Odor Profile of Four Cultivated and Freeze-Dried Edible Mushrooms by Using Sensory Panel, Electronic Nose and GC-MS

Cultivated mushrooms are well-known nutrient inputs for an equilibrated diet. Some species are broadly appreciated due to their medicinal properties. Lately, a number of novel foods and nutraceuticals based on dehydrated and freeze-dried powder obtained from cultivated mushrooms has been reaching the market. The food industry requires fast and reliable tools to prevent fraud. In this, work we have cultivated Agaricus bisporus sp. bisporus (AB) (white button mushroom), Agaricus bisporus sp. brunnescens (ABP) (portobello), Lentinula edodes (LE) (shiitake) and Grifola frondosa (GF) (maitake) using tailor-made substrates for the different species and standardized cropping conditions, which were individually freeze-dried to obtain the samples under evaluation. The aim of this article was to validate the use of two different methodologies, namely, electronic nose and sensory panel, to discriminate the olfactory profile of nutritional products based on freeze-dried mushrooms from the different cultivated species. Additionally, GC-MS was used to detect and quantify the most abundant volatile organic compounds (VOCs) in the samples. The multivariate analysis performed proved the utility of electronic nose as an analytical tool, which was similar to the classical sensory panel but faster in distinguishing among the different species, with one limitation it being unable to differentiate between the same species. GC-MS analysis showed the chemical volatile formulation of the samples, also showing significant differences between different samples but high similarities between varieties of the same cultivated species. The techniques employed can be used to prevent fraud and have the potential to evaluate further medicinal mushroom species and build solid and trustful connections between these novel food products and potential consumers.Publishe

Holistic assessment of the microbiome dynamics in the substrates used for commercial champignon (Agaricus bisporus) cultivation

Microorganisms strongly influence and are required to generate the selective substrate that provides nutrients and support for fungal growth, and ultimately to induce mushroom fructification under controlled environmental conditions. In this work, the fungal and bacterial microbiota living in the different substrates employed in a commercial crop (compost phase I, II and III, flush 1 and 2, and casing material on day 1, 6 and 8 after compost casing and during flush 1 and 2) have been characterized along the different stages of cultivation by metataxonomic analysis (16S rRNA and ITS2), analysis of phospholipid fatty acid content (PLFAs) and RT-qPCR. Additionally, laccase activity and the content of lignin and complex carbohydrates in compost and casing have been quantified. The bacterial diversity in compost and casing increased throughout the crop cycle boosted by the connection of both substrates. As reflected by the PLFAs, the total living bacterial biomass appears to be negatively correlated with the mycelium of the crop. Agaricus bisporus was the dominant fungal species in colonized substrates, displacing the pre-eminent Ascomycota, accompanied by a sustained increase in laccase activity, which is considered to be a major product of protein synthesis during the mycelial growth of champignon. From phase II onwards, the metabolic machinery of the fungal crop degrades lignin and carbohydrates in compost, while these components are hardly degraded in casing, which reflects the minor role of the casing for nourishing the crop. The techniques employed in this study provide a holistic and detailed characterization of the changing microbial composition in commercial champignon substrates. The knowledge generated will contribute to improve compost formulations (selection of base materials) and accelerate compost production, for instance, through biotechnological interventions in the form of tailored biostimulants and to design environmentally sustainable bio-based casing materialsThe project was funded by the H2020 programme under the Marie Sklodowska-Curie grant agreement no. 742966 and also funded by the ADER project grant no. 2016-IDD-00013. [Correction added on 07 August 2020 after first online publication: Figures 3 and 5 have been corrected in this version

Caracterización de la estructura, dinámica, microbioma y propiedades funcionales de los hongos cultivados en La Rioja

