zinc oxide nanoparticles for food packaging

Antimicrobial starch/PBAT films with the combination of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) were prepared by extrusion blowing. SEM demonstrated the relatively homogeneous distribution of nanoparticles on the fracture surfaces of the nanocomposite films. The incorporation of nanoparticles improved mechanical and barrier properties of the film. The UV-vis spectroscopy revealed that the SP-ZnO(1) film had the highest UV-absorbance. The inhibition effects of the nanocomposite films against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria were observed. The antimicrobial efficiency of SP-Ag(0.8)-ZnO(0.2) and SP-Ag(0.6)-ZnO(0.4) films reached more than 95% within 3 h of contact. The combination of AgNPs and ZnONPs into starch/PBAT blends showed synergistic effects on improving material properties and antimicrobial efficiency of the films. Furthermore, preliminary packaging studies on peaches and nectarines revealed that the antimicrobial films inhibited spoilage of fresh produce and extended their shelf life compared with commercial LDPE packaging films.