香菇菌汤及酶解液中滋味成分及呈味特性的对比分析

为对比分析香菇酶解液与香菇菌汤中滋味成分及呈味特性的变化,采用氨基酸自动分析仪和高效液相色谱仪检测香菇酶解液、复水原液及菌汤中的游离氨基酸和5’-核苷酸等呈味物质的含量,利用经典公式计算等鲜浓度（equivalent umami concentration,EUC）值,对其鲜味进行评价,并用电子舌对比分析其滋味轮廓。结果表明,酶解液中的游离氨基酸总量最高,为3 453.98 μg/g。三者呈味氨基酸占总游离氨基酸的比例相近且均含有较多的苦味氨基酸。香菇菌汤中5’-鸟苷酸的含量最高,为967.84 μg/g,而酶解液和复水原液中5’-腺苷酸的含量最高。EUC值结果表明,香菇酶解液EUC值最高,为30.54 g MSG/100 g,说明其呈鲜效果最明显。电子舌主成分分析结果显示,判别指数为94,香菇菌汤、酶解液及复水原液的整体滋味有显著差异。     

食用菌复合香鲜味面包馅料的试制

采用香菇、茶树菇、平菇三种香鲜味突出、来源广的食用菌,应用正交实验研究食用菌复配物的配方及复合香鲜味面包馅料的配方与工艺。实验显示:食用菌复配物综合感官评分最高的配比为香菇粉:茶树菇粉:平菇浆=1:0.5:30(w:w:w)。面包馅料最佳配方与工艺为食用菌复配物:食用油:芋泥=31.5:5.5:20(w:w:w),微波加热熟化增香7min。     

复水温度对香菇复水特性及品质的影响

香菇是中国产量最高和市场消费量最大的食用菌。干制是香菇的主要加工方式,而干香菇需复水后才能作为原料被烹调或进一步加工。本研究将热风干燥的香菇分别在25,45,65℃和85℃下复水,研究香菇复水过程中复水比、外观、质构和风味品质的变化。结果表明,在45℃复水270 min,干香菇吸水后表面的褶皱较为舒展,微观结构显示其菌丝恢复膨胀且伸展。同时,其复水比稳定保持在3.88,剪切力(1 290.28 g)、弹力(0.66 g)和复原力(0.34 g)适中,咀嚼性(656.02 g)最大,说明香菇复水完全且质地柔软适中,易被切开。此外,45℃复水香菇所含特征含硫化合物的含量较高,以1,2,3,5,6-五硫杂环庚烷(67.02%)和1,2,4-三硫环戊烷(39.06%)为主,风味较浓郁。综上,复水温度显著影响香菇复水后的食用品质,将干香菇在45℃复水270 min可获得品质较好的复水香菇。     

臭氧处理对草菇采后外观品质的影响

对草菇进行臭氧气体、臭氧水、护色液(0.1g/kgEDTA-2Na+3.0g/kgVC+5.0g/kg柠檬酸)和护色液+臭氧水和对照处理,15℃下贮藏。发现,臭氧水处理的草菇C*值和a*值小于对照,h0值和L*值大于对照和其他处理草菇的h0值和L*值,失重率显著低于对照的失重率,贮藏寿命比对照延长了2d。可以认为臭氧水处理草菇有护色,抑制褐变和延长保鲜期的效果。     

炒制时间对不同复配比例黑皮鸡枞菌-平菇复合酱风味的影响

以珍稀的黑皮鸡枞菌和常见的平菇为材料,研制一种味道鲜美的复合型菌酱。通过主成分和最小偏二乘判别分析,探究不同复配比例的复合型菌酱在不同炒制时间下的风味变化。结果表明：炒制时间4 min、平菇和黑皮鸡枞菌质量比4∶6复配时,复合酱的鲜味水平最高;炒制时间4～5 min、质量比4∶6复配时,复合酱香味品质最好;谷氨酸和香叶基丙酮等14 种风味化合物导致不同炒制时间下复合酱风味差异显著。本研究为提高该复合型菌酱风味品质提供了一定理论基础,可促进食用菌加工产业的发展。     

