柑橘汁中糖苷键合态香气物质的研究进展

糖苷键合态香气物质是一类不具有挥发性、以糖苷形式存在的香气前体物质,在酸或酶的作用下可以水解释放出游离态香气。香气是影响柑橘汁品质的重要因素,研究糖苷键合态香气物质对减少加工过程的香气损失、提高柑橘汁香气质量具有重要意义。文章综述了柑橘汁中糖苷键合态香气物质的化学结构、提取和分析方法、香气物质的释放方式和柑橘汁中主要的香气物质及其阈值。      

水解释放刺梨汁键合态香气化合物及糖基组成解析

利用GC-MS分析采用酶解及酸解法水解、Amberlite XAD-2树脂分离的刺梨汁键合态香气物质的挥发性化合物组分,通过相对气味活化值(ROAV)确定刺梨汁键合态风味物质中重要挥发性物质,并采用衍生化法探究刺梨汁键合态香气前体糖基组成。结果表明:刺梨汁键合态风味前体水解释放共检出49种挥发性物质,其中酶解释放31种挥发性物质,以醇类和酸类为主,乙醛、硬脂酸、愈创木酚等含量较高;酸解释放24种挥发性物质,以烯烃类和酮类为主,2,6-二叔基对甲酚、胡薄荷酮等含量较高。经R(OAV值分析,酶解法释放主要挥发性物质较酸解法多,贡献率较大的典型风味物质为3-羟基丁醛、β-桉叶醇、愈创木酚、羟基香茅醛。研究结果表明,刺梨汁键合态香气前体物质的糖基有葡萄糖、鼠李糖和甘露糖。     

树莓汁中键合态香气物质提取方法及糖基组成的研究

本文采用Amberlite XAD-2树脂吸附洗脱分离的方法和甲醇直接提取法对树莓汁中的键合态香气物质进行了分离,对得到的键合态香气物质进行了酶水解释放,采用GC-MS分析方法对水解得到的键合态香气物质进行了分析鉴定,重点比较了这两种方法的提取效果,并对酶水解后的糖基部分进行了分析研究。结果显示,甲醇直接提取法只提取得到4种键合态香气物质,总含量为77.1μg/kg,包括2种苯系物和2种脂肪醇类物质;Amberlite XAD-2树脂吸附洗脱提取法共提取得到20种键合态香气物质,包括11种苯系物,6种醇类物质及3种萜烯类物质,总含量达3042μg/L。两种方法提取得到的键合态香气物质在种类和含量上存在很大的差异,Amberlite XAD-2树脂吸附提取法提取得到的键合态香气物质种类丰富。树莓汁中糖苷键合态香气物质的糖基部分含有甘露糖和葡萄糖两种单糖。     

不同来源的增香酶酶解橙汁(皮)中键合态主要芳香物质的效果分析

通过来源于微生物的 β 葡萄糖苷酶与常规的杏仁酶酶解糖苷键 ,释放出的键合态芳香组分的成分和含量比较表明 :杏仁酶对橙汁的键合态组分的酶解效果好于微生物酶 ,但对橙皮的作用效果相反 ;橙汁 (皮 )中键合态芳香物质成分近似于游离态芳香组分。说明来源于微生物的 β 葡萄糖苷酶是一种来源广泛、价格低廉适合于工业化生产 ,具有自然增香作用的催化剂     

不同来源的增香酶酶解澄汁（皮）中键合态主要芳香物质的效果分析

通过来源于微生物的β-葡萄糖苷酶与常规的杏仁酶酶解糖苷键,释放出的键合态芳香组分的成分和含量比较表明：杏仁酶对橙汁的键合态组分的酶解效果好于微生物酶,但对橙皮的作用效果相反;橙汁（皮）中键合态芳香物质成分近似于游离态芳香组分。说明来源于微生物的β-葡萄苷酶是一种来源广泛、价格低廉适合于工业化生产,具有自然增香作用的催化剂。     

