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.

Effect of Pediococcus acidilactici and mango seed polyphenols on the fermentative profile of the indigestible fraction of yam bean.

Yam bean is an important source of dietary fiber and other components that comprise the total indigestible fraction (TIF), which can be fermented by the colonic microbiota and produce metabolites with beneficial health effects. Therefore, the objective of this study was to evaluate the in vitro colonic fermentation of yam bean TIF and the changes caused by the addition of a polyphenolic extract of mango seed and the lactic acid bacteria Pediococcus acidilactici. The mango seed extract was obtained by ultrasound-assisted extraction, and the microbial growth rate and viability of P. acidilactici were determined using a Neubauer chamber. Yam bean TIF was isolated by triple enzymatic hydrolysis and subjected to in vitro colonic fermentation in combination with treatments with mango seed extract and P. acidilactici suspensions. Changes in pH, total soluble phenols (TSP), and antioxidant capacity (AOX) were evaluated. Furthermore, the production of metabolites was quantified by HPLC-DAD-MS and GC-MS. The Growth rate of P. acidilactici was 0.1097 h-1 with 97.5 % viability at 7 h of incubation. All TIF treatments showed a high capacity of fermentation, and the addition of mango seed extract increased the TSP content and AOX in DPPH and FRAP assays. A total of Forty-six volatile metabolites were detected, with highlighting the presence of esters, benzenes, aldehydes, and short-chain fatty acids. Five phenolic compounds associated with mango by-products were quantified during all fermentation process, despite the concentration of the extract. P. acidilactici did not substantially modify the fermentative profile of TIF. However, further studies such as the evaluation of the abundance of microbial communities may be necessary to observe whether it can generate changes during colonic fermentation.

Guamara and Cocuixtle: Source of Proteases for the Transformation of Shrimp By-Products into Hydrolysates with Potential Application.

Since the fruits of Bromelia pinguin and Bromelia karatas are rich in proteases, the aim of this research was to optimize the hydrolysis process of cooked white shrimp by-products due to the effect of these proteases. A robust Taguchi L16' design was used to optimize the hydrolysis process. Similarly, the amino acid profile by GC-MS and antioxidant capacity (ABTS and FRAP) were determined. The optimal conditions for hydrolysis of cooked shrimp by-products were pH 8.0, 30 °C, 0.5 h, 1 g of substrate and 100 µg/mL of B. karatas, pH 7.5, 40 °C, 0.5 h, 0.5 g substrate and 100 µg/mL enzyme extract from B. pinguin and pH 7.0, 37 °C, 1 h, 1.5 g substrate and 100 µg/mL enzyme bromelain. The optimized hydrolyzates of B. karatas B. pinguin and bromelain had 8 essential amino acids in their composition. The evaluation of the antioxidant capacity of the hydrolyzates under optimal conditions showed more than 80% inhibition of in ABTS radical, B. karatas hydrolyzates had better higher ferric ion reduction capacity with 10.09 ± 0.02 mM TE/mL. Finally, the use of proteolytic extracts from B. pinguin and B. karatas to optimize hydrolysis process allowed obtaining hydrolyzates of cooked shrimp by-products with potential antioxidant capacity.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Characterization of submicron emulsion processed by ultrasound homogenization to protect a bioactive extract from sea grape (Coccoloba uvifera L.).

In this study, the stability of a submicron emulsion to protect an extract obtained from sea grape fruit (Coccoloba uvifera L.) was evaluated. Extract characterization by MS-HPLC revealed the presence of 3 anthocyanins (cyanidin 3-glucoside, malvidin 3-glucoside, and delphinidin 3-glucoside), the content of total phenols was 263.86 ± 1.86 mg gallic acid equivalent/100 g, with an antioxidant capacity determined by ABTS and DPPH of 128.95 ± 1.00 and 26.18 ± 0.60 µg Trolox equivalents/mL, respectively. A submicron emulsion (0.424 µm) by Ultrasound with monomodal distribution, stable over time and low viscosity (1.94 mPa s) classified as a shear-thinning fluid was obtained. The thermogravimetric analysis (TGA) demonstrated the stability of the C. uvifera extract in the emulsion, which is thermostable (212 °C). These emulsions can be added into a beverage as a nutraceutical, dried for later use as pills or incorporated in foods.

Production and characterization of an enzyme extract with cellulase activity produced by an indigenous strain of Fusarium verticillioides ITV03 using sweet sorghum bagasse.

