Fruit Coatings Research Articles

Development of Pericarp-Based Coatings from Corn Nixtamalization Residue for Stone Fruits: Applications for Peach and Tejocote

This study investigated corn pericarp, a by-product of the nixtamalization process, in developing sustainable films for fruit coatings. These films were evaluated for their optical, structural, barrier, and mechanical properties. The results showed that the pericarp films were transparent, had heterogeneous surfaces, and exhibited favorable mechanical and barrier properties, suggesting their potential as fruit coatings. The pericarp films significantly extended shelf life when applied to peaches and tejocotes postharvest. The films slowed the maturation process, as evidenced by minimal changes in peel and mesocarp color for up to five days for tejocotes and even longer for peaches. Additionally, coated fruits showed slower rates of weight loss, firmness reduction, and decreases in titratable acidity, total soluble solids, and total sugar content compared to control samples. These findings demonstrate the potential of corn pericarp films as effective coatings for extending the shelf life of stone fruits.

Unveiling the effects of ZnO nanoparticle incorporated chitosan coating on postharvest quality of eggplant (Solanum melongena L.)

Due to rapid moisture loss, eggplant (Solanum melongena L.), a significant economic product, has a short postharvest shelf life. This study examined at 4 °C for 20 days at the effects of chitosan (CH) 1% and CH with micro ZnO (0.25 g/L) on eggplant quality. After 0, 5, 10, 15, and 20 days, coating effects on parameters (weight loss, pH, respiration rate, total acidity, soluble solids, firmness, total anthocyanin, antioxidant, phenolic, antioxidant enzymes superoxide dismutase, peroxidase and malondialdehyde activity), as well as microbiological count (total bacteria and yeast), were examined. When compared to the control, the coatings significantly affected the quality parameters, eggplant fruit coatings with CH (1 %) + nano ZnO (0.25 g/L) had the significantly least respiratory rate, weight loss, firmness, TAC, TPC, TAA and enzyme activity (P < 0.05). The microbial load during fruit preservation was suppressed by nano ZnO treatments (total bacterial and fungal count in control and eggplant treated with nano ZnO were 4.46, 4.33 and 3.96, 3.17 log CFU g−1 respectively). Treatments had little effect on fruit's flavour or aroma, but ZnO-treated fruit had improved texture, colour, and acceptance overall compared to control fruit. Finally, nano ZnO may offer a chance to preserve quality and limit deterioration during extended storage.

Starch and Shellac Polymer Blends: A Promising Material for Extending Postharvest Fruit Shelf Life

AbstractThis study optimizes edible coatings made from starch and shellac (SHL) polymer blends to enhance postharvest preservation of fruits. Various starch:SHL ratios are explored for the following four different starch sources: rice (RIC), corn (COR), glutinous rice (GLU), and tapioca (TAP). The resulting polymer blend films are comprehensively analyzed via X‐ray diffraction, Fourier‐transform infrared spectroscopy, contact angle measurements, and studies of swelling behavior, water solubility, water vapor permeability, and mechanical properties. Phase separation is noted in the RIC:SHL and COR:SHL polymer blend films, while the TAP:SHL and GLU:SHL polymer blend films exhibit homogeneity without discernible interactions between starch and SHL. However, the TAP:SHL blend films exhibit superior mechanical properties compared with the GLU:SHL polymer blend films. Furthermore, the wettability, swelling, and water vapor permeability decrease upon increasing the SHL content in the polymer blend films. Noteworthily, the TAP:SHL polymer blend demonstrates favorable properties for use in fruit coatings. In contrast to the 100% SHL film, the TAP:SHL coatings do not exacerbate anaerobic respiration‐related browning during storage assessment. The findings highlight TAP:SHL polymer blend as a promising renewable material for extending fruit shelf life postharvest.

