Indole compounds in fruiting bodies of some edible Basidiomycota species

The contents of nonhallucinogenic indole compounds were determined in methanol extracts from fruiting bodies of four common edible European species of higher fungi representing the most popular taxon Basidiomycota: Agaricus bisporus (J.E. Lange), Cantharellus cibarius Fr., Lactarius deliciosus (L. Fr.) S.F. Gray and Leccinum rufum (Schaef.) Kreisel. Amongst eleven compounds under analysis, 6–7 metabolites, distinct in different species, were identified in the extracts of fruiting bodies. Serotonin and melatonin were the only common compounds to all species. The contents of the analyzed compounds were diverse, ranging from 0.01 to almost 40 mg/100 g d.w. The contents of tryptophan, 5-hydroxytryptophan, tryptamine and melatonin were low (below 1.40 mg/100 g d.w.). Noteworthy, the serotonin contents were very high in all species under study and amounted to 5.21, 29.61, 18.42 and 31.71 mg/100 g d.w., respectively. Moreover, the fruiting bodies of these species contained indoleacetic acid (max. 2.04 mg/100 g d.w.) and tryptophan degradation products: kynureine sulfate (max. 39.20 mg/100 g d.w.) and kynurenic acid (6.21 mg/100 g d.w.).     

Kinetics of extracted bioactive components from mushrooms in artificial digestive juices

This article presents a study on fruiting bodies of Boletus badius, Boletus edulis, Cantharellus cibarius, Lactarius deliciosus, Leccinum scabrum, Suillus bovinus, Suillus luteus, Pleurotus ostreatus, Tricholoma equestre, Armillaria mellea, Agaricus bisporus, and Auricularia polytricha. The amounts of their health-promoting bioelements and physiologically significant indole and phenolic compounds were determined. The significance of edible mushrooms in the human diet and in disease prevention were also established. The high-performance liquid chromatography was used to assess the contents of indole compounds and phenolic acids. The atomic absorption spectroscopy was applied to determine bioelements. In all samples, the content of 5-hydroxy-L-tryptophan was studied. The highest extraction amount of serotonin was found for P. ostreatus species. Phenolic compounds were determined in the conditions described in the present study for the first time. Additionally, protocatechuic, p-hydroxybenzoic, syringic, and gallic acids were determined.     

Bioactive compounds and antioxidant capacities in different edible tissues of citrus fruit of four species

Different edible tissues of citrus fruit, namely juice sacs (JS), segment membrane (SM), and segment (Seg), of four species, were examined for contents of bioactive compounds and total antioxidant capacities (TAC) by ferric reducing antioxidant power (FRAP) assay. Two flavanones (naringin and hesperidin) were identified by HPLC; hesperidin accounted for 18.5–38.5% of the total phenolics in the species Citrus unshiu, Citrus reticulata, and Citrus sinensis, while naringin was only found in Citrus changshanensis and it accounted for 53.7% of the total phenolics in SM of this species. In SM of all selected species, the contents of phenolic compounds and TAC were significantly higher than those in JS and Seg. Highest total phenolics, total flavonoids, naringin, and TAC were found in SM of C. changshanensis, while the highest carotenoid content was found in JS of C. reticulata. The contribution of vitamin C to TAC ranged from 26.9% to 45.9% in JS and Seg of all selected species. In SM, however, a high contribution from hesperidin was observed in C. unshiu (54.0%), C. sinensis (46.7%) and C. reticulata (30.0%). The results indicated that SM of citrus fruit were high in contents of bioactive compounds and TAC; it is thus recommended to consume citrus fruit with all edible tissues rather than juice or JS alone.     

Anti-inflammatory activity of methanolic extracts from edible mushrooms in LPS activated RAW 264.7 macrophages

Nowadays there is a great interest in the use of edible mushrooms as functional food since they are rich in bioactive compounds. Although their immunomostimulant activity has been largely demonstrated, their potential anti-inflammatory activity has been scarcely explored. We have investigated the anti-inflammatory activity of methanolic extracts from different edible mushrooms species: Agaricus bisporus, Boletus edulis, Cantherellus cibarius, Cratarellus cornucopioides, Lactarius deliciosus and Pleurotus ostreatus, in activated macrophages. The species that exhibited higher anti-inflammatory activities were A. bisporus, C. cibarius and L. deliciosus, inducing inhibition of NO production and iNOS, IL-1β and IL6 mRNAs expression in response to LPS stimulation. C. cornucopioides only induced inhibition of NO production and iNOS expression, and the other species did not present anti-inflammatory effects. Therefore, some edible mushrooms species have a potential anti-inflammatory capacity in vitro, suggesting that they could be regarded as a potential source of natural anti-inflammatory agents.     

