Combination of Cinnamaldehyde/ß-cyclodextrin inclusion complex and L-phenylalanine effectively reduces the postharvest green mold in citrus fruit.

The essential oil and ß-cyclodextrin inclusion complex was able to inhibit the growth of Penicillium digitatum, a damaging pathogen that causes green mold in citrus fruit. In this study, cinnamaldehyde-ß-cyclodextrin inclusion complex (ß-CDCA) for controlling citrus green mold was synthesized by the co-precipitation method. Characterization of ß-CDCA revealed that the aromatic ring skeleton of cinnamaldehyde (CA) was successfully embedded into the cavity of ß-CD to form the inclusion complex. ß-CDCA inhibited P. digitatum at a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 4.0 g/L. FT-IR spectroscopy analysis, calcofluor white staining, extracellular alkaline phosphatase (AKP) activity and propidium iodide (PI) staining of hyphae morphology showed that ß-CDCA may damage the cell ultrastructure and membrane permeability of P. digitatum. The study further demonstrated that hydrogen peroxide (H2O2), malondialdehyde (MDA), and reactive oxygen species (ROS) markedly accumulated in 1/2 MIC ß-CDCA treated hyphae. This implied that ß-CDCA inhibited growth of P. digitatum by the triggering oxidative stress, which may have caused cell death by altering cell membrane permeability. In addition, in vivo results showed that ß-CDCA alone or combined with L-phenylalanine (L-PHe) displayed a comparable level to that of prochloraz. Therefore, ß-CDCA combined with L-PHe can thus be used as an eco-friendly preservative for the control green mold in postharvest citrus fruit.

Identification of chitinase from Bacillus velezensis strain S161 and its antifungal activity against Penicillium digitatum.

Previous studies have demonstrated the presence of chitinase in Bacillus velezensis through extensive genomic sequencing and experimental analyses. However, the detailed structure, functional roles, and antifungal activity of these chitinases remain poorly characterized. In this study, genomic screening identified three genes-chiA, chiB, and lpmo10-associated with chitinase degradation in B. velezensis S161. These genes encode chitinases ChiA and ChiB, and lytic polysaccharide monooxygenase LPMO10. Both ChiA and ChiB contain two CBM50 binding domains and one catalytic domain, whereas LPMO10 includes a signal peptide and a single catalytic domain. The chitinases ChiA, its truncated variant ChiA2, and ChiB were heterologously expressed in Escherichia coli. The purified enzymes efficiently degraded colloidal chitin and inhibited the spore germination of Penicillium digitatum. Notably, even after losing one CBM50 domain, the resultant enzyme, consisting of the remaining CBM50 domain and the catalytic domain, maintained its colloidal chitin hydrolysis and antifungal activity, indicating commendable stability. These results underscore the role of B. velezensis chitinases in suppressing plant pathogenic fungi and provide a solid foundation for developing and applying chitinase-based biocontrol strategies.

Evaluating the efficacy of probiotic bacterial strain Lactobacillus plantarum for inhibition of fungal strains associated with historical manuscript deterioration: An experimental study.

The aim of this study is to develop safe biological methods for controlling fungal deterioration of historical manuscripts. Therefore, fifteen fungal isolates were obtained from paper sheets and leather skins of a deteriorated historical manuscript (dated back to the 13th century). Those isolates were identified using both traditional methods and ITS-sequencing analysis. Aspergillus niger accounted for seven strains, Penicillium citrinum for one strain, Aspergillus flavus for three, Aspergillus fumigatus for one, Aspergillus nidulans for one, and Penicillium chrysogenum for two of the fungal strains that were obtained. The ability of fungal strains for the secretion of cellulase, amylase, gelatinase, and pectinase as hydrolytic enzymes was evaluated. The capability of the probiotic-bacterial strain Lactobacillus plantarum DSM 20174 for inhibition of fungal strains that cause severe deterioration was studied using ethyl acetate-extract. The metabolic profile of the ethyl acetate-extract showed the presence of both high- and low-molecular-weight active compounds as revealed by GC-MS analysis. The safe dose to prevent fungal growth was determined by testing the ethyl acetate extract's biocompatibility against Wi38 and HFB4 as normal cell lines. The extract was found to have a concentration-dependent cytotoxic impact on Wi38 and HFB4, with IC50 values of 416 ± 4.5 and 349.7 ± 5.9 µg mL-1, respectively. It was suggested that 100 µg mL-1 as a safe concentration could be used for paper preservation. Whatman filter paper treated with ethyl acetate extract was used to cultivate the fungal strain Penicillium citrinum AX2. According to data analysis, fungal inhibition measurement, SEM, ATR-FT-IR, XRD, color change measurement, and mechanical property assessment, the recommended concentration of ethyl acetate extract was adequate to protect paper inoculated with the highest enzymatic producer fungi, P. citrinum AX2.

