The smell and odorous components of dried shiitake mushroom, Lentinula edodes III: substances that increase the odorous compound content

This study formed part of an effort to improve the quality of dried shiitake mushroom [Lentinula edodes (Berk.) Pegler], in accordance with consumer preferences, and deals with the search for substances that increase the odorous component content. From analysis of sulfur and sulfur-containing substances in the culture substrate, rice bran was found to be the main source of sulfur, and 75% of this was present as cysteine and methionine. The sulfur-containing substances were added to a sawdust medium containing only rice bran and sawdust as a substrate; shiitake mushrooms were cultivated in the medium, the fruiting bodies were dried, and the 1,2,4-trithiolane content in the fruiting bodies was measured as an indicator of the odorous compounds. Of the sulfur-containing substances, those that increased odorous compounds the most were cysteine and methionine. The efficiency of cysteine in this regard was higher than that of methionine. It was also noted that the amount of glutamic acid increased the odorous compounds in combination with cysteine and methionine. Furthermore, the addition of both amino acids and glutamic acid had no negative effect on the yield. These results showed that it is possible to produce dried shiitake mushrooms with a smell suitable for particular consumer preferences.     

The smell and odorous components of dried shiitake mushroom, Lentinula edodes V: changes in lenthionine and lentinic acid contents during the drying process

This study on dried shiitake mushroom [Lentinula edodes (Berk.) Pegler] focuses on the behavior of the aromatic lenthionine compound and its precursor, lentinic acid, during the drying process. Only a small amount of lenthionine was present after the drying process, regardless of the drying temperature or time; however, the amount increased during the rehydration process using pH 8.0 buffer. The lenthionine content after incubation in the buffer was correlated with the lentinic acid content in the dried shiitake mushroom. The lentinic acid content increased signifi cantly during the drying process at 40°C up to 4 h. The results show that the characteristic smell of dried shiitake mushroom was weak after drying, and that rehydration in a mild alkaline solution was necessary to increase the smell. The lentinic acid content of dried shiitake could serve as an indicator of the smell produced by rehydration and would be useful in screening to select odor-rich strains. Moderate heating likely caused the increase in lentinic acid content, which might be related to a reaction to heat.     

The smell and odorous components of dried shiitake mushroom, Lentinula edodes II: sensory evaluation by ordinary people

This study is part of an effort to improve the quality of dried shiitake mushrooms [Lentinula edodes (Berk.) Pegler], in accordance with consumer preference, and deals with a preference survey using questionnaires combined with sensory evaluation. The smell was evaluated using powdered dried shiitake mushrooms. Age, original preference (OP), sex, sensory intensity (SI), hedonic preference (HP), and sample amount were set as parameters. About 70% of panelists liked dried shiitake mushrooms. There were significant correlations among age, OP, and SI. There was also a significant correlation between OP and HP, but no significant correlation between SI and HP. However, when the panelists were classified by OP, there was an optimal value between SI and HP for likers and neutralists. The calculated optimal concentration of dried shiitake mushrooms for likers and neutralists ranged widely. On the other hand, there was a significant negative correlation between SI and HP for dislikers, and their HP decreased according to the increase in the amount of the substance. The results showed that different concentrations of odorous components in dried shiitake mushrooms were needed to satisfy different consumer preferences.     

The smell and odorous components of dried shiitake mushroom, <Emphasis Type="Italic">Lentinula edodes</Emphasis> I: relationship between sensory evaluations and amounts of odorous components

The smell of food is one of the most important factors in assessing its quality. Concerning the smell of dried shiitake mushrooms [Lentinula edodes (Berk.) Pegler], 1,2,3,5,6-pentathiepane, commonly known as lenthionine, has been reported as a key compound. However, other compounds have not been studied sufficiently in connection with smell. From the results of sensory intensity studies and sensory evaluations of dried shiitake mushrooms, a positive significant correlation at 1% risk was observed between sensory intensity and sulfur perception. This showed that the smell of dried shiitake mushrooms was characterized by a sulfurous smell. Also, comparing the sensory intensity with the amounts of volatile components showed positive significant correlations at 1% risk between sensory intensity and three compounds: 1,2,4-trithiolane, 1,2,4,6-tetrathiepane, and lenthionine. Furthermore, significant correlations at 5% risk were obtained between the amounts of these three compounds and sensory intensity by multiple regression analysis. This showed that the smell of dried shiitake mushrooms depended on these compounds. The partial regression coefficient of 1,2,4-trithiolane was larger than those of the others, and so it was proposed that 1,2,4-trithiolane could serve as an indicator to estimate the smell of dried shiitake mushroom.     

