Characterization and evaluation of antifungal activity in vitro of Aloe vera fractions against postharvest fungi

Aloe vera leaves can be separated in a liquid fraction (exudate) and a mucilaginous pulp (gel). Recently, the antifungal activity of their components has been reported. The common technique for gel extraction from A. vera leaves are the traditional manual (in this case the liquid fraction is not separated) and a mechanical methods. Moreover, as a result of its processing the bagasse is obtained. The aim of this work was to recover and characterize the fractions of A. vera and to identify the fraction with highest antifungal activity against phytopathogen postharvest fungi (Botrytis cinerea and Penicillium spp.). A simple and inexpensive extraction method was used to obtain A. vera fractions from 50 kg leaves by means of a designed laboratory roll processor. The yields of extraction were as follows: 15.76% ± 4.0, 51.20% ± 5.20, and 33.02% ± 5.0 for gel, liquid fraction and bagasse, respectively. The three fractions were physico-chemically characterized (protein, monosaccharide composition, ashes, lipids) and resulted to be mainly composed by glucose and mannose in all the cases. Results showed the effectiveness of A. vera fractions in the growth control of phytopathogen postharvest fungi, with visible reduction of fungal growth

Fermented Flourensia cernua Extracts and Their in vitro Assay Against Penicillium expansum and Fusarium oxysporum

Ispitani su antioksidativna aktivnost i antimikrobni učinak vodenih ekstrakata fermentiranih listova biljke Fluorensia cernua DC na dvije fitopatogene plijesni, i to Penicillium expansum i Fusarium oxysporum. Za poboljšanje biološke aktivnosti ekstrakata provedena je fermentacija listova biljke Fluorensia cernua s pomoću soja Aspergillus niger GH1. Uvjeti tijekom 96 h fermentacije bili su: početna vlažnost od 60 %, pH-vrijednost od 5,5 i temperatura od 30 °C. Vodeni su ekstrakti izdvajani svakih 12 sati uzgoja. Antioksidativna aktivnost ekstrakata ispitana je pomoću DPPH metode, te je utvrđeno da su najveću aktivnost imali vodeni ekstrakti dobiveni nakon 12 h fermentacije, i to 63 % veću u usporedbi s kontrolnim, nefermentiranim uzorkom. Fermentacija je povećala fungicidni učinak 0,5 g/L ekstrakta na oba ispitana fitopatogena mikroorganizma. Istraživanjem je dokazano da se biološka aktivnost vodenih ekstrakata biljke Fluorensia cernua može poboljšati prethodnom fermentacijom lišća s pomoću plijesni.The antioxidant activity and efficiency of aqueous extracts of fermented tarbush (Fluorensia cernua DC) in the inhibition of two phytopathogenic fungi, Penicillium expansum and Fusarium oxysporum, have been evaluated. A solid-state fermentation of tarbush leaves by Aspergillus niger GH1 was performed to enhance the biological activities of the obtained extracts. Fungal culture conditions were: initial moisture of 60 %, pH=5.5 and temperature of 30 °C during 96 h. Aqueous extracts were obtained every 12 hours during the culture time. Antioxidant activity was evaluated by DPPH method. The aqueous extract of fermented tarbush had the highest antioxidant activity at 12 h, which was 63 % higher than the control (unfermented material). Fermentation enhanced the fungicidal effect against both phytopathogenic microorganisms at a concentration of 0.5 g/L. This study demonstrated that fungal fermentation of tarbush increased the biological activities of the aqueous extracts

Empirical modeling as an experimental approach to evaluate simultaneous saccharification and wheat straw fermentation for bioethanol production

In simultaneous saccharification and fermentation (SSF) of lignocellulosic materials, a rapid conversion to ethanol of the produced glucose is expected. The principal benefits are to minimize enzyme sugar inhibition, to improve cellulose conversion rates and to reduce cost compared with separated hydrolysis and fermentation, due to the occurring synergy between enzyme-yeast-substrate in one bioreactor. Wheat straw (WS) is an abundant by-product from worldwide wheat production making it an important substrate for bioethanol production. The aim of this work was to evaluate the effect of temperature, substrate concentration and loading enzyme on bioethanol production by SSF having as substrate WS pretreated by autohydrolysis (AH) and using flocculating Saccharomyces cerevisiae CA11. A 23 central composite design was applied and the limits of the different parameters were: 30-45ºC; 2-3 % of substrate; 5-30 FPU of cellulose enzyme (Celluclast 1.5) per g dry substrate and 30-60 of β-glucosidase (Novozym 188) IU per g substrate. Ethanol production, residual glucose, and cellobiose were analyzed by HPLC. CO2 was kinetically monitored by weight loss in Erlenmeyer flasks. Results showed that after 60 h of fermentation the highest ethanol concentration – 14.84 g/l (with a corresponding CO2 value of 14.27 g/l) was obtained at 45ºC, 3% of substrate, 30 FPU and 60 IU. This value, corresponding to an ethanol yield of 84.2%, shows a low enzyme inhibition during SSF process as the glucose produced by enzymatic hydrolysis is rapidly assimilated for yeast cells. Overall, it may be concluded that WS pretreated by AH is a good substrate for SSF process as high substrate conversion into ethanol can be achieved as a result of the synergy between enzyme-yeast-substrate

Application of edible nanolaminate coatings with antimicrobial extract of Flourensia cernua to extend the shelf-life of tomato (Solanum lycopersicum L.) fruit