Trace element contents in European species of wild growing edible mushrooms: A review for the period 2000–2009

The review follows a previous report (Kala? & Svoboda, 2000), focused on cadmium, mercury and lead. Numerous papers on the topic, published during the last decade, rendered a lot of new information on 15 reviewed metals and metalloids and limited information on a further 14 elements and lanthanides. Usual reported contents for most of species grown in unpolluted sites are 20–150 (Al), 0.5–5 (As), 2–4 (Ba), 1–5 (Cd), <0.5 (Co), 0.5–5 (Cr), 20–100 (Cu), 50–300 (Fe), <0.5–5 (Hg), 10–60 (Mn), traces-15 (Ni), <5 (Pb), <2 (Se), <0.1 (Sb) and 25–200 (Zn) mg kg⁻¹ dry matter. These values can be considerably, even by order of magnitude, increased in mushrooms picked in polluted areas. Moreover, some species have accumulating and even hyperaccumulating ability for various elements. The possibility to evaluate toxicological risk or nutritional asset has been thus limited.     

Antimicrobial activity and bioactive compounds of Portuguese wild edible mushrooms methanolic extracts

The antimicrobial properties of phenolic extracts of Portuguese wild edible mushroom species (Lactarius deliciosus, Sarcodon imbricatus and Tricholoma portentosum) against pathogens were investigated. The minimal inhibitory concentrations (MICs) were evaluated for the entire mushroom, the cap and the stipe, separately; the portion of the mushroom used proved to be influenced in the results obtained, which are directly correlated with the content of total phenols and flavonoids in the extracts. The growth of Gram-positive bacteria (Bacillus cereus, B. subtilis,) was well inhibited by these mushrooms, while Escherichia coli (Gram-negative bacteria) was resistant. The study on the antifungal effect of these mushrooms revealed that Candida albicans and Cryptococcus neoformans were differently inhibited for the mushrooms used.     

食用仙人掌功能性成分研究进展

对食用仙人掌中的功能性成分的研究进展进行了全面的综合，并对其开发应用现状及前景进行了分析和展望。     

多组学技术在食用菌采后保鲜的应用进展

食用菌采后保鲜技术的研究及应用对提升食用菌全产业链的竞争力有着不可或缺的作用。近年来,随着生鲜菌菇消费量大幅增长,消费者对菌菇品质也愈发关注。因此,提高对生鲜菌菇品质劣变机制的科学认知和开发精准高效的智能保鲜技术将对促进食用菌物流贮运和鲜食消费具有重要意义。当前,多种组学技术可以从不同层面、多尺度、深维度解析子实体组织、细胞结构、细胞器、胞内胞外生物大分子及代谢物的时空变化特征,涉及食用菌采后劣变及衰老过程的基因表达、蛋白变化、代谢调控和微生物侵染等诸多方面,为深入探求食用菌采后劣变机制提供了新方法、新途径和新视角。本文重点阐述了近年来多种组学技术(转录组学、蛋白质组学、代谢组学和微生物组学)在食用菌采后保鲜方面的应用进展,对应用效果进行了分析总结,并对相关研究趋势进行展望,以期为食用菌采后保鲜研究提供参考,并为探索新型、绿色、高效的、低成本的食用菌保鲜方法打开新思路。     

A rapid HPLC post-column reaction analysis for the quantification of ergothioneine in edible mushrooms and in animals fed a diet supplemented with extracts from the processing waste of cultivated mushrooms

For establishing an efficient and sensitive method for the quantitative determination of 2-thiol-l-histidine-betaine (ergothioneine, ERG) in edible mushrooms and the blood and muscles of animals, a technique using reversed-phase separation and post-column reaction between 2′-dipyridyl disulphide and ERG was developed. A corresponding derivative 2-thiopyridone, detected at 343 nm, was used for estimating ERG concentration. The flow rate, temperature, pH, and composition of the solution were optimised. A low limit of quantification (1.41 ppm) and a simpler sample preparation made this technique more rapid compared to other methods using liquid chromatography–mass spectrometry. The coefficient of variation (CV) values for the reproducibility and recovery of ERG were within the acceptable values of 6% and 97.5–100.0%, respectively. The efficiency of this methodology was compared with that of spectrophotometric and mass-spectrometric quantitative methods, and was assessed in the light of previous studies. The ERG contents in different mushrooms were 12.69–234.85 mg/kg wet weight basis. Dietary supplementation with extracts from mushroom processing waste significantly improved ERG bioavailability in the blood of yellowtail fish and muscle tissue of cattle.     