Effect of increased harvests on saccharification ratio of waste mushroom medium from the cultivation of shiitake mushroom (Lentinula edodes)

Waste mushroom medium (WM) was saccharized with cellulase to obtain glucose after shiitake fruiting bodies were harvested 3 and 5 times (WM-3 and WM-5, respectively). Glucose can be used as a feedstock for the production of bioethanol or other bioproducts. WM-3 and WM-5 were analyzed for the amounts of shiitake fruiting bodies harvested and chemical components. The fresh weight ratio of shiitake fruiting bodies from the 4th and 5th harvests relative to the total fresh weight of shiitake fruiting bodies until the 5th harvest was 4.1 %. The additional 2 harvests decreased WM dry weight to 78.0 % and slightly decreased acid-insoluble lignin and xylan contents from 11.9 and 12.0 % to 10.0 and 9.6 %, respectively. The additional 2 harvests did not decrease glucan content. WM-5 included 31.6 % of glucan relative to dry weight, and 54.5 % of the glucan was saccharized to glucose with Meicelase (5 FPU/g substrate) at 40 °C for 48 h without pretreatment. The saccharification ratio of WM-3 was 45.0 % under the same saccharification condition. The amounts of saccharized glucose in WM-3 and WM-5 were 155.1 ± 9.8 mg/g substrate and 191.3 ± 9.2 mg/g substrate, respectively.     

白灵菇菌丝体与子实体有效成分分析比较

采用原子吸收、紫外扫描以及氨基酸分析等方法对白灵菇菌丝体和子实体的营养成分进行测定分析。结果表明：白灵菇菌丝体和子实体可溶性物质、可溶性蛋白、总糖、还原糖、氨基态氮含量相近;菌丝体与子实体紫外扫描峰形基本相似;氨基酸的组成一致,并且都含有人体必需的8种氨基酸,且菌丝体中的氨基酸含量明显高于子实体。     

Effect of drying method as a pretreatment on CUAZ preservative impregnation in Japanese cedar logs

Green Japanese cedar logs 2 m in length and 18 cm in diameter were dried to a mean moisture content of less than 30% by either air drying or kiln drying. Dried logs were impregnated with copper azole (CUAZ) solution according to Japanese Industrial Standard (JIS) A9002. Preservative absorption was calculated from the log weight before and after preservative impregnation. Impregnated logs were then dried in the air and cut at the center to determine preservative penetration. The penetration area was determined after visualizing the preservative with chrome azurol S. The visualized area indicated that the preservative solution penetrated into the sapwood portion of almost all the air-dried logs. However, the kiln-dried logs did not show full penetration into the sapwood portion. The visualized area of some kiln-dried sapwood showed a penetration value of less than 80%, which is the minimum requirement set by the Japanese Agricultural Standard (JAS) for sawn timber. Statistical analysis showed that penetration in the air-dried sapwood was significantly better than that in the kiln-dried sapwood. It was concluded that air drying is more favorable than kiln drying as the predrying method for CUAZ impregnation. On the other hand, preservative absorption was not affected by the drying method.     

省沽油种子营养成分分析与评价

省沽油是一种很好的木本油料树种,其种子营养价值较高。为了规模化推广这一森林特色资源,为其开发利用提供理论和技术依据,采用常规方法和GC-MS对其种子营养成分及含量进行了测定,并比较分析了种子、花蕾、嫩梢和嫩叶中营养成分的差异情况。结果表明:种子中营养成分种类多、含量丰富,种源间没有变异,且栽培种子略高于野生种子,所含矿质元素具有K∶Na之值高而Zn∶Cu之值低的特点,18种氨基酸总含量为14.1%,其中人体必需氨基酸为5.1%;花蕾中常规成分的营养价值高于种子、嫩梢和嫩叶;种子油脂含有12种主要脂肪酸,其中的不饱和脂肪酸以油酸(9.8%~14.9%)、亚油酸(24.0%~45.5%)和亚麻酸(4.1%~7.3%)为主,不同种子之间其各种不饱和脂肪酸含量的差异大,2004年栽培种子>2004年野生种子>2003年野生种子。     

The smell and odorous components of dried shiitake mushroom, <Emphasis Type="Italic">Lentinula edodes</Emphasis> IV: survey of trends in consumer preferences and changes in sensory evaluation

