Flavour components and antioxidant properties of several cultivated mushrooms

Three mushrooms, Clitocybe maxima, Pleurotus ferulae and Pleurotus ostreatus grey strain were used to study their flavour components and antioxidant properties. The volatile flavour components found comprised of six eight-membered carbon compounds and two aromatic compounds. The content total of soluble sugars and polyols was 125–270 mg/g. The content of monosodium glutamate-like components was 1.76–8.89 mg/g. The contents of flavour 5′-nucleotides ranged from 1.89 to 7.59 mg/g. Based on the results obtained, three mushrooms possessed highly intense umami taste. Ethanolic extracts were more effective in the inhibition of conjugated diene and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals, whereas hot water extracts were more effective in the scavenging ability of hydroxyl radicals. EC₅₀ values were less than 14 and 30 mg/ml for ethanolic and hot water extracts, respectively, indicating that the three mushrooms were relatively effective as they exhibited antioxidant properties, despite having scavenging abilities for hydroxyl radicals. Phenols were the major antioxidant components and the total contents were 5.10–11.1 mg gallic acid equivalents/g.     

Total phenols,ascorbic acid, β-carotene and lycopene in Portuguese wild edible mushrooms and their antioxidant activities

The antioxidant activities of three Portuguese wild edible mushroom species, Leucopaxillus giganteus, Sarcodon imbricatus, andAgaricus arvensis, were evaluated. Methanolic extracts were screened for their reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity, inhibition of erythrocytes hemolysis and antioxidant activity using the β-carotene linoleate model system. The amounts of ascorbic acid, β-carotene and lycopene found in the mushroom extracts were very low. Otherwise, the high contents of phenolic compounds might account for the good antioxidant properties found in all species. L. giganteus had the highest content of phenols and proved to be the most active, presenting lower EC₅₀ values in all the antioxidant activity assays.     

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.     

酶解制备褐藻胶寡糖及其抗氧化活性研究

从本实验室筛选的琼氏不动杆菌中获得褐藻胶裂解酶,酶解制备褐藻胶寡糖,用氧自由基吸收能力(ORAC)法测定抗氧化活性,并研究提高其抗氧化效果的方法。结果显示,该酶的最适酶解温度30℃,pH7.5。加入初始浓度为0.75%的海藻酸钠反应,2h达到最大降解率,且此时的平均聚合度(DP)为2;此时的抗氧化能力也达到最大值,平均ORAC值为1374.25μmol TE/g。反应体系中加入VC的平均ORAC值有所增加,且随浓度增加先增大后减少,在浓度为0.004g/L时达到最大值。实验表明:褐藻胶裂解酶制备的褐藻胶寡糖具有较强的抗氧化能力,且抗氧化效果与还原糖含量有关。VC保护反应能提高抗氧化能力,且与VC浓度有关。     

Quantification of phenolic contents and antioxidant capacity of Atlantic sea cucumber, Cucumaria frondosa

The antioxidant activity (oxygen radical absorbance capacity, ORAC) and total phenols and flavonoids were determined in extracts from digestive tract, gonads, muscles and respiratory apparatus of sea cucumber, Cucumaria frondosa. Total phenols content varied from 22.5 to 236.0 mg of gallic acid equivalents/100 g dw, and flavonoids from 2.9 to 59.8 mg of rutin equivalents/100 g. ORAC values ranged from 140 to 800 μmol of Trolox equivalents/g dw. Among all extracts, best antioxidant potencies were observed in ethyl acetate extracts from digestive tract, and in acetonitrile-rich fractions obtained from mixed extracts using acetonitrile/TFA (trifluoroacetic acid) acidified water on muscles, gonads and respiratory apparatus. The weakest potencies were observed with water extracts from digestive tract and respiratory apparatus, and with water-rich fractions obtained from mixed extraction of gonads and muscles. A significant correlation was observed between ORAC values and total phenol content in extracts and fractions of gonads and muscles, but ORAC and phenols were not correlated in digestive tract and respiratory apparatus extracts. ORAC values were significantly correlated (p < 0.05) with total flavonoids in all extracts. Successive eluates obtained from solid-phase extraction of water-rich fractions using C₁₈ cartridge showed ORAC values (105–500 μmol of TE/g) reaching up to 2.3 times the potency of their parent fractions. Flavonoids are suggested to be mainly responsible for observed activities. Our results provide a first quantitative evaluation of C. frondosa tissues as useful sources of antioxidants for human consumption.     

