Effect of Aloe vera gel coating enriched with Fagonia indica plant extract on physicochemical and antioxidant activity of sapodilla fruit during postharvest storage

Effect of PVA-based films incorporated with postbiotics, flax seed mucilage and guar gum to enhance the postharvest quality of fig fruits

Eco-friendly antimicrobial bio-composite films (BCF) were produced by using guar gum (GG), flax seed mucilage (FM) and polyvinyl alcohol (PVA), supplemented with cell-free supernatant (CFS) of Lactobacillus plantarum (L. p) and Lactobacillus delbrueckii (L. d) by the solvent casting technique. The BCF was categorized into: PVA, PVA + FM, PVA + GG, PVA + FM + GG, PVA + FM + CFS, PVA + GG + CFS, PVA + FM + GG + CFS. The film's mechanical, morphological, physical, and antimicrobial properties were characterised. The mechanical, and hydrophobic features of the BCF were increased with the incorporation of FM, GG, and these attributes were faintly decreased with the fusion of postbiotics in films. However, BCF with postbiotics exhibited antimicrobial activity and UV barrier and biodegradable traits, while BCF without postbiotics did not show any antimicrobial effect. According to the characterization study the fabricated PVA + FM + GG and PVA + FM + GG + CFS was employed as packaging material for fig fruit to prolong the shelf life. Overall, PVA + FM + GG + CFS-based packed fig fruits has prolonged shelf life of till 12 days.

Improved konjac glucomannan/curdlan-based emulsion coating by mung bean protein addition for cherry tomato preservation

Biopolymer-based emulsion systems have been used for food preservation. In this study, mung bean protein (MBP) was added to konjac glucomannan (KGM)/curdlan-based camellia oil emulsion (KC-CO) to develop KCM-CO emulsion system. KCM-CO emulsions showed good compatibility and stability during storage. The confocal laser scanning microscopy, atomic force microscope, and infrared spectroscopy revealed that camellia oil was successfully emulsified by MBP, and the resulting droplets were evenly distributed in the polysaccharide network formed by KGM and curdlan micelles based on hydrogen bonds. The emulsions behaved as an elastic solid, and the KCM-CO emulsion films exhibited a compact microstructure, and the emulsification of MBP enhanced the compatibility, as K54C40M6-CO had the smoothest surface. The addition of MBP significantly improved the elongation at break (EAB), water contact angle (WCA), dissolution, and gas permeability of the emulsion films. K54C40M6-CO showed the largest EAB (37.6 %), strong hydrophobicity (WCA = 97.8°), and low water vapor and oxygen permeability. In the preservation experiments, K54C40M6-CO coating significantly delayed the weight loss (by 41.2 %) and firmness decline (by 54.5 %), and maintained the appearance, total solids, total acids, and ascorbic acid content of cherry tomatoes, and inhibited the respiratory intensity by 44.2 %. This coating showed great potential for fruit and vegetable preservation.

Improvement of antioxidant capacity, aroma quality, and antifungal ability of cherry by phenyllactic acid treatment during low temperature storage

Introduction

Sweet cherries (Prunus avium L.) are highly valued for their taste and nutrients but are prone to decay due to their delicate skin and high respiration rate. Traditional chemical preservatives have drawbacks like residues and resistance, prompting the search for natural alternatives. Phenylactic acid (PLA) has shown promise due to its antibacterial and antioxidant properties, making it a potential natural preservative to extend cherry shelf life.

Methods

'Stella' sweet cherries were treated with varying concentrations of PLA (0, 2, 4, 8, 16 mmol·L-1) and stored at 4°C. Key quality indicators, including firmness, total acidity, total soluble solids, weight loss, decay index, and antioxidant activity, were assessed over time. Additionally, HPLC, GC-MS, GC-IMS, colony counts, in vivo inhibition analyses were conducted to evaluate phenolic content, aroma compounds and antifungal ability.

Results and Discussion

PLA at 8 mmol·L-1 effectively maintained cherry quality by reducing weight loss and decay of cherries, delaying the decline of firmness, while enhancing antioxidant capacity, flavor stability, and antifungal ability. Higher concentrations (16 mmol·L-1) provided stronger antimicrobial effects but caused slight surface wrinkling. Thus, 8 mmol·L-1 was optimal, balancing preservation and appearance, making it a promising natural preservative for extending cherry shelf life.

A comprehensive study on mechanisms of action of fibroin, aloe vera, and ginger extracts through histochemical, inflammation biomarkers, and matrix metalloproteinases analysis against diabetic wounds

INTRODUCTION

Diabetes causes complications like delayed wound healing for a long time. Fibroin, aloe vera, and ginger extracts along with their combinations are used for diabetic wound healing.

METHODS

After induction of diabetes, The wound healing effects of fibroin (50 mg/ml), aloe vera gel (50 mg/ml), and ginger extract (30 mg/ml), individually and in combination, were assessed. The pro-inflammatory cytokines including tumor narcosis factor-α (TNF-α) interleukin (IL-6, IL-8, IL-1β), matrix metalloproteinases (MMP 2, MMP7, MMP 9), vascular endothelial growth factor (VEGF) and tissue inhibitors of metalloproteinases (TIMPs) levels were analyzed in the serum.

RESULTS

A combination of fibroin + aloe vera gel + ginger extract (Fi + Al + Gi) healed the wounds in 11 days via wound contraction of 98.5 ± 0.9 % as compared to diabetic control (58.2 ± 0.7 %) and positive control (73.3 ± 0.6 %) groups. However, the wounds of the Polyfax and the diabetic control groups were healed in 17 and 19 days, corresponding to a contraction of: 96.7 ± 1.4 % and 96.3 ± 1.1 %. The histological assay showed that the Fi + Al + Gi group indicated an increased growth of collagen fibers, fibroblasts, keratinocytes and blood vessels with lessened inflammation. The Fi + Al + Gi group alleviated the serum level of TNF-α (12.7 ± 0.9 pg/ml), IL-6 (9.6 ± 0.9 pg/ml), IL-8 (19.6 ± 1.0 pg/ml), MMP2 (217.0 ± 9.2 pg/ml), MMP7 (279.0 ± 9.8 pg/ml), and MMP9 (156.0 ± 11.6 pg/ml) significantly as compared to the diabetic control (P ≤ 0.05). TIMP serum level (202.0 ± 6.9 pg/ml) was significantly elevated as compared to the diabetes control group.

CONCLUSION

The present study concludes that the biomaterials in their combinations possess high regenerative and healing abilities.