This study is part of an effort to improve the quality of dried shiitake mushrooms (Lentinula edodes) in accordance with consumer preference. Results are presented of a trend survey that examined the preferences of consumers using questionnaires combined with sensory evaluation. From the original preference (OP) survey, the distributions of OP divided by age class (AC) were statistically equal to the results obtained in 2000. The medians of OP for teenagers and twenties were “neutral” and “slightly like,” respectively. A firm preference change occurred between teenagers and those in their twenties. It is empirically realized that sensory intensity (SI) scores that were too high or too low led to a low hedonic preference (HP) score. The same tendency was seen for “neutralists” and “likers.” In addition, almost all distributions concerned with HP had no significant difference between 2000 and 2005; for example, that of SI divided by AC. These results showed that the preference for dried shiitake mushroom has been unaffected by the passage of the past 5 years. Dried shiitake mushrooms have been used from ancient times and for many dishes; therefore, the overall preference appears to have remained unchanged.     

Fomes annosus sporocarps - their abundance on decayed logs left in the forest

On logs of Norway spruce, discarded and left lying after thinning because of severe decay by Fomes annosus, numerous sporocarps of F. annosus develop after one to two years. The surface area, position, number, and time of appearance of the fruiting bodies varied between two test areas. Removal of rotted logs is recommended as a prophylactic method of Fomes control in Picea abies stands.     

Evaluation of dried-wood odors: comparison between analytical and sensory data on odors from dried sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) wood

The emissions of volatile organic compounds from air-dried, conventionally dried, and high-temperaturedried sugi wood were compared by gas chromatographymass spectrometry. Terpenes were clearly the main compound group in the air-dried wood samples, whereas acetic acid was only detected in the high-temperature-dried wood samples, indicating that considerable changes occurred in the volatile compound emission profile during hightemperature processing. The most abundant compounds in the air-dried wood and conventionally dried wood were δ-cadinene, α-muurolene, and β-cadinene (sesquiterpenes) for all specimens, and a-pinene and D-limonene (monoterpenes) for conventionally dried wood and air-dried wood. In contrast, acetic acid was detected only in the hightemperature-dried wood. Sensory evaluation of volatile organic compounds was performed by 18 male university students. Volatile compounds of air-dried wood and conventionally dried wood were assessed as being significantly more soothing than those from high-temperature-dried wood. This study was presented in part at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007     

采后处理方式对五倍子品质的影响

对比了蒸汽烫漂(SB)和沸水浸烫(BWB)2种预处理方式对新鲜五倍子的影响,以及经过预处理后分别采用烘箱干燥(OD)、流化床干燥(FBD)、自然干燥(ND)和紫外光辐照(UVI)4种干燥方式所得五倍子产品的品质。对干燥速率及产品指标的分析结果表明:预处理后五倍子含水率和单宁酸含量均有所降低,尤其是蒸汽烫漂后,含水率降为47.68%,与未处理五倍子含水率(55.77%)呈显著性差异;加热处理会使五倍子干燥产品中单宁酸的含量降低而没食子酸的含量增加,自然干燥的五倍子单宁酸质量分数在50.12%~56.84%之间,没食子酸质量分数在0.29%~0.46%之间,而烘箱干燥后五倍子中单宁酸质量分数仅为32.48%~42.43%,没食子酸质量分数高达2.97%~4.39%;不同采后处理方式对产品品质有不同的影响,沸水浸烫或蒸汽烫漂与紫外光辐照相结合可提高五倍子的干燥速率,且对产品单宁酸含量影响较小;烘箱和流化床干燥可将干燥时间降为5 h以内,但所得五倍子产品中单宁酸质量分数显著降低,均在32%~43%之间;沸水浸烫或蒸汽烫漂后自然干燥能保证单宁酸的结构最接近原始状态,但干燥时间高达200 h以上;所以可根据实际的操作条件和后续的应用选择五倍子的采后处理方式。工业化五倍子的采后处理因更注重干燥效率,以蒸汽烫漂预处理辅之以流化床干燥方式为佳。     