蓝靛果多酚冻干粉稳定性及其总抗氧化能力研究

对采自长白山的蓝靛果忍冬冻果经提取、纯化,并制成蓝靛果多酚冻干粉,研究p H、光照、温度、氧化剂H2O2、还原剂Na₂SO3、防腐剂苯甲酸钠和葡萄糖、蔗糖、D-果糖对蓝靛果多酚冻干粉稳定性的影响,并通过总抗氧化能力（Total Antioxidant Capacity,T-AOC）测试,进一步分析了蓝靛果多酚冻干粉在不同条件下的抗氧化活性。结果表明:蓝靛果多酚在p H为2和3、低温避光条件下保存效果较好,蓝靛果多酚耐还原能力比耐氧化能力强,防腐剂苯甲酸钠对蓝靛果多酚稳定性无显著影响（p>0.05）,糖的加入有助于多酚保存率的提高,使其稳定性增强;通过总抗氧化能力（T-AOC）测试发现,在p H为2、3时,蓝靛果多酚的总抗氧化能力明显高于其他受试p H范围（p<0.05）,温度、光照对蓝靛果多酚抗氧化活性的影响存在显著性差异（p<0.05）,添加氧化剂H2O2会降低多酚的抗氧化活性,添加不同质量浓度的糖类对蓝靛果多酚抗氧化活性的影响显著（p<0.05）。      

Increasing the antioxidant power of tea extracts by biotransformation of polyphenols

Green tea (Camellia sinensis) and yerba mate (Ilex paraguariensis) are rich in polyphenolic compounds, which are thought to contribute to the health benefits of tea. The aim of this study was to evaluate the potential antioxidant properties of green tea and yerba mate extracts before and after the enzymatic biotransformation reaction catalysed by the Paecilomyces variotii tannase. The antiradical properties of the tea extracts, as well as the standards of chlorogenic acid and EGCG, were assessed using the ORAC and DPPH assays before and after the tannase biotransformation. The antioxidant power of enzyme-treated green tea and yerba mate increased by 55% and 43%, respectively, compared with that of untreated teas. The antioxidant power of the standards was also highly increased by enzyme treatment. These results provide relevant data about the potential of the tannase application on various polyphenol sources and to increase the antioxidant power of two widely consumed beverages.     

Effect of soaking,boiling, and steaming on total phenolic contentand antioxidant activities of cool season food legumes

The effects of soaking, boiling and steaming processes on the total phenolic components and antioxidant activity in commonly consumed cool season food legumes (CSFL’s), including green pea, yellow pea, chickpea and lentil were investigated. As compared to original unprocessed legumes, all processing steps caused significant (p < 0.05) decreases in total phenolic content (TPC), DPPH free radical scavenging activity (DPPH) in all tested CSFL’s. All soaking and atmospheric boiling treatments caused significant (p < 0.05) decreases in oxygen radical absorbing capacity (ORAC). However, pressure boiling and pressure steaming caused significant (p < 0.05) increases in ORAC values. Steaming treatments resulted in a greater retention of TPC, DPPH, and ORAC values in all tested CSFL’s as compared to boiling treatments. To obtain cooked legumes with similar palatability and firmness, pressure boiling shortened processing time as compared to atmospheric boiling, resulted in insignificant differences in TPC, DPPH for green and yellow pea. However, TPC and DPPH in cooked lentils differed significantly between atmospheric and pressure boiling. As compared to atmospheric processes, pressure processes significantly increased ORAC values in both boiled and steamed CSFL’s. Greater TPC, DPPH and ORAC values were detected in boiling water than that in soaking and steaming water. Boiling also caused more solid loss than steaming. Steam processing exhibited several advantages in retaining the integrity of the legume appearance and texture of the cooked product, shortening process time, and greater retention of antioxidant components and activities.     