Effect of antifungal proteins (AFPs) on the viability of heat-resistant fungi (HRFs) and the preservation of fruit juices.

The control of heat-resistant fungi (HRFs), which cause spoilage of heat-treated fruit products, is considered a challenge for the fruit juice and beverage industry and requires new strategies for the development of antifungal compounds. In this study, four antifungal proteins (AFPs) from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC), were evaluated against conidia from a representative collection of HRFs. A total of 19 strains from 16 different species belonging to the genera Aspergillus, Hamigera, Paecilomyces, Rasamsonia, Sarocladium, Talaromyces and Thermoascus were included in the study. PeAfpA and PdAfpB exhibited potent antifungal activity in synthetic media, completely inhibiting the growth of most of the fungi evaluated in the range of 0.5-32 µg/mL. The efficacy of the four AFPs was also tested in fruit juices against ascospores of five HRFs relevant to the food industry, including P. fulvus, P. niveus, P. variotii, A. fischeri and T. flavus. PdAfpB was the most effective protein in fruit juices, since it completely inhibited the growth of the five species tested in at least one of the fruit juices evaluated. This is the first study to demonstrate the activity of AFPs against fungal ascospores. Finally, a challenge test study showed that PdAfpB, at a concentration of 32 µg/mL, protected apple fruit juice artificially inoculated with ascospores of P. variotii for 17 days, highlighting the potential of the protein as a preservative in the fruit juice industry.

5-Azacytidine accelerates mandarin fruit post-ripening and enhances lignin-based pathogen defense through remarkable gene expression activation.

5-Azacytidine (AZ) is a DNA methylation inhibitor that has recently demonstrated potential in regulating fruit quality through exogenous application. In this study, we treated mandarin fruits for 4-day storage. Noteworthy were the induced degreening and the enhanced citrus aroma of fruits under AZ treatment, involving the promotion of chlorophyll degradation, carotenoid biosynthesis, and limonene biosynthesis. Key genes associated with these processes exhibited expression level increases of up to 123.8 times. Additionally, AZ treatment activated defense-related enzymes and altered phenylpropanoid carbon allocation towards lignin biosynthesis instead of flavonoid biosynthesis. The expression levels of lignin biosynthesis-related genes increased by nearly 100 times, leading to fortified lignin that is crucial for citrus defense against Penicillium italicum. Currently, the underlying mechanisms of such intense AZ-induced changes in gene expressions remain unclear and further research could help establish AZ treatment as a viable strategy for citrus preservation.

Deciphering the antiochratoxigenic activity of plant extracts and Debaryomyces hansenii against Penicillium nordicum in a "chorizo"-based medium by proteomic analysis.