Application and evaluation of plant-based edible active coatings to enhance the shelf-life and quality attributes of Jara lebu (Citrus medica)

Edible coatings for fruits and vegetables are the subject of intensive agro-based research. These coatings provide value to the product due to their multifunctionality and sustainability. The current study focuses on the development and evaluation of plant-based edible active coatings for Jara lebu (Citrus medica), with the aim of determining the effectiveness of these coatings in extending the shelf-life and preserving the quality attributes. Different blends of corn starch and various plant extracts were formulated and all formulations were applied by immersion onto the fruit surface. The study had five treatment groups: T0, T1, T2, T3, and T4. T0 served as the control group, while T1 consisted of a mixture of 2% corn starch and 0.5% glycerol. T2 included a combination of 2% corn starch, 0.5% glycerol, and 1.5% holy basil. T3 comprises 2% corn starch, 0.5% glycerol, and 1.5% wild turmeric. Lastly, T4 consisted of 2% corn starch, 0.5% glycerol, and 1.5% Indian pennywort. Control and coated samples were kept under the same conditions for 35 days before being evaluated for changes in their physiological, physicochemical, and sensory qualities. Coated sample T2 significantly prolonged the shelf-life of Jara lebu samples, having the least weight reduction (26.25%) and retaining most of the essential nutrients (TSS = 7.09%, pH = 3.0, vitamin C = 22.03 mg/100 g, TPC = 44.57 mg GAE/g DW, TFC = 45.24 mg QE/g DW, antioxidant = 86.09%). This sample received the highest overall acceptability score, a maximum of 8.24. Sensory evaluations revealed no adverse effects on taste, aroma or appearance, suggesting these coatings can be an eco-friendly and efficient method for preserving the freshness and quality of Jara lebu and potentially other citrus fruits.

A multifunctional biogenic films and coatings from synergistic aqueous dispersion of wood-derived suberin and cellulose nanofibers

Here, biogenic and multifunctional active food coatings and packaging with UV shielding and antimicrobial properties were structured from the aqueous dispersion of an industrial byproduct, suberin, which was stabilized with amphiphilic cellulose nanofibers (CNF). The dual-functioning CNF, synthesized in a deep eutectic solvent, functioned as an efficient suberin dispersant and reinforcing agent in the packaging design. The nanofibrillar percolation network of CNF provided a steric hindrance against the coalescence of the suberin particles. The low CNF dosage of 0.5 wt% resulted in dispersion with optimal viscosity (208.70 Pa.s), enhanced stability (instability index of <0.001), and reduced particle size (9.37 ± 2.43 μm). The dispersion of suberin and CNF was further converted into self-standing films with superior UV-blocking capability, good thermal stability, improved hydrophobicity (increase in water contact angle from 61° ± 0.15 to 83° ± 5.11), and antimicrobial properties against gram-negative bacteria. Finally, the synergistic bicomponent dispersions were demonstrated as fruit coatings for bananas and packaging for strawberries to promote their self-life. The coatings and packaging considerably mitigated fruit deterioration and improved their freshness by preventing moisture loss and microbial attack. This sustainable approach is expected to pave the way toward advanced, biogenic, and active food packaging based on widely available bioresources.

Green and facile fabrication of multifunctional cellulose nanocrystal and carvacrol together reinforced chitosan bio-nanocomposite coatings for fruit preservation

The continuous development of sustainable food-active packaging materials and practices with high performance is a response to the increasing challenges posed by microbial food safety and environmental contamination. In this study, a multifunctional bio-nanocomposite composed primarily of chitosan, cellulose nanomaterials and carvacrol was proposed as a conformal coating for fruit preservation. The coating exhibits excellent antioxidant and antibacterial activities owing to the incorporation of the carvacrol. The inhibition rate of the coating on E. coli and S. aureus is enhanced by 57.13 % and 62.18 %, respectively. And its antioxidant activities is also improved by 77.45 %. In addition, the oxygen permeability (OP) and water vapor permeability (WVP) of this CS/CNC coating are significantly lowered by 67 % and 46 %, respectively, comparing with the CS coating. The coating exhibited excellent biosafety and cytocompatibility because of over 90 % of the HepG2 cells remained alive in each concentration of the coating after 24 h incubation. Additionally, the efficacy of the coating in prolonging the freshness and visual appeal of perishable fruits is substantiated by the experiment involving two fruit specimens. Furthermore, the coating's ease of production, ingestibility, washability, and utilization of cost-effective and easily accessible biomaterials, including renewable waste materials, indicate its potential as a viable economic substitute for commercially accessible fruit coatings.

