Field and postharvest application of microencapsulated Yamadazyma mexicana LPa14: anthracnose control and effect on postharvest quality in avocado (Persea americana Mill. cv. Hass).

BACKGROUND: Anthracnose caused by species of Colletotrichum is the most important disease of avocado fruit. The quiescent infection develops in the field, hence, its control from the preharvest stage is necessary. The field application of microencapsulated Yamadazyma mexicana LPa14 could prevent the establishment of Colletotrichum gloeosporioides and reduce the losses in avocado production. This study aimed to evaluate the effectiveness of microencapsulated Y. mexicana applied in the field and postharvest for the anthracnose control in avocado, to evaluate the population dynamics of Y. mexicana in flowers and fruits and the effect of the yeast on the avocado quality. RESULTS: The concentrations of microencapsulated Y. mexicana after field application ranged from 4.58 to 6.35 log CFU g-1 . The population of microencapsulated yeast in flowers and fruits was always higher than treatments with fresh cells. Preharvest application of fresh and microencapsulated Y. mexicana significantly reduced the severity of anthracnose by 71-80% and 84-96%, respectively, in avocado fruits stored at 25 °C. Moreover, at 6 °C and ripening at 25 °C, the fresh yeast reduced the severity by 87-90% and the microencapsulated yeast by 91-93%. However, yeast treatments applied in the field + postharvest under cool conditions were more effective in reducing 100% of anthracnose. Treatments did not negatively affect the quality parameters of the avocado fruits. CONCLUSION: Yamadazyma mexicana microencapsulated by electrospraying is a promising bioformulation for the management of anthracnose in avocados at preharvest and postharvest levels. Yamadazyma mexicana offers a new biological control solution for growers in avocado orchards. © 2024 Society of Chemical Industry.

High-pressure pulses for Aspergillus niger spore inactivation in a model pharmaceutical lipid emulsion.

High hydrostatic pressure (HHP) is a non-thermal process widely used in the food industry to reduce microbial populations. However, rarely its effect has been assessed in products with high oil content. This study evaluated the efficacy of HHP (200, 250, and 300 MPa) at different temperatures (25, 35, and 45 °C) by cycles (1, 2, or 3) of 10 min in the inactivation of Aspergillus niger spores in a lipid emulsion. After treatments at 300 MPa for 1 cycle at 35 or 45 °C, no surviving spores were recovered. All treatments were modeled by the linear and Weibull models. The presence of shoulders and tails in the treatments at 300 MPa at 35 or 45 °C resulted in sigmoidal curves which cannot be described by the linear model, hence the Weibull + Tail, Shoulder + Log-lin + Tail, and double Weibull models were evaluated to elucidate the inactivation kinetics. The tailing formation could be related to the presence of resistance subpopulations. The double Weibull model showed better goodness of fit (RMSE <0.2) to describe the inactivation kinetics of the treatments with the higher spore reductions. HHP at 200-300 MPa and 25 °C did not reduce the Aspergillus niger spores. The combined HHP and mild temperatures (35-45 °C) favored fungal spore inactivation. Spore inactivation in lipid emulsions by HHP did not follow a linear inactivation. HHP at mild temperatures is an alternative to the thermal process in lipid emulsions.

A standardized method for genus Colletotrichum characterization by isothermal microcalorimetry using thermokinetic parameters.

A new standardized method, using isothermal microcalorimetry (IMC), was established to determine thermokinetic parameters from heat flow curves and to demonstrate the reproducibility and repeatability of the parameters of five Colletotrichum species on different days. Measurements on IMC were made at different periods and by two operators. Repeatability and reproducibility (R&R) measurement system analysis was performed on the technique used to measure the heat flow of Colletotrichum strains. The results showed that the %GageR&R was found to be within the acceptable ranges of a measurement system. Also, the parameters obtained from the curves were subjected to a combination of Principal Component Analysis (PCA) and Clustering, the data showed that the total heat (Ht) and maximum growth rate (µmax) are probably the most specific distinguishing characteristic of the strains evaluated in this study. This study demonstrates, for the first time, the usefulness of IMC in obtaining heat flow curves and thermokinetic parameters, providing repeatable and reproducible measurements over a period and under controlled conditions, for future identifications of phytopathogenic fungi.