Penicillium nordicum is the main ochratoxin A (OTA)-producing species on the surface of dry-fermented sausages, such as the "chorizo". New antifungal strategies are being developed using biocontrol agents (BCAs), such as plant extracts and native microorganisms. This work aimed to evaluate the antiochratoxigenic capacity and the causative modes of action of BCAs (rosemary essential oil (REO), acorn shell extract and the yeast Debaryomyces hansenii (Dh)) in a "chorizo"-based medium (Ch-DS). BCAs were inoculated on Ch-DS together with P. nordicum and incubated at 12 °C for 15 days to collect mycelia for OTA analyses and comparative proteomics. Both REO and Dh alone decreased OTA accumulation up to 99% and affected the abundance of P. nordicum proteins linked to cell wall organisation, synthesis of OTA-related metabolites and ergosterol synthesis. It is worth highlighting the increased abundance of an amidase by REO, matching with the decrease in OTA. The use of REO and Dh as BCAs could be an effective strategy to reduce the OTA hazard in the meat industry. Based on their not fully coincident modes of action, their combined application could be of interest in "chorizo" to maximise their potential against ochratoxigenic strains.

Isolation and Identification of Postharvest Rot Pathogens in Citrus × tangelo and Their Potential Inhibition with Acidic Electrolyzed Water.

This study focused on the identification of rot-causing fungi in Citrus × tangelo (tangelo) with a particular emphasis on investigating the inhibitory effects of acidic electrolyzed water on the identified pathogens. The dominant strains responsible for postharvest decay were isolated from infected tangelo fruits and characterized through morphological observation, molecular identification, and pathogenicity detection. Two strains were isolated from postharvest diseased tangelo fruits, cultured and morphologically characterized, and had their gene fragments amplified using primers ITS1 and ITS4. The results revealed the rDNA-ITS sequence of two dominant pathogens were 100% homologous with those of Penicillium citrinum and Aspergillus sydowii. These isolated fungi were confirmed to induce tangelo disease, and subsequent re-isolation validated their consistency with the inoculum. Antifungal tests demonstrated that acidic electrolyzed water (AEW) exhibited a potent inhibitory effect on P. citrinum and A. sydowii, with EC50 values of 85.4 µg/mL and 60.12 µg/mL, respectively. The inhibition zones of 150 µg/mL AEW to 2 kinds of pathogenic fungi were over 75 mm in diameter. Furthermore, treatment with AEW resulted in morphological changes such as bending and shrinking of the fungal hyphae surface. In addition, extracellular pH, conductivity, and absorbance at 260 nm of the fungi hypha significantly increased post-treatment with AEW. Pathogenic morphology and IST sequencing analysis confirmed P. citrinum and A. sydowii as the primary pathogenic fungi, with their growth effectively inhibited by AEW.

Nobiletin enhances the antifungal activity of eugenol nanoemulsion against Penicillium italicum in both in vitro and in vivo settings.

The study prepared and used eugenol nanoemulsion loaded with nobiletin as fungistat to study its antifungal activity and potential mechanism of Penicillium italicum (P. italicum). The results showed that the minimum inhibitory concentration (MIC) of eugenol nanoemulsion loaded with nobiletin (EGN) was lower than that of pure eugenol nanoemulsion (EG), which were 160 µg/mL and 320 µg/mL, respectively. At the same time, the mycelial growth inhibition rate of EGN nanoemulsion (54.68 %) was also higher than that of EG nanoemulsion (9.92 %). This indicates that EGN nanoemulsion is more effective than EG nanoemulsion. Compared with EG nanoemulsion, the treatment of EGN nanoemulsion caused more serious damage to the cell structure of P. italicum. At the same time, in vitro inoculation experiments found that EGN nanoemulsion has better control and delay the growth and reproduction of P. italicum in citrus fruits. And the results reflected that EGN nanoemulsion may be considered as potential resouces of natural antiseptic to inhibit blue mold disease of citrus fruits, because it has good antifungal activity.

Type III sourdough: Evaluation of biopreservative potential in bakery products with enhanced antifungal activity.

