Free and Bound Volatile Chemicals in Mulberry (Morus atropurpurea Roxb.)

Mulberry (Morus atropurpurea Roxb.) is a popular and desirable fruit that is widely cultivated in China. Despite its popularity, the free volatile chemicals and glycosidically bound volatiles (GBVs) of mulberry have been minimally studied. To this end, we have investigated these compounds in 4 mulberry cultivars via solid phase extraction (SPE) and headspace solid phase microextraction with gas chromatography–mass spectrometry (HS‐SPME‐GC‐MS). A total of 55 free volatile chemicals and 57 GBVs were identified and quantified. In 3 of the cultivars (“YFS,” “T10,” and “D10”), the GBVs were found in higher amounts than their free counterparts, corresponding to a ratio of 1.2 to 1.8. The characteristic aromas were determined by their odor activity values (OAVs) and by generating an aroma series (AS). A total of 20 volatile compounds had OAVs ≥ 1.0. In particular, ethyl butanoate, hexanal, (Z)‐3‐hexenal (E)‐2‐hexenal, (E)‐2‐nonenal, and eugenol had relatively high OAVs and were considered to be the key aromas contributing to the mulberry flavor. Consequently, mulberry was characterized by a variety of herbaceous scents having a background of sweet, spicy, fruity, and floral notes. The free volatiles exhibited strong herbaceous notes, whereas the GBVs were responsible for the sweet and spicy qualities of the fruit. Based on our results, 2 cultivars (“YFS” and “D10”) are proposed to be good candidates suitable for the further development of mulberry‐based food products due to their complex and desirable aromas.     

45个桑种质和品种资源叶的营养品质综合评价

为适应桑树多元化开发对食用专用桑品种的需求,本研究采用因子分析法对45个不同桑树种质和品种资源叶的营养品质进行综合评价分析,以期筛选桑叶食用专用品种。结果表明,45个不同桑树种质和品种资源叶的13个营养成分差异明显,部分营养成分之间存在显著相关关系,为桑叶食用专用种质和品种筛选提供理论依据;影响桑叶营养品质的主要指标为有害微量元素因子、有益微量元素因子、重量因子、碳水化合物因子和营养品质辅助因子,这些公因子对桑叶营养品质综合评价的累计方差贡献率达89%;45个桑种质和品种资源叶的营养品质综合评价结果表明排名前3位的品种分别是嘉陵20号、红果1号和白玉王,其中嘉陵20号为高产叶用桑,该品种是这些资源中最佳桑叶食用专用品种的候选。     

Physicochemical properties and antioxidant activities of Korean traditional alcoholic beverage, yakju, enriched with mulberry

Mulberry fruits (Morus alba L.), rich in health beneficial compounds such as polyphenols, flavonoids, and anthocyananis, have traditionally been used as nutritional foodstuffs and fork medicines. In this study, physicochemical properties and antioxidant activities of a traditional Korean alcoholic beverage ``yakju' enriched with mulberry were evaluated. The beverage was enriched with smoothies prepared from Korean mulberry cultivars of Cheongilppong (CP), Suwonppong (SP), and Daesungppong (DP). In comparison to the control, an increase in alcohol content and total acidity and a decrease in sugar level in yakju enriched with mulberry were observed during 15 d of fermentation. The total polyphenol and total flavonoid content increased in the following order: DP yakju > SP yakju > CP yakju > control yakju. In contrast, the anthocyanin content decreased during the fermentation periods. The trans-resveratrol content of mulberry yakju increased during the fermentation and the resveratrol content of DP yakju (0.24 mg/L) was significantly higher than that of SP yakju (0.21 mg/L) and CP yakju (0.14 mg/L) on the 15th day of fermentation (P < 0.05). The antioxidant activities of mulberry yakju, which was assessed using the 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenozothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and reducing power assays, decreased during the 1st day of fermentation and increased into thereafter. The increase in antioxidant activities of mulberry yakju might have been affected primarily by the total flavonoid and total polyphenol content with increasing alcohol concentration, as a good extractor, during the fermentation; however, the antioxidant activities may have also been affected by the total anthocyanin content up to the 1st day of fermentation. PRACTICAL APPLICATION: The physicochemical properties and antioxidant activities of a traditional Korean alcoholic beverage ``yakju' enriched with mulberry were investigated. This analysis is important for the potential applications of mulberry yakju as functional alcoholic drinks.     