Microencapsulation of Phenolic Extract from Sea Grape (Coccoloba uvifera L.) with Antimutagenic Activity.

This study aimed to microencapsulate the sea grape ethanolic extract by the spray drying process, characterizing the obtained powder, and evaluating its antimutagenicity activity. Microparticles showed a mean size of 6.28 µm and a spherical shape with a smooth surface. The powder had a low moisture content (4.02±0.92 %) and water activity (0.27±0.01), and high solubility (76±3.60 %). Moreover, hygroscopicity (14.75±2.63 g/100 g of powder) and bulk density (0.63±0.03 g/cm3 ) values suggested that this powder can be easily handled at a pilot or industrial scale. In addition, microencapsulation protected the extract against oxidation by ultraviolet light, improved its thermal stability, and its antimutagenicity activity was similar to fresh sea grape extract. In conclusion, the microencapsulation with maltodextrin by spray drying technique is an alternative to protect bioactive compounds from sea grapes against environmental conditions, maintaining their antimutagenic activity.

Deconstructing sugarcane bagasse lignocellulose by acid-based deep eutectic solvents to enhance enzymatic digestibility.

Biorefinery with deep eutectic solvent (DES) is an emerging processing technology to overcome the shortcomings of conventional biomass pretreatments. This work evaluates the biorefinery of sugarcane bagasse (SCB) with DES formulated with choline chloride as hydrogen bond acceptor and three hydrogen bond donors: lactic acid, citric acid, and acetic acid. Acetic acid showed unique ionic properties responsible for the selective removal of lignin and the deconstruction of cellulose to improve the digestibility of up to 97.61 % of glucan and 63.95 % of xylan during enzymatic hydrolysis. In addition, the structural characteristics of the polysaccharide-rich material (PRM) were analyzed by X-rays, ATR-FTIR, SEM, and enzymatic hydrolysis, and compared with the original material sample, for a comprehensive understanding of biomass deconstruction using different hydrogen bond donors (HBD) as DES pretreatment.

Determination by isothermal microcalorimetry of the sensitivity of phytopathogenic fungi of tropical fruits against an ethanolic extract of jackfruit leaf (Artocarpus heterophyllus Lam.).

Conventional microbiological methods to evaluate the in vitro antifungal activity of bioactive compounds usually consume a long time. It is also difficult to calculate different kinetic parameters. For this reason, this study aimed to evaluate the sensitivity of phytopathogenic fungi to an ethanolic extract of jackfruit leaf by the poison agar and isothermal microcalorimetry (IMC) tests. The kinetic parameters (maximum growth rate (µMax), total heat (ϕMax), time to peak (T1), and lag (λ) phase) varied by fungal isolate. However, the results indicated a reduction of the total heat produced from the fungi at 5 mg/mL of the extract referred to as the control without extract (p < 0.05). Pearson coefficients were established to determine the relationship between both techniques. Correlations demonstrated that the λ phase and µMax are highly related (> 0.51) to the in vitro percentage inhibition. Therefore, this study contributes to the use of the IMC as an alternative to complement the classical methods of fungal inhibition, providing data in real-time.

Antimutagenic and Antiproliferative Activity of the Coccoloba uvifera L. Extract Loaded in Nanofibers of Gelatin/Agave Fructans Elaborated by Electrospinning.

BACKGROUND: The Coccoloba uvifera L. species is currently considered an important source of compounds of high biological value such as lupeol. This is related to different and important biological activities to human health. OBJECTIVE: The objective of this study was to encapsulate the C. uvifera extract in nanofibers made with the biopolymers gelatin (G)/high-grade polymerization agave fructans (HDPAF) in the proportions 1:0, 1:1, 1:2, 1:3 and 0:1, through the electrospinning process, in addition to evaluating the antimutagenic and antiproliferative properties of the encapsulated extract. METHODS: The physicochemical characteristics of the nanofibers were evaluated, as well as the antiproliferative and antimutagenic activities of the encapsulated and unencapsulated extract. SEM evaluation shows nanofibers of smooth, continuous morphology and nanometric size (50-250 nm). The TGA, FTIR-ATR, HPLC-MS analyses reveal the presence of the extract in the nanofibers. RESULTS: The extract did not show a mutagenic effect during the development of the Ames test, on the other hand, the MTT test showed the antiproliferative effect at the concentrations of 50 and 100 µg/mL of extract. CONCLUSION: The extract of C. uvifera loaded in nanofibers elaborated by electrospinning with the G/HDPAF biopolymers conserves its antimutagenic and antiproliferative properties.