The potential biopreservative role of a Type III sourdough (tIII-SD), produced by starter cultures of Fructilactobacillus sanfranciscensis and Lactiplantibacillus plantarum ATCC 8014, was assessed for its antifungal activity in baking applications. Fermentation was carried out using different substrates to enhance the production of antifungal metabolites for 24 and 48 h. The tIII-SD samples were analyzed in relation to pH, total titratable acidity (TTA) and the production of organic acids. The water/salt-soluble extract of the tIII-SD was evaluated in relation to the inhibition potential against key fungi that contaminate bakery products including Penicillium roqueforti, Penicillium chrysogenum and Aspergillus niger. Finally, breads with 10 % of the tIII-SD were prepared and the fungi contamination was evaluated throughout the shelf life period. The lowest pH value in sourdough was obtained from 48-hour fermentation by L. plantarum. The saline extracts exhibited varying degrees of inhibition in the in vitro test; however, the greatest enhancement of this effect was obtained when whole wheat grain flour was used. The tIII-SD crafted from a blend of wheat and flaxseed flours and fermented with F. sanfranciscensis for 48 h (BSWF48h-FS), demonstrated superior performance compared to other formulations. This variant exhibited a total shelf life of 10 days, suggesting that the utilization of tIII-SD could serve as a viable alternative for natural antifungal agents, proving beneficial for the bakery industry.

Application of edible nanocomposites from chitosan/fenugreek seed mucilage/selenium nanoparticles for protecting lemon from green mold.

Green (Penicillium digitatum) mold can severely endanger the citrus fruits production and quality. Targeting the protection of lemon fruits from green mold infestations with nanobiotechnology approach, the fenugreek seed mucilage (FM) was extracted and exploited for biosynthesis of selenium (SeNPs) nanoparticles; their nanocomposites (NCs) with chitosan (CT) was constructed and employed as antifungal materials and edible coating (ECs) to protect lemon fruits against green mold. The nanoparticles formation and conjugations were verified by infrared (FTIR) analysis and electron microscopy. The FM-synthesized SeNPs had particles average of 8.35 nm, were the NCs of them with CT had size mean of 49.33 nm and charged with +22.8 mV. The CT/FM/SeNPs composite exhibited superior antifungal actions toward P. digitatum isolates, up to 32.2 mm inhibition diameter and 12.5 mg/mL inhibitory concentration, which exceeded the actions of imazilil. The microscopic screening of exposed P. digitatum to NCs clarified their mycelial destructive action within 30 h. The coating of infected lemons with fabricated NCs led to complete elimination of green mold development after 10 days of coating, without any infestation remarks. The innovative fabrication of NCs from CT/FM/SeNPs is strongly suggested to protect citrus crops from green mold and preserve fruits quality.

Evaluation of Cold Plasma-Activated water " Enriched Metal " Cations as an Antifungal Agent for Controlling of Penicillium italicum and Penicillium digitatum Molds.

The utilization of Cold Plasma (CP) technology for decontamination and disinfection has garnered considerable attention across diverse industries. This study aims to investigate the interaction between pH and electrical conductivity (EC) (µS/cm) in Cold Plasma-Activated Water (CPAW) enriched with metal cations and its potential as an antifungal agent against two Penicillium (P.) mold strains. The investigation focuses on elucidating the augmented chemical interactions induced by plasma between radicals, charged particles, and microorganisms' cell membranes within an aqueous environment. Our findings demonstrate a positive correlation between the inactivation potential of CPAW (operating at 10 kV voltage, 2.5 kHz high frequency, and 500 mA current intensity) and pH and EC(µS/cm) values. Notably, the relative chemical reactivity and solubility of calcium oxide emerge as significant factors, highlighting the pronounced link between P. Italicum and Plasma-Activated Water containing Copper cations (CPAW + Cu2+) (p < 0.05). Our study distinctly emphasizes (1) the substantial impact of both activated water type and mold species on CFU/mL values (p < 0.05); (2) the mold-specific effect of activated water on CFU/mL; and (3) the noteworthy EC(µS/cm) enhancement and pH decrease with prolonged activation time, attaining statistical significance (p < 0.01).

Novel Pyrido[4,3-d]pyrimidine Derivatives as Potential Sterol 14α-Demethylase Inhibitors: Design, Synthesis, Inhibitory Activity, and Molecular Modeling.