A novel edible coating based on Albizia [Albizia lebbeck (L.) Benth.] gum delays softening and maintains quality of harvested guava fruits during storage

Guava, a commercially important fruit crop, is being grown in tropical and subtropical regions around the world. Due to the perishable nature of guava fruits, there are great losses during marketing, transport and storage. The application of edible coating is emerging as a low-cost, simple to implement and efficient method for extending the postharvest life of fresh horticultural produces, such as fruits and vegetables. This study aimed to assess the potential of Albizia gum (AZG) to improve storability and maintain the overall fruit quality of stored guava fruits. Freshly harvested guava fruits were coated with 0 % (control), 1.5 %, 3 % or 4.5 % AZG. After coating treatment, the fruits were stored at 20 ± 1 °C and 85-90 % relative humidity for 15 days. The results revealed that 4.5% AZG coating suppressed the weight loss and decay incidence up to 27 % and 36 %, respectively, as compared with control. The fruits coated with 4.5 % AZG had the maximum titratable acidity (0.40 %), ascorbic acid (104.47 mg·100 g-1), total antioxidants (118.84 mmol Trolox·100 g-1), total phenolics (285.57 mg·kg-1) and flavonoids (60.12 g·kg-1) on 15th day of storage. However, the minimum total soluble solids (11.97 %), sugar-acid ratio (29.31), relative ion leakage (68.40 %), malondialdehyde (0.11 nmol·kg-1 FW) and hydrogen peroxide (16.05 μmol·kg-1 FW) were recorded in the fruits of same treatment on 15th day of storage. Furthermore, the activities of antioxidant enzymes "i.e., superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)" were increased under the influence of AZG coating. Consequently, as compared to uncoated fruits, AZG-coated fruits exhibited reduced activities of fruit softening enzymes "i.e., cellulase, pectin methylesterase (PME), and polygalacturonase (PG)". To sum up, the application of AZG-based edible coating could markedly improve the storage life of guavas and maintain overall fruit quality.

Antibacterial evaluation of garlic extracts on chitosan/starch packaging film using response surface methodology and its application for shelf-life extension of bell peppers (Capsicum annuum)

In this study, garlic extract (GE) was assessed as a potential additive in chitosan/starch (Ch/De) coatings, focusing on phenolic and flavonoid content analyses and antibacterial properties. Using response surface methodology approach, an optimization method was employed to achieve the optimal antibacterial formulation, with Ch, De, and GE identified as key variables in the Design of Experiment. Fourier transform infrared spectroscopy and X-ray diffraction analyses elucidated interactions among these primary components within the films, while thermogravimetric analysis confirmed the enhanced thermal stability of GE-coated film formulations (Ch/De/GE). The Ch/De/GE exhibited antibacterial efficacy against Escherichia coli (ATCC 25922) with an inhibition zone of 7.2 mm at optimized concentrations of 2% w/v Ch, 1.5% w/v starch, and 0.5% v/v GE. In silico molecular docking studies provided insights into GE's inhibitory role as an antibacterial agent. Evaluation of green and yellow bell peppers (Capsicum annuum) over 18 days showed that coated peppers maintained better visual appearance and mass stability, with a weight loss decrease of 40.54%-48.96%, compared to uncoated ones. Additionally, the Ch/De/GE coating effectively inhibited bacterial growth, reducing it by 1-1.23 log CFU, during the storage period. In conclusion, the Ch/De/GE coating effectively extends the shelf-life of bell peppers and maintains their quality, demonstrating its potential for use in food packaging to preserve perishable items. PRACTICAL APPLICATION: The optimized chitosan/starch/garlic extract (Ch/De/GE) film developed in this study shows promising potential for application in the food packaging industry, particularly in extending the shelf life of perishable items like bell peppers. Its enhanced antibacterial properties, along with its ability to maintain visual appearance and reduce weight loss, make it an effective natural preservative that could replace synthetic additives in food packaging. By incorporating this biodegradable film into packaging solutions, producers can offer safer, more sustainable products that meet consumer demand for natural and environmentally friendly options.

Development of multifunctional chitosan-based composite film loaded with tea polyphenol nanoparticles for strawberry preservation

Incorporating polysaccharide-based composite films with nanobiotechnology offers a new strategy for food preservation. This study initially focuses on the preparation of tea polyphenol nanoparticles (TPNP), novel and derived from natural antibacterial agents, which serve to improve stability. Afterwards chitosan-based composite films loaded with TPNP (CTN film) were developed using solution casting method. The incorporation of TPNP significantly improved the UV/water/oxygen barrier properties, mechanical properties and thermal stability, alongside notable physical properties including water contact angle (93.65 ± 0.04°), low water vapor permeability (33.72 ± 3.32 g/m2h) and oxygen permeability (0.11 ± 0.02 g/m2h), tensile strength (61.83 ± 0.70 %), and elongation at break (31.60 ± 6.12 %). The CTN film not only exhibited exceptional biodegradability and nontoxicity, but also demonstrated remarkable antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Additionally, it showcased potent antioxidant activity, boasting DPPH and ABTS radical scavenging rates up to 89.25 ± 0.18 % and 93.84 ± 0.42 %. The CTN film was successfully formed on the surface of strawberries through dip-coating process and their shelf life was extended from 4 to 6 days at 20 °C without side-effect on the weight loss, harness, pH and total soluble solids, illustrating its potential for enhancing food preservation.

Rapid in situ formation of κ-carrageenan-carboxymethyl chitosan-kaolin clay hydrogel films enriched with arbutin for enhanced preservation of cherry tomatoes

Food waste resulting from perishable fruits and vegetables, coupled with the utilization of non-renewable petroleum-based packaging materials, presents pressing challenges demanding resolution. This study addresses these critical issues through the innovative development of a biodegradable functional plastic wrap. Specifically, the proposed solution involves the creation of a κ-carrageenan/carboxymethyl chitosan/arbutin/kaolin clay composite film. This film, capable of rapid in-situ formation on the surfaces of perishable fruits, adeptly conforms to their distinct shapes. The incorporation of kaolin clay in the composite film plays a pivotal role in mitigating water vapor and oxygen permeability, concurrently bolstering water resistance. Accordingly, tensile strength of the composite film experiences a remarkable enhancement, escalating from 20.60 MPa to 34.71 MPa with the incorporation of kaolin clay. The composite film proves its efficacy by preserving cherry tomatoes for an extended period of 9 days at 28 °C through the deliberate delay of fruit ripening, respiration, dehydration and microbial invasion. Crucially, the economic viability of the raw materials utilized in the film, coupled with the expeditious and straightforward preparation method, underscores the practicality of this innovative approach. This study thus introduces an easy and sustainable method for preserving perishable fruits, offering a cost-effective and efficient alternative to petroleum-based packaging materials.