Preparation and Characterization of Electrospun Polysaccharide FucoPol-Based Nanofiber Systems.

The electrospinnability of FucoPol, a bacterial exopolysaccharide, is presented for the first time, evaluated alone and in combination with other polymers, such as polyethylene oxide (PEO) and pullulan. The obtained fibers were characterized in terms of their morphological, structural and thermal properties. Pure FucoPol fibers could not be obtained due to FucoPol's low water solubility and a lack of molecular entanglements. Nanofibers were obtained via blending with PEO and pullulan. FucoPol:PEO (1:3 w/w) showed fibers with well-defined cylindrical structure, since the higher molecular weight of PEO helps the continuity of the erupted jet towards the collector, forming stable fibers. WAXS, DSC and TGA showed that FucoPol is an amorphous biopolymer, stable until 220 °C, whereas FucoPol-PEO fibers were stable until 140 °C, and FucoPol:pullulan fibers were stable until 130 °C. Interestingly, blended components influenced one another in intermolecular order, since new peaks associated to intermolecular hierarchical assemblies were seen by WAXS. These results make FucoPol-based systems viable candidates for production of nanofibers for packaging, agriculture, biomedicine, pharmacy and cosmetic applications.

Formulation of the biological control yeast Meyerozyma caribbica by electrospraying process: effect on postharvest control of anthracnose in mango (Mangifera indica L.) and papaya (Carica papaya L.).

BACKGROUND: Microorganism for biological control of fruit diseases is an eco-friendly alternative to the use of chemical fungicides. RESULTS: This is the first study evaluating the electrospraying process to encapsulate the biocontrol yeast Meyerozyma caribbica. The effect of encapsulating material [Wey protein concentrate (WPC), Fibersol® and Trehalose], its concentration and storage temperature on the cell viability of M. caribbica, and in vitro and in vivo control of Colletotrichum gloeosporioides was evaluated. The processing with commercial resistant maltodextrin (Fibersol®) 30% (w/v) as encapsulating material showed the highest initial cell viability (95.97 ± 1.01%). The storage at 4 ± 1 °C showed lower losses of viability compared to 25 ± 1 °C. Finally, the encapsulated yeast with Fibersol 30% w/v showed inhibitory activity against anthracnose in the in vitro and in vivo tests, similar to yeast fresh cells. CONCLUSION: Electrospraying was a highly efficient process due to the high cell viability, and consequently, a low quantity of capsules is required for the postharvest treatment of fruits. Additionally, the yeast retained its antagonistic power during storage. © 2021 Society of Chemical Industry.

Enzymatic hydrolysis of lignocellulosic biomass using native cellulase produced by Aspergillus niger ITV02 under liquid state fermentation.

The objective of this work was to evaluate the biochemical characteristics of an enzymatic extract obtained from autochthonous fungus Aspergillus niger ITV02 and its application in the enzymatic hydrolysis of wheat straw and corn stubble pretreated by steam explosion. The enzymatic extract was obtained by submerged fermentation using delignified sweet sorghum bagasse as a carbon source. The results obtained showed that the enzymatic extract had ß-glucosidase and endoglucanase activities. The effects of pH and temperature on cellulase activity were evaluated and its thermostability was determined. The optimal parameters of the ß-glucosidase and endoglucanase activities obtained were pH 5 and 70 °C. The enzymatic extract of A. niger ITV02 was used to hydrolyze wheat straw and corn stubble, and the hydrolysis yields were compared with those obtained by a commercial cellulase (Celluclast 1.5L NS 50013) and CellicCTec3. The results showed that with the use the mixture of Celluclast 1.5L-A. niger ITV02 and CellicCTec3-A. niger ITV02 in the hydrolysis, conversions of 86.36% and 67.8% were obtained, respectively. Glucose production for the mixture extract increased 2.15 times more than when the enzyme was used independently alone. The present work shows that A. niger ITV02 has a potential as an enzyme producer for lignocellulosic hydrolysis.