The profile in polyphenols and volatile compounds in alcoholic beverages from different cultivars of mulberry

Abstract: Mulberry fruits have different chemical compositions because of cultivar variation. In this study, polyphenol profile and volatile composition of alcoholic beverages produced from different mulberries of Da 10, Hongguo 2 hao, and Hongguo 1 hao were investigated. Statistically significant differences were detected in the chemical composition of the analyzed alcoholic beverage samples. The beverage of Da 10 possessed the highest content of total phenols, total flavonoids, and total anthocyanins, which was determined by spectrophotometry analysis, contrarily Hongguo 1 hao beverage showing the lowest. Phenolic acids and flavonols were analyzed by high performance liquid chromatography analysis. Protocatechuic acid was the main phenolic acid in all analyzed alcoholic beverage samples, and its concentration ranged from 8.20 mg L^?1 (Hongguo 1 hao beverage) to 29.98 mg L^?1 (Da 10 beverage). High level of flavonols was found in both Da 10 and Hongguo 2 hao beverage samples, whereas Hongguo 1 hao beverage sample was characterized with lower level of flavonols. Furthermore, volatile compounds were analyzed by solid phase microextraction‐gas chromatography mass spectrometry analysis. The amount of esters varied widely among the 3 alcoholic beverage samples. The concentration of aliphatic alcohols in Hongguo 2 hao and 1 hao beverage samples was higher than Da 10 sample, whereas Da 10 beverage sample contained more aromatic alcohols than the others. Hongguo 1 beverage sample showed the highest concentration of acetic acid. This study demonstrated that quantitative differences of phenolic compounds and volatile compounds among cultivars were significant, which highly affected the quality of alcoholic beverage from mulberry. Practical Application: Mulberry fruits had different chemical compositions because of cultivar variation. The analyzed Da 10 cultivar of mulberry appeared to be a good raw material for alcoholic beverage‐making because of its high level of total sugar and acidity. This study demonstrated that alcoholic beverages from mulberry contain high amounts of polyphenols. These bioactive compounds may act synergistically to promote health, and reduce risk factors of chronic diseases.     

不同品种桑椹的蜂蜜发酵酒香气成分的GC-MS分析

本实验采用溶剂萃取法提取并浓缩蜂蜜桑椹酒的香气成分,利用气相色谱- 质谱联用法(GC-MS)对不同品种桑椹(混种家桑、无核大十桑椹、红果2 号桑椹和红果1 号桑椹)的蜂蜜发酵酒的香气成分进行了分析研究。结果表明,四个品种桑椹的蜂蜜发酵酒中共鉴定出的香气成分种数为混种家桑酒59 种、大十桑椹酒56 种、红果2 号桑椹酒50 种、红果1 号桑椹酒50 种;四种酒中共有的香气成分为45 种,含量排在前10 位的成分有5 种相同,为四种醇3- 甲基-1- 丁醇、2- 甲基-1- 丙醇、苯乙醇、4- 羟基苯乙醇和一种待定物质,但其相对含量差异较大;四种蜂蜜桑椹酒中各自还含有一些独有的香气成分;这些香气成分共同构成了不同品种桑椹的蜂蜜发酵酒相似和独特的香气与风格。     

不同品种桑葚与桑叶中氨基酸含量差异研究

目的比较不同品种果桑中游离氨基酸总量、必需氨基酸及药用氨基酸含量差异。方法以6个品种果桑(中葚1号、红果3号、831A、四季果桑、大白葚、江米果桑)的桑葚果实和桑叶为检测样品,利用全自动氨基酸分析仪分别测定成熟期桑葚和桑叶中游离氨基酸含量。结果 6个供试品种桑葚和桑叶均含有19种游离氨基酸,桑叶中氨基酸含量明显高于桑葚中氨基酸含量,紫色果实品种的叶片中氨基酸总量高于白色果实品种,紫色果实品种果实中的氨基酸总量又都低于白色果实品种,两者呈相反趋势。结论不同品种桑葚与桑叶中氨基酸存在较大差异。     

Comparison of Polyphenol Profile and Inhibitory Activities Against Oxidation and α‐Glucosidase in Mulberry (Genus Morus) Cultivars from China