Thirty-four new pyrido[4,3-d]pyrimidine analogs were designed, synthesized, and characterized. The crystal structures for compounds 2c and 4f were measured by means of X-ray diffraction of single crystals. The bioassay results showed that most target compounds exhibited good fungicidal activities against Pyricularia oryzae, Rhizoctonia cerealis, Sclerotinia sclerotiorum, Botrytis cinerea, and Penicillium italicum at 16 µg/mL. Compounds 2l, 2m, 4f, and 4g possessed better fungicidal activities than the commercial fungicide epoxiconazole against B. cinerea. Their half maximal effective concentration (EC50) values were 0.191, 0.487, 0.369, 0.586, and 0.670 µg/mL, respectively. Furthermore, the inhibitory activities of the bioactive compounds were determined against sterol 14α-demethylase (CYP51). The results displayed that they had prominent activities. Compounds 2l, 2m, 4f, and 4g also showed better inhibitory activities than epoxiconazole against CYP51. Their half maximal inhibitory concentration (IC50) values were 0.219, 0.602, 0.422, 0.726, and 0.802 µg/mL, respectively. The results of molecular dynamics (MD) simulations exhibited that compounds 2l and 4f possessed a stronger affinity to CYP51 than epoxiconazole.

Strong antagonism of an endophyte of Fraxinus excelsior towards the ash dieback pathogen, Hymenoscyphus fraxineus, is mediated by the antifungal secondary metabolite PF1140.

Ash dieback, caused by the fungal pathogen Hymenoscyphus fraxineus (Helotiales, Ascomycota), is threatening the existence of the European ash, Fraxineus excelsior. During our search for biological control agents for this devastating disease, endophytic fungi were isolated from healthy plant tissues and co-cultivated with H. fraxineus to assess their antagonistic potential. Among the strains screened, Penicillium cf. manginii DSM 104493 most strongly inhibited the pathogen. Initially, DSM 104493 showed promise in planta as a biocontrol agent. Inoculation of DSM 104493 into axenically cultured ash seedlings greatly decreased the development of disease symptoms in seedlings infected with H. fraxineus. The fungus was thus cultivated on a larger scale in order to obtain sufficient material to identify active metabolites that accounted for the antibiosis observed in dual culture. We isolated PF1140 (1) and identified it as the main active compound in the course of a bioassay-guided isolation strategy. Furthermore, its derivative 2, the mycotoxin citreoviridin (3), three tetramic acids of the vancouverone type (4-6), and penidiamide (7) were isolated by preparative chromatography. The structures were elucidated mainly by NMR spectroscopy and high-resolution mass spectrometry (HRMS), of which compounds 2 and 6 represent novel natural products. Of the compounds tested, not only PF1140 (1) strongly inhibited H. fraxineus in an agar diffusion assay but also showed phytotoxic effects in a leaf puncture assay. Unfortunately, both the latent virulent attributes of DSM 104493 observed subsequent to these experiments in planta and the production of mycotoxins exclude strain Penicillium cf. manginii DSM 104493 from further development as a safe biocontrol agent.IMPORTANCEEnvironmentally friendly measures are urgently needed to control the causative agent of ash dieback, Hymenoscyphus fraxineus. Herein, we show that the endophyte DSM 104493 exhibits protective effects in vitro and in planta. We traced the activity of DSM 104493 to the antifungal natural product PF1140, which unfortunately also showed phytotoxic effects. Our results have important implications for understanding plant-fungal interactions mediated by secondary metabolites, not only in the context of ash dieback but also generally in plant-microbial interactions.

Sanxiapeptin is an ideal preservative with a dual effect of controlling green mold and inducing systemic defense in postharvest citrus.