Edible pectin film added with peptides from jackfruit leaves obtained by high-hydrostatic pressure and pepsin hydrolysis.

Jackfruit (Artocarpus heterophyllus Lam.) is an evergreen tree that produces a high waste of leaves. This study evaluated the obtention of peptides from jackfruit leaves using pancreatin and pepsin, their antifungal activity, and their effect on pectin films. The protein content was 7.64 ± 0.12 g/100 g of jackfruit fresh leaves. Pancreatin produced a higher yield than pepsin in the obtention of peptides (p ≤ 0.05). However, peptides obtained after 2 h by pepsin hydrolysis (Pep-P) had six essential amino acids and inhibited > 99% of mycelial growth and spore germination of Colletotrichum gloeosporioides. Pectin films with Pep-P showed a slight brown color, lower thickness, water vapor permeability, and moisture content, as well as higher thermal stability and better inhibition properties against C. gloeosporioides than pectin films without Pep-P (p ≤ 0.05). Pectin films added with Pep-P from jackfruit leaf could be a green alternative to anthracnose control in tropical fruits.

Optimization of microwave assisted extraction of Artocarpus Heterophyllus leaf polyphenols with inhibitory action against Alternaria sp. and antioxidant capacity.

The Artocarpus heterophyllus extracts are receiving attention due to their agro-food applications. Then, the simultaneous optimization of microwave-assisted extraction of polyphenols from jackfruit leaf with growth inhibitory action against Alternaria sp. was studied. The effects of power and time on total soluble polyphenols and total flavonoids contents, and antifungal activity were investigated using response surface methodology. Temperature behavior was considered also. Models showed good prediction and successfully validation. Treatment at 840 W and 2 min allowed the responses maximization (148.75 mg galic acid equivalent /g dried weight of total soluble polyphenols, 13.28 mg rutin equivalent /g dried weight of total flavonoids, and 39.9% of antifungal activity). Furthermore, high ABTS+ (97%) and DPPH (92%) inhibition was exhibited, as a function of the polyphenol's concentration and composition. Mainly flavonoids with potential antioxidant and antifungal properties were detected. These findings suggest the potentialities of these extracts for Alternaria sp. control during tomato postharvest.

Use of jackfruit leaf (Artocarpus heterophyllus L.) protein hydrolysates as a stabilizer of the nanoemulsions loaded with extract-rich in pentacyclic triterpenes obtained from Coccoloba uvifera L. leaf.

This study aimed to evaluate the encapsulating potential of a jackfruit leaf protein hydrolysate, through obtaining pentacyclic triterpenes-rich extract loaded nanoemulsion. Response surface methodology (RSM) was used to optimize the conditions to obtain an optimal nanoemulsion (NE-Opt). The effect of protein hydrolysate concentration (0.5-2%), oil loaded with extract (2.5-7.5%), and ultrasound time (5-15 min) on the polydispersity index (PDI) and droplet size of the emulsion (D[3,2] and D[4,3]) was evaluated. RSM revealed that 1.25% protein hydrolysate, 2.5% oil, and ultrasound time of 15 min produced the NE-Opt with the lowest PDI (0.85), D[3,2] (330 nm), and D[4,3] (360 nm). Encapsulation efficiency and extract loading of the NE-Opt was of 40.15 ± 1.46 and 18.03 ± 2.78% respectively. The NE-Opt was relatively stable during storage (at 4 and 25 °C), pH, temperature, and ionic strength. Then, the protein hydrolysate could be used as an alternative to conventional emulsifiers.

An Extensive Review of Natural Polymers Used as Coatings for Postharvest Shelf-Life Extension: Trends and Challenges.

Global demand for minimally processed fruits and vegetables is increasing due to the tendency to acquire a healthy lifestyle. Losses of these foods during the chain supply reach as much as 30%; reducing them represents a challenge for the industry and scientific sectors. The use of edible packaging based on biopolymers is an alternative to mitigate the negative impact of conventional films and coatings on environmental and human health. Moreover, it has been demonstrated that natural coatings added with functional compounds reduce the post-harvest losses of fruits and vegetables without altering their sensorial and nutritive properties. Furthermore, the enhancement of their mechanical, structural, and barrier properties can be achieved through mixing two or more biopolymers to form composite coatings and adding plasticizers and/or cross-linking agents. This review shows the latest updates, tendencies, and challenges in the food industry to develop eco-friendly food packaging from diverse natural sources, added with bioactive compounds, and their effect on perishable foods. Moreover, the methods used in the food industry and the new techniques used to coat foods such as electrospinning and electrospraying are also discussed. Finally, the tendency and challenges in the development of edible films and coatings for fresh foods are reviewed.