GC-O-MS法分析野生刺梨汁游离态和O-糖苷键合态香气活性物质

采用顶空-固相微萃取法提取刺梨汁中游离态挥发性物质和酶法释放刺梨汁中O-糖苷键合态挥发性物质,结合气相色谱-嗅觉探测-质谱技术,对野生种刺梨汁中游离态和O-糖苷键合态香气活性物质进行分析。结果表明,刺梨汁中游离态和O-糖苷键合态香气活性物质分别有23 种和17 种。构成刺梨汁游离态香气活性物质主要有丁酸乙酯（青草）、正己醇（酒香）、正辛醇（甜香）、异戊酸乙酯（菠萝香）、叶醇（茶香）、苯乙烯（果香）、月桂烯（甜香脂）和芳樟醇（柠檬香）等。而构成刺梨汁O-糖苷键合态香气活性物质有3-羟基己酸乙酯（水果香）、2-庚醇（柠檬香）、3-羟基丁酸乙酯（果香）、叶醇（茶香）、正辛醇（甜香）、苯乙醇（玫瑰香）和2’-羟基-4’,5’-二甲基苯乙酮（花香、甜香）等。叶醇、正辛醇和辛酸为刺梨汁中以游离态和O-糖苷键合态共存的香气活性成分。刺梨中游离态和O-糖苷键合态香气活性物质均以果香/甜香味为主,但O-糖苷键合态香气活性物质的香气总强度较游离态的弱。     

水果及其加工产品中糖苷键合态香气物质的研究进展

香气作为消费者衡量水果及其加工产品品质的关键指标,其优劣可以显著影响消费者对水果及其加工产品的接受程度.香气主要以游离态和键合态2种形式存在于果实中,其中糖苷键合态香气物质因其以糖苷形式存在而不易被人直接感知,糖苷键合态香气物质的研究对于提升、平衡、恢复水果及其加工产品的风味至关重要.该文综述了水果及其加工产品中糖苷键...     

树莓汁中游离态和键合态香气物质的成分分析

采用Amberlite XAD-2树脂吸附洗脱分离的方法,对树莓汁中的游离态和键合态香气物质进行了分离,对提取得到的键合态香气物质进行酸法或酶法(β-D-葡萄糖苷酶)水解释放,并采用气相色谱进行检测分析,以明确树莓汁中游离态和键合态香气物质的种类和含量。结果表明,在树莓汁中共检出23种游离态香气物质,主要为脂肪醇类、酮类和酯类物质,苯甲醛是游离态组分中含量最高的物质;酶法水解后共检出20种键合态香气物质,主要为苯系物和脂肪醇类物质;酸法水解后共检出11种键合态香气成分,主要为萜烯类和脂肪醇类物质。     

β-葡萄糖苷酶对刺梨汁香气物质的影响

以贵州龙里刺梨为研究对象,通过Amberlite XAD-2树脂对刺梨汁中游离态和键合态香气物质进行分离,不同来源β-葡萄糖苷酶酶解刺梨汁,经气质联用(GC-MS)仪分析,比较其酶解效果及差异性。结果表明,木霉β-葡萄糖苷酶酶解刺梨汁释放11种风味物质。杏仁β-葡萄糖苷酶酶解释放26种风味物质,其中叶醇、己醇、茶香酮、异香叶醇、紫罗烯、棕榈酸等20种风味物质均为嗅感物质且含量较高,可作为刺梨汁的增香酶制剂。刺梨汁中共检测出43种游离态风味物质,主要以酚类和酯类为主;通过杏仁β-葡萄糖苷酶酶解后检出33种键合态风味物质,以酮类和醛类为主,8种物质同时存在于游离态和键合态物质中,且在键合态中释放出新的风味物质26种。     

茶叶中键合态香气前驱物的利用

基础研究表明,茶叶中的香气物质绝大部分是以键合态的糖苷类香气前体存在,难以被开发利用。为了有效将对香气贡献极微的前体物质有效转化为可挥发性香气物质,该文采用正交试验优化酸解时间、酸解温度、酸解p H值、提香酶添加量和酶解时间等因素。研究结果表明,对挥发性香气物质总量影响因素从强到弱依次为:酸解时间、酶解时间、酶用量、酸解温度、酸解p H值。获得最多量的茶叶挥发性香气总量的最优参数为:在温度为60℃、p H=3.0条件下酸解0.5 h,随后添加质量分数0.5%的提香酶在45℃中处理0.5 h。对比空白组,处理组的挥发性香气总量提升89%,其中萜烯醇类糖苷物质提升11.1倍。     