Development and characterization of edible and active coating based on xanthan gum nanoemulsion incorporating betel leaf extract for fresh produce preservation

Developing an edible and active coating, incorporating environmentally-friendly antimicrobial agents into edible polymers, provides an eco-friendly alternative to conventional packaging and exhibits significant potential in preserving the quality of postharvest food. Herein, we aim to develop a novel edible and active coating based on xanthan gum (XG) nanoemulsion (NE) incorporating betel leaf extract (BLE) for the preservation of fresh produce. The total phenolic content, total flavonoid content, and antioxidant capacity of the methanol extract of BLE at various concentrations were characterized. Further development of the active coating at different formulations of Tween 80 (1 % and 3 % w/v), XG (0.1 % to 0.5 % w/v), and BLE (1 % to 5 % w/v) was characterized by physical stability, viscosity, and antimicrobial properties. Results showed that the active coating at 1 % BLE showed significant antimicrobial properties against diverse bacterial and fungal foodborne pathogens (e.g., B. cereus, S. aureus) and fungal cultures (e.g., C. albicans). The study also examined the shelf-life of tomatoes coated with the BLE-XG NE solution, stored at 4 °C for 27 days. Analyses of weight retention, soluble solids, pH, texture, sensory attributes, and microbial populations showed that the coating effectively preserved tomato quality, highlighting its potential to preserve fresh produce and enhance food security.

Robust construction of konjac glucomannan/polylactic acid nanofibrous films incorporated with carvacrol via microfluidic blow spinning for food packaging

In recent years, the application of biopolymer-based nanofibers prepared via microfluidic blow spinning (MBS) for food packaging has continuously increased due to their advantages of biocompatibility, biodegradability, and safety. However, the poor spinnability, undesirable water barrier capacity, and loss of antibacterial and antioxidant properties of biopolymer-based nanofibers strictly restrict their real-world applications. In this work, carvacrol (CV) incorporated konjac glucomannan (KGM)/polylactic acid (PLA) nanofibrous films (KP-CV) were produced by MBS. The FTIR spectra and XRD analysis revealed the hydrogen bonding interactions among CV, PLA, and KGM, thus significantly improving the TS of KP-CV nanofibrous films from 0.23 to 1.27 MPa with increased content of CV from 0 % to 5 %. Besides, KP-CV nanofibrous films showed improved thermal stability, excellent hydrophobicity (WCA: 128.19°, WVP: 1.02 g mm/m2 h kPa), and sustained release of CV combined with good antioxidant activities (DPPH radical scavenging activity: 77.51 ± 1.57 %), and antibacterial properties against S. aureus (inhibition zone: 26.33 mm) and E. coli (inhibition zone: 22.67 mm). Therefore, as prepared KP-CV nanofibrous films can be potentially applied as packaging materials for the extended shelf life of cherry tomatoes.

Development and Characterization of Modified Gelatin-Based Cling Films with Antimicrobial and Antioxidant Activities and Their Application in the Preservation of Cherry Tomatoes

The utilization of functional cling films presents a promising approach to alleviate post-harvest spoilage caused by microbial activity, oxidative metabolism, and moisture loss in agricultural products. To overcome the environmental problems of conventional packaging materials, in this study, we developed functional fruit and vegetable cling films based on glycidyltrimethylammonium chloride and rosemarinic acid cross-linked gelatin (RQ-GEL). The results indicate that the prepared RQ-GEL film possesses excellent UV light barrier properties and mechanical performance. RQ-GEL inhibited S. aureus and E. coli by 93.79% and 92.04%, respectively. DPPH and ABTS free radical scavenging activities were as high as 87.69% and 84.6%. In the cherry tomato preservation experiment, when compared to uncovered samples, the RQ-GEL group had a 29.77% reduction in weight loss and a significant 26.92% reduction in hardness. Meanwhile, the RQ-GEL group delays the decline of fruit total soluble solids and titratable acidity content, and prolongs the preservation period of cherry tomatoes. Hence, RQ-GEL cling film is poised to emerge as a promising packaging material for the post-harvest preservation of agricultural products.

Postbiotics-enriched flaxseed mucilage coating: A solution to improving postharvest quality and shelf life of strawberry

This research aimed to assess the effects of flaxseed mucilage (Mu) coatings supplemented with postbiotics (P) obtained from Lactobacillus acidophilus LA-5 on various physical, biochemical, and microbial characteristics of strawberry fruits. Strawberry fruits were immersed for 2 min in Mu2.5 (2.5 % mucilage in distilled water), Mu5 (5 % mucilage in distilled water), P-Mu2.5 (2.5 % mucilage in undiluted postbiotics) and P-Mu5 (5 % mucilage in undiluted postbiotics) solutions and were stored at 4 °C and 85 RH for 12 days. All coatings were effective in reducing fungal count compared to the uncoated control fruits. Mu5 coating exhibited the highest efficacy, reducing fungal count by 2.85 log10 CFU/g, followed by Mu2.5 (1.47 log10 CFU/g reduction) and P-Mu2.5 groups (0.90 log10 CFU/g reduction). The fruits coated with edible coatings showed significant delays in the change of weight loss, pH, and total soluble solids as compared to the uncoated fruits. The coating containing postbiotics i.e., P-Mu5 also showed a significant increase in the total phenolic contents, total flavonoid content, antioxidant capacity, and total anthocyanin content at the end of storage relative to the uncoated fruits. Thus, Mu and P-Mu coatings may be a useful approach to maintaining the postharvest quality of strawberry fruits during cold storage.

A review on versatile applications of biomaterial/polycationic chitosan: An insight into the structure-property relationship

Chitosan is a versatile and generous biopolymer obtained by alkaline deacetylation of naturally occurring chitin, the second most abundant biopolymer after cellulose. The excellent physicochemical properties of polycationic chitosan are attributed to the presence of varied functional groups such as amino, hydroxyl, and acetamido groups enabling researchers to tailor the structure and properties of chitosan by different methods such as crosslinking, grafting, copolymerization, composites, and molecular imprinting techniques. The prepared derivatives have diverse applications in the food industry, water treatment, cosmetics, pharmaceuticals, agriculture, textiles, and biomedical applications. In this review, numerous applications of chitosan and its derivatives in various fields have been discussed in detail with an insight into their structure-property relationship. This review article concludes and explains the chitosan's biocompatibility and efficiency that has been done so far with future usage and applications as well. Moreover, the possible mechanism of chitosan's activity towards several emerging fields such as energy storage, biodegradable packaging, photocatalysis, biorefinery, and environmental bioremediation are also discussed. Overall, this comprehensive review discusses the science and complete information behind chitosan's wonder function to improve our understanding which is much needful as well as will pave the way towards a sustainable future.