Enhancing hygroscopic stability of agave fructans capsules obtained by electrospraying.

In this work, different whey protein (WP) ratios (5, 10, 20, 30, 40 and 50% w/w) were added as stabilizers to high degree of polymerization Agave fructans (HDPAF) capsules to decrease the hygroscopicity. Results showed that the WP and HDPAF in 1:520:80 ratio (20/80 w/w) decreased significantly the hygroscopicity of capsules from 12.19 to 8.34%. Additionally, this polymeric mixture was assessed for the encapsulation of sea grape (Coccoloba uvifera L.) leaf extract was achieved by via electrospray, using this biopolymers mixture. Scanning electron microscopy (SEM) images exhibited spherical particles with sizes from 655 to 7250 nm. The thermal stability of encapsulated extract was demonstrated by via thermogravimetric analysis. The in vitro release study in simulated stomach (0-180 min) and intestine conditions (0-300 min) showed the controlled release of the controlled release of the encapsulated extract. The encapsulated extract and its bioavailability in simulating the stomach (0-180 min) and small intestine (0-300 min) Therefore, HDPAF-WP is a viable option as an encapsulating matrix susceptible to be used in the food, pharmaceutical, and cosmetic industries.

Antimutagenic, Antiproliferative and Antioxidant Properties of Sea Grape Leaf Extract Fractions (Coccoloba uvifera L.).

BACKGROUND: Cancer is a disease characterized by the invasion and uncontrolled growth of cells. One of the best ways to minimize the harmful effects of mutagens is through the use of natural antimutagens. In this regard, the search for new antimutagens that act in the chemoprevention could represent a promising field in this area. OBJECTIVE: In this study biological potential of 11 fractions from Coccoloba uvifera L. leaf hexane extract was evaluated by several in vitro tests. METHODS: Leaves were lyophilized and hexane extraction was performed. The extract was fractionated by column chromatography with hexane, ethyl acetate, and methanol. The antimutagenic (Ames test), antiproliferative (MTT test), and antioxidant capacity (DPPH, ABTS, and ferrous ion chelation) of the fractions were evaluated. RESULTS: Fractions 4, 6, 8, and 9 have antimutagenic activity (against sodium azide in strain TA100), fraction 11 showed antiproliferative capacity (IC50 of 24 ± 9 µg/mL in cells of HCT 116). The fractions with the highest activity were analyzed by HPLC-MS and lupeol, acacetin, and ß-sitosterol were identified. CONCLUSION: This study demonstrates, for the first time, the bioactivity of C. uvifera leaf as a new source of High Biological Value Compounds (HBVC), which can be of interest to the food and pharmaceutical industries.

Volatile profiles of five jackfruit (Artocarpus heterophyllus Lam.) cultivars grown in the Mexican Pacific area.

The volatile compounds of five kind of cultivars of jackfruit (Artocarpus heterophyllus Lam.) grown in Nayarit, Mexico, was researched by using extraction and chromatographic methods such as headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Eighty-six volatile compounds were identified. The most prominent compounds in the analyzed cultivars were alkyl esters of 3-methylbutanoic acid. Ethyl 3-methylbutanoate was the most abundant ester in FMC, JMC and RMC cultivars (190.7-961.2 µg/kg), whereas butyl 3-methylbutanoate (152.8-205.2 µg/kg) and pentyl 3-methylbutanoate (105.1-210.9 µg/kg) were predominant in DMC and BMC cultivars. By utilizing clustering statistical techniques such as principal component analysis was possible to identify certain esters compounds (number and concentration) to differentiate each cultivar.

Phytotoxicity, cytotoxicity, and in vivo antifungal efficacy of chitosan nanobiocomposites on prokaryotic and eukaryotic cells.

Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo and in vitro assays of CS nanosystems have experienced increased activity due to improved physicochemical properties, biological activity, and reactivity. Hence, it is important to determine whether their application involves toxicological risks. The aim of this study was to evaluate the mutagenic, cytotoxic, phytotoxic, and in vivo antifungal activity of chitosan-pyrrole-2-carboxylic acid nanobiocomposites (CS-PCA). The CS-PCA nanoparticles were synthesized by means of the nanoprecipitation technique with a size and ζ-potential of 502 ± 72 nm and + 54.7 ± 15.0 mV, respectively. According to the Ames test, no evidence of mutagenic activity was observed in Salmonella typhimurium strains. The cytotoxic assay showed that the incorporation of PCA into the CS matrix increased the toxic effect on ARPE-19 cells. However, fluorescence microscopy of ARPE-19 cells did not reveal morphostructural changes allusive to cell injury. CS-PCA exhibited strong phytotoxicity on lettuce seeds and the complete inhibition of seed development. The antifungal assay demonstrated that the CS-PCA delayed Aspergillus niger infection in tomato fruit until day 3; however, its use for the pre-treatment of seeds might exert adverse effects on plant development.

Encapsulation by Electrospraying of Anticancer Compounds from Jackfruit Extract (Artocarpus heterophyllus Lam): Identification, Characterization and Antiproliferative Properties.

BACKGROUND: Compounds with biological activities had been reported in the jackfruit. These compounds are susceptible to structural changes such as isomerization and/or loss of bonds due to environmental factors. Then, the encapsulation for protecting is a necessary process. OBJECTIVE: In this study, encapsulation of High-Value Biological Compounds (HVBC) was performed using High Degree of Polymerization Agave Fructans (HDPAF) and Whey Protein (WP) as encapsulating materials to preserve the biological properties of the HVBC. METHODS: The extract was characterized by HPLC-MS in order to show the presence of compounds with preventive or therapeutic effects on chronic degenerative diseases such as cancer. The micrographs by Scanning Electron Microscopy (SEM), Thermal Analysis (TGA and DSC), photostabilization and antiproliferation of M12.C3.F6 cell line of capsules were evaluated. RESULTS: The micrographs of the nanocapsules obtained by Scanning Electron Microscopy (SEM) showed spherical capsules with sizes between 700 and 800nm. No cracks, dents or deformations were observed. The Thermogravimetric Analysis (TGA) evidenced the decomposition of the unencapsulated extract ranging from 154 to 221°C. On the other hand, the fructan-whey protein mixture demonstrated that nanocapsules have a thermoprotective effect because the decomposition temperature of the encapsulated extract increased 32.1°C. Differential Scanning Calorimetry (DSC) exhibited similar values of the glass transition temperature (Tg) between the capsules with and without extract; which indicates that the polymeric material does not interact with the extract compounds. The photoprotection study revealed that nanocapsules materials protect the jackfruit extract compounds from the UV radiation. Finally, the cell viability on the proliferation of M12.C3.F6 cell line was not affected by powder nanocapsules without jackfruit extract, indicating that capsules are not toxic for these cells. However, microcapsules with jackfruit extract (50µg/ml) were able to inhibit significantly the proliferation cells. CONCLUSION: The encapsulation process provides thermoprotection and photostability, and the antiproliferative activity of HVBC from jackfruit extract was preserved.

Green technologies for the extraction of proteins from jackfruit leaves (Artocarpus heterophyllus Lam).

The application of emerging technologies such as ultrasound, microwaves and high hydrostatic pressure, allows the extraction of compounds in a sustainable manner from a vegetable matrix with a high value such as jackfruit leaf proteins (Artocarpus heterophyllus Lam). Currently, the main method of protein extraction is based on the precipitation with the use of an aggressive solvent, therefore it is necessary to optimize extraction methods with a minimum waste production. In the protein extraction of jackfruit leaves, we obtained a content of 84.1 mg/g using solvents. On the other hand, emergent extractions such as ultrasound, microwaves, and high hydrostatic pressure showed concentrations of 96.3, 95.6 and 147.3 mg/g, respectively. In addition, we found that the best extraction agent was 0.5 M NaCl, offering a range of possibilities that support green technologies as an imperative change in the food industry.