Supplementarymaterialrelatedtothisarticlecanbefound,inthe online version, at doi:https://doi.org/10.1016/j.postharvbio.2018.12. 008.Edible coatings have potential to reduce postharvest losses of fruit such as tomato. In this study, the effects of nanolaminate coatings incorporated with extracts of Flourensia cernua, an endemic plant of the arid and semi-arid regions of Mexico, has been investigated. Ethanol extracts of F. cernua (FcE) were prepared and incorporated into polyelectrolyte solutions of alginate and chitosan. The nanolaminates were characterized by determining the zeta potential, contact angle and water vapor and oxygen permeabilities. Shelf-life analyses (20°C for 15 d) were carried out with uncoated fruit (UCF), nanolaminate coating (NL) and nanolaminate coating with FcE (NL+FcE). Physicochemical analyses, gas exchange rates of O2 and CO2 and ethylene production, as well as microbiological analyses of treated fruit were measured. Zeta potential and contact angle measurements confirmed the successful assembly of successive nanolayers of alginate and chitosan, as well as those with F. cernua. The nanolaminate coatings resulted in decreased permeabilities to water and O2. The best treatment of NL+FcE, extended the shelf-life of fruit by reducing weight loss and microbial growth, reducing gas exchange and ethylene production, and maintaining firmness and color. The NL+FcE treatment are an alternative to extend the shelf-life of tomato fruit.Author E. de J. Salas-Méndez thanks Mexican Science and Technology Council (CONACYT, Mexico) for PhD fellowship support. Authors want to thank PhD Zlatina Genisheva for the proof reading of the manuscript and suggestions to the same; also, to:MaríaGuadalupe Moreno Esquivel, Edith E. Chaires Colunga, Olga L. Solís Hernández and M. Leticia Rodríguez González of the Phytochemistry Laboratory from Universidad Autónoma Agraria Antonio Narro, for their assistance in obtaining extracts and chemical composition.info:eu-repo/semantics/publishedVersio

Layer-by-layer technique to developing functional nanolaminate films with antifungal activity

The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.The authors acknowledge financial support from FP7 IP project BECOBIOCAP^. M. J. Fabra is recipients of a Juan de la Cierva contract from the Spanish Ministry of Economy and Competitivity. Maria L. Flores-López thanks Mexican Science and Technology Council (CONACyT, Mexico) for PhD fellowship support (CONACyT Grant Number 215499/310847). The author Miguel A. Cerqueira is a recipient of a fellowship (SFRH/BPD/72753/2010) supported by Fundação para a Ciência e Tecnologia, POPH-QREN and FSE (FCT, Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP- 01-0124-FEDER-027462) and the project BBioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,^ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER. The support of EU Cost Action FA0904 is gratefully acknowledged

Perspectives on utilization of edible coatings and nano-laminate coatings for extension of postharvest storage of fruits and vegetables

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.María L. Flores-López thanks Mexican Science and Technology Council (CONACYT, Mexico) for PhD fellowship support (CONACYT Grant Number: 215499/310847). Miguel A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundação para a Ciência e Tecnologia (FCT, POPH-QREN and FSE Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project ‘‘BioInd Biotechnology and Bioengineering for improved Industrial and AgroFood processes,’’ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico – FUNCAP, CE Brazil (CI10080-00055.01.00/13)

Scale-up and evaluation of hydrothermal pretreatment in isothermal and non-isothermal regimen for bioethanol production using agave bagasse

The production of tequila in Mexico generates a large amount of agave bagasse per year. However, this biomass can be considered as a potential source for biofuel production. In this study, it is described how the hydrothermal pretreatment was scaled in a bench scale, considering the severity index as a strategy. The best condition was at 180°C in isothermal regime for 20min with 65.87% of cellulose content and high concentration of xylooligosaccharides (15.31g/L). This condition was scaled up (using severity factor: [logR0]=4.11), in order to obtain a rich pretreated solid in cellulose to perform the enzymatic hydrolysis, obtaining saccharification yields of 98.5 and 99.5% at high-solids loading (10 and 15%, respectively). The pre-saccharification and fermentation strategy was used in the bioethanol production at 10 and 15% of total pretreated solids, obtaining 38.39 and 55.02g/L of ethanol concentration, corresponding to 90.84% and 87.56% of ethanol yield, respectively.Financial support is gratefully acknowledged from the Energy Sustainability Fund 2014-05 (CONACYT-SENER), Mexican Centre for Innovation in Bioenergy (Cemie-Bio), Cluster of Bioalcohols (Ref. 249564). We gratefully acknowledge support for this research by the Mexican Science and Technology Council (CONACYT, Mexico) for the Infrastructure Project – INFR201601 (Ref. 269461) and Basic Science Project – 2015-01 (Ref. 254808). Author Daniela L. Aguilar would like to thank the Mexican Science and Technology Council (CONACY, Mexico) for their master fellowship support (grant number: 582801/ 414478) andauthor ElisaZanuso thanksthe EnergySustainability Fund 2014-05 (CONACYT-SENER, Ref. 249564) for the undergraduate fellowship granted. Also, the authors thank Prof. Lucília Domingues and José Teixeira (University of Minho, Portugal) for kindly providing the yeast strain.info:eu-repo/semantics/publishedVersio

El género Gentiana (Gentianaceae) en México

El género Gentiana (Gentianaceae), con distribución en la regiones templadas y frías del hemisferio norte, registra para México 13 especies y una subespecie, casi todas endémicas, sólo dos con registros para Guatemala. Se presenta una sinopsis del género para México, incluyendo una clave para determinación de especies, descripciones y datos de distribución y ecológicos.The genus Gentiana (Gentianaceae), distributed in temperate and cold regions of the Northern Hemisphere, is represented in Mexico by 13 species plus one subspecies. Most of these are endemic, with only two also registered from Guatemala. A synopsis of the genus in Mexico is presented, including a key for the identification of the species, descriptions, and ecological and distributional information