Contribution of Free and Glycosidically Bound Volatile Compounds to the Aroma of Muscadine Grape Juice

Free and glycosidically bound volatile compounds were isolated and identified from muscadine grape juice. Most abundant in free and bound form was the muscadine character-impact aroma compound 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol). Other aroma compounds, such as o-aminoacetophenone and 2-phenylethanol were found in free and bound forms. A high level of 2-phenylethanol was intheglycosideformand many bound monoterpenes were identified. p-Vinylguaiacol, a potential off-flavor in muscadine juice was found at a low level in bound form. Enzymatic hydrolysis of glycoside precursors could lead to release of volatile compounds with both potentially positive and deleterious effects on the overall aroma.     

Free and bound volatile compounds in juice and peel of Jincheng oranges

Free and glycosidically bound volatile compounds in juice and peel of Jincheng oranges were investigated. Solid phase microextraction (SPME) was used for extraction of free volatile compounds. Bound volatile compounds in juice were isolated by using Amberlite XAD-2 column adsorption and methanol elution. Subsequently, they were hydrolyzed by almond β-glucosidase. Acid hydrolysis was also applied on the release of the bound fraction in juice. Both free and bound volatile compounds were then determined by GC-MS. A total of 26 and 40 free volatile compounds were identified in juice and peel, respectively. Terpenes followed by aldehydes were the major free volatile compounds both in juice and peel. Eleven and ten aglycons hydrolyzed by enzyme were identified in juice and peel, respectively. Benzenic compounds and hydroxyl esters were the main bound volatile compounds in juice, while C₁₃-norisoprenoid and monoterpenes were the most abundant bound volatile compounds in peel. 3-Oxo-α-ionol (41%) predominated in bound fraction of peel. Five aglycons hydrolyzed by acid were found in juice. p-Vinylguaiacol and eugenol were the two compounds found both after enzymatic and acid hydrolysis. Rhamnose, xylose, and glucose were determined as sugar moieties in juice.     

酶解和酸解处理对杨梅汁键合态香气释放的影响

采用Amberlite XAD-2树脂吸附洗脱分离得到杨梅汁键合态香气物质,在不同的酶解和酸解条件下处理键合态组分,基于固相微萃取-气相色谱-质谱联用(SPME-GC-MS)技术对水解得到的键合态香气物质进行鉴定.结果显示,用果胶酶、β-葡萄糖苷酶2种酶水解,共检出22种键合态物质,包括顺-3-壬烯-1-醇、β-石竹烯...     

加料前后烟草中游离及糖苷结合态香味成分的分析研究

对加料前后烟草中游离及糖苷结合态香味成分进行了分析研究。烟末经乙醚萃取和同时蒸馏萃取(SDE)分离得游离香味成分。糖苷成分用甲醇萃取,采用非离子型大孔树脂(AB8,相当于AmberliteXAD-2)吸附,然后用不同选择性溶剂洗脱和溶剂萃取,使糖苷与可溶性糖、氨基酸、有机酸、游离香味成分分离。糖苷集份在弱酸条件下(pH2.5)SDE水解,同时萃取出精苷结合态香味成分。采用毛细管气相色谱(HRcGC)和气相色谱/质谱联用(GC/MS)技术鉴定了25种游离及糖苷结合态香味成分。对加料前后的烟草样品进行了对比分析,结果发现:在所分析的烟草样品中,糠醇、苯乙醇、茄酮、香叶基丙酮、β-紫罗兰酮等成分,游离态含量高于结合态的含量;苯酚、香草醛、巨豆三烯酮等成分,游离态和结合态的含量相当;糠醛、苯甲醛、苯乙酮、异佛尔酮、氧化异佛尔酮、4-乙烯基愈创木酚、大马酮、二氢大马酮等成分,结合态的含量高于游离态含量。加料前后的烟草样品相比,加料后烟草中游离态香味成分呈减少趋势,但结合态含量呈增加趋势。      