Biomass derived cellulose nanofiber loaded PVA-nanocurcumin coating for extending the shelf life of Mandarin oranges (Citrus reticulata)

The concern over agricultural waste disposal can be resolved by converting them into value-added products. Here, sustainable fruit coatings and films have been developed via. wealth from waste concept. The cellulose nanofibers (CNF) have been extracted from the waste onion skin. The isolated CNF has been characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), optical microscopy (OM), dynamic light scattering (DLS) and solid-state 13C NMR spectroscopy. A combination of cellulose nanofiber (CNF) and nanocurcumin in polyvinyl alcohol (PVA) matrix has been used for the fabrication of coating over fresh mandarin oranges. The effect of nanocurcumin in PVA-CNF nanocomposite on the post-harvest maintenance of mandarin oranges has been investigated. The morphology of the prepared films is studied by SEM and atomic force microscopy (AFM). The quality of the orange fruits coated using the above formulation by dip coating method was analysed via. weight loss analysis, total soluble solid (TSS), pH, titrable acidity (TA) and antioxidant activities. It was found that the nanocurcumin incorporated PVA-CNF coating was effective in reducing mass loss and maintaining the physiochemical properties of oranges in comparison with other formulations. The developed method could be extended to use as food packaging films, which would be a sustainable solution for agricultural waste valorisation and plastic pollution. Through this research work, we propose an environment friendly approach for the preservation of fruits and vegetables.

Carnauba wax-based edible coatings retain quality enhancement of orange (Citrus sinensis cv. Moro) fruits during storage

Fruit coatings serve a dual purpose in preserving the quality of fruits. Not only do they act as a barrier against water evaporation and fungal infiltration, but they also enhance the fruit’s visual appeal in the market. Yet, their influence on the fruit’s quality components, which play a crucial role in determining its nutritional value, taste, and overall flavor, has remained relatively unexplored. This study aimed to evaluate the effects of carnauba wax coating on the quality of Moro oranges during storage. The selected fruits were meticulously chosen for uniformity in size. The experiment involved applying carnauba wax, a commonly used type among local producers, at four different concentrations: 0%, 0.5%, 1%, and 1.5%. These treatments were applied during various storage periods, including immediately after fruits were harvested and after 40 and 80 days. Following the application of these treatments, the oranges were stored in a controlled environment (morgue) at a temperature of 4 ± 1 °C. Subsequently, several physicochemical parameters of both the fruit flesh and skin were examined. The results unveiled a decline in the overall ascorbic acid content of the fruits. In terms of phenol content, a general decreasing trend was observed after harvesting. At each sampling interval during storage, the phenol content in uncoated fruits consistently exceeded that of their waxed counterparts. Significant reduction in fruit weight was observed throughout the storage period. Both vitamin C and total acidity levels in the fruit exhibited decreases during the storage period. As time passed, fruit firmness gradually declined, while fruit decay increased during the 40- and 80-day storage periods for untreated Moro oranges. The anthocyanin content showed an increasing trend. The study also unveiled a decline in the antioxidant capacity of citrus fruits during storage. Strong significant positive correlations were observed between total phenol content and key parameters, such as antioxidant activity (0.941**), MDA (0.364*), vitamin C content, and total carbohydrate content (0.475**). Skin radiance showed a perfect correlation with chroma and hue (1.000**). Principal component analysis revealed that the first principal component accounted for 34.27% of the total variance, out of a total of five principal components that explained 77.14% of the variance. Through cluster analysis, the variables were categorized into three distinct groups; one associated with weight loss and another with ion leakage. Considering these findings, carnauba wax-based coating emerges as a promising solution for preserving Moro oranges. It effectively mitigates fruit weight loss and helps maintain fruit firmness during storage, making it a valuable tool for fruit preservation.