GC-IMS评价双螺杆挤压处理对香菇柄挥发性成分的影响

本文以香菇柄为研究对象,采用气相离子色谱技术分析在不同加水量(20%、50%)条件下经双螺杆挤压膨化处理香菇柄的挥发性成分的变化。结果表明,实验共检测并定性了醇、酯、醛、酮、呋喃类、含硫化合物6大类共35种挥发性物质。香菇柄在120℃加20%水的条件下经双螺杆挤压处理后,主要特征风味成分含硫化合物二甲基二硫醚相对百分含量从2.67%增加至3.62%。增加含水量至50%进行双螺挤压,二甲基二硫醚含量进一步增至6.66%;但对于1-辛烯-3-醇影响不显著。利用ROAV及主成分得分分析确定了1-辛烯-3-醇、芳樟醇、正己酸乙酯、丙酸乙酯、正辛醛、3-甲基丁醛、庚醛-M、异丁醛、丁醛、2-正戊基呋喃、二甲基二硫共11种物质为主要香味贡献成分,且感官评价与主成分得分分析显示在120℃加水20%条件下进行双螺杆挤压得分更高,可以增加挥发性风味成分的释放,改善风味。     

Selenium Bioaccumulation in Shiitake Mushrooms: A Nutritional Alternative Source of this Element

Mushrooms have effective mechanisms to absorb and accumulate trace elements from substrates and, therefore could be used as a strategy to produce mineral-enriched food and nutritional supplements. This study aimed to enrich shiitake mushrooms with selenium (Se), an important dietary element in human health. Strains of Lentinula edodes (Berk.) were grown on artificial logs composed of eucalyptus sawdust, and were subjected to cold shock in water containing sodium selenite (Na(2) SeO(3) ) at concentrations of up to 1.28 mM. The content of Se in the mushrooms increased linearly with increasing amounts of Na(2) SeO(3) added to the cold water although above 0.96 mM, mushroom formation was inhibited. Concentrations greater than 17 mg Se 100/g of dried mushrooms were observed after treatment with 0.64 mM Na(2) SeO(3) . Shiitake mushroom had a demonstrate potential to offer an effective and economical way to produce Se-enriched products and, the strategy of adding selenite in cold water, used in this study, showed promising once it does not interfere with mycelial growth. Practical Application: Selenium is an essential trace element for both human and animals and is required for the 21st amino acid, selenocysteine, which is used for the synthesis of about a dozen selenoenzymes. In this study, it is demonstrated that shiitake mushroom is a good Se accumulator and only one step during fructification was necessary to obtained enriched mushroom. Se enriched shiitake mushroom can be considered to be an excellent source of this element and used to consumption in different ways.     

Antioxidant activity and total phenolics of edible mushroom extracts

Methanol and water crude extracts from Shiitake mushroom (Lentinus edodes) and straw mushroom (Volvariella volvacea) were investigated for their antioxidant capacity in three different assays, namely, the β-carotene and linoleic acid system, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibition of hemolysis of rat erythrocyte induced by peroxyl radicals. Among the four mushroom extracts, the water extract from L. edodes showed the most potent radical scavenging activity in each assay, showing 75.9% (at 20 mg/ml) in the β-carotene bleaching method, 55.4% in the DPPH radical scavenging method (at 6 mg/ml) and 94.9% of inhibition of erythrocyte hemolysis (at 5 mg/ml). Total phenolics in the water extracts were higher than that of the methanol ones. Positive correlations were found between total phenolic content in the mushroom extracts and their antioxidant activities. Edible mushrooms may have potential as natural antioxidants.     

蘑菇风味强化及其胶囊化的研究

本文研究了以豆油水解物为风味前体,强化蘑菇风味的最优条件和胶囊化的最佳载体配比。 蘑菇风味的关键化合物1—辛烯—3—醇,经3种不同色谱柱定性以及用柯瓦特保留指数与文献对照,再用GC—MS定性及合理断裂鉴定。用RSA确定了最佳的强化蘑菇风味的条件:添加0.3％(w/w)的豆油水解物,pH6.5,温度26～32℃,保温时间30分钟。在此条件下蘑菇风味可增加4.7倍。本文还比较了蘑菇伞部和根部强化蘑菇风味的效果。用正交实验确定了蘑菇风味胶囊化的最佳载体配比:以蘑菇浆液重量计算:11％(W/W)猪血浆,25％(W/W)糊精和1.3％(W/W)的阿拉伯胶。     

蕈菌挥发性风味物质研究进展

蕈菌中挥发性风味物质的研究在国外已有许多系统和深入的研究,而我国对蕈菌中挥发性风味物质的研究还处在起步阶段。对蕈菌中的风味物质、液体深层发酵过程中蕈菌挥发性风味物质的形成、蕈菌中挥发性风味物质的形成机理进行了综述。     