Mulberry (genus Morus) is a significant source of polyphenols, which can promote positive effects on human health. China has various mulberry cultivars, however, many Chinese mulberry cultivars have been only minimally studied. To solve this lack of research, 8 mulberry cultivars (Da10, Tang10, Yueshen74, Yuefenshen, Longsang, Ningxia1hao, Taiwanguosang, and Baiyuwang) from 4 regions of China were assessed to determine their polyphenol profiles using HPLC‐MS/MS and then tested for their antioxidant and anti‐α‐glucosidase activities in vitro. A total of 18 nonanthocyanins and 4 anthocyanins were quantified in mulberry cultivars; among these polyphenols, chlorogenic acid, quercetin 3‐O‐rutinoside, and cyanidin 3‐O‐glucoside were confirmed as the major phenolic acid, flavonol derivative, and anthocyanin, respectively. Two types of stilbene compounds, piceid, and piceatannol, were detected for the 1st time in all mulberry cultivars. Moreover, the methanolic extracts of different mulberry cultivars showed disparate antioxidant and α‐glucosidase inhibitory activities, and this discrepancy was mainly attributed to varying the anthocyanin content. Based on our results, Taiwanguosang is proposed to be a good candidate suitable for further process due to its high level of anthocyanins.     

对影响桑椹酒酿造工艺关键因素的优化

以桑椹鲜果为原料,利用现代发酵工艺与传统技术相结合可获得桑椹酒。通过对桑椹酒主发酵的正交试验分析和明胶澄清试验的选择,实现了对影响桑椹酒的酿造工艺关键因素的优化。结果表明:桑椹果汁中添加SO2含量为50 mg/L、初始含糖量为23%和酵母含量为0.02%可以得到最佳发酵结果。在桑椹酒的澄清工艺试验中,添加0.11%的明胶含量可以获得最佳澄清效果,当大于这个浓度时,原酒的色度将会持续降低,腥味将增大,从而影响桑椹果酒的品质。     

不同品种桑椹香气成分的GC-MS分析

采用溶剂萃取结合气相色谱- 质谱联用(GC-MS)的方法,对农用桑椹、大十桑椹、红果2 号桑椹和红果1 号桑椹4 个品种果实的香气成分进行分析。结果表明,分别从4 种桑椹中鉴定出挥发性成分42、51、44、46种,主要包括高级脂肪酸、脂肪酸酯、脂肪醇、芳香醇、脂肪醛、以及脂肪酮等。桑椹中高级脂肪酸的相对含量很高,它们是重要的香气前体物质。己醛、壬醛、己醇、3- 甲基- 丁醇、2,3- 丁二醇、苯乙醇和3- 羟基-2- 丁酮则是桑椹的主体香气成分。此外,每种桑椹还含有一些独特的香气成分。     

Effect of cellulase and Lactobacillus casei on ensiling characteristics,chemical composition,antioxidant activity,and digestibility of mulberry leaf silage

With the lack of feed resources in China, mulberry leaves have been developed as a ruminant forage rich in protein and functional components. To make full use of mulberry leaves, including their nutrients and biological activities, we investigated the effects of cellulase and Lactobacillus casei LC on the nutritive value and antioxidant capacity of mulberry leaf silage. Mulberry leaves from 2 locally prevailing high-yield cultivars were separately subjected to ensiling treatments either with or without addition of Lactobacillus culture, in combination with variable levels of cellulase application. After 60-d ensiling, the resulting silage was sampled and analyzed for fermentation parameters, antioxidant activity, carbohydrates, and protein fractions, as well as in vitro rumen gas production. The results showed that nutrients, including functional components of mulberry leaves, were well preserved during the ensiling process. Compared with the control, the application of cellulase and Lactobacillus casei LC resulted in greater dry matter recovery, higher contents of lactic acid, true protein, and total flavonoid, and increased antioxidant activity and microbial protein production, as well as decreased pH value, lower concentrations of ammonium nitrogen, and lower fiber fractions in the mulberry leaf silage, which varied between the 2 selected mulberry cultivars. These results suggest that mulberry leaf silage could be a quality feed with robust antioxidant capacity, which could be improved by the application of cellulase and Lactobacillus casei LC.     

四川不同品种桑葚品质比较

本研究对四川地区五个不同品种桑葚(红果2号、嘉陵30号、云桑2号、蜀椹1号、无核大十)的基本品质及营养成分进行了比较,通过主成分分析(PCA)和系统聚类分析(CA)进行综合评价.结果表明,四川不同桑葚品种各个品质指标之间大多存在显著性差异(P<0.05),主成分分析得分综合排名为云桑2号>蜀椹1号>无核大十>嘉陵30号...     