Assessing the potential of chitosan based coatings in modulation of bacteriome on tomato carposphere

Chitosan based edible fruit coatings are being considered today as an unconventional, ecofriendly and safe alternative of postharvest chemical treatments. The mechanism of action of chitosan coatings, like its antifungal nature or forming a barrier for transpiration and respiration, is already known. We intended to study the effect of the chitosan on natural carposphere microbiome, specifically on non-culturalable bacterial communities during storage to explore the prebiotic like nature of the chitosan based coatings. Hence the effect of coatings viz. CS (1% Chitosan), TL (Tulsi or Ocimum sanctum leaf, 1 g L-1 aqueous extract), and CS/TL mixed (2:1, 1% Chitosan and Tulsi leaf extract) was observed on coated tomato fruit. Metagenomic bacteriome analyses revealed that the untreated samples were comparatively rich epiphytic bacterial flora though the core microbiome was conserved in all the samples. Bacterial community in ripened tomato fruit (after 7 d) was mostly dominated by Acetobacter (49%) while on treatment of coatings genera like Lactobacillus, Weissella, Methylovoruse, Bacillus and Pseudomonas increased. These bacteria can act as potential bio agents in carposphere while the probiotic nature of genera as Lactobacillus or Weissella can also help in delaying the ripening of fruit. As this was a pilot study, more such studies are needed on microbial communities associated with fruits, their assembly and dynamics as well as the nature of their contribution to fruit quality and pathogen resistance during fruit ripening and storage.

Potential Applications of Electrospun Nanofibers in Agriculture

Some of the major challenges associated with current agricultural practices include inefficient delivery and utilization of agrochemicals; fertilizers, pesticides, and pheromones; to crops. This results in low nutrient utilization efficiency with respect to applied fertilizers which leads to a greater economic burden to farmers to maintain crop yields at optimum levels. In addition, plant diseases by various pathogens also pose a threat to agriculture. In an effort to address some of the aforementioned challenges, electrospun nanofibers have emerged as a potential class of one-dimensional nanomaterials for use in agricultural applications. Unique characteristics of electrospun nanofibers such as enhanced surface area: volume ratio, high porosity distribution, and increased specific surface area pave the potential for agricultural applications that will be elaborated in this review. These applications include slow-release of fertilizers, pheromones and insecticides, seed and fruit coatings, plant protection, and nanofiber fabricated sensors. In addition, this review also focuses briefly on other preparation methods of nanofibers, and most importantly on the parameters that govern the electrospinning process; solution parameters, processing parameters, and ambient parameters. Furthermore, many more unexplored applications in the field of agriculture employing nanofiber usage exist, and it is believed that a greater understanding of the current nanofiber research and practices of green electrospinning will enable the upliftment of current boundaries to enable agricultural applications of nanofibers on a commercial scale.&#x0D; Keywords: nanofiber - agriculture - electrospinning - slow-release – sensor

Antifungal edible coatings for fruits based on zein and chitosan nanowhiskers.

Fresh produce have a more limited shelf life than processed ones. Their sensory attributes such as appearance and surface texture are important features in consumer perception and liking. The decomposition of fresh produce, which is caused by enzymes, chemical reactions, and microbial infections, often caused by Colletotrichum species, is inevitable. However, it can be slowed down. Several materials have been developed for this purpose, with an emphasis on active coatings using nanomaterials. In this study, the protective effects of a zein coating containing chitosan nanowhiskers (CSW) for the maintenance of fruit quality were investigated using guava (Psidium guajava L.) as a model fruit. CSW were previously characterized, and their antifungal effects against distinct Colletotrichum species (Colletotrichum asianum, Colletotrichum tropicale, Colletotrichum gloeosporioides, and Colletotrichum brevisporum) were proven. Coatings were characterized by thermogravimetric analysis, optical profilometry, and mechanical properties. Total soluble solids, pH, mass loss, and visual inspection of uncoated and coated guava fruits were also verified during 9 days. Results show that CSW length and aspect ratio decreased for longer extraction times. A similar behavior was found for x-ray diffraction in which peak intensity decreases under the same conditions. CSW degradation (ca. 250-400°C) also depends on extraction time in which more crystalline whiskers are the most thermally stable ones. The addition of CSW did not significantly (p<0.05) modify the homogeneity and continuity of coating but prevented microbial growth assuring fruit quality during storage. In summary, coatings protected guava fruits from post-harvest spoilage while preserving quality and extending shelf life. PRACTICAL APPLICATION: Fresh foods such as fruits and vegetables have a more limited shelf life than processed ones.

