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Costa Rica es el principal exportador mundial de piña fresca (Ananas comosus); asociado a la producción agrícola de la piña, viene el tema de los residuos agrícolas y el interés en el rastrojo de piña como principal material de descarte. Hicimos una estimación de la biomasa que se genera de rastrojo de piña, los costos asociados con el manejo en campo e identificamos el tratamiento actual que se da a este residuo; además de un análisis inicial de fortalezas, debilidades, oportunidades y amenazas. Estimamos que la biomasa de rastrojo de piña para 43 000Ha actuales de cultivo es de 4,282 x 106 ton/año en base húmeda (640 mil ton/año base seca). Los costos asociados para la gestión en el campo del rastrojo de piña oscilan entre US$ 1 000 y US$ 2 500 por hectárea, dependiendo del tipo de manejo; en seco (secado químico con Paraquat) o manejo en verde (trituración de la planta verde) y su incorporación al terreno. Dentro de la economía de exportación de productos agrícolas es la segunda mayor, detrás del banano, ya que se exportan más de US$ 900 millones al año (2017), lo cual hace que existan oportunidades de mejora en el manejo y aprovechamiento de esta biomasa, y se deba valorar el estudio a mayor profundidad del desarrollo de un proceso de biorrefinería para la obtención de productos de mayor valor agregado como biocombustibles, energía, biomoléculas, entre otros. Es importante que los procesos de biorrefinería que se propongan se integren en modelos de ecología industrial o economía circular, para minimizar la producción de gases de efecto invernadero y permitir la seguridad alimentaria en las regiones, con la finalidad de alcanzar los objetivos del desarrollo sostenible.

An optimized method of solid-state fermentation (SSF) is reported for the valorization of fig (Ficus carica L.) by-products. Four fungal strains were screened for their capacity to enhance the release of total phenolic compounds (TPCs). Temperature, pH, moisture, and mineral composition were evaluated and optimized using a Box–Hunter–Hunter design and then central composite design was performed. The optimized SSF conditions were as follows: A. niger HT4 for 36 h at 40 °C; moisture, 60%; pH: 5.0; mineral composition (g/L): NaNO3: 0.57; KH2PO4: 3.04; MgSO4·7H2O: 1.52; and KCl: 5.37. Under the optimal SSF conditions, the experimental values (10.19 ± 0.04 mg of GAE/g of dm) matched with those predicted (10.37 mg of GAE/g of dm) within a 95% confidence level. A total of eight phenolic compounds were identified by High Performance Liquid Chromatography-Mass Spectrophotometry (HPCL-MS). The optimized SSF bioprocess increased the TPC release and antioxidant activity values up to 5.48 and 98.54 times, respectively, showing its feasibility as a reliable alternative for the use of fig by-products.

The Chihuahua desert has different plant species that have historically been used as food for a long time. Some of these plants can be novel sources of dietetic fiber, which is considered a functional ingredient. The aim of this work was determine the chemical and functional properties of six desert sources of dietary fiber: cabuche, palm flower, leaves of smooth amaranth, peel pickle pears, green and ashen agave bagasse. A proximate analysis was carried out to determine moisture, ash, protein and extractable lipid. Content of insoluble fiber (IF), soluble fiber (SF), and dietary total fiber (DTF), as well as the functional properties of dietary fiber as water holding capacity (WHC), swelling capacity (SW), oil holding capacity (OHC) and cation exchange capacity (CEC) were determined. The results showed that leaves of smooth amaranth were chemically different to the other analyzed samples. On the other side, the best DTF and IF content was observed in cabuche, while agave bagasses (green and ashen), peel of prickly pears and leaves of smooth amaranth showed the highest SF content. The dietary fiber sources that presented the best functional properties were cabuche and palm flower for water hold capacity and swelling capacity properties and for the oil hold capacity and cation exchange capacity properties were agave bagasses (green and ashen) which suggest that they could be a good source of dietary fiber.

Flavor and aroma molecules (FAMs) are high-value compounds used as safe additives to increase the sensorial properties of product formulations. Natural production of these compounds is preferred by consumers; hence, several strategies for this have been developed over time, including the use of biological systems such as bacteria, fungus, and yeast. However, most of these microorganisms are inhibited by the substrate or the product, limiting production. Continued development in bioreactor design to overcome these limitations has been reported, especially in the use of partitioning bioreactors. The concept of partitioning bioreactors presents great potential for improving the productivity of several bioprocesses. The proper selection of the dispersed phase is the key to the successful application of this approach in industrial practice. The integration of the bioprocess and the separation of the product have a positive impact on the productivity of FAMs processes. Controlling the supply of the substrate from the dispersed to the aqueous phase opens a new application for this strategy in the production and bioconversion of FAMs. However, it is necessary for the academic community to continue studying partitioning reactors and the phenomena that occur in such reactors in bioconversion systems used for the production of flavor and aroma molecules.