Changes of phenolic compounds and antioxidant capacity in cocoa beans processing

A number of studies have shown that the consumption of cocoa and chocolate products has positive health effects on humans. The object of this research was to monitor changes of total and individual phenolics and antioxidant capacity during the cocoa bean manufacturing. The loss of cocoa phenolics and their antioxidant activity vary with the degree of technological process. The process of roasting and cocoa nib alkalisation had the major influence on phenolic compounds as well as on antioxidant capacity. The roasting treatment resulted in 14% loss of the total phenolics content, while alkalisation resulted in 64% loss of total phenolics content. Procyanidins B1 and B2 as well as (?)‐epigallocatechin were the unstable components, while caffeic acid derivate showed the greatest stability in all technological process. Furthermore, PCA showed that phenolic contents, antioxidant capacity and non‐fat cocoa solids parts of the samples were classified in groups according technological conditions.     

Phenolic content and antioxidant capacity of hybrid variety cocoa beans

Cocoa (Theobroma cacao L.) is a major, economically important, international crop and has been associated with several nutritional benefits including high antioxidant capacity. New cocoa hybrids have been developed in Ghana that exhibit resistance to pest damage during storage. The aim of this work was to assess the phenolic content and antioxidant capacity of these new hybrids in comparison to more traditional cocoa varieties. Total extractable phenolics were similar in all the four hybrids tested ranging from 69.9 to 81.6 FAE g⁻¹. These levels were very similar to that extracted from traditional beans (73.8 ± 2.5 FAE g⁻¹). The “phenolic profile” was determined by HPLC. A total of 25 peaks was observed but there were only minor differences in this profile between traditional and hybrid bean extracts. Antioxidant capacity was determined using the FRAP assay and traditional beans were found to possess 12.4 μmol TE g⁻¹. In comparison the hybrid beans had antioxidant capacities ranging from 21.6 to 45.5 μmol TE g⁻¹, and these were significantly higher than in the traditional beans for three out of the four hybrids. Since the phenolic and antioxidant levels and in these hybrid varieties were either similar to, or higher than, that obtained from traditional beans, the introduction of these new varieties would be unlikely to impact detrimentally on these nutritional components of the beans.     

Tocopherols composition of Portuguese wild mushrooms with antioxidant capacity

The antioxidant composition and properties of 18 Portuguese wild mushrooms (Clitocybe alexandri, Cortinarius glaucopus, Fistulina hepatica, Hydnum repandum, Hygrophoropsis aurantiaca, Hypholoma capnoides, Laccaria amethystina, Laccaria laccata, Lactarius aurantiacus, Lactarius salmonicolor, Lepista inversa, Lepista sordida, Mycena rosea, Russula delica, Russula vesca, Suillus collinitus, Suillus mediterraneensis, Tricholoma sulphureum) were evaluated, in order to contribute to the overall characterisation of these products. Their radical-scavenging capacity, reducing power and inhibition of lipid peroxidation measured in liposome solutions was fully studied. Furthermore, the tocopherols composition was determined by HPLC-fluorescence. The analysed mushrooms contain powerful antioxidants such as phenols (0.51–7.90 mg/g) and tocopherols (0.02–8.04 μg/g). β-Tocopherol was the vitamer detected in higher amounts, while δ-tocopherol was not detected in the majority of the samples. All the species proved to have antioxidant activity being more significant for H. aurantiaca (EC₅₀ values lower than 1.35 mg/ml) due to the contribution of antioxidants such as phenols (7.90 mg/g) and tocopherols (0.02–1.94 μg/g). The ongoing research states the nutraceutical potential of all these unique species, making the information available for a better management and conservation of mushrooms and related habitats.     