Novel determination of green life based on image processing data of Cavendish banana after receiving post-harvest treatments

Conventional methods used in determining green-life are still relatively difficult to use because they are subjective. The initial phase shift from green to yellowish-green as the end of green-life is very difficult to detect and quantify with naked eyes. Therefore, we need a standard method that can be used to determine its green-life. The purpose of this study was to test a new method for determining the green-life based on image processing data of Cavendish banana after receiving post-harvest treatments. The data were collected from Cavendish banana at various maturity levels which had received post-harvest treatments of fruit coatings and storage temperatures. The results showed that the intensity of red (I-Red) as a component of the yellow colour has increased, while the intensity of green (I-Green) has decreased until the end of the observation. Green life ended when I-Red showed a greater value than I-Green. Cavendish banana in cold temperature storage showed a longer green life than room temperature storage with an average of 17.83 days and the longest was 35 days. Meanwhile, storage at room temperature showed an average green life length of 13.25 days with the longest period was 16 days.

Chitosan-based fruit coating as postharvest treatments on two pineapples (Ananas comosus L. Merr) clones

Production of fresh pineapple fruit is dominated by the MD2 clone, while the GP3 clone is used as canned fruit. To be promoted as fresh fruit, the GP3 has some defects, namely a less sweet taste and sensitivity to internal browning (IB) disorders. The clones need fruit coatings, and the two might get responded differently. This study aimed to study the effects of chitosan-based fruit coating mixed with palm stearin and Aloe vera gel on the fruit qualities of the two clones, as well as to seek the potential of the GP3 clone as a fresh fruit. The study used 2 x 4 factorials. The first factor was two clones (GP3 and MD2). The second factor was fruit coatings (control, chitosan, palm stearin + chitosan, and Aloe vera gel + chitosan). The fruits were stored at 7 °C. The results showed that the GP3 started to show the incidence of IB disorders on the 21st day, 2 weeks earlier than the MD2. The MD2 showed a °Brix of 16.82% and vitamin C of 391.45 mg/L, which were significantly higher than the GP3. Meanwhile, the GP3 showed 0.60% acidity, which was significantly higher than the MD2. These indicated that the GP3 should not be used for fresh fruit consumption, mainly because of its sensitivity to IB and lower sweetness compared to the MD2 clone. The chitosan treatment, which was added with Aloe vera or palm stearin, showed a higher vitamin C value than the other treatments.

Recent Developments in Edible Films and Coatings for Fruits and Vegetables

As a novel post-harvesting strategy, edible films and coatings for fruits and vegetables offer preservation measures to meet the growing needs of hunger and agricultural management. The functionality of edible films and coatings is distinctly the same. However, edible films and coatings differ in their processing and physicomechanical characteristics as they are designed to improve the shelf life, barrier, and nutritional properties of the food. With emerging concerns about sustainability, biomacromolecules have been widely considered in preparing edible films and coatings, which are Generally Recognized as Safe (GRAS) substances. Biopolymers, including polysaccharides, proteins, and lipids, are the main sources of preparing edible films and coatings. These biomacromolecules make stable colloidal dispersions that deliver processing convenience with various formulation, blending, casting, coating, and film-forming methods. Edible films and coating from biopolymers require improvements for their extended performance due to several structural and barrier limitations. Therefore, preparing blends and composites, incorporating target molecules to introduce different functionalities, and designing complex multilayers are among the many recent research approaches developed to overcome those limitations. These recent research approaches ensure enhanced food preservation and extended shelf life, essential requirements of food waste management, with or without minimal influence on the texture, flavor, and nutritional value of food and vegetables. This review focuses on the recent developments in edible films and coatings for fruits and vegetables. Furthermore, this review includes characteristics and functionalities, processing, structural and chemical significance, different sources and their performances, health effects, and recent trends related to edible films and coatings.