Green mold is a common postharvest disease infected by Penicillium digitatum that causes citrus fruit decay, and severely affects fruit storage quality. This work aimed to investigate the antifungal activity of Sanxiapeptin against P. digitatum, and elucidate the possible mechanisms involved. Sanxiapeptin was capable of inhibiting spore germination, germ tube length and mycelial growth. The SYTOX green staining assay revealed that Sanxiapeptin targeted the fungal membrane, and changed the membrane permeability, leading to the leakage of cell constituents. Meanwhile, Sanxiapeptin could influence the cell wall permeability and integrity by increasing the activities of chitinase and glucanase, resulting in abnormal chitin consumption and the decrease of glucan. Intriguingly, Sanxiapeptin could effectively control postharvest decay in citrus fruits, and activate the host resistance responses by regulating the phenylpropanoid pathway. In conclusion, Sanxiapeptin exhibits multiphasic antifungal mechanisms of action to control green mold in citrus fruits, shows great potential as novel food preservatives.

A novel antifungal nanoemulsion based on reuterin-assisted synergistic essential oils: Preparation and in vitro/in vivo characterization.

This research aimed to develop, optimize, and evaluate a new antifungal nanoemulsion system based on the crude reuterin-synergistic essential oils (EOs) hybrid to overcome the EOs application limits. At first, the antifungal effects of the Lactobacillus plantarum and Lactobacillus reuteri cell-free extracts (CFE) were tested against the Botrytis cinerea, Penicillium expansum, and Alternaria alternata as indicator fungus using broth microdilution method. The L. reuteri CFE with the MIC of 125 µL/mL for B. cinerea and 250 µL/mL for P. expansum and A. alternata showed more inhibitory effects than L. plantarum. Next, reuterin as a significant antibacterial compound in the L. reuteri CFE was induced in glycerol-containing culture media. To reach a nanoemulsion with maximum antifungal activity and stability, the reuterin concentration, Tween 80 %, and ultrasound time were optimized using response surface methodology (RSM) with a volumetric constant ratio of 5 % v/v oil phase including triple synergistic EOs (thyme, cinnamon, and rosemary) at MIC concentrations. Based on the Box-Behnken Design, the maximum antifungal effect was observed in the treatment with 40 mM reuterin, 1 % Tween 80, and 3 min of ultrasound. The growth inhibitory diameter zones of B. cinerea, P. expansum, and A. alternata were estimated 6.15, 4.25, and 4.35 cm in optimum nanoemulsion, respectively. Also, the minimum average particle size diameter (16.3 nm) was observed in nanoemulsion with reuterin 40 mM, Tween 80 5 %, and 3 min of ultrasound treatment. Zeta potential was relatively high within -30 mV range in all designed nanoemulsions which indicates the nanoemulsion's stability. Also, the prepared nanoemulsions, despite initial particle size showed good stability in a 90-d storage period at 25 °C. In vivo assay, showed a significant improvement in the protection of apple fruit treated with reuterin-EOs nanoemulsions against fungal spoilage compared to free reuterin nanoemulsion. Treatment of apples with nanoemulsion containing 40 mM reuterin showed a maximum inhibitory effect on B. cinerea (5.1 mm lesion diameter compared to 29.2 mm for control fruit) within 7 d at 25 °C. In summary, the present study demonstrated that reuterin-synergistic EOs hybrid with boosted antifungal activities can be considered as a biopreservative for food applications.

The cryptic metabolites and anti-phytopathogenic activities from Nigrospora lacticolonia and Penicillium rubens uncovered by the synergism with host Paris polyphylla, monoculture, and co-culture.

The synergism of host Paris polyphylla medium, the monoculture, and the coculture led to seventeen new metabolites, including eight sesquiterpenes, 1-7 having uncommon structural motifs compared to similar caryophyllene derivatives, 8 with an unprecedented bicyclic framework, and three xyloketals (13-15) with unprecedented frameworks from Nigrospora lacticolonia; one polyketide, 17 with novel bicyclo [2.2.2] undecane skeleton, and five polyketide-terpenoid hybrids, 20 (one novel sulfated), 21-24 from Penicillium rubens. The structures were determined mainly by the NMR, HRESIMS, ECD calculation, and single-crystal X-ray diffraction. Nine cryptic compounds (2-4, 5, 12-15, 17) were produced by the inductions of host medium and the coculture. The compounds 13 from N. lacticolonia, 24-26, 28, 29, and 31 from P. rubens indicated significant antiphytopathogenic activities against N. lacticolonia with MICs at 2-4 µg/mL. Moreover, compounds 22-26, 28, 29, and 31 from P. rubens showed antifungal activities against P. rubens with MICs at 2-4 µg/mL. The synergistic effects of host medium and the coculture can induce the structural diversity of metabolites.