Twelve strains of fungi from residues of Agave durangensis were isolated and identified by molecular techniques for evaluation of their hydrolytic enzyme production capability. A proportion (50%) of the fungal strains belonged to the Aspergillus genus and the other strains used belonged to Alternaria, Neurospora crassa, Mucor sp, Rhizopus sp., Botryosphaeria sp., and Scytalidium sp. The isolated strains were evaluated for their potential to produce extracellular enzymes using different substrates (cellulose, xylan, inulin, Agave fructans, starch, and tannic acid). It was observed that most of the tested strains were capable of simultaneously secreting cellulases, xylanases, inulinases, fructanases, and laccases. Botryosphaeria sp. ITD-G6 was selected for its evaluation in the production of inulinase, using different substrates. Showing high inulinase activities (5.22 U / mL for Agave waste, 4.37 U/ mL for inulin and 5.00 U / mL for Agave fructans).

A thermostable extracellular serine protease from Aspergillus fumigatus was purified 8.8-fold using a 4-step protocol. The enzyme was produced using a 36 h solid-state culture, had a molecular weight of 88 kDa and exhibited maximal enzyme activity at pH 7 and 60 °C. Structural analysis revealed that the protease is monomeric and non-glycosylated. Thermal inactivation of the pure enzyme followed first-order kinetics. The half-life (t1/2) of the pure enzyme at 50, 60 and 70 °C was 65, 34 and 14 min, respectively. The denaturation and activation energies were 69 and 62 kJ mol−1, respectively. Thermodynamic parameters (entropy and enthalpy) suggested that the protease was highly thermostable. This is the first report on the thermodynamic parameters of proteases produced by A. fumigatus.

Proteolytic extract (CPE) was produced by Aspergillus oryzae 2095 under solid state fermentation using a mix of fish flour with polyurethane foam (70:30, w/w) of particle size of 0.5 mm. The proteolytic activity from CPE was compared to a commercial protease (Flavourzyme 500 MG ® ). The maximal activity for both extracts was found at pH 8 and 50 °C. The half-lives of CPE and Flavourzyme 500 MG ® were 52 and 25 min at 50 °C, respectively. Furthermore, the hydrolytic activity for both extracts was tested on muscle of giant sea bass ( Epinephelus morio ), CPE produced a higher degree of hydrolysis (DH) than Flavourzyme 500 MG ® (22.2 and 9.1%, respectively) under optimal experimental conditions for each extract.

The ability of Aspergillus niger GH1 in converting creosote bush ellagitannins into ellagic acid (EA) was evaluated in solid state culture. Creosote bush leaves were used to extract the ellagitannins fraction, which was impregnated in polyurethane foam used as support of solid state culture. Ellagitannins content, EA accumulation, and the related enzymatic activities were evaluated. A. niger GH1 was able to completely degrade creosote bush ellagitannins with an EA yield of 23.1% at 36 h of culture. The ability to degrade creosote bush ellagitannins exhibited by A. niger GH1 was clearly associated to an ellagitannin-hydrolysing enzyme with a maximum activity of 43 U/l, while that ability was not associated to tannase activity that was detected in the culture extract. This study demonstrated the great ability of A. niger GH1 to hydrolyze ellagitannins and the potential of solid state culture to produce the antioxidant EA by degradation of creosote bush ellagitannins.

The combined effects of pH, temperature (T), substrate/buffer ratio (S:B) and enzyme concentration (E) on protein recovery from gold carp (Carassius auratus) processing waste with Flavourzyme® were characterised. The effect of hydrolysis parameters on the degree of hydrolysis (DH) was described through response surface analysis (RSA) and the model obtained was defined as follows: DH = −316.30 + 7.1T + 44.5pH + 0.292S:B + 0.27E − 0.048T2 − 2.407pH2 − 0.002S:B2 − 0.307TxpH − 0.002S:BxE. All regression coefficients were significant (α = 0.05). The model showed a good fit with the experimental data, since the R2 of 0.923 indicated that 92.3% of the variability within the range of values studied could be explained by the model. The mathematical model presented a plateau region with a maximum DH (>26.6%) at the following critical values: pH = 5.9, T = 53 °C, S:B = 14.7% and E = 80 LAPU (leucine aminopeptidase units) g−1. Electrophoretic (SDS-PAGE) patterns showed a progressive reduction in molecular weight of the peptidic fractions from 10 min of hydrolysis onwards. By controlling the enzymatic process, it was possible to predict the molecular weight of the peptides obtained, in turn affecting the functional and nutritional properties of the peptidic fractions. Copyright © 2004 Society of Chemical Industry