Biovalorization of Fruit Wastes for Development of Biodegradable Antimicrobial Chitosan-Based Coatings for Fruits (Tomatoes and Grapes).

Organic wastes are generated from high consumption of fruits. In this paper, fruit residual wastes collected from fruit-juice centres were transformed into fine powder, and thereafter, proximate analysis along with SEM, EDX and XRD was done to get into the surface morphology, minerals and ash content of fine powder. Aqueous extract (AE) prepared from this powder was studied using gas chromatography-mass spectroscopy (GC-MS). The phytochemicals identified are N-hexadecanoic acid; 1,3-dioxane,2,4-dimethyl-, diglycerol, 4-ethyl-2-hydroxycyclopent-2-en-1-one, eicosanoic acid, etc. AE showed high antioxidant and a low MIC value (2mg/ml) against Pseudomonas aeruginosa MZ269380. AE having acceptance as nontoxic to biological system, formulation of chitosan (2%)-based coating was done with 1% AQ. Surface coatings of tomatoes and grapes showed significant inhibition of microbial growth even after 10days of storage at ambient temperature (25 ± 2°C). Colour, texture, firmness and aceptability of coated fruits showed no degradation compared to negative control. Additionally, the extracts showed insignificance haemolysis of goat RBC and damage of Calf Thymus DNA which exhibited its biocompatible nature. Biovalorization of fruit wastes yields useful phytochemicals and can be utilized in various sectors thereby finding a sustainable solution for disposal of fruit wastes.

Influence of organic manures and fruit coatings on biochemical parameters of papaya cv. Arka Prabhat

Influence of organic manures and fruit coatings on biochemical parameters of papaya cv. Arka Prabhat

Films and coatings from pequi mesocarp incorporated with nano-ZnO: Properties and capacity to increase mango shelf life

The need for new packaging technologies to decrease environmental pollution, while contributing to food preservation is driving the development of innovative materials using renewable sources and active substances. Pectin extracted from pequi (Caryocar brasiliense Camb.) mesocarp was used to produce films and coating incorporated with ZnO nanoparticles (nano-ZnO). Films incorporated with different concentrations of nanoparticles (0.25%, 0.5%, and 1.0%) were characterized by their packaging performance, structure, antimicrobial activity, and biodegradability. Control pectin coatings and coatings incorporated with nanoparticles were applied to mango fruits to estimate their capacity to slow down the ripening process. The incorporation of nano-ZnO in pectin films affected some of the packaging properties, such as tensile strength, and water vapor permeability, which decreased. In the higher concentration of nano-ZnO tested, the maximum tensile strength was 1.54 MPa, the strength at break was 0.82 MPa, and elongation at break was 14.45%. The water vapor permeability decreased from 10.57 to 8.85 g.mm/m².dia.kPa adding 1.0% of nano-ZnO. The characterization of the film’s structure demonstrated that nano-ZnO had a physical interaction with the pectin matrix. The antimicrobial assay showed that control pectin films could inhibit microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella Enteritidis). ZnO incorporation in films did not present significant differences probably due to the low concentrations applied. All the film formulations tested were completely biodegraded in 2 days in soil and all coatings could slow down the ripening process of mango fruits within 12 days of analysis. Control and ZnO incorporated formulations are promising for use as biodegradable films for food packaging and fruit coatings.

A Systematic Approach of Formulating Chitosan– Nanosilica Coating for Mango (Mangifera indica L. ‘Carabao’) Fruit