热喷膨化食用骨粉加工工艺的研究

对热喷膨化食用骨粉加工工艺进行了研究,确定骨粉热喷膨化的最佳工艺参数为:热喷膨化前物料的水分含量为25%、热喷膨化时的压力为0.7MPa、保温时间为7min。     

Analysis of volatile compounds in edible oils using simultaneous distillation-solvent extraction and direct coupling of liquid chromatography with gas chromatography

 Identification of volatile compounds in different edible oils (i.e. olive oil, almond oil, hazelnut oil, peanut oil and walnut oil) was performed using simultaneous distillation-solvent extraction followed by gas chromatographic-mass spectrometric analysis. An alternative approach which allows the direct injection of the oil sample (i.e. without any kind of pre-treatment) and involves the use of on-line coupled reversed phase liquid chromatography-gas chromatography (RPLC-GC) was also considered and the advantages of avoiding off-line preseparation for the analysis of volatile compounds were underlined regarding difficulties associated with the lipophilic nature of most volatile compounds and, hence, with the reliability of their analysis. Received: 14 June 1999 / Revised version: 3 August 1999     

外源物质在食品加工过程中的变化与安全性

许多农药、兽药、毒素、食品添加剂、重金属、环境污染物等外源物质不但本身有一定毒性, 污染食品后对人体造成危害, 而且在食品加工过程中也会发生变化而导致食品的二次污染, 可能分解为毒性更强的物质, 或与食品内源组分发生反应产生新的有害物质, 或与其他物质之间存在毒性协同增强作用等。实际上, 大量的外源物质在食品加工过程中的变化与安全性问题尚未研究。本文对该领域的研究进展进行了综述, 期望引起相关研究者的重视。     

Volatile compounds from the fruiting bodies of three Hygrophorus mushroom species from Northern Greece

The volatile composition of the wild edible mushroom species Hygrophorus chrysodon , Hygrophorus eburneus and Hygrophorus russocoriaceus was analysed by headspace-solid phase microextraction combined with gas chromatography–mass spectrometry. Forty-five volatile compounds were detected, including alcohols, aldehydes, ketones, hydrocarbons, esters and terpenes. The most abundant compounds in the three species were 3-methyl butanal, hexanal, p -cymene, 3-octanone, 1-octen-3-one, 3-octanol, 1-octen-3-ol and benzoic acid methyl ester. The concentration of eight-carbon (C₈) compounds relative to the total volatiles varied widely ranging from 24.14% to 61.41% among the three species. Finally, the presence of sesquiterpenes only in Hygrophorus russocoriaceus , confirms the characteristic distinctive cedar odour of this species.     

Contents of cadmium,mercury and lead in edible mushrooms growing in a historical silver-mining area

Three harmful metals were determined using AAS techniques in 285 samples of fruiting bodies of 15 wild-growing edible mushroom species. The mushrooms were collected from a forest on the fringe of a historical area of silver mining. The metals were also determined in a topsoil organic layer sampled from nine sites within the observed area. As compared to background levels from unpolluted sites from several European countries, cadmium contents were considerably elevated in nearly all the tested species; lead contents were increased in most of the species, while mercury contents were elevated only in certain species. Thus, many species from the observed area may contribute considerably to the body burden of the metals. Agaricus silvaticus accumulated cadmium extremely and Lepista nuda accumulated mercury. There were no obvious simple positive relationships between the contents of the observed metals in fruiting bodies and the contents of total metals in the soil organic layer.     

Heat stability of agaritine in water extracts from Agaricus blazei and other edible fungi,and removal of agaritine by ethanol fractionation

An analytical system to quantify agaritine present in Agaricus blazei,Agaricus bisporus, and other food mushrooms was established using high pressure liquid chromatography combined with mass-spectroscopy (HPLC–MS). Water extracts from dried, homogenised mushrooms were kept at differing temperatures for defined periods to investigate the heat-stability of agaritine. Homogenates were then freeze-dried, and agaritine was extracted using methanol. After evaporation of methanol, agaritine levels were analysed by HPLC–MS. A. bisporus contained 341 ± 32 μg/g agaritine, and A. blazei contained 22–57 μg/g agaritine. While pure agaritine in H₂O solution was heat-unstable and decomposed exponentially at 120 °C, agaritine in Agaricus water extracts was partially heat stable, and 20–50% of agaritine remained after 120 min at 120 °C. Thus agaritine, a known carcinogen, is likely to be present in Agaricus extracts sold as nutritional supplements. Therefore, a method was developed that can be used to remove agaritine from water extracts in order to prevent health risk. Agaritine was successfully removed from Agaricus water extracts by ethanol fractionation.     