桑果醋发酵工艺研究

以桑果、糯米为原料，采用液态发酵法，酿制风味独特、营养丰富的桑果醋。通过对桑果汁压榨、浸提、澄清和酒精发酵、醋酸发酵等工艺的研究，确定桑果汁酶解澄清的最佳方案是：果胶酶添加量为0．035％、淀粉酶0．014%、明胶0．018％、硅溶胶0．018％；确定主要工艺参数为：酒精发酵阶段桑果清汁：糯米糖化醪=2：1，接种量5％，25℃发酵72h，酒精浓度6．0％，醋酸发酵阶段温度为33℃-35℃，接种量6．0％，起始pH6．0，500mL三角瓶装液量100mL，在转速140r／min条件下振荡培养72h左右，得到的成品醋酸度适宜，口感、风味良好。     

葡萄桑葚复合果醋工艺优化和不同发酵时期的风味成分检测

采用葡萄和桑葚为原料,探讨葡萄桑葚经酒精发酵和醋酸发酵酿制复合果醋的最优发酵工艺。以乙醇浓度,发酵温度,pH及醋酸菌接种量进行单因素实验,以产酸量为响应值,通过响应面试验优化葡萄桑葚复合果醋发酵工艺。结果表明:葡萄桑葚复合果醋发酵最优工艺条件为初始乙醇浓度7.4%,pH5.0,接种量9.8%,温度32 ℃,在此条件下,果醋产酸量最大为5.38 g/100 mL。同时运用电子鼻技术对葡萄桑葚复合果醋不同发酵时期即果醋未进行酒精发酵前的果汁时期、醋酸发酵时期和发酵完成时期进行检测,结合主成分分析（PDA）,负荷加载分析（Loading）及线性判别分析（LDA）,确定葡萄桑葚复合果醋的主要风味成分为氮氧化物、硫化物等,且不同发酵时期的气味差异显著（P<0.05）,不同发酵时期的气味浓度大小顺序为:成品果醋>发酵中期>果汁,说明电子鼻能准确区分不同发酵时期葡萄桑葚复合果醋产品。     

桑葚果酒的发酵工艺研究

以桑葚为原料,安琪活性干酵母SY为发酵菌种,采用全汁发酵法酿造桑葚果酒,通过单因素和响应面试验优化,确定了桑葚果酒的最佳发酵工艺条件：起始糖度为204 g/L,活性干酵母接种量为1.4 g/L,不添加偏重亚硫酸钾,起始pH自然,发酵温度为30 ℃,发酵时间8 d,制备得到的桑葚果酒的酒精度可达到9.3%vol,残总糖18.48 g/L,总酸8.12 g/L。该条件下,桑葚果酒酒液澄清透亮,颜色纯正,酒香果香浓郁,酸甜适口,口感醇厚,风味独特,感官评分为88.7分。     

春秋桑叶总黄酮含量分析及提取工艺优化

采用分光光度法测定了不同桑种不同种质春、秋桑叶总黄酮含量。分析的12 份种质中,9 份种质秋季桑叶总黄酮含量高于春季,3 份种质春季总黄酮含量高于秋季。鲁桑、广东桑、瑞穗桑、白桑相比较,白桑叶总黄酮含量最低。在单因素试验基础上,通过正交试验,优化了桑叶总黄酮的提取工艺。最佳提取工艺为乙醇浓度70%、提取温度80℃、料液比1:20、提取时间1h。     

Flavour evaluation of three black mulberry (Morus nigra) cultivars using GC/MS,chemical and sensory data

The flavour characteristics of three black mulberry (Morus nigra) cultivars from the Aegean region of Turkey were investigated using GC/MS and sensory analysis techniques. A total of 18 flavour compounds were identified by GC/MS in the three cultivars. Total sugar content varied between 11.3 and 16.2%, pH between 3.60 and 3.80 and total acidity between 1.51 and 1.79%. The sensory assessment indicated that black mulberry has fruity, sweet, sour, musky and woody flavour notes and fruity, acid, musky, leafy and woody‐fresh aroma characteristics. The evaluation of GC/MS and sensory data revealed that ethyl linolenate was the most effective compound contributing to the unique flavour of black mulberry. © 2002 Society of Chemical Industry     