Tannic acid is commonly employed as the main component in culture media for the selection of tannase-producing strains. In biotechnological processes it is the favorite substrate used to induce the tannase enzyme in both solid and submerged culture for microbial and/or enzymatic production of gallic acid. However, the results found in literature are inconsistent notwithstanding the strict control of all parameters that rule the bioprocesses. The present work, for the first time, reveals the importance of differences in the quality and chemical profile of tannic acid from different suppliers and their influence on the fungal and enzymatic hydrolytic pattern obtained when it is used as a substrate. A degree of hydrolysis between 64.7 % and 100 % has been determined in different tannic acid samples. The specific growth rate of 0.712 h−1, 0.792 h−1, 0.477 h−1, 0.536 h−1 for Jalmek®, Faga Lab®, Division Food®, and Riedel de Häen®, respectively, was obtained at the concentration of 80 g L−1 of each of the tannic acids.

Ellagic acid (EA) was quantified by reversed-phase high-performance liquid chromatography (RPHPLC) coupled with photodiode array detection (DAD) in five fine-powdered plants collected from the semiarid region of Mexico. Samples analysed included Jatropha dioica branches (Dragon’s blood), Euphorbia antisyphyllitica branches (Candelilla), Turnera diffusa Willd leaves (Damiana), Flourensia cernua leaves (hojasén) and Punica granatum husk (pomegranate) at two maturity stages (“turning” or intermediate and maturated fruit, considered as positive controls). The results demonstrated high EA concentrations in all tested samples which are novel sources of this natural antioxidant. The method developed for the EA analysis is fast and it showed an excellent linearity range, repeatability, intra-and inter-day precision and accuracy with respect to the methods reported for the EA analysis.

Se evaluaron las condiciones de producción de proteasas fúngicas inducidas con pelo de cerdo usando dos sistemas de cultivo, el proceso de cultivo en estado sólido y el cultivo líquido sumergido. El medio de cultivo fue Czapek-Dox en ambos casos. La cinética fue monitoreada cada 24 horas durante un periodo de incubación de 120 horas. La actividad proteolítica fue evaluada por hidrólisis de azocaseína y la producción de la biomasa fue estimada por el método gravimétrico. Rhizopus oryzae fue el microorganismo capaz de utilizar el pelo de cerdo como única fuente de carbono-nitrógeno, produciendo en cultivo sumergido los mayores títulos de actividad queratinasa. Se determinó el efecto que tiene el pH, el pretratamiento del sustrato y la adición de diferentes niveles de material queratinoso sobre el crecimiento fúngico y la actividad enzimática. Los resultados permitieron obtener títulos de actividad proteolítica de 975 U/L.

In the last years, tannin biodegradation has been the subject of a lot of studies due to its commercial importance and scientific relevance. Tannins are molecules of low biodegradation and represent the main chemical group of natural anti-microbials occurring in the plants. Among the different kinds of tannins, ellagitannins represent the group less studied manly due to their diversity and chemical complexity. The general outline of this work includes information on tannins, their classification and properties, biodegradation, ellagic acid production, and potential applications. In addition, it describes molecular, catalytic, and functional information. Special attention has been focused on the biodegradation of ellagitannins describing the possible role of microbial enzymes in the production of ellagic acid.

In the last years, tannase has been the subject of a lot of studies due to its commercial importance and complexity as catalytic molecule. Tannases are capable of hydrolyzing complex tannins, which represent the main chemical group of natural anti-microbials occurring in the plants. The general outline of this work includes information of the substrates, the enzyme, and the applications. This review considers in its introduction the concepts and history of tannase and explores scientific and technological aspects. The "advances" trace the route from the general, molecular, catalytic, and functional information obtained under close to optimal conditions for microbial production through purification, description of the enzyme properties, and the commercial applications to the "perspectives" including expression studies, regulation, and potential uses; aspects related to the progress in our understanding of tannin biodegradation are also included.