蘑菇酱加工条件及其风味

以干杏鲍菇和黄豆酱为主要原料,并对干杏鲍菇复水条件进行研究。采用模糊感官评定和响应面实验设计对配方进行优化,研制出风味独特的蘑菇酱,最后运用GC-MS对其最优配方酱进行风味分析。结果表明,蘑菇酱制作的工艺为:酱与蘑菇的比例为2∶1,盐添加质量分数为7.50%,糖添加质量分数6.66%;蘑菇酱中风味物质主要由酮类、醛类、醇类、酯类、酸类、含硫化合物组成,其中蘑菇风味的主要挥发性成分1-辛烯-3-醇的质量分数达11.26%。     

Mycobial enhancement of ergothioneine by submerged cultivation of edible mushroom mycelia and its application as an antioxidative compound

Ergothioneine (2-mercaptohistidine trimethylbetaine, ESH) in mushroom is one of bioactive and functional components. In the present study, a method of producing ESH within a short period and with high productivity was established by applying submerged fermentation of edible Shiitake mushroom (Lentinula edodes) mycelia. High-resolution mass spectrometry and online flow injection analysis of 2,2-diphenyl-1-picrylhydrazyl scavenging activity clearly confirmed that ESH was the most potent antioxidant in the mycelial extract. Among several mushroom mycelia, Shiitake produced the highest amount of ESH (0.60 mg/g dry weight (DW)). Optimisation of the culture medium was performed to achieve higher ESH production. The monosaccharide content in the medium, particularly fructose in combination with aspartic acid, was one of the factors that enhanced ESH production by 3.15-fold (1.89 mg/g DW). Individual supplementation of 2 mM methionine as an amino acid precursor yielded a significantly higher amount of ESH (3.45 mg/g DW) compared to that of the control medium (1.85 mg/g DW). The mycelial extracts containing ESH were effective in retarding the formation of secondary lipid oxidation products in the yellowtail red meat model during chilled storage as well as in the oxidation of linoleate and bleaching of beta-carotene in an oil-in-water emulsion system.     

草菇鲜味肽的分离鉴定及呈味特性分析

通过超滤、凝胶过滤色谱结合电子舌与感官引导对草菇水提物进行初步分离纯化，得到鲜味最佳组分F1，利用反相高效液相色谱结合主成分分析从F1中分离出更接近草菇原始滋味的组分F1-a，进一步采用超高效液相色谱-四极杆飞行时间质谱从F1-a中鉴定出鲜味肽；并将所鉴定的鲜味肽合成后通过感官评价与电子舌分析对其呈味特性进行研究。结果表明：草菇水提物中含有4 种鲜味肽，分别为Asp-Asp-Cys-Pro-Asp-Lys、Leu-Val-Asp-Lys-Pro-Arg、Gln-Ala-Asp-Lys-Arg-Lys、Asp-Thr-Phe-Asn-Asp-Lys，鲜味阈值分别为0.10、0.33、0.42、0.17 mg/mL；草菇中4 种鲜味肽的呈味特性是氨基酸通过肽键形成特定的结构引起，其中鲜味肽Asp-Asp-Cys-Pro-Asp-Lys对味精溶液的增鲜效果最佳，且最佳添加量为20 mg/mL。     

Cultivation of the shiitake mushroom (Lentinus edodes) on lignocellulosic waste

The Shiitake mushroom (Lentinus edodes) was successfully grown and fruited on a substrate containing 7 parts hardwood sawdust and 3 parts oatmeal. Colonised blocks of substrate placed in a fruiting environment produced edible mushrooms in 9–15 days with an average total yield of c. 135% fresh weight mushrooms per unit dry weight of substrate. The mushroom fruited when daily temperatures ranged between 11 and 26°C.     

菌菇速溶茶加工关键技术研究与开发

以红茶和香菇为原料,通过微波程序化升温混料直提、二级切向流微滤-反渗透膜组合浓缩和喷雾干燥制备菌菇速溶茶产品,并对加工过程中的相关各工艺参数进行了研究。所制得的菌菇速溶茶产品呈粉末状,无结块,色泽红棕色,有较显著的菌香;冲泡后,汤色橙红,滋味醇厚伴有浓浓的菌菇味;产品中多糖含量高于15%,多酚含量高于16%,兼具菌菇和红茶的功效和风味,市场前景广阔。     

Production of a β-d-glucan-rich extract from Shiitake mushrooms (Lentinula edodes) by an extraction/microfiltration/reverse osmosis (nanofiltration) process