Effect of thermal and non-thermal processing on antioxidant potential of cowpea seeds

Legumes are a good source of bioactive components, besides being nutrient dense. These components have antioxidant properties and have a protective role against free radicals. Legumes like cowpeas are usually consumed after certain processing, so the present study was intended to assess antioxidant property of selected four cultivars of cowpea after going through various thermal (autoclaving, microwave, boiling, and roasting) and non-thermal (soaking and fermentation) processings. Thermal processing reduced total phenolic content (TPC), total flavonoid content (TFC), and ferric reducing antioxidant power (FRAP) in all cultivars with respect to antioxidant activity of raw cultivars, while DPPH scavenging activity increased after all thermal treatments excluding few thermal processings. Non-thermal processing revealed increase in TPC, DPPH scavenging activity, and FRAP values, while TFC content showed a decreasing trend. A moderately high correlation between TPC and DPPH scavenging activity was observed in both kinds of thermal treatments indicating the role of phenolic compounds for antioxidant activity. It was concluded from the study that fermentation processing has promising effects on retention and enhancement of antioxidant activity of cowpea cultivars.     

Identification of phenolic compounds in edible aroids

The objective of these experiments was to study the phenolic compounds present in the cormels of the edible aroids, Colocasia spp and Xanthosoma spp. This investigation shows the existence of a range of phenolic compounds which includes gallic acid, chlorogenic acid, ( + )-catechin, ( ? )-epicatechin and ( ? )-epigallocatechin and the possible presence of proanthocyanidins and jlavonols. Aqueous acetone extracts were examined by thin layer chromatography and high performance liquid chromatography for their phenolic constituents.     

Enhanced functional properties of tannic acid after thermal hydrolysis

Thermal hydrolysis processing of fresh tannic acid was carried out in a closed reactor at four different temperatures (65, 100, 150 and 200 °C). Pressures reached in the system were 1.3 and 4.8 MPa at 150 and 200 °C, respectively. Hydrolysis products (gallic acid and pyrogallol) were separated and quantified by HPLC. Gallic acid and pyrogallol production was increased (p ? 0.05) when heated to 150 °C. Pyrogallol production reached (p ? 0.05) up to 4.6 mg/ml at 200 °C. Antioxidant activity of processed tannic acid at different temperatures was measured by the Rancimat® method using soybean oil. Processed tannic acid at 200 °C showed a ∼3-fold increase (p ? 0.05) in induction time from ∼7 h for the control. Pyrogallol had higher (p ? 0.05) antioxidant capacity than gallic acid, thus pyrogallol was proven to be one of the major compounds responsible for enhanced antioxidant capacity in processed tannic acid. However, the induction point of processed tannic acid at 200 °C was higher than that of synthetic pyrogallol at higher concentration. This shows that pyrogallol alone is not responsible for the antioxidant capacity of processed tannic acid. A disc diffusion assay showed that tested Gram positive pathogenic strains (Listeria monocytogenes and Staphylococcus aureus) were more (p ? 0.05) sensitive (40–51 mm) to processed tannic acid than Gram negative pathogens (22.8–26.8 mm). Regardless of bacterial species, pyrogallol also showed higher antimicrobial activity than gallic acid. Simple thermal processing of hydrolyzable tannic acid could be used to produce gallic acid and pyrogallol with enhanced antioxidant and antimicrobial capacity.     

Rapid screening of volatile compounds in edible plants by direct chromatographic analysis

A method based on the use of the on-line coupling of two programmed temperature vaporizers (PTVs) is proposed to perform the concentration step required prior to the gas chromatographic determination of volatile compounds in edible plants. The reported procedure does not demand a previous sample handling stage whilst allowing the rapid and reliable screening of plant materials to be performed. The matrix to be analysed is directly introduced into the PTV of a gas chromatograph, thus avoiding the risk of losses and contamination typically observed when external concentration techniques are applied. The analytes in the vapour phase are swept from the matrix and then retained onto a suitable adsorbent material placed inside the second PTV injector. The described set-up allows the simple and rapid performance of the experimental work as the overall analysis of naturally occurring compounds with potential application as food ingredients can be performed in less than 1 h.