The application of fruit coatings reduces gas exchange between the environment and the fruit by creating additional layer to the fruit’s surface. If there is insufficient gas exchange, fruit coatings could induce anaerobic respiration and physiological disorders. Chitosan (CS) and nanosilica (NS) composite coatings for fresh ‘Carabao’ mango fruits were developed by calculating the required oxygen (O2) transmission rate of the coating given the fruit’s respiration rate, surface area and mass. To maintain the respiration requirements of the fruit, computed O2 transmission rates of the coating material should be equal or higher to 0.3270 mL∙cm-2 ∙hr-1 , 0.4530 mL∙cm-2 ∙hr-1 and 0.9608 mL∙cm-2 ∙hr-1 , at 15°C, 20°C and 25°C, respectively. At all temperature regimes, 0.75% CS has higher O2 transmission rate (0.814 mL∙cm-2 ∙hr-1 , 0.935 mL∙cm-2 ∙hr-1 , 1.136 mL∙cm-2 ∙hr-1 ) than 1% CS (0.450 mL∙cm-2 ∙hr-1 , 0.582 mL∙cm-2 ∙hr-1 , and 0.595 mL∙cm-2 ∙hr-1 ). Subsequent laboratory trials using 0.75% CS for mango at 20°C showed that the fruit coating could slow down weight loss and retard the peel color change for five days when compared to the uncoated fruits. Sensory tests in terms of color, taste, flavor, and aroma showed that the coated fruits are acceptable and of comparable quality as the control. Fruits coated with 1% CS exhibited delayed peel color change and weight loss but have symptoms of anaerobic respiration and acetaldehyde formation.

Locust bean gum/carboxycellulose nanocrystal coating incorporating ZnO clusters built by the accretion of micro spindles or sheets for strawberries preservation

Two shapes of ZnO clusters constructed by the growth of spindle-like (I-ZnO) and sheet-like (II-ZnO) microparticles added to Locust bean gum/carboxycellulose nanocrystal (LBG/C-CNC) coating for improving properties as the enhancers and antibacterial agents. Subsequently, active LBG/C-CNC/ZnO (LCZ) coatings were evaluated to combat the fruits rot triggered by microorganisms aiming to extend their shelf life. The results showed that II-ZnO clusters with flower-shape enhanced the properties more obviously due to more interaction sites. The oxygen and water vapor permeability of the coating containing 5 % II-ZnO (LCZII-5) decreased from 2.00 and 5.98 × 10−11 to 0.6 cm3 mm m−2 day−1 atm−1 and 1.85 × 10−11 g m−1 s−1 Pa−1, respectively. And the antibacterial rate against E. coli and S. aureus could reach more than 75 %. Meanwhile, the tensile strength (TS) increased by 50.95 %. The inhibition rates on strawberries of weight and Vc loss by LCZII-5 coating were 30.64 % and 53.59 %, respectively. More importantly, the coatings could be easily washed off with water in spite of tightly being connected with the surface of the strawberries. As was expected, this study provides a feasible method for preparing novel fruit coatings with an effective preservation.

A Horticultural Cuticle Supplement Can Impact Quality Characters and Drosophila suzukii Damage of Several Small and Stone Fruit.

Surface wax and other cellular building blocks play an important role in preserving fruit integrity from biotic and abiotic adversities. Huge energy expenses are made by plants to place these protective compounds onto the epidermal cuticle. Sprayable plant and fruit coatings have been developed to protect plant tissues from environmental stresses, pathogens, and arthropods. The aim of this study was to determine if an experimental cuticle supplement containing waxes can affect fruit quality parameters such as firmness and size of various crops. Cherry, blueberry, and winegrape plants treated with the cuticle supplement showed significant increases in berry firmness ranging from 4.6 to 11.6%. No quality benefits were however observed on blackberry. Cuticle supplement applications did not significantly affect berry size. Laboratory trials resulted in a 54% mean reduction in a model pest insect i.e., Drosophila suzukii egg laying on blueberry. Short-duration field trials over 72 ± 2 to 96 ± 2 h on commercial-standard blueberry bushes resulted in 50-93.4% reductions of D. suzukii damage. Longer-term field trials on cherry and blueberry challenged with egg-laying D. suzukii showed reductions of damage ranging from 45 to 95%, up to 30 d after initial cuticle supplement applications. These results indicate that the cuticle supplement significantly alters berry firmness and reduces D. suzukii damage under commercial production conditions. One factor that may contribute to this reduction includes improved fruit quality parameters. The current work serves to expand integrated pest management options to control D. suzukii populations in commercial field settings.