Recovery and evaluation of aroma development in apple peels

Aroma in Delicious apple peels was generated by conditioning peels at ambient temperature (19–23°c) for 24 h. The conditioned peels were processed, and the developed aroma was recovered in a pilot-scale apparatus. The recovered aroma was evaluated for intensity and quality against standard apple essences derived from whole apples and unconditioned or no-delay peels. The strength or ‘flavouring capacity’ of the concentrated aroma solution was estimated by threshold analysis and by a matching standard procedure at single-strength juice equivalence. The aroma recovered from conditioned peels was 2–7 times stronger than that from similar no-delay peels. Quality of the aroma solution from conditioned peels was statistically (P > 0.05), indistinguishable from standard aroma solutions prepared from whole apples or no-delay peels. Thus, the conditioned peels gave aroma solutions with 2–7 times more ‘flavouring capacity’ than no-delay peels, without significant sacrifice in quality.     

Factors influencing the clarification of apple juice with honey

Six apple cultivars were studied to determine the effect of pH, degree of browning and polyphenol composition on clarification of apple juice by addition of honey. The optimum pH for all apple cultivars was about 3·5. Only browned apple juices, those prepared with no ascorbic acid, flocculated with the honey and consequently clarified. The flocculation time was inversely related to the degree of browning of all apple cultivars except Golden Delicious. The clarification rate did not correlate well with the different phenolic groups present in the juices.     

利用苹果皮核开发苹果醋饮料工艺技术研究

以苹果皮核为主要原料,采用液体深层发酵技术,研究了经酒精发酵、醋酸发酵生产苹果醋饮料的工艺条件;分析比较了苹果皮核汁和正常苹果汁的基本成分;探讨了酵母菌种、醋酸菌种的驯化培养;并对苹果醋饮料的配方通过正交实验和感官评定进行了优化设计。苹果醋饮料产品的质量达到了有关标准的要求。     

苹果酒香气成分研究进展

苹果酒的香气成分是构成苹果酒质量的重要因素,决定着苹果酒的风味和典型性.文中综述了苹果酒中主要的香气成分及其来源,并介绍了国内外苹果酒中香气成分的提取和分析方法.     

Mechanical properties and microstructure of apple peels during storage

The apple peel (i.e., outermost tissue) plays a crucial role in protecting and preserving apple life, as well as in reducing fruit injury. Apple peels of the Danxia and Starkrimson varieties were compared for their tensile properties, shear properties, and tensile-property variations after 0, 14, and 28 days of storage at room temperature. Apple peel microstructures were observed and imaged using scanning electron microscopy. Cubic polynomials proved superior for quantifying the stress–strain non-linear relationship of peels. With increased storage period, tensile strength and fracture strain gradually decreased but elastic modulus increased. The mechanical indices of Starkrimson peels were greater than those of Danxia peels after the same storage period. Significant differences between cultivars were observed in terms of tensile strength, elastic modulus, and shear strength; significant storage differences also existed for both cultivars. Mechanical properties were closely related to peel microstructures. Strengths and weaknesses mainly depended on the number and width of microcracks on the cuticle, cuticle form, cell aspect radio, and space between cells.     

苹果汁香气物质研究进展

香气成分是构成苹果汁典型风味、影响其整体品质的重要因素。研究其香气化合物对于保持苹果汁的特征香气、提高苹果汁的整体香气品质具有重要意义。该文概述了苹果汁中主要的香气成分、苹果汁香气物质分析方法、香气活性物质及其阈值的研究、苹果汁香气的主要来源和影响因素,以期为进一步深入研究和工业化生产提供理论指导。     

苹果汁香气物质研究进展

香气成分是构成苹果汁典型风味、影响其整体品质的重要因素。研究其香气化合物对于保持苹果汁的特征香气、提高苹果汁的整体香气品质具有重要意义。该文概述了苹果汁中主要的香气成分、苹果汁香气物质分析方法、香气活性物质及其阈值的研究、苹果汁香气的主要来源和影响因素,以期为进一步深入研究和工业化生产提供理论指导。      

苹果酒、醋中香气物质分析

采用GC-MS法对'95-54'、'95-117'苹果酒、醋中的香气物质的种类与含量进行检测分析.95-54苹果酒中检测出48种香气物质,占总峰面积的90.36％.95-54苹果醋中检测出42种香气物质,占总峰面积的98.66％.95-117苹果酒中检测出43种香气类物质,占总峰面积的86.59％.95-117苹果醋中检测出49种香气物质,占总峰面积的99.37％.这些香气物质主要是醇类、醛类、酮类、酸类、酯类、缩醛类和萜烯类.分析得出不同品种的苹果酒和苹果醋都存在一定的共性和差异,苹果酒和醋之间的香气差异也均符合酒醋基本特征.     

