Mexican Coccoloba uvifera L. Leaf and Fruit Extracts: Identification of Pentacyclic Triterpenes and Volatile Profile by GC-MS.

Mexican Coccoloba uvifera fruit contains polyphenols, flavonoids, and anthocyanins, while in the leaves, lupeol, α- and ß-amyrin have been previously identified by HPLC. However, the low resolution by HPLC of pentacyclic triterpenes (PTs) is a limitation. Moreover, the volatile profile of C. uvifera fruit is still unknown. Therefore, this study aimed to identify PTs in C. uvifera leaf and fruit extracts by CG-MS analysis and to determine the volatile profile of C. uvifera pulp by headspace solid-phase microextraction. The results showed trimethylsilylated compounds of standards lupeol, α- and ß-amyrin, indicating that the silylation reaction was suitable. These trimethylsilylated compounds were identified in leaf and fruit extracts. The fruit volatile profile revealed the presence of 278 esters, 20 terpenes, 9 aldehydes, 5 alcohols, and 4 ketones. The fruit showed a high content of esters and terpenes. Due to their flavour properties, esters are essential for the food, cosmetics, and pharmaceutics industries. Moreover, terpenes in the fruit, such as menthone, ß-elemene, junipene, and ß-caryophyllene have the potential as anticancer and phytopathogen agents. The results indicated that GC-MS is an alternative to HPLC approaches for identifying PTs. Besides, identifying volatile compounds in the fruit will increase the value of this plant and expand its application. Identifying PTs and volatile compounds in Mexican C. uvifera leads to a better understanding of the potential benefits of this plant. This would increase the consumption of Mexican C. uvifera fresh or as functional ingredients in nutraceutical or pharmaceutical products.

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.

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.

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.

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.

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.

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.

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.

Use of a Taguchi Design in Hibiscus sabdariffa Extracts Encapsulated by Spray-Drying.

Aqueous and ethanolic extracts of Hibiscus sabdariffa were spray-dried using maltodextrin (MD) and gum arabic (GA) as carrier agents. A Taguchi L8 experimental design with seven variables was implemented. Physicochemical properties in the encapsulates were evaluated by Ultraviolet-Visible (UV-Vis,) X-ray Diffraction (XRD), spectroscopy and gravimetric techniques. Treatments with aqueous extracts showed the highest concentration of total soluble polyphenols (TSP) 32.12-21.23 mg equivalent gallic acid (EAG)/g dry weight (DW), and antioxidant capacity (AOX) in the 2,2-azinobis-3-ethylbenzotiazoline-6-sulfonic acid (ABTS) assay. The best treatment for TSP and AOX was T4: 2.5% Hibiscus w/w, aqueous extract, decoction, extract-to-carrier ratio 1:1 (w/w), proportion to carriers (MD:GA) 80:20 (w/w), 10,000 rpm, 150 °C. The Taguchi L8 design is a tool that allows the use of multiple variables with a low number of treatments that indicate the drying conditions that give the best parameters, focusing mainly on TSP and AOX, also, it is a good alternative for the preservation and stability of the phenolic compoudns in Hibiscus.

Cold Plasma Treatment as an Alternative for Ochratoxin a Detoxification and Inhibition of Mycotoxigenic Fungi in Roasted Coffee.

Ochratoxin A (OTA) produced by mycotoxigenic fungi (Aspergillus and Penicillium spp.) is an extremely toxic and carcinogenic metabolite. The use of cold plasma to inhibit toxin-producing microorganisms in coffee could be an important alternative to avoid proliferation of mycotoxigenic fungi. Roasted coffee samples were artificially inoculated with A. westerdijikiae, A. steynii, A. versicolor, and A. niger, and incubated at 27 °C over 21 days for OTA production. Samples were cold plasma treated at 30 W input power and 850 V output voltage with helium at 1.5 L/min flow. OTA production in coffee was analyzed by high performance liquid chromatography coupled to a mass spectrometer (HPLC-MS). After 6 min of treatment with cold plasma, fungi were completely inhibited (4 log reduction). Cold plasma reduces 50% of OTA content after 30 min of treatment. Toxicity was estimated for extracts of artificially contaminated roasted coffee samples using the brine shrimp (Artemia salina) lethality assay. Toxicity for untreated roasted coffee was shown to be "toxic", while toxicity for cold plasma treated coffee was reduced to "slightly toxic". These results suggested that cold plasma may be considered as an alternative method for the degradation and reduction of toxin production by mycotoxigenic fungi in the processing of foods and feedstuffs.

Are biological control agents, isolated from tropical fruits, harmless to potential consumers?