不同优株花椒甲醇提取物麻味素、总多酚、总黄酮含量测定及抗氧化能力研究

为了从17种不同品种的花椒中筛选出最佳的优良品种,本研究以17种不同丰产优株花椒果皮为原材料,测定了花椒中麻味素、总多酚和总黄酮含量及抗氧化能力,并进行相关性分析。结果表明在17种不同花椒优株椒皮中,花椒果皮中总多酚、总黄酮和麻味素含量最高的样品分别是来自绳池的M37、M1和来自陕县的S1,而M31样品中总黄酮和总多酚含量最低,M4样品中麻味素含量最低。不同花椒果皮提取物均具有很好的还原能力和DPPH自由基清除力,且总多酚和总黄酮均与还原能力和DPPH自由基清除力之间呈现良好的相关性。研究表明,从大田中优选出的17株花椒丰产优株中,花椒果皮的主要活性成分具有显著差异,来自渑池的M37、M1和来自陕县的S1、来自灵宝的L1等丰产优株树可以作为不同花椒良种进行培植。      

Correlation of tocopherol,tocotrienol, γ-oryzanol and total polyphenol content in rice bran with different antioxidant capacity assays

The relationship between antioxidant capacity and levels of various antioxidants in rice bran and brown rice powder was evaluated. Three different varieties of Venezuelan rice, namely, Cimarrón, Zeta 15 and FONAIAP-1, were studied using ferric reducing antioxidant power (FRAP), 2,2′-azinobis-3-ethylbenzotiazoline-6-sulphonic acid (ABTS), and oxygen radical absorbance capacity (ORAC) to measure antioxidant capacity. The results showed that rice varieties contained different levels and combinations of total polyphenols, γ-oryzanol, α- and γ-tocopherols and α-, γ- and δ-tocotrienols. Compared to brown rice powder, rice bran contained most of the antioxidants and had correspondingly higher values of antioxidant capacity. Principal components analysis and multiple regression on the data indicate that FRAP was sensitive to polyphenols and total tocotrienols, while ORAC was sensitive to polyphenols and total tocopherols. ABTS was the least sensitive of all assays tested. Thus, results from antioxidant capacity assays must be interpreted with caution particularly in complex systems and that further study is necessary to define more precisely the nature of the relevant chemical reactions.     

海带多酚的纯化及其抗氧化活性研究

利用XDA-l大孔吸附树脂纯化海带多酚,并通过测定1,1-二联苯基-2-苦肼自由基(DPPH.)、羟自由基(.OH)、超氧阴离子自由基(O-2.)清除率,还原力,亚油酸体系脂质过氧化抑制活性及Fe2+的螯合作用研究其抗氧化活性。结果表明,XDA-l大孔吸附树脂能有效提高海带多酚的纯度。海带多酚对DPPH.、.OH、O-2.都有较强的清除活性,其中对.OH清除活性显著高于茶多酚,DPPH.清除活性与茶多酚相当;其还原力和抑制亚油酸过氧化能力高于茶多酚;其螯合Fe2+能力与抑制亚油酸过氧化能力一致。海带多酚具有较强的抗氧化活性,是一类潜在的海洋生物天然抗氧化剂。     

丁香多酚细胞抗氧化活性的研究

目的：研究丁香多酚对由H2O2引起的人肝细胞RBL氧化损伤的保护作用。方法：采用H2O2诱导建立细胞氧化损伤模型,通过测定细胞存活率、细胞抗氧化酶活性、丙二醛等指标,分析探讨丁香多酚对细胞损伤的保护作用。结果：结果表明,100μmol/L H2O2孵育24h可显著诱导RBL细胞损伤,使细胞存活力下降到24.64%,细胞经不同浓度的丁香多酚（0.1、0.5、2、10mg/L）与H2O2共孵育后,特别是10mg/L丁香多酚可使细胞存活率达到59.18%。丁香多酚可通过提高SOD、CAT、GSH-Px酶活性,降低MDA含量,促进受损的RBL细胞修复。结论：丁香多酚对H2O2诱导氧化损伤的RBL细胞具有显著的保护作用,可作为食源性抗氧化剂。     