Characterisation of bound volatile compounds of a low flavour kiwifruit species: Actinidia eriantha

Aroma compounds in fruit are known to occur in free and glycosidically bound forms. The bound volatile fraction of a low flavour kiwifruit species, Actinidia eriantha, was studied. The fruit have a bland and grassy flavour. Glycosidic precursors were isolated from juice by adsorption onto an Amberlite XAD-2 column. After enzymatic hydrolysis with Rapidase AR2000, the released aglycones were analysed by GC–MS. Alcohols, terpenoids and phenolics were the most numerously represented compound classes. Alcohols, benzenoids and phenolics showed the highest concentrations. Major compounds were 2-phenylethanol, furfuryl alcohol, (Z)-3-hexen-1-ol, coniferyl alcohol, isoamyl alcohol and linolenic acid. Several of the bound compounds found, including linoleic, linolenic and benzoic acids and coniferyl alcohol, are precursors of odorous volatiles. Many compounds detected as bound volatiles have not been previously reported as free volatiles in A. eriantha. The bound volatile composition of A. eriantha also showed differences with those of other kiwifruit species.     

Chemical composition and antioxidant test of free and glycosidically bound volatile compounds of savory (Satureja montana L. subsp. montana) from Croatia

The evaluation of antioxidant power of glycosidically bound volatile aglycones from savory shows that these compounds possess antioxidative activity comparable to that of the essential oil, but less effective compared to the well-known antioxidant butylated hydroxytoluene (BHT) and alpha-tocopherol. Thus, since the glycosides are able to release their aglycones by enzymatic hydrolysis, they could be considered as possible precursors of antioxidant substances in savory.     

怀枝荔枝中游离态和键合态风味物质的检测分析

以怀枝荔枝为研究对象,采用β- 葡萄糖苷酶水解,结合Amberlite XAD-2 树脂吸附和GC-MS 分析技术研究其游离态和键合态香气组成。结果表明,怀枝荔枝中游离态和键合态香气成分在组成和含量上差异较大。怀枝荔枝中游离态香气成分有41 种,含量较高的有苯甲酸、香叶醇、1,2- 苯二羧酸二异辛酯、苯乙醇、棕榈酸甲酯、富马酸二甲酯、苯甲醇等;键合态香气成分有33 种,含量较高的有苯甲酸、香叶醇、山梨酸、苯乙醇、苯甲醇、邻苯二甲酸二丁酯、金合欢醇、香茅醇等。其中有15 种物质包括1- 十一醇、1- 己醇、2- 庚醇、3- 辛醇、β- 月桂烯、苯甲醛等在游离态组分中并不存在,且荔枝中典型香气成分包括香叶醇、苯甲醇、苯乙醇、香茅醇等在含量上键合态都比游离态多。     

The effect of air-drying on glycosidically bound volatiles from seasonally collected origano (Origanum vulgare ssp. hirtum) from Croatia

The glycosidically bound volatiles were isolated from fresh and airdried origano by exhaustive percolation with ethyl acetate. After the purification of glycosidic fraction, the enzymatic hydrolysis with beta-glucosidase was performed. The obtained aglycones were analysed by GC-MS. Eighteen compounds were identified. The seasonal variations of main aglycone contents from the fresh plant material were: thymoquinone (3.10-6.18 mg/kg), benzyl alcohol (1.33-3.62 mg/kg), 3,5,5-trimethyl-4-(3-hydroxy-1-buthenyl)-2-cyclohexen-1-on (0.51-3.35 mg/kg), 2-phenyl ethanol (0.42-2.98 mg/kg), eugenol (0.93-2.55 mg/kg), thymol (0.70-1.40 mg/kg) and carvacrol (0.88-1.40 mg/kg). The season of collecting influenced the content and composition of the glycosidically bound volatiles of origano. Air-drying effected mostly the yield of these compounds.