西伯利亚杏仁粕营养物质测定与其氨基酸组成评价

为了探究西伯利亚杏仁粕的营养成分及其特点,以西伯利亚杏仁粕为试材,分别采用溶剂法、灼烧法、凯氏定氮法等方法对杏仁粕营养成分的含量与组成进行了测定与分析;采用氨基酸自动分析仪测定了杏仁粕中氨基酸的组成,并应用氨基酸比值系数法,以WHO/FAO氨基酸参考模式为评价标准,对其必需氨基酸的组成进行了评价。测定结果表明:西伯利亚杏仁粕中蛋白质的含量为648.00 mg·g^-1,粗脂肪含量为54.00 mg·g^-1,粗纤维含量为3.20 mg·g^-1,灰分含量为44.00 mg·g^-1。西伯利亚杏仁粕中含有17种氨基酸,氨基酸总含量为65.86%;西伯利亚杏仁粕中8种人体必需氨基酸的总含量为20.59%,其中谷氨酸含量最高,为8.70%,其必需氨基酸与非必需氨基酸的含量比为0.45;其药用氨基酸含量高达41.79%。杏仁粕中还含有丰富的Cu、Zn、Fe、Mn、K、Ca、Mg、P等微量元素和多种维生素,其中维生素E和维生素B2的含量分别为1.39×10-2与0.38×10-3 mg·g^-1。其必需氨基酸的构成比例基本符合食品法典委员会(WHO/FAO)的标准,其氨基酸的比值系数评分(SRC)为76.51。研究结果表明:西伯利亚杏仁粕营养丰富,所含人体必需氨基酸的种类齐全,且配比均衡,是有利于人体氨基酸营养平衡的优质食品原料。     

超声波辅助萃取蟹味菇子实体呈鲜味物质氨基酸的工艺优化

采用超声波辅助萃取法从蟹味菇子实体中提取呈鲜味物质氨基酸,以茚三酮为显色剂,吸光度为衡量指标,进行单因素及正交试验。试验结果表明,最佳提取条件为超声温度50℃,料液比1∶50,超声功率150W,超声时间10min。     

3种氨基酸对火炬松苗期生长的影响

分析1 a 生火炬松（Pinus taeda）幼苗施复合肥前后氨基酸含量变化,筛选出含量变化较大的3种氨基酸,设置3种氨基酸不同浓度组合,采用土壤施肥和叶面喷施,通过方差分析及 Duncan 多重比较检验,筛选出合适火炬松的氨基酸浓度组合和施肥方法。结果表明：（1）施用复合肥前后氨基酸含量变化较大的有9种,其中缬氨酸、组氨酸、天冬酰胺含量较大,且均为水溶性氨基酸;（2）总整体来看,芭田复合肥对苗木的生长促进效果不如氨基酸施肥;（3）采用土壤施肥,缬氨酸0.192 g/L+组氨酸0.163 g/L+天冬酰胺0.309 g/L 对苗高和生物量的促进效果最好;采用叶面喷施,缬氨酸0.256 g/L+组氨酸0.163 g/L+天冬酰胺0.412 g/L 对苗高和生物量的促进效果最好;（4）在5项生长量指标测定中,叶面喷施的指标值大部分高于土壤施肥。综上所述,对火炬松幼苗生长促进效果最优的施肥方式为叶面喷施缬氨酸0.256 g/L+组氨酸0.163 g/L+天冬酰胺0.412 g/L。     

不同日期采摘的不同品种澳洲坚果的氨基酸分析

为深入了解不同时间采收的不同品种澳洲坚果果仁中氨基酸的含量差异性,从而为其有针对性和选择性的采收和加工提供参考依据,对广西壮族自治区内3个主栽品种(桂热1号、OC、695)澳洲坚果果仁中氨基酸的含量与组成进行了测定与分析,比较分析了不同品种间氨基酸的差异性、必需氨基酸和氨基酸总含量的变化情况,并采用模糊识别法和氨基酸比值系数法对其营养价值进行了评价。结果表明:澳洲坚果果仁中含有7种人体必需氨基酸,其中蛋氨酸的含量差异性较大,其必需氨基酸含量和氨基酸总量呈显著正相关关系,限制性必需氨基酸的种类随采摘时间的改变而有所改变,其果仁蛋白与FAO/WHO推荐模式值和全蛋白模式值的贴近度均较高。澳洲坚果果仁中氨基酸的组成合理,各种氨基酸的比例均衡且有较高的营养价值;广西壮族自治区内3个主栽品种中的695品种,虽为搭配品种,但其氨基酸营养价值最高。     

腌制竹笋品质研究

竹笋腌制是我国传统竹产品加工方法之一。近年来,降低含盐量,及变腌干笋为及食、休闲、风味食品,在大中城市和国际市场需求中有上升的趋势,但这类产品货架期寿命、夏季高温导致质量难以控制等系列问题已经成为研究者和商家关注的焦点。就腌制及品质通过正交实验和方差分析,结果表明:新鲜竹笋氨基酸种类和含量丰富,腌制后氨基酸种类及含量均有变化:种类增加、含量减少;含盐量对腌制竹笋中的黄酮、粗纤维和氨基酸含量有很大影响;以总黄酮、粗纤维、氨基酸含量作为产品质量考察指标,竹笋腌制的最优组合为A1B3(含盐量为25％,有笋衣);竹笋腌制过程中的变色可能与氨基酸分子中羟基变性有关;竹笋腌制后氨基酸种类增加与竹笋蛋白质变性及腌制中微生物有关。     