多菌灵对红富士苹果香气的影响

田间喷洒稀释400倍的多菌灵,分别于喷药前、喷药后4h和喷药后10d采样,研究多菌灵对苹果香气的影响,通过高效液相色谱仪（HPLC）分析多菌灵残留量,然后采用顶空固相微萃取（HS—SPME）结合气质联用（GC—MS）对三个处理样品的香气物质进行测定。结果表明：多菌灵残留量测定结果分别为0．217、1．651、0．352mg／kg;多菌灵喷洒使香气物质减少．尤以酯类化合物的减少较显著;三个处理样品测定出17种共有成分,其中5个是红富士苹果特征香气物质．乙酸丁酯、a-法呢烯受多菌灵喷洒影响较显著;喷药后比喷药前少了15种香气化合物,这些化合物不是红富士苹果风味的主要香气物质．10d后又检测出4种化合物。     

Kinetics of haze formation and factors influencing the development of haze in clarified apple juice

The rate of haze formation in commercial clarified apple juice stored at 4, 25 and 37°C was monitored over a 16 to 35-week storage period. Changes in turbidity, tannin content and browning index were evaluated. The juice appeared virtually clear and had very little colloidal particles during the initial stages of storage. After 24 weeks, an increase in turbidity of 2.32 NTU was observed for juice samples stored at 37°C. An increase of 0.58 and 0.95 NTU was observed for samples stored at 25 and 4°C, respectively. There was a general decrease in tannin content and an increase in browning index with storage; this effect was most pronounced for samples stored at 37°C. The rate of haze formation and tannin depletion in juice samples followed first-order reaction kinetics. Light and headspace did not affect haze formation. NaCl and CaCl₂ increased haze development while sucrose (up to 60%), urea (0.5 M), and EDTA (up to 0.01 M) had little effect. Addition of sodium dodecyl sulfate retarded haze formation.     

超声波辅助提取苹果皮中总黄酮工艺条件的优化

采用超声波辅助法对苹果皮中的总黄酮进行提取和条件优化。在单因素实验的基础上,用响应面研究了乙醇体积分数、液固比、提取时间对黄酮得率的影响。并由此确定了超声波辅助提取苹果皮中总黄酮最佳提取工艺条件:乙醇体积分数50.3%、液固比28.9∶1、时间49.1min,黄酮得率为19.32mg/g。     

The volatile components of an industrial apple aroma concentrate

European Food Research and Technology - Acidic and neutral fractions of the apple aroma concentrate were analysed using GLC or GLCMS: 42 components, of which nine were determined only tentatively,...     

Isolation of ursolic acid from apple peels by high speed counter-current chromatography

Cuticular waxes of four varieties of Malus domestica were investigated regarding their content of ursolic acid. Peels from Fuji, Gala, Smith and Granny Smith apples were extracted with chloroform, ethyl acetate and/or ethanol. The crude extracts were purified by high speed counter-current chromatography (HSCCC), by using mobile and stationary phases derived from the two-phase solvent system composed by n-hexane:ethyl acetate:methanol:water in the proportion of 10:5:2.5:1. The phase proportions and the relative distribution of ursolic acid between the two-phases were optimized by TLC and optical densitometry, by comparison with an authentic sample of ursolic acid. The amount of ursolic acid present in the extracts as well as the characterization of the isolated compound were made by high resolution gas chromatography coupled to mass spectrometry (GC–MS), ¹³C nuclear magnetic resonance (¹³C NMR), Infrared; and by comparing thin layer chromatography and flame ionization detection gas chromatography (GC–FID) patterns with the commercial sample. The average content of ursolic acid of 0.8 mg/cm² in the peel (around 50 mg per medium sized fruit with a surface area of 50–70 cm²) was found in the Fuji and Smith varieties, whereas 0.5 mg/cm² and 0.2 mg/cm² were the amounts calculated for Granny Smith and Gala, respectively. The HSCCC technique was shown to be a good method to purify free ursolic acid from apple peels and could represent a new technological tool to be developed to exploit industrially this source of product.     

气相色谱-质谱联用法分析不同品种苹果酿造蒸馏酒中香气成分及特征

以不同品种苹果为原料酿造苹果蒸馏酒,采用顶空固相微萃取-气相色谱-质谱（HS-SPME-GC-MS）技术分析其香气成分。结果表明,3种苹果蒸馏酒共检测出50种挥发性香气成分,包括酯类28种、醇类8种、酸类4种、醛类3种、烷烃类7种。延长红、澳洲青萍、长富2号苹果蒸馏酒中酯类分别为22种、21种、15种,相对含量分别为39.43%、38.44%、46.28%;醇类分别为7种、6种、8种,相对含量分别为42.90%、42.42%、37.11%;酸类分别为4种、0种、1种,相对含量分别为1.65%、0、0.27%;醛类分别为3种、1种、1种,相对含量分别为9.58%、9.98%、14.32%;烷烃类分别为5种、6种、5种,相对含量分别为4.01%、4.39%、3.81%。综上所述,延长红苹果蒸馏酒挥发性香气成分种类丰富,含量较高,是酿造苹果蒸馏酒的良好原料。     

苹果沙棘复合果泥配方优化及品质分析

以苹果和沙棘原浆为原料,可溶性固形物、褐变度、感官评分为评价指标,通过单因素、Box-Behnken响应面设计优化苹果沙棘复合果泥配方.同时采用顶空固相微萃取-气相色谱-质谱联用技术分析苹果沙棘复合果泥的香气构成.试验优化果泥配方:苹果浆为基料,添加沙棘原浆7％、白砂糖12％、果胶0.3％(均为质量分数),该配方所制备...     