阿克陶引种栽培的5个果桑品种桑葚氨基酸分析与评价

对新疆阿克陶县玉麦乡引种栽植的5个果桑品种的成熟桑葚的氨基酸含量进行了检测,分析了不同品种间的氨基酸组成、总氨基酸、必需氨基酸、鲜味氨基酸、药用氨基酸及支链氨基酸含量的差异,采用RAA、RC、SRC等氨基酸评价指标进行了营养评价。结果表明:5个果桑品种的成熟桑葚中均含有16种氨基酸,总含量为0.802~1.323 g/100 g,其中谷氨酸含量最高,色氨酸和蛋氨酸含量最低,不同品种之间EAA/TAA差异不显著(P>0.05);8632的总氨基酸、必需氨基酸、鲜味氨基酸、药用氨基酸和支链氨基酸的含量均显著高于其它品种,红果2号次之;与FAO/WHO氨基酸模式谱比较得出,除蛋氨酸+胱氨酸之外,其它必需氨基酸接近或符合FAO/WHO氨基酸模式要求;氨基酸比值系数法评定可知第一限制氨基酸为蛋氨酸+胱氨酸,不同品种的SRC评分依次为红果2号>8632>台果>大10>果选2号,红果2号和8632的SRC分别为84.863和82.859。说明5个果桑品种中8632和红果2号的氨基酸营养价值高,作为新疆地区推广的果桑品种具有明显的优势。     

Changes in Radical-scavenging Activity and Components of Mulberry Fruit During Maturation

ABSTRACT Extracts of mulberry fruits (Morus sp.) were prepared from 8 cultivars harvested at 4 stages of maturity, and their radicalscavenging activity, anthocyanin content, and total phenolic content were measured. The radical‐scavenging activity was evaluated by a spectrophotometric assay using the 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) in a 96‐well microplate. Mulberry fruit extracts exhibited the DPPH‐scavenging activities, ranging from 2.5 to 20.3 μmol‐Trolox equiv/g‐FW. Their activities were variable during maturation, and the highest activity was observed in the fully mature mulberry fruit in all cultivars. Anthocyanin was scarcely present in the immature mulberry fruits; however, its content increased as the fruit matured in all cultivars. On the other hand, all immature mulberry fruits contained non‐anthocyanin phenolic compound. An on‐line high‐performance liquid chromatography (HPLC) method for the detection of DPPH‐scavenging compounds revealed the difference in predominant radical scavengers between the immature and fully mature stages in the Miran 5 cultivar. Four major radical scavengers in the Miran 5 cultivar were assigned to 2 caffeoylquinic acids (chlorogenic acid and its isomer) and 2 anthocyanins (cyanidin 3‐glucoside and cyanidin 3‐rutinoside) in the immature and fully mature stages, respectively, by LC‐ESI‐MS/MS analysis. The change in the content of 4 compounds in mulberry fruits during maturation demonstrated that the most likely contributors to the DPPH‐scavenging activity were caffeoylquinic acids in the immature mulberry and anthocyanins in the mature and fully mature mulberry.     

Physiological optimality,allocation trade‐offs and antioxidant protection linked to better leaf yield performance in drought exposed mulberry

BACKGROUND: Mulberry (Morus spp. L.), usually linked to silkworm rearing, is now considered as a potential forage for livestock feeding and has great potential in world agriculture. Trait‐based investigations for leaf yield stability in mulberry under water stress have not been studied extensively. The present study aims to identify candidate traits conferring leaf yield stability in mulberry under drought. RESULTS: Four popular, indigenous mulberry cultivars (Morus indica L. cvs AR‐12, K‐2, M. Local and V‐1) were investigated. Low leaf temperature (T_l), higher internal/ambient CO₂ ratios (C_i/C_a), greater stomatal conductance to CO₂ (g_s) and stability in photosystem II efficiency were associated with better net photosynthetic rates (P_n) in V‐1, generating maximum leaf yield when compared to other drought‐exposed cultivars. Increased accumulation of foliar α‐tocopherol and ascorbic acid–glutathione pool, associated with higher carotenoids, proline and glycine betaine, facilitated lower lipid peroxidation and better leaf yield in V‐1 under drought. CONCLUSION: Minimal plasticity in photosynthetic gas exchange traits and better quantitative growth characteristics were attributed to leaf yield stability under drought. Lower photoinhibition, stabilized photochemistry, effective osmoregulation and enhanced activity of foliar antioxidants extensively contributed to drought tolerance and higher leaf yield in mulberry. Copyright © 2010 Society of Chemical Industry     

黑桑椹的营养成分和抗氧化作用的研究

本文分析了山西地产黑桑椹的13种微量无素和VC、VE、β-胡萝卜素、黄酮等多种营养成分,并观察了其对大鼠机体脂质过氧化作用和果蝇寿命的影响。用10%桑椹鲜果或原汁饲喂大鼠8w,可显著降低大鼠血浆和肝脏组织中脂质过氧化产物丙二醛(MAD)含量及肝脏中脂褐素含量(p<0.05～0.01),增加超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活性(p<0.05～0.01)。黑桑椹能显著延长果蝇寿命(p<0.05～0.01)。