Recent Approaches to the Formulation, Uses, and Impact of Edible Coatings on Fresh Peach Fruit

Peaches are among the most well-known fruits in the world due to their appealing taste and high nutritional value. Peach fruit, on the other hand, has a variety of postharvest quality issues like chilling injury symptoms, internal breakdown, weight loss, decay, shriveling, and over-ripeness, which makes a challenging environment for industries and researchers to develop sophisticated strategies for fruit quality preservation and extending shelf life. All over the world, consumers prefer excellent-quality, high-nutritional-value, and long-lasting fresh fruits that are free of chemicals. An eco-friendly solution to this issue is the coating and filming of fresh produce with natural edible materials. The edible coating utilization eliminates the adulteration risk, presents fruit hygienically, and improves aesthetics. Coatings are used in a way that combines food chemistry and preservation technology. This review, therefore, examines a variety of natural coatings (proteins, lipids, polysaccharides, and composite) and their effects on the quality aspects of fresh peach fruit, as well as their advantages and mode of action. From this useful information, the processors could benefit in choosing the suitable edible coating material for a variety of fresh peach fruits and their application on a commercial scale. In addition, prospects of the application of natural coatings on peach fruit and gaps observed in the literature are identified.

Physical stability, microstructure and antimicrobial properties of konjac glucomannan coatings enriched with Litsea cubeba essential oil nanoemulsion and its effect on citruses preservation

This study purposed to develop konjac glucomannan (KGM) based antimicrobial coatings containing Litsea cubeba essential oil nanoemulsion (LNE) for citruses preservation. Physical stability, rheological, structural and antimicrobial properties of the coating solutions were investigated, along with the release characteristics of Litsea cubeba essential oil (LCO). Results showed that the coating solutions displayed shear thinning behavior. The oil droplets were distributed homogeneously in KGM phase with good stability. The coating structure became loose with increasing LNE content due to LNE interfering with molecular interactions and entanglement of KGM. The coating solutions showed stronger antibacterial activity against Escherichia coli than against Staphylococcus aureus and were effective in inhibiting the growth of Penicillium italicum on citrus surfaces. KGM-LNE 10 negatively affected citruses due to phytotoxicity caused by high levels of LCO. LCO was released slowly and continuously from the coatings, and its release was faster in deionized water than in an ethanol-water solution. KGM-LNE 2.5 coated citruses had the least weight loss, the greatest hardness, and kept the minimum changes in total soluble solids, total acid and vitamin C content, implying that KGM-LNE 2.5 best maintained the quality of citruses. The findings suggest that KGM-based coatings containing LNE have high potential for citruses preservation.

Combined application of hot water treatment and eucalyptus leaf extract postpones seneṣcence in harvested green chilies by conserving their antioxidants: a sustainable approach

BACKGROUND

Green chili is the predominant vegetable in tropical and subtropical regions with high economic value. However, after harvest, it exhibits vigorous metabolic activities due to the high moisture level, leading to a reduction in bioactive compounds and hence reduced shelf life and nutritional quality. Low temperature storage results in the onset of chilling injury symptoms. Therefore, developing techniques to increase the shelf life of green chilies and safeguard their nutritional value has become a serious concern for researchers. In this regard, an experiment was conducted to evaluate the impact of the alone or combined application of hot water treatment (HWT) (45 °C for 15 min) and eucalyptus leaf extract (ELE) (30%) on 'Golden Hot' chilies in comparison to the control. After treatment, chilies were stored at 20 ± 1.5 °C for 20 days.

RESULTS

HWT + ELE-treated chilies had a significant reduction in fruit weight loss (14.6%), fungal decay index (35%), red chili percentage (41.2%), soluble solid content (42.9%), ripening index (48.9%), and reactive oxygen species production like H2O2 (55.1%) and O-2 (46.5%) during shelf in comparison to control, followed by the alone application of HWT and ELE. Furthermore, the combined use of HWT and ELE effectively improved the antioxidative properties of stored chilies including DPPH radical scavenging activities (54.6%), ascorbic acid content (28.4%), phenolic content (31.8%), as well as the enzyme activities of POD (103%), CAT (128%), SOD (26.5%), and APX (43.8%) in comparison to the control. Additionally, the green chilies underwent HWT + ELE treatment also exhibited higher chlorophyll levels (100%) and general appearance (79.6%) with reduced anthocyanin content (40.8%) and wrinkling (43%), leading to a higher marketable fruit (41.3%) than the control.

CONCLUSION

The pre-storage application of HWT and ELE could be used as an antimicrobial, non-chemical, non-toxic, and eco-friendly treatment for preserving the postharvest quality of green chilies at ambient temperature (20 ± 1.5 °C).

Development of Active Antibacterial CEO/CS@PLA Nonwovens and the Application on Food Preservation

The biodegradable activity antibacterial materials have been widely applied on food preservation because they not only protect foods from pathogenic attacks but also relieve environmental pollution. Biodegradable melt-blown nonwovens (MB) have several advantages over the other materials in terms of a simpler and more environmentally friendly fabrication process, higher specific surface area, and lower cost. Herein, polylactic acid (PLA) MB is first modified by polydopamine (PDA) to activate the surface. Then, chitosan (CS) and cinnamon essential oil (CEO) are used to decorate the surface of the modified PLA MB via a simple one-pot method to prepare CEO/CS@PLA MB with different CEO contents. Compared with PLA MB, CEO/CS@PLA MB had a rougher surface and larger average fiber diameter, while the average pore diameter and air permeability reduced. The input of CEO led to a decrease in the tensile strength of CEO/CS@PLA MB and an obvious increase in the elongation at break. The combination of CS and CEO shows excellent synergistic antibacterial effect. The antibacterial efficiencies of CEO/CS@PLA MB against Escherichia coli and Staphylococcus aureus enhance with the increase of the CEO content. When the weight ratio of CS to CEO is 1:2, the antibacterial efficiencies of CEO2/CS@PLA MB against E. coli and S. aureus are 99.98 and 99.99%, respectively. When being applied to the preservation of fresh strawberry, CEO2/CS@PLA MB can effectively inhibit the microbial growth in strawberry and reduce decay, which extends the shelf time of strawberry.