Postharvest losses of fruits and vegetables can reach up to 25% in developed and up to 50% in developing countries. (Sub)tropical fruits are especially susceptible because their protecting peel can easily be damaged. Traditionally used pesticides are associated to environmental pollution and possible harmful health effects. An alternative are biocontrol agents (BCA), means bacteria or yeasts applied onto the fruits to inhibit the growth of phytopathogens. Many reports on their effectiveness have been published, however, reports on their harmlessness to consumers are still rare. Culture extracts of six BCAs, tested on two human lines (Caco-2, HeLa), exhibited no cytotoxic effect, when used directly (1×) to protect the fruits; however, when they are 5×overconcentrated, the confluence of proliferating cells was reduced, but not of differentiated Caco-2. In both cases necrosis was not increased. On proliferating cells, the 5×-extract from Cryptococcus laurentii or Debaryomyces hansenii reduced lysosome functionality and the 6.25×extract from Meyerozyma guilliermondii or Candida famata increased membrane permeability, while only the 25×-extract from M. guilliermondii or M. caribbica reduced slightly the metabolic activity. The extract of Bacillus subtilis showed no cytotoxic effect up to 10× concentration. Overall, their low cytotoxicity combined with high biodegradability make these products suitable for sustainable agriculture.

Covalently Cross-Linked Arabinoxylans Films for Debaryomyces hansenii Entrapment.

In the present study, wheat water extractable arabinoxylans (WEAX) were isolated and characterized, and their capability to form covalently cross-linked films in presence of Debaryomyces hansenii was evaluated. WEAX presented an arabinose to xylose ratio of 0.60, a ferulic acid and diferulic acid content of 2.1 and 0.04 µg∙mg(-1) WEAX, respectively and a Fourier Transform Infra-Red (FT-IR) spectrum typical of WEAX. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.6 dL∙g(-1) and 440 kDa, respectively. The gelation of WEAX (1% w/v) with and without D. hansenii (1 × 10(7) CFU∙cm(-2)) was rheologically investigated by small amplitude oscillatory shear. The entrapment of D. hansenii decreased gel elasticity from 1.4 to 0.3 Pa, probably by affecting the physical interactions between WEAX chains. Covalently cross-linked WEAX films containing D. hansenii were prepared by casting. Scanning electron microscopy images show that WEAX films containing D. hansenii were porous and consisted of granular-like and fibre microstructures. Average tensile strength, elongation at break and Young's modulus values dropped when D. hansenii was present in the film. Covalently cross-lined WEAX containing D. hansenii could be a suitable as a functional entrapping film.

Saccharomyces cerevisiae mixed culture of blackberry (Rubus ulmifolius L.) juice: synergism in the aroma compounds production.

Blackberry (Rubus sp.) juice was fermented using four different strains of Saccharomyces cerevisiae (Vitilevure-CM4457, Enoferm-T306, ICV-K1, and Greroche Rhona-L3574) recognized because of their use in the wine industry. A medium alcoholic graduation spirit (<6°GL) with potential to be produced at an industrial scale was obtained. Alcoholic fermentations were performed at 28°C, 200 rpm, and noncontrolled pH. The synergistic effect on the aromatic compounds production during fermentation in mixed culture was compared with those obtained by monoculture and physic mixture of spirits produced in monoculture. The aromatic composition was determined by HS-SPME-GC. The differences in aromatic profile principally rely on the proportions in aromatic compounds and not on the number of those compounds. The multivariance analysis, principal component analysis (PCA), and factorial discriminant analysis (DFA) permit to demonstrate the synergism between the strains.

Identification of Saccharomyces cerevisiae strains for alcoholic fermentation by discriminant factorial analysis on electronic nose signals

An electronic nose (E-nose) coupled to gas chromatography was tested to monitor alcoholic fermentation by Saccharomyces cerevisiae ICV-K1 and Saccharomyces cerevisiae T306, two strains well-known for their use in oenology. The biomass and ethanol concentrations and conductance changes were measured during cultivations and allowed to observe the standard growth phases for both yeast strains. The two strains were characterized by a very similar tendency in biomass or ethanol production during the fermentation. E-nose was able to establish a kinetic of the production of aroma compounds production and which was then easy to associate with the fermentation phases. Principal Component Analysis (PCA) showed that the data collected by E-nose during the fermentation mainly contained cultivation course information. Discriminant factorial analysis (DFA) was able to clearly identify differences between the two strains using the four main principal components of PCA as input data. Nevertheless, the electronic nose responses being mainly influenced by cultivation course, a specific data treatment limiting the time influence on data was carried out and permitted to achieve an overall performance of 83.5 percent.