OBJECTIVES: To evaluate a strain of Fusarium verticillioides ITV03 isolated from wood residues in the Veracruz region of Mexico. Endoglucanase and ß-glucosidase production by submerged fermentation was optimized using a Box-Behnken design, where the independent variables were urea, ammonium sulfate and yeast extract. RESULTS: After optimization, an endoglucanase activity of 0.27 U/mL was achieved; subsequently, three carbon sources were evaluated (carboxymethyl cellulose, sweet sorghum bagasse cellulose and delignified sweet sorghum bagasse (DSSB). The results showed that DSSB yielded the greatest endoglucanase (0.28 U/mL) and ß-glucosidase (0.12 U/mL) activities. Both enzymatic activities were characterized for the effect of pH, temperature and thermostability. The optimal parameters of ß-glucosidase and endoglucanase activity were pH 5 and 4 respectively, the optimum temperature 60 °C. These enzymes were stable at 50 °C for 150.68 h and 8.54 h, with an activation energy (Ea(day)) of 265.55 kJ/mol and 44.40 kJ/mol respectively, for ß-glucosidase and endoglucanase. CONCLUSION: The present work shows that a native strain like F. verticillioides ITV03 using DSSB supplemented with nitrogen has a great potential as a producer of cellulase for lignocellulosic residue hydrolysis.

Characterization and antifungal activity of jackfruit (Artocarpus heterophyllus Lam.) leaf extract obtained using conventional and emerging technologies.

With the current agro-food industry demands for more environmentally-friendly production, the use of natural antifungal compounds extracted by emerging technologies led to a sustainable alternative to control microorganisms. Therefore, the present work aimed to: (i) determine antifungal activity against Colletotrichum gloeosporioides and Penicillium italicum of jackfruit leaf extracts obtained by different methods, and (ii) identify compounds by HPLC-DAD-ESI-MS. Microwave (MAE), high-hydrostatic pressure (HHP) and ultrasound (UAE) assisted extractions were tested, followed by fractionation with different polarity solvents. The concentration of total soluble phenols (TSP), tannins (TT) and flavonoids (TF) were determined. Differences not only in the amounts of extracted phytochemicals were found but in the antifungal properties (MAE against P. italicum and HHP against C. gloeosporioides at 5 mg/ml) as well as in the chemical composition determined by HPLC-MS. These results suggest the possible application of jackfruit leaf extracts as a suitable postharvest antifungal treatment.

Application of essential oils and polyphenols as natural antimicrobial agents in postharvest treatments: Advances and challenges.

The use of natural antimicrobial agents is an attractive ecological alternative to the synthetic fungicides applied to control pathogens during postharvest. In order to improve industrial production systems, postharvest research has evolved toward integration with science and technology aspects. Thus, the present review aims to draw attention to the achieved advances and challenges must be overcome, to promote application of essential oils and polyphenols as antimicrobial agents, against phytopathogens and foodborne microorganisms during postharvest. Besides that, it attempts to highlight the use of coating and encapsulation techniques as emerging methods that improve their effectiveness. The integral knowledge about the vegetable systems, molecular mechanisms of pathogens and mechanisms of these substances would ensure more efficient in vitro and in vivo experiences. Finally, the cost-benefit, toxicity, and ecotoxicity evaluation will be guaranteed the successful implementation and commercialization of these technologies, as a sustainable alternative to minimize production losses of vegetable commodities.

Predictive Model for the Effect of Environmental Conditions on the Postharvest Development of Colletotrichum gloeosporioides Strains Isolated from Papaya (Carica papaya L.).

ABSTRACT: Colletotrichum species are the most important postharvest spoilage fungi of papaya fruit. The objective of this research was to evaluate the effect of temperature and relative humidity on growth rate and time for growth to become visible of five strains of Colletotrichum gloeosporioides isolated from papaya fruit in a complex medium. As a primary model, the radial growth rates were estimated using the Baranyi and Roberts model in papaya agar. The Solver MS Excel function was used to obtain the time to visible mycelium (tv). Secondary models obtained with the Rosso et al. cardinal model of inflection were applied to describe the effect of temperature on the growth rate (µ). The Arrhenius-Davey model was used to model tv. The obtained models seem to be satisfactory for describing both µ and tv. The relative humidity had an effect on µ and tv for all tested C. gloeosporioides isolates, but no model accurately described the behavior of the fungus. External validation of models was performed with papaya fruit. Growth models were developed with the same models used in vitro. The bias and the accuracy factors as indices for performance evaluation of predictive models in food microbiology as a function of temperature and RH were 1.22 and 1.33, respectively, for µ and 1.18 and 1.62, respectively, for tv, indicating accurate predictions. The supply chain of papaya is complex and requires constant conditions, and poor conditions can result in damage to the fruit. Knowledge of the behavior of C. gloeosporioides on papaya fruit and application of the developed models in the supply chain will help to establish transport control strategies to combat these fungi. This research has contributed to development of the first models of growth for C. gloeosporioides in Mexico.