Concurrent application of bacterial-mediated and mycosynthesized ZnO nanofungicides to maintain high ascorbic acid and delay postharvest decay of apricot

Quality of apricot fruit is affected by different biotic stresses during growth, harvesting and storage. Due to fungal attack, huge losses of its quality and quantity are observed. The present research was designed for the diagnoses and management of postharvest rot disease of apricot. Infected apricot fruit were collected, and the causative agent was identified as A. tubingensis. To control this disease, both bacterial-mediated nanoparticles (b-ZnO NPs) and mycosynthesized nanoparticles (f-ZnO NPs) were used. Herein, biomass filtrates of one selected fungus (Trichoderma harzianum) and one bacterium (Bacillus safensis) were used to reduce zinc acetate into ZnO NPs. The physiochemical and morphological characters of both types of NPs were determined. UV-vis spectroscopy displayed absorption peaks of f-ZnO NPs and b-ZnO NPs at 310-380 nm, respectively, indicating successful reduction of Zinc acetate by the metabolites of both fungus and bacteria. Fourier transform infrared (FTIR) determined the presence of organic compounds like amines, aromatics, alkenes and alkyl halides, on both types of NPs, while X-ray diffraction (XRD) confirmed nano-size of f-ZnO NPs (30 nm) and b-ZnO NPs (35 nm). Scanning electron microscopy showed flower-crystalline shape for b-ZnO NPs and spherical-crystalline shape for f-ZnO NPs. Both NPs showed variable antifungal activities at four different concentrations (0.25, 0.50, 0.75 and 1.00 mg/ml). Diseases control and postharvest changes in apricot fruit were analyzed for 15 days. Among all treatments, 0.50 mg/ml concentration of f-ZnO NPs and 0.75 mg/ml concentration of b-ZnO NPs exhibited the strongest antifungal activity. Comparatively, f-ZnO NPs performed slightly better than b-ZnO NPs. Application of both NPs reduced fruit decay and weight, maintained higher ascorbic acid contents, sustained titratable acidity, and preserved firmness of diseased fruit. Our results suggest that microbial synthesized ZnO NPs can efficiently control fruit rot, extend shelf life, and preserve the quality of apricot.

Fabrication of Bio-Nanocomposite Packaging Films with PVA, MMt Clay Nanoparticles, CNCs, and Essential Oils for the Postharvest Preservation of Sapota Fruits

Sapota is an important climacteric fruit with limited shelf life. A special system must be employed to extend the shelf life of sapota fruits. In the present study, polyvinyl alcohol (PVA) and montmorillonite clay (MMt)-based bio-nanocomposite films (BNFs) were integrated at various concentrations (2%, 4%, 6%, and 8%) into cellulose nanocrystals (CNCs), produced from garlic peels (GPs). The BNF loaded with 8% CNC has a better crystallinity index and mechanical properties than the other concentrations of CNC. Therefore, the 8% CNC-incorporated BNF (BNF-8) was selected for further packaging studies. The combined effect of BNF-8 with ajwain essential oil (AO) and oregano essential oil (OO) vapors and BNF-8 with carbendazim (commercial fungicide-CARB) were investigated. In this study, the BNF-based packagings are categorized into five types, viz: BNF+8% CNC (BNF-8), BNF-8+AO, BNF-8+OO, BNF-8+CARB and the non-packaged fruits (control). The shelf-life duration, antioxidant activity, firmness, decay index, and sensory quality were evaluated in order to identify the effectiveness of packaging treatment on sapota fruits. BNF-8+CARB, BNF-8+AO, and BNF-8+OO packaging extended the shelf life of sapota fruits to up to 12 days and maintained the overall physiochemical parameters and sensory qualities of the fruits. Therefore, the BNF-8+AO and BNF-8+OO packaging materials are appropriate alternatives to commercial fungicides for the preservation of sapota during postharvest storage.

Effects of Hydroxyethyl Cellulose and Sulfated Rice Bran Polysaccharide Coating on Quality Maintenance of Cherry Tomatoes during Cold Storage

Cherry tomatoes are easily damaged due to their high moisture content. A composite coating was developed to delay deterioration and prolong storage by mixing antibacterial sulfated rice bran polysaccharides (SRBP) and edible hydroxyethyl cellulose (HEC) with film-forming properties. The effects of HEC, HEC-5% SRBP, and HEC-20% SRBP preservative coatings on the maintenance of the quality of cherry tomatoes (LycopersivonesculentumMill., Xiaohuang F2) during cold storage were investigated. The HEC-20% SRBP coating significantly reduced tomato deterioration and weight loss, delayed firmness loss, decreased polyphenol oxidase activity, and increased peroxidase activity. Furthermore, cherry tomatoes treated with HEC-20% SRBP maintained high levels of titratable acid, ascorbic acid, total phenols, and carotenoids. Cherry tomatoes coated with HEC-SRBP also had higher levels of volatile substances and a greater variety of these substances compared to uncoated tomatoes. In conclusion, the HEC-20% SRBP coating effectively delayed deterioration and preserved cherry tomatoes' nutrient and flavor qualities during postharvest cold storage, suggesting it could be a novel food preservation method.

Development, characterization and use of rosemary essential oil loaded water-chestnut starch based nanoemulsion coatings for enhancing post-harvest quality of apples var. Golden delicious

The study aimed at evaluating the influence of water-chestnut starch-based coatings loaded with rosemary essential oil (REO) at concentrations of 0.10%, 0.25% and 0.50% (w/v) on postharvest cold storage stability of apple var. Golden delicious for 120 days. Average droplet diameter of nanoemulsions was in range of 315-450 nm and it increased with increase in the REO concentration. Minimum weight loss was observed in fruits treated with coating material containing 0.50% REO. Samples coated with starch+0.50% REO exhibited highest firmness value of 68.22 ± 1.02 N under controlled atmosphere storage (CAS). Anthocyanins, ascorbic acid, total phenolic content and antioxidant activity were retained in all samples coated with formulated emulsion. Antifungal assay against Pencillium expansum indicated that 0.50% REO had maximum antifungal activity. Increase in REO concentration from 0.10 to 0.50% in starch coating formulations resulted in reduced lesion diameter in coated samples under both the storage conditions. Lesion diameter (LD) was found highest in control (39.40 ± 0.20 mm) under ambient conditions. Coated fruit samples showed a significant (p≤0.05) reduction in LD under both the ambient and CAS conditions however, more pronounced effect was reported under CAS. Fruits coated with edible coatings enriched with different REO concentrations under CAS exhibited significantly (p≤0.05) lower chilling injury index (ST+0.50%REO < ST+0.25%REO<0.10%REO) compared to control.