Antifungal Activities of Biogenic Silver Nanoparticles Mediated by Marine Algae: In Vitro and In Vivo Insights of Coating Tomato Fruit to Protect against Penicillium italicum Blue Mold.

In an attempt to reduce such decay induced by pathogenic causes, several studies investigated the effectiveness of nanoparticles (NPs) that play a vital role in saving food products, especially fruits. Current research delves into biogenic silver nanoparticles (using marine alga Turbinaria turbinata (Tt/Ag-NPs) and their characterization using FT-IR, TEM, EDS, and zeta potential. Some pathogenic fungi, which cause fruit spoilage, were isolated. We studied the impact of using Tt/Ag-NPs to protect against isolated fungi in vitro, and the influence of Tt/Ag-NPs as a coating of tomato fruit to protect against blue mold caused by Penicillium italicum (OR770486) over 17 days of storage time. Five treatments were examined: T1, healthy fruits were used as the positive control; T2, healthy fruits sprayed with Tt/Ag-NPs; T3, fruits infected with P. italicum followed by coating with Tt/Ag-NPs (pre-coating); T4, fruits coated with Tt/Ag-NPs followed by infection by P. italicum (post-coating); and T5, the negative control, fruits infected by P. italicum. The results displayed that Tt/Ag-NPs are crystalline, spherical in shape, with size ranges between 14.5 and 39.85 nm, and negative charges. Different concentrations of Tt/Ag-NPs possessed antifungal activities against Botrytis cinerea, Rhodotorula mucilaginosa, Penicillium expansum, Alternaria alternate, and Stemphylium vesicarium. After two days of tomatoes being infected with P. italicum, 55% of the fruits were spoilage. The tomato fruit coated with Tt/Ag-NPs delayed weight loss, increased titratable acidity (TA%), antioxidant%, and polyphenol contents, and decreased pH and total soluble solids (TSSs). There were no significant results between pre-coating and post-coating except in phenol contents increased in pre-coating. A particular focus is placed on the novel and promising approach of utilizing nanoparticles to combat foodborne pathogens and preserve commodities, with a spotlight on the application of nanoparticles in safeguarding tomatoes from decay.

Antagonistic Activities of Metschnikowia pulcherrima Isolates Against Penicillium expansum on Amasya Apples.

Postharvest fungal diseases cause serious fruit losses and food safety issues worldwide. The trend in preventing food loss and waste has shifted to environmentally friendly and sustainable methods, such as biological control. Penicillium expansum is a common postharvest contaminant fungus that causes blue mould disease and patulin formation on apples. This study aimed to provide biocontrol using Metschnikowia pulcherrima isolates against P. expansum, and to understand their antagonistic action mechanisms. In vitro, 38.77-51.69% of mycelial growth inhibition of P. expansum was achieved by M. pulcherrima isolates with the dual culture assay, while this rate was 69.45-84.89% in the disc diffusion assay. The disease symptoms of P. expansum on wounds were reduced by M. pulcherrima, on Amasya apples. The lesion diameter, 41.84 mm after 12 d of incubation in control, was measured as 24.14 mm when treated with the most effective M. pulcherrima DN-MP in vivo. Although the antagonistic mechanisms of M. pulcherrima isolates were similar, there was a difference between their activities. In general, DN-HS and DN-MP isolates were found to be more effective. In light of all these results, it can be said that M. pulcherrima isolates used in the study have an antagonistic effect against the growth of P. expansum both in vitro and in vivo in Amasya apples, therefore, when the appropriate formulation is provided, they can be used as an alternative biocontrol agent to chemical fungicides in the prevention of postharvest diseases.

Formulation of essential oils-loaded solid lipid nanoparticles-based chitosan/PVA hydrogels to control the growth of Botrytis cinerea and Penicillium expansum.