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Física Aplicada. Fecha de Lectura: 26-04-2023Esta tesis tiene embargado el acceso al texto completo hasta el 26-10-2024El objetivo principal de la presente Tesis Doctoral es la caracterización del sustrato a lo largo del ciclo de cultivo de las tres principales setas cultivadas en La Rioja (Agaricus bisporus, Agaricus bisporus var brunnescens y Lentinula edodes) desde el punto de vista de su composición química, enzimática y microbiológica. También se relacionaron esos parámetros con la producción de cuerpos fructíferos que se obtuvieron y sus propiedades beneficiosas para la salud humana. Para ello, se realizó una caracterización inicial de los sustratos de varios ciclos de cultivo de cada hongo cultivado en las instalaciones del Centro Tecnológico de Investigación del Champiñón de La Rioja (CTICH) mediante los análisis de composición centesimal, contenido en fibras, actividad enzimática y eficiencia biológica. Tras esta primera caracterización, se seleccionó un ciclo de cada variedad de las tres estudiadas y se estudió en detalle la composición elemental, dinámica de las comunidades bacterianas y actividades enzimáticas adicionales. Posteriormente, se calculó el rendimiento de cuerpos fructíferos y se investigó su potencial como alimentos antioxidantes y antiinflamatorios por métodos in vitro incluyendo determinación espectrofotométrica, cultivos celulares y cuantificación de compuestos con actividad biológica como los -glucanos. Los resultados obtenidos mostraron la evolución físico-química y los cambios que sufre el sustrato durante los ciclos de cultivo. Además, pusieron de manifiesto el importante rol de las enzimas (proteasas y peroxidasas) en la degradación de las materias primas, y mostraron la variación de la dinámica de las comunidades microbianas. Los estudios revelaron que son necesarios determinados filos y clases bacterianas en los momentos de fructificación y desarrollo de primordios para que el paso de fase vegetativa a reproductiva permita alcanzar una alta tasa de eficiencia biológica. Los datos obtenidos podrán ser utilizados como base para poder desarrollar productos como bioestimulantes o agentes de biocontrol para aumentar los rendimientos del cultivo. Además, los hongos obtenidos de los sustratos evaluados indicaron que las tres especies cultivadas tenían potencial como alimentos antioxidantes y antiinflamatorios, lo que hace de estos alimentos una rica fuente de compuestos bioactivos beneficiosos para la salud. Los datos obtenidos podrán emplearse como base para el desarrollo y comercialización de nuevos complementos alimenticios y nutracéuticosThe main objective of this Doctoral Thesis was the characterization of the cultivation substrate of the three main mushrooms cultivated in La Rioja (Agaricus bisporus, Agaricus bisporus var brunnescens and Lentinula edodes) from the point of view of their chemical, enzymatic and microbiological composition. These parameters were also related to the production of fruiting bodies that were obtained and their beneficial properties for human health. For this, an initial characterization of the substrates of several cultivation cycles of each mushroom cultivated in the facilities of the Technological Centre for Mushroom Research in La Rioja (CTICH) was carried out through the analysis of centesimal composition, fibre content, enzymatic activity and biological efficiency. After this first description, a cycle of each variety of the three studied was selected and the elemental composition, the bacterial dynamics and additional enzymatic activities were studied in detail. Subsequently, the yield of fruiting bodies was calculated and their potential as antioxidant and anti-inflammatory foods was investigated by in vitro methods, including spectrophotometric determination, cell cultures and quantification of biological compounds such as β-glucans. The results obtained showed the physical-chemical evolution and the changes suffered by the substrate during the cultivation cycles. In addition, it revealed the important role of enzymes (proteases and peroxidases) in the degradation of raw materials, and showed the variation in the dynamics of microbial communities. The studies revealed that certain bacterial phyla and classes are necessary at the moments of fruiting and primordia development so that the passage from the vegetative to the reproductive phase allows reaching a high rate of biological efficiency. The data obtained may be used as a basis to develop products such as biostimulants or biocontrol agents to increase crop yields. In addition, the fungi obtained from the evaluated substrates indicated that the three cultivated species have potential as antioxidant and anti-inflammatory foods, which makes these foods a rich source of beneficial bioactive compounds for health. The data obtained may be used as a basis for the development and marketing of new food supplements and nutraceutical

Holistic assessment of the microbiome dynamics in the substrates used for commercial champignon (Agaricus bisporus) cultivation

15 páginas, 6 figuras, 1 tablaMicroorganisms strongly influence and are required to generate the selective substrate that provides nutrients and support for fungal growth, and ultimately to induce mushroom fructification under controlled environmental conditions. In this work, the fungal and bacterial microbiota living in the different substrates employed in a commercial crop (compost phase I, II and III, flush 1 and 2, and casing material on day 1, 6 and 8 after compost casing and during flush 1 and 2) have been characterized along the different stages of cultivation by metataxonomic analysis (16S rRNA and ITS2), analysis of phospholipid fatty acid content (PLFAs) and RT-qPCR. Additionally, laccase activity and the content of lignin and complex carbohydrates in compost and casing have been quantified. The bacterial diversity in compost and casing increased throughout the crop cycle boosted by the connection of both substrates. As reflected by the PLFAs, the total living bacterial biomass appears to be negatively correlated with the mycelium of the crop. Agaricus bisporus was the dominant fungal species in colonized substrates, displacing the pre-eminent Ascomycota, accompanied by a sustained increase in laccase activity, which is considered to be a major product of protein synthesis during the mycelial growth of champignon. From phase II onwards, the metabolic machinery of the fungal crop degrades lignin and carbohydrates in compost, while these components are hardly degraded in casing, which reflects the minor role of the casing for nourishing the crop. The techniques employed in this study provide a holistic and detailed characterization of the changing microbial composition in commercial champignon substrates. The knowledge generated will contribute to improve compost formulations (selection of base materials) and accelerate compost production, for instance, through biotechnological interventions in the form of tailored biostimulants and to design environmentally sustainable bio-based casing materialsThe project was funded by the H2020 programme under the MarieSklodowska-Curie grant agreement no. 742966 and also funded bythe ADER project grant no. 2016-IDD-00013Peer reviewe

Influence of Agaricus bisporus establishment and fungicidal treatments on casing soil metataxonomy during mushroom cultivation

The cultivation of edible mushroom is an emerging sector with a potential yet to be discovered. Unlike plants, it is a less developed agriculture where many studies are lacking to optimize the cultivation. In this work we have employed high-throughput techniques by next generation sequencing to screen the microbial structure of casing soil employed in mushroom cultivation (Agaricus bisporus) while sequencing V3-V4 of the 16S rRNA gene for bacteria and the ITS2 region of rRNA for. In addition, the microbiota dynamics and evolution (bacterial and fungal communities) in peat-based casing along the process of incubation of A. bisporus have been studied, while comparing the effect of fungicide treatment (chlorothalonil and metrafenone). Statistically significant changes in populations of bacteria and fungi were observed. Microbial composition differed significantly based on incubation day, changing radically from the original communities in the raw material to a specific microbial composition driven by the A. bisporus mycelium growth. Chlorothalonil treatment seems to delay casing colonization by A. bisporus. Proteobacteria and Bacteroidota appeared as the most dominant bacterial phyla. We observed a great change in the structure of the bacteria populations between day 0 and the following days. Fungi populations changed more gradually, with A. bisporus displacing the rest of the species as the cultivation cycle progresses. A better understanding of the microbial communities in the casing will hopefully allow us to increase the biological efficiency of the crop.This work was co-funded by the FEDER Operational Program La Rioja 2014–2020 (Project CT21_04), the Department of Economic Development and Innovation of La Rioja. Res. n° 1168/2018 and the H2020 Marie Sklodowska-Curie Actions, Grant agreement no. 742966