Quality assurance of postharvest grapes against Botrytis cinerea by terbinafine

Worldwide, fruit is an indispensable treasure house of nutrition for human beings, occupying a vital position of human diet. Postharvest fruit storage requires efficient antifungal agents to control Botrytis cinerea, which is a vital postharvest disease affecting fruit and leading to enormous losses. However, with the enormous abuse of existing antifungal drugs, the problem of drug-resistant fungi is imminent, making the controlling diseases caused by pathogenic fungi even more challenging. Drug repurposing is an efficient alternative method, we evaluated a well-known antifungal chemical, terbinafine, against the agricultural pathogen, B. cinerea in vitro, as a result, terbinafine showed strong antifungal activity. Furthermore, the in vivo antifungal activity of terbinafine was evaluated, the results showed that terbinafine could reduce the decay area on grapes. Terbinafine could disrupt the cell membrane integrity, increase cell membrane permeability, and eventual cell death of B. cinerea. In addition, terbinafine reduced decay incidence, and weight loss and maintained the soluble solids, titratable acidity, ascorbic acid, total phenolic, and malondialdehyde content during the storage period of grapes. Overall, terbinafine could be an antifungal preservative for postharvest table grapes fresh-keeping.

Effect of oxyresveratrol on the quality and membrane lipid metabolism of shiitake mushroom (Lentinus edodes) during storage

The effect of oxyresveratrol on postharvest quality and membrane lipid metabolism of shiitake mushroom was investigated. The result exhibited that oxyresveratrol retarded browning, maintained firmness and alleviated occurrence of decay of shiitake mushroom. The oxidation and hydrolysis of membrane phospholipids were suppressed by oxyresveratrol treatment, which was associated with reduced LOX and PLD activities and increased SOD and CAT activities. The membrane lipidomics of shiitake mushroom was determined by LC-MS. 385 lipid species and 13 fatty acids in membrane lipids were identified by multiple reaction monitoring method. Compared with control group, the phospholipic acid and lysophospholipid reduced by 29.24% and 21.29% in oxyresveratrol-treated group, respectively, which alleviated hydrolysis of phospholipid. Meanwhile, oxyresveratrol maintained the unsaturation of fatty acids and alleviated oxidation of phospholipid. These results demonstrated that oxyresveratrol could play a dual role of inhibiting the oxidation and hydrolysis of phospholipids to mitigate cellular damage of shiitake mushroom.

Application of Plant-Based Edible Coatings and Extracts Influences the Postharvest Quality and Shelf Life Potential of "Surahi" Guava Fruits

Guava fruits have a short shelf life due to climacteric nature. The current work was conducted to extend the shelf life of guavas with garlic extract (GRE), ginger extract (GNE), gum arabic (GA), and Aloe vera (AV) gel coatings. After coating, fruits of guava were stored at 25 ± 3 °C and RH 85 ± 2% for 15 days. Results showed that guavas treated with plant-based edible coatings and extracts had lower weight loss than that of the control. GRE-treated guavas had the maximum shelf life in contrast to all other treatments including the control. GNE-treated guavas showed the lowest nonreducing sugar content, whereas they had higher antioxidant activity, vitamin C content, and total phenolics compared with all other coating treatments. After the control, antioxidant capacity was the highest in GNE- and GRE-treated fruits. On the other hand, GA-treated guavas had reduced total soluble solids and juice pH (more acidic) and exhibited higher total flavonoids compared with the control, while both GA- and GNE-treated guavas had the highest flavonoid content. GRE-treated fruits exhibited the highest total sugar content and taste and aroma scores. In conclusion, GRE treatment was more effective in conserving the quality and extending the shelf life of guava fruits.

Storability and Linear Regression Models of Pericarp Browning and Decay in Fifty Litchi (Litchi chinensis Sonn.) Cultivars at Room Temperature Storage

The primary cause for the limited shelf life of litchi fruit is rapid pericarp browning and decay. This study aims to evaluate the storability of 50 litchi varieties and establish a linear regression model for pericarp browning and decay based on 11 postharvest physical and chemical indices after 9 days of storage at room temperature. The results indicated that the average value of the browning index and decay rate significantly increased to 3.29% and 63.84% of 50 litchi varieties at day 9, respectively. Different litchi varieties showed different variations in appearance indicators, quality indicators, and physiological indicators. Furthermore, principal component analysis and cluster analysis revealed that Liu Li 2 Hao exhibited the highest resistance to storage, whereas Dong Long Mi Li, Jiao Pan Li, E Dan Li 2 Hao, and Ren Shan Li were not resistant. Stepwise multiple regression analysis further demonstrated that the factors were highly correlated with the decay index, with a partial correlation coefficient of 0.437 between the effective index and the decay index. Therefore, pericarp thickness, relative conductivity, pericarp laccase activity, and total soluble solids were significant indicators for the comprehensive evaluation of litchi browning and decay, and relative conductivity was the significant determinant causing fruit browning. These findings provide a new perspective on the sustainable development of the litchi industry.

Characterizations of konjac glucomannan/curdlan edible coatings and the preservation effect on cherry tomatoes

In this study, konjac glucomannan (KGM) and curdlan were used to fabricate composite coating (KC). The coating solutions were investigated using a rheological method, and the coatings were characterized by water solubility tests, water vapor permeability (WVP), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The preservation effect of KC coating on cherry tomatoes stored at room temperature was determined. Results indicated that the curdlan addition can adjust the hydrophilicity/hydrophobicity of KGM coatings. Curdlan addition enhanced intermolecular entanglement and film-forming property. Increasing curdlan content in KC coatings significantly decreased the moisture content, dissolution and swelling ratio, and WVP. The KGM-curdlan composites behaved as high-performance coatings with good compatibility and uniformity. The K₃C₂ coating showed the best uniformity, water barrier, and thermal stability. The application of K₃C₂ coating significantly reduced the weight loss, decay loss, and delayed the decreases of firmness, soluble solids, total acid, and VC contents of cherry tomatoes. The KGM/curdlan edible coatings have promising potential for prolonging the shelf life of cherry tomatoes and applications in fruits preservation in the future.

Preparation of Vanillin-Taurine Antioxidant Compound, Characterization, and Evaluation for Improving the Post-Harvest Quality of Litchi

Litchi’s post-harvest pericarp browning is one of the main constraints that drastically affect its visual attributes and market potential. Therefore, the vanillin-taurine Schiff base (VTSB) compound prepared from natural compounds of vanillin and taurine exhibited higher DPPH-radical-scavenging invitro antioxidant activity than vanillin. VTSB first-time report to mitigate the postharvest browning of litchi fruit. In this study, litchi fruits were dipped in 0.3 mM (based on pre-experiment) VTSB solution and stored at 25 ± 1 °C for six days to examine their effects on browning and postharvest quality. Fruit treated with VTSB had lower levels of browning degree (BD), browning index (BI), weight loss, soluble quinone (SQ), relative electrolyte leakage (REL), and malondialdehyde (MDA) than control fruit. Additionally, total anthocyanins and phenolic concentrations, Total soluble solids (TSS), and 2,2-diphenyl-1-picrylhydrazyl-free radical scavenging activity (DPPH-RSA) were preserved higher in VTSB-treated litchi fruit. The levels of Ascorbate peroxidase (APX), Superoxide dismutase (SOD), and Catalase (CAT) were higher in treated fruit, whereas polyphenol oxidase (PPO) and Peroxidase (POD) were decreased during the postharvest period. This study suggested that VTSB would be very useful for different post-harvest problems in the fruit and vegetable industry.