Botrytis cinerea and Penicillium expansum are phytopathogenic fungi that produce the deterioration of fruits. Thus, essential oil (EO) has emerged as a sustainable strategy to minimize the use of synthetic fungicides, but their volatility and scarce solubility restrict their application. This study proposes the EO of Oreganum vulgare and Thymus vulgaris-loaded solid lipid nanoparticles (SLN) based chitosan/PVA hydrogels to reduce the infestation of fungi phytopathogen. EO of O. vulgare and T. vulgaris-loaded SLN had a good homogeneity (0.21-0.35) and stability (-28.8 to -33.0 mV) with a mean size of 180.4-188.4 nm. The optimization of EO-loaded SLN showed that the encapsulation of 800 and 1200 µL L-1 of EO of O vulgare and T. vulgaris had the best particle size. EO-loaded SLN significantly reduced the mycelial growth and spore germination of both fungi pathogen. EO-loaded SLN into hydrogels showed appropriate physicochemical characteristics to apply under environmental conditions. Furthermore, rheological analyses evidenced that hydrogels had solid-like characteristics and elastic behavior. EO-loaded SLN-based hydrogels inhibited the spore germination in B. cinerea (80.9 %) and P. expansum (55.7 %). These results show that SLN and hydrogels are eco-friendly strategies for applying EO with antifungal activity.

Comparative study on effect of pomegranate peel powder as natural preservative and chemical preservatives on quality and shelf life of muffins.

This research aims to investigate the potential of utilizing pomegranate peel powder (PPP) as a natural preservative in muffin preparation. Pomegranate peel is a rich source of bioactive compounds, including phenolics, flavonoids, and tannins, which possess high antioxidant and antimicrobial properties. The In-Vitro antifungal activity of pomegranate peel powder (8% PPP), potassium sorbate (0.1% PS) and calcium propionate (0.5% CP) was assessed against Penicillium sp. and Aspergillus sp. using poison food technique. The PPP showed the anti-fungal activity by delaying the growth of microorganism on media plate similar to the PS and CP. The effect of utilization of PPP on quality characteristics of muffins were compared with the muffins with chemical preservatives (0.1% PS and 0.5% CP). The viscosity and specific gravity of batter significantly increased from 7.98 to 11.87 Pa s and 1.089-1.398 respectively on addition of 8% PPP. The optical microscopic structure of PPP added batter revealed the decrease in the number of air cells from 24 to 12 with radius range of 6.42-72.72 µm and area range of 511.03-15,383.17 µm2. The functional properties of flour with PPP had higher water absorption capacity, foaming stability, emulsification activity and emulsion stability than others. The addition of PPP significantly increase the weight (32.83 g), and decrease the height (31.3 mm), volume (61.43 cm3), specific volume (1.67 cm3/g) and baking loss (10.19%). The 418.36% increase in fibre content, 14.46% and 18.46% decrease in carbohydrates and energy value was observed in muffin with 8% PPP as compared to control respectively. The total phenols was increased from 0.92 to 12.5 mg GAE/100 g, total tannin from 0.2 to 8.27 mg GAE/100 g, In-vitro antioxidant activity by DPPH from 6.97 to 29.34% and In-vitro antioxidant activity by FRAP from 0.497 to 2.934 mg AAE/100 g in muffins added with 8% PPP. The muffin with PPP was softer than control and muffin with 0.1% PS. The addition of PPP resulted to improve in muffin texture but taste slightly bitter. During the storage of muffins at room temperature (27-30 °C), the moisture content of muffin with PPP was reduced from 17.04 to 13.23% which was higher than the rest of the treatments. Similarly, the hardness of sample with PPP was higher than the sample with 0.5% CP, but lowers than control and sample with 0.1% PS throughout the storage period. The results suggest that pomegranate peel powder can be successfully used as a natural preservative in place of chemical preservatives in muffins, to extend the shelf life. This study provides the opportunity to use PPP as functional ingredient and natural preservative in different bakery products.