乌饭树果实中氨基酸种类及含量的地理差异分析

性状和遗传资源的地理多样性是野生种质资源利用的基础。为给乌饭树遗传资源的选优和开发利用奠定理论基础,分别于江苏宜兴、湖南浏阳、江西萍乡和赣州峰山4个地区采集成熟的乌饭树果实,对其果实中氨基酸的成分和含量进行了测定与分析。结果表明:4个地区所产乌饭树果实中含有17种氨基酸,所含氨基酸的种类齐全;氨基酸总含量为16.66～32.34 mg/g,极差值为15.68 mg/g,不同地区的果实样本中氨基酸含量的大小顺序为:湖南浏阳>江西萍乡>江苏宜兴>赣州峰山。在4个地区的果实样本中,人体必需氨基酸含量与氨基酸总量的比值以及人体必需氨基酸含量与人体非必需氨基酸含量的比值均未达到1973年FAO/WHO提出的理想蛋白质的标准,但均与之接近;其鲜味谷氨酸含量均最高,鲜味氨基酸∶甜味氨基酸∶苦味氨基酸的含量比接近1∶1∶1,表明果实风味独特;药用氨基酸含量与氨基酸总量的平均比值为0.617,说明其药用氨基酸含量较丰富;呈味类氨基酸含量与氨基酸总量的平均比值为0.95,说明其呈味类氨基酸的含量亦十分丰富;药用氨基酸与呈味氨基酸的含量均存在明显的地理差异性,其在湖南浏阳和江西萍乡地区的含量相近,且均远高于其在江苏宜兴和赣州峰山地区的含量,17种氨基酸中每种氨基酸含量的地理差异情况均与之相同。乌饭树果实中人体必需氨基酸、呈味类氨基酸的含量和氨基酸总量均远远高于苹果、蓝莓和巴旦杏果实,其果实中所含氨基酸的种类比同属植物蓝莓的多。不同产地的乌饭树果实中氨基酸的含量均丰富,并且其氨基酸总量、药用氨基酸、呈味类氨基酸、人体必需氨基酸等不同种类氨基酸含量的高低顺序均为江西萍乡≈湖南浏阳>江苏宜兴>赣州峰山,表明江西萍乡和湖南浏阳均为乌饭树果用遗传资源优选的重点区域。     

Production and investment evaluation of oyster mushroom cultivation on the waste dendromass: a case study on aspen wood in Slovakia

This paper addresses the processes and investment evaluation of utilizing available dendromass in an easy and close-to-nature way under Central European conditions in Slovakia. Wood of the European aspen (Populus tremula L.) that has generally been considered of little economic value was efficiently used as a growth medium for the oyster mushroom (Pleurotus ostreatus (Jacq.) P. Kumm.). The production of the fruiting bodies of this mushroom were evaluated for 5 years under natural forest conditions. The evaluation focused solely on aspen wood, specifically, the most valuable part – the trunk. The investment assessment revealed the high economic value of the fruiting bodies of the oyster mushroom inoculated into aspen wood blocks for the period of five years. In particular, the results of the net present value (NPV?=?347.78 €/m³) as well as the profitability index (PI?=?1.63) and discounted payback period (DPP ≈ 2 years and 8 months) point to the high profitability of such a project under the given conditions. The results could be helpful and inspiring for forest and garden owners when deciding how to utilize low-value waste dendromass, low-quality aspen wood and other tree species in small-scale forest management.     

冬青苦丁茶氨基酸分析

氨基酸对苦丁茶口感、香味以及营养价值均有重要影响．采用岛津LC-4A高效液相色谱仪分析了湖南、海南、广西、广东的商品冬青苦了茶以及广西大新小明山林场种植的冬青苦了茶树老叶的氨基酸组分及其含量．结果表明：苦丁茶游离氨基酸与水解氨基酸种类相同,均为17种;苦了茶游离氨基酸含量低,仅34．24～119．93mg／100g．其中,以组氨酸占绝对优势,占总量的90％左右;苦丁茶水解氨基酸含量较高,达4．38～11．52g／100g,其中以组氨酸稍高,占总量的14％左右;湖南、海南苦丁茶游离氨基酸含量比广东、广西的高,水解氨基酸则是湖南、广西比海南、广东的高;老叶苦丁茶氨基酸比嫩芽叶的低得多。但组分相同,且老叶产量高,收购价格低,老叶仍有较大开发利用前景．