Inversion Theory Leveling as a New Methodological Approach to Antioxidant Thermodynamics: A Case Study on Phenol

Antioxidants are various types of compounds that represent a link between biology and chemistry. With the development of theoretical and computational methods, antioxidants are now being studied theoretically. Here, a novel method is presented that aims to reduce the estimated wall times for DFT calculations that result in the same or higher degree of accuracy in the second derivatives over energy than is the case with the regular computational route (i.e., optimizing the reaction system at a lower model and then recalculating the energies at a higher level of theory) by applying the inversion of theory level to the universal chemical scavenger model, i.e., phenol. The resulting accuracy and wall time obtained with such a methodological setup strongly suggest that this methodology could be generally applied to antioxidant thermodynamics for some costly DFT methods with relative absolute deviation.

Recent advances in polysaccharide-based edible coatings for preservation of fruits and vegetables: A review

Harvested fruits and vegetables are prone to decay and quality deterioration during storage. Although traditional packaging and chemical treatments are effective, they are harmful to the environment and human health. Hence, higher requirements for food preservation technology are increasingly proposed. Nontoxic, renewable, degradable, and edible packaging for fruits and vegetables has become a research hotspot in recent years. Chitosan, alginate, cellulose, pectin, starch, and other polysaccharides as coating materials have been widely used. Compared with traditional plastic packaging and chemical treatment, these coatings exhibited a better preservation effect and higher safety. In this paper, the preservation mechanism of fruits and vegetables by edible coatings treatment was described, and the research on edible coatings used in fruits and vegetables was summarized. The effects polysaccharide-based edible coatings on physicochemical quality and antimicrobial effect of fruits and vegetables were reviewed.

Essential oils and plant extracts for tropical fruits protection: From farm to table

The tropical fruit industry in Malaysia makes up a large proportion of the agriculture sector, contributing to the local economy. Due to their high sugar and water content, tropical fruits are prone to pathogenic infections, providing optimal microorganism growth conditions. As one of the largest exporters of these fruits globally, following other Southeast Asian countries such as Thailand, Indonesia and the Philippines, the quality control of exported goods is of great interest to farmers and entrepreneurs. Traditional methods of managing diseases in fruits depend on chemical pesticides, which have attracted much negative perception due to their questionable safety. Therefore, the use of natural products as organic pesticides has been considered a generally safer alternative. The extracts of aromatic plants, known as essential oils or plant extracts, have garnered much interest, especially in Asian regions, due to their historical use in traditional medicine. In addition, the presence of antimicrobial compounds further advocates the assessment of these extracts for use in crop disease prevention and control. Herein, we reviewed the current developments and understanding of the use of essential oils and plant extracts in crop disease management, mainly focusing on tropical fruits. Studies reviewed suggest that essential oils and plant extracts can be effective at preventing fungal and bacterial infections, as well as controlling crop disease progression at the pre and postharvest stages of the tropical fruit supply chain. Positive results from edible coatings and as juice preservatives formulated with essential oils and plant extracts also point towards the potential for commercial use in the industry as more chemically safe and environmentally friendly biopesticides.

Natural Plant Extracts: An Update about Novel Spraying as an Alternative of Chemical Pesticides to Extend the Postharvest Shelf Life of Fruits and Vegetables

Fresh fruits and vegetables, being the source of important vitamins, minerals, and other plant chemicals, are of boundless importance these days. Although in agriculture, the green revolution was a milestone, it was accompanied by the intensive utilization of chemical pesticides. However, chemical pesticides have hazardous effects on human health and the environment. Therefore, increasingly stimulating toward more eco-friendly and safer alternatives to prevent postharvest losses and lead to improving the shelf life of fresh fruits and vegetables. Proposed alternatives, natural plant extracts, are very promising due to their high efficacy. The plant-based extract is from a natural source and has no or few health concerns. Many researchers have elaborated on the harmful effects of synthetic chemicals on human life. People are now much more aware of safety and health concerns than ever before. In the present review, we discussed the latest research on natural alternatives for chemical synthetic pesticides. Considering that the use of plant-based extracts from aloe vera, lemongrass, or neem is non-chemical by-products of the fruits and vegetable industry, they are proved safe for human health and may be integrated with economic strategies. Such natural plant extracts can be a good alternative to chemical pesticides and preservatives.

Enzymatic Extraction of Sapodilla (Manilkara achras L.) Juice: Process Optimization and Characterization

Conventional treatment of sapodilla pulp yields very viscous, turbid, and low juice recovery. Sapodilla processing for juice requires liquefying enzyme that leads to rectifying flow of juice. This study was conducted to optimize the enzymatic pectolytic conditions of sapodilla fruit processing to extract maximum juice using a central composite design (CCD). The effect of processing variables on recovery of juice, total soluble solids (TSS), viscosity, clarity, and L-value along with physicochemical analysis was investigated. The optimized processing conditions were pectinase concentration (0.120%) at 42.02°C for 167.83 min resulting in juice recovery (62.08 ± 0.38%), viscosity (4.81 ± 0.02cP), TSS (21.48 ± 0.19 °Brix), clarity (0.72 ± 0.05%T), and L-value (28.79 ± 0.96). Optimized sapodilla juice showed higher filterability (24.16 ± 1.04 min−1), conductivity (69.46 ± 0.30 S/m), total phenolic content (35.86 ± 0.60 mg/100 mL), ascorbic acid (6.38 ± 0.58 mg/100 mL), moisture content (84.85 ± 0.21% WB), and titratable acidity (0.143 ± 0.0% citric acid) as compared to control sample (60.5 ± 1.80 min−1, 30.43 ± 0.35 S/m, 30.68 ± 0.85 mg/100 mL, 4.64 ± 0.0 mg/100 mL, 83.69 ± 0.18%, and 0.130 ± 0.0%). Optimized sapodilla juice was lower in sedimentation index (0.73 ± 0.11%), turbidity (13.73 ± 1.10 NTU), ash (0.57 ± 0.031%), and β-carotene (0.173 ± 0.008 μg/100 mL) as compared to control sample (1.07 ± 0.02%, 79 ± 0.75 NTU, 0.65 ± 0.031%, and 0.306 ± 0.007 μg/100 mL). The flow behavior index (n) was closer to 1 in both juice samples, which indicated Newtonian-like flow behavior. Conclusively, sapodilla juice extraction at optimal condition (0.120% of pectinase concentration) and 42.02°C/167.83 min would be potentiated to the beverage industry. The use of pectinase might reduce membrane fouling and facilitates processing operation efficiently.