Comparison of total antioxidant capacity and phenolic composition of some apple juices with combined HPLC–CUPRAC assay

It was aimed in this study to identify and quantify various constituents (particularly phenolics) of apple juice and to quantitatively compare the total antioxidant capacities of juices obtained from apple varieties grown in Turkey.     

Juice components and antioxidant capacity of citrus varieties cultivated in China

Juices from fifteen citrus varieties (seven mandarins, four sweet oranges, one lemon, one grapefruit, and two pummeloes) of China were investigated mainly on quality parameters, total carotenoid, phenolic compounds (total phenolics, flavanone glycosides (FGs), and phenolic acids), and antioxidant capacity (ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay). Among the fifteen varieties, Bendizao had the highest content of total carotenoid (10.02 mg/L), Satsuma had the highest content of narirutin (288.12 mg/L), Yinzaocheng had the highest content of hesperidin (533.64 mg/L), and Huyou had the highest content of naringin (348.53 mg/L), neohesperidin (265.25 mg/L) and total FGs (746.08 mg/L). As for total phenolic acids, Liubencheng had the highest content (72.61 mg/L). Hybrid 439 achieved the highest AA content (631.25 mg/L), and the highest total phenolics (1555.49 mg/L) and the greatest inhibition of DPPH radical (61.62%). Hamlin had the highest ascorbic acid equivalent antioxidant capacity (AEAC: 899.31 mg/L) determined by FRAP assay. Correlation coefficients of AA, total phenolics (gallic acid equivalent), FRAP (AEAC), DPPH (I%), total FGs and total phenolic acids indicated that AA played a major role for the antioxidant capacity of citrus juices, and phenolics also played an important role, which may be mainly ascribed to FGs, whilst phenolic acids seemed to play a minimal role. Furthermore, Huyou and Hybrid 439 were considered two valuable varieties from the view of antioxidant capacity and nutrition.     

Review: On published data and methods for selenium in mushrooms

Selected data published on selenium in several species of mushrooms are outlined and discussed in light of performance of analytical methods employed. Data was shown to be either dubious or concentrations too high to be credible and valid in some data reported by authors. Examples of methods and specifically the measurement techniques of Se as reported by authors studying mushrooms are outlined. Also examples of valid and incorrect data on Se in a given mushroom species with data by two or more analytical methods are illustrated. Excessive values reported due to selection of improper method of determination of Se in mushrooms relate largely to improper use of flame atomic absorption spectroscopy (AAS) and inductively coupled plasma – atomic emission spectroscopy (ICP-AES). The biased analytical data published gave a false picture on the composition and nutritional value of mushrooms with respect to selenium.     

2020年北京市售食用菌中重金属含量及健康风险分析

目的 检测北京市售食用菌中重金属含量并进行健康风险评测。方法 采用随机采样的方法,选取北京市售常见新鲜食用菌,采用电感耦合等离子体质谱对食用菌中重金属砷、镉、铅、汞含量进行检测;采用靶标危害系数法 (target hazard quotients, THQ),评估人体每日通过食用菌摄入重金属所带来的健康风险。结果 共采集食用菌样品5类42份,重金属砷、镉、铅、汞含量均未超过国标限量要求,其中香菇中各种重金属的含量相对较高,各种重金属在不同种类食用菌中含量差异变化较大;儿童、成人摄入食用菌中重金属的THQ值和总THQ值依次递减。不同年龄人群膳食摄入食用菌中砷、镉、铅、汞的THQ值均＜1。结论 本次采集的北京市售食用菌中砷、镉、铅、汞的含量均未超标,通过膳食途径摄入食用菌中重金属的健康风险较低。