苹果浓缩汁加工中香气回收成分分析

以同一苹果浓缩汁生产线上收集的300倍回收香精、预浓缩回收液水和浓缩回收液水为实验材料,分析了三个样品中香气物质成分,旨在确定苹果浓缩汁加工过程中香气物质的变化特性和浓缩回收冷凝水中香气物质的主要成分。顶空固相微萃取结合气质联用测定各样品香气成分的差异,共检测出47种香气成分。结果表明:a.300倍回收香精中富含酯类、醛类、醇类香气物质,苹果浓缩汁预浓缩过程中,香精回收工艺收集了主要的芳香酯类(乙酸-2-甲基-1-丁酯、乙酸-2-苯基乙酯、乙酸乙酯等)和醛类[(E)-2-己烯醛、苯甲醛等]香气物质,芳香醇类香气物质相对较少。b.苹果汁预浓缩回收液水中苹果的典型醇类(1-己醇41.70%)香气物质含量高且丰富,同时预浓缩回收液水含有较高相对含量枯焦气息的苯酚类化合物(2,5-二叔丁基-对甲基苯酚13.26%、2,4-二叔丁基苯酚11.16%)。c.苹果汁浓缩回收液水富含苹果典型酯类香气物质(乙酸-2-甲基-1-丁酯、乙酸丁酯、乙酸甲酯等)和醇类香气物质(2-甲基-1-丁醇等),由加工过程中苹果汁中香气物质进一步逸散产生。     

白茶香气成分及影响因素研究进展

白茶, 作为中国六大茶类之一, 因其清香鲜甜的品质、独特的健康功效及可存储等特点受到消费者的喜爱。茶叶香气物质含量少、种类多且化学性质各不同, 既存在于茶树鲜叶中, 也可通过茶叶加工过程转化形成新的香气物质, 是评判茶叶品质优劣的重要依据。白茶香气成分的组成、含量及所呈现的香气特征因茶树品种、生长生态环境、生长季节、原料采摘等级、加工工艺的不同而有所差异, 且与是否贮藏等因素密切相关。本文总结了近年来白茶香气研究中涉及的萃取、检测、分析及评价方法, 白茶香气在萎凋、干燥、形制等工序中的变化规律, 创新工艺、贮藏与陈化等处理对白茶香气的影响, 并梳理了不同类型白茶的主要香气成分, 最后对未来白茶香气研究技术发展、香气提升等方面进行了讨论与展望, 旨在为白茶相关标准的建立提供理论参考。     

基于电子鼻技术的不同苹果品种香气的表征与识别

采用电子鼻技术,对4个品系8个品种的苹果香气进行描述,并探究各品系品种间风味轮廓的差异,从而实现电子鼻对不同品种苹果香气的识别。采用主成分分析(principal component analysis,PCA)、载荷分析(loadings analysis,LA)以及线性判别分析(linear discriminant analysis,LDA)分别对电子鼻10个传感器的响应信息进行分析。结果表明:线性判别分析的区分效果要优于主成分分析,电子鼻对不同品种苹果的区分效果有重叠,部分同品系的苹果品种风味特征极其接近。其中乔纳金、斯塔克矮金冠、华帅一号苹果的香气在主成分分析和线性判别分析中都显著区分于其他品种,而同品系的垂枝国光和国光苹果风味轮廓重叠严重,香气无明显差异。因此,基于苹果香气物质的差异,电子鼻可以作为识别苹果品种的一种重要手段。     

基于电子鼻和气相色谱-质谱联用技术分析不同品种苹果酒香气物质

以陕西白水的嘎啦、红星、瑞雪、瑞阳4种苹果为原料酿造苹果酒,采用电子鼻（E-nose）和顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）技术分析4种苹果酒香气物质。结果表明,电子鼻检测到4种苹果酒的香气特性差异较大,利用主成分分析（PCA）法和线性判别分析（LDA）法可完全将其区分开;HS-SPME-GC-MS共检测出76种挥发性香气物质,包括醇类11种、酯类43种、醛类7种、酮类3种、酸类7种、萜烯和其他5种;嘎啦、红星、瑞雪、瑞阳苹果酒分别有66种、43种、45种、47种香气物质,总含量分别为7.17 mg/L、7.08 mg/L、6.64 mg/L、7.56 mg/L,且4种酒共有特征香气物质包括：丁酸乙酯、2-甲基丁酸乙酯、乙酸异戊酯、己酸乙酯、辛酸乙酯、癸酸乙酯。电子鼻结合HS-SPME-GC-MS分析可以成功区分不同品种苹果酿造苹果酒的挥发性成分。