A pilot-scale process combining extraction of Shiitake mushroom (Lentinula edodes) powder in water (98 °C, 1 h), cross-flow microfiltration and reverse osmosis (nanofiltration) was performed to obtain β-glucan-rich extracts. Suspensions (45–80 L) obtained after 3 extractions were clarified by microfiltration reducing their turbidity to <1 NTU. Membrane flux was completely recovered after filtration. One of the clarified extracts was concentrated (to 6–7 L) by reverse osmosis (Nanomax95) and the other two by nanofiltration (Nanomax50 and ALNF99-2517). Different physicochemical parameters (permeate flux, total soluble substances, total suspended particles and electrical conductivity) were monitored during filtration and the bioactive compounds present in the obtained fractions (β-glucans, total carbohydrates, chitins, eritadenine, lenthionine, ergosterol) were analyzed. The more adequate membrane for Shiitake extract concentration was Nanomax50 because it showed higher filtration flux and higher values of bioactive compounds in the obtained extract than the extracts obtained with the other two membranes.Industrial relevanceThis work describes a pilot-scale procedure for obtaining β-d-glucan-rich extracts from Lentinula edodes (Shiitake mushrooms). The extracts might be used in novel functional foods due to their high content in hypocholesterolemic compounds. The process combines extraction with boiling water, cross-flow membrane clarification and reverse osmosis/nanofiltration concentration of β-d-glucans. The procedure is scalable to industrial level.     

酱香型白酒堆积发酵过程中不同空间位置酒醅差异性比较

为建立堆积发酵评价效果的客观判断标准,了解堆积对基酒风味物质成分的贡献,对酱香型白酒堆积发酵过程中不同空间位置（分别标记为W1～W9）酒醅各项理化指标及风味成分的差异进行研究,并对风味成分含量测定结果进行主成分分析（PCA）及偏最小二乘法判别分析（PLS-DA）。结果表明,酸度、乙醇、淀粉、水分、还原糖含量的最佳建议取样位点分别为W3、W9、W7、W7、W9,乙醇可以作为堆积发酵终点判断的有效检测指标之一。风味物质检测结果表明,各种风味物质成分均在位点W2（酒堆顶部到酒堆中部之间等距离位置）处出现峰值,该位点可以作为评价风味物质生成的最佳取样位点。异丁酸、己酸、棕榈酸乙酯、乳酸乙酯等13种物质成分可以拟定为堆积发酵终点判断的参考指标。     

汉中地区泡菜水品质评价

该研究以29份汉中泡菜水为对象,采用电子舌、电子鼻及高效液相色谱（HPLC）和气相色谱-质谱联用（GC-MS）等方法,对汉中地区泡菜水的品质进行了研究。结果发现,汉中地区泡菜水在酸味和后味A等滋味指标以及芳香类物质、烷烃类物质和硫化物等风味指标上的差异相对较大。通过聚类分析（CA）和主成分分析（PCA）发现,汉中泡菜水按其品质可分为三个聚类,其主要差异是由风味所导致的,且隶属于聚类Ⅲ的泡菜水样本在芳香类物质的含量上显著高于其他聚类（P＜0.05）,后味A的强度显著较低（P＜0.05）,其品质要优于其他泡菜水样本。     

固态发酵的白酒在碱性条件下变色原因的探讨

固态发酵酒是以高级脂肪酸酯为胶核构成的溶胶复杂体系，辅以众多的微量成分，具有固有的浓郁复合香气，而配制酒是由几种简单有限的低碳酸酯醇等形成的乙醇水溶液，体现的是浮香或单一的酯香。固态发酵酒在碱性条件下加热变黄的原因从化学反应的角度推理，可能是酒体中的高级脂肪酸酯或某一种物质与Fe^3＋络合的结果。（孙悟）     

利用电子鼻分析熬制时间对3 种食用菌汤风味的影响

对香菇、双孢蘑菇、牛肝菌3 种食用菌进行熬制,得到不同熬制时间的菌汤。利用电子鼻技术对菌汤分别进行测定,通过主成分分析(PCA)和线性判别分析(LDA)两种分析方法对所得数据进行分析。结果表明：利用PCA 不能很好区分不同熬制时间的菌汤风味,但能区分不同品种菌汤的风味,说明PCA 是分辨不同种类菌汤的有效分析方法;利用LDA 能明显区分不同种类食用菌汤及不同熬制时间的菌汤风味,说明LDA 是分辨不同菌汤风味的有效分析方法。