Carvacrol delays Phomopsis stem-end rot development in pummelo fruit in relation to maintaining energy status and antioxidant system

Pummelo fruit rapidly depreciate in commodity value due to postharvest fungal decay and fruit quality deterioration. Here, we used carvacrol (CVR) to control Phomopsis stem-end rot (SER) caused by Diaporthe citri in pummelo fruit stored at 25 °C. Antifungal activity of CVR inhibited D. citri growth and Phomopsis SER development. Harvested pummelo fruit treated with CVR delayed firmness loss and lowered electrolyte leakage, and retarded hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) accumulation. Unlike the control fruit, the CVR-treated fruit maintained higher levels of adenosine triphosphate and energy charge, and increased ATPase, succinate dehydrogenase (SDH), malate dehydrogenase (MDH), and cytochrome C oxidase (CCO) activities, along with up-regulated expression levels of the respective genes. CVR improved the antioxidant capacity, as evidenced by higher non-enzymatic antioxidants amounts, higher activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR), and up-regulated expression levels of ROS-scavenging-related genes. Collectively, CVR treatment maintained the energy status and antioxidant capacity in D. citri-infected pummelo fruit, which revealed antifungal mechanisms critical for controlling postharvest fungal diseases.

Aloe vera gel coating delays softening and maintains quality of stored persimmon (Diospyros kaki Thunb.) Fruits

The effect of Aloe vera (AV) gel coating was studied on antioxidant enzymes activities, oxidative stress, softening and associated quality attributes of persimmon fruits. The fruits were coated with 0 and 50% AV-gel coating and stored for 20 days at 20 ± 1 ºC. AV-gel coated fruits exhibited considerably less weight loss, hydrogen peroxide level, electrolyte leakage and malondialdehyde content. AV-gel coated fruits had significantly higher ascorbate peroxidase, peroxidase, superoxide dismutase and catalase activities. In addition, AV-gel coating suppressed pectin methylesterase, polygalacturonase and cellulase activities and showed higher ascorbic acid, DPPH scavenging antioxidants and phenolics, and lower sugars and carotenoids. To the best of our knowledge, these results are the first evidence that AV-gel coating modulates the activities of cell wall degrading enzymes to delay ripening in climacteric fruits. So, AV-gel coating prohibited the onset of senescence by activating enzymatic antioxidant system, accumulating bioactive compounds and suppressing cell wall degradation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05412-5.

Optimization of Osmotic Dehydration of Sapodilla (Achras zapota L.)

Sapodilla (Achras zapota L.) is a fruit with a great nutritional potential; however, its perishable nature is a great obstacle for commercialization/exportation. Herein, osmotic dehydration was applied to sapodilla to reduce post-harvest losses and obtain a stable product with acceptable sensorial characteristics. Initially, a 2³ full-factorial design was performed to determine the effect of temperature (30−50 °C), sucrose concentration (40−60% °Brix) and immersion time (90−240 min) on the moisture loss (ML), solid gain (SG) and dehydration efficiency index (DEI). The samples with higher DEI values were subjected to sensory analysis, followed by physicochemical, microbiological and structural analyses. The temperature and the concentration of the osmotic solution had significant influence (p < 0.05) on ML and SG, whereas DEI was significantly influenced (p < 0.05) by the concentration of osmotic solution and the immersion time. The sample produced by osmotic dehydration using the optimized conditions (40 °C, 50 °Brix; 165 min) obtained higher scores on the sensorial attributes, greater compliance with microbiological standards and generated turgor reduction and ruptures of sapodilla cell walls.

Effects of chitosan coatings fused with medicinal plant extracts on postharvest quality and storage stability of purple passion fruit (Passiflora edulis var. Ester)

Chitosan edible coating (Ch; 2% w/v) enriched with 2% of 0.1 mg/L Bidens pilosa (Ch+B), Lippia javanica (Ch+L), Syzygium cordatum (Ch+S), or Ximenia caffra (Ch+X) was applied as a composite edible coating in alleviating shrivel and maintaining the quality of purple passion fruit (Passiflora edulis var. Ester). Treated fruit were dipped for 3 min in the coating solution, and control fruit were dipped in distilled water. The fruit were stored at 8±2 °C and 90±5% relative humidity (RH) for 32 d. Sampling was done every 8 d plus 3 d (20±2 °C and 50±5% RH) to simulate retail conditions. Efficacy of medicinal plant extracts in the chitosan matrix varied; lower ethylene production (82.42 µL C2H4/kg h) was seen in fruit coated with Ch+S, and the lowest respiration rate (75 mL CO2/kg h) was observed in fruit coated with Ch+B. The control fruit showed the highest ethylene production (84.90 µL C2H4/kg h) and respiration rate (117.98 mL CO2/kg h). Fruit coated with Ch+B had the lowest weight loss (41.67%), higher juice content (60.13%) and BrimA (3.31), while the control fruit had the highest weight loss (88.03%), lowest juice content (21.90%), and BrimA (2.49). Shrivel incidence was lowest (23.70%) on fruit coated with Ch+L and highest (83.30%) on the control fruit. Fruit coated with Ch+X had the lowest electrolyte leakage (71.40%), while the control fruit had the highest (91.97%). Fruit coated with chitosan alone performed better than the control fruit but did not exceed the quality of composite chitosan coated fruit. Based on the principal component analysis, it can be concluded that passion fruit coated with Ch+B was more effective in alleviating shrivel incidence, better maintained the quality of passion fruit during storage, and shows potential for commercial applications.

Application of plant mucilage polysaccharides and their techno-functional properties' modification for fresh produce preservation

The use of edible coating/film to improve fresh produce's quality and shelf life is an old but reliable and popular method of preservation. Recently, plant-derived mucilages have been extensively used to prepare edible packages (MEPs). This review focuses on recent studies that characterize mucilages from different plants, and examine their specific applications as edible packages in preserving fruits and vegetables. Structure-function relations and corresponding influence on film-forming properties are discussed. This review also surveys the additive-modifications of MEPs techno-functional properties. MEPs from a range of plant sources are effective in preventing quality loss and improving the storability of various fruits and vegetables. The preservative mechanisms and essential techno-functional properties of MEPs required for fruit and vegetable packaging were summarized. The key findings summarized in this study will help promote the utilization of mucilages and draw attention to other novel applications of this valuable polymer.