Diverse metabolism of cell wall components of melting and non‐melting peach genotypes during ripening after harvest or cold storage

The mode of change in a range of physiological, physicochemical and biochemical parameters during fruit ripening between distinct peach genotypes (Prunus persica L. Batsch) after cold storage for up to 4 weeks was determined. The nectarine cultivar ‘Caldesi 2000’ was selected as a genotype with melting flesh (MF) characteristic (fruits characterized by extensive flesh softening during ripening) and the cultivar ‘Andross’ as a genotype with non‐melting flesh (NMF) characteristic (fruits characterized by limited flesh softening during ripening). Flesh firmness, ethylene production, physicochemical and biochemical properties of the cell wall were determined and significant differences between the fruits of the two genotypes were recorded. Fruits of the NMF genotype were characterized by higher tissue retention and ethylene production during their ripening, higher content of uronic acids, as well as higher capacity for calcium binding in the water‐insoluble pectin fraction compared with fruits of the MF genotype. Additionally, the ripening of MF‐type fruits was characterized by higher losses of neutral sugars, especially those of arabinose and galactose than the NMF‐type fruits and these losses were more intense after extended cold storage periods. In fruits of the NMF genotype the decreased activity of pectin methyl esterase (PME) combined with higher levels of calcium in the water‐insoluble pectin fraction possibly provided less substrate for polygalacturonase (exo‐, endo‐PG) activity and less solubility of cell wall pectin compared with fruits of the MF genotype. Overall, the data indicate the existence of a wide range of diverse metabolic pathways during fruit ripening of fresh fruits with MF and NMF characteristics. Copyright © 2005 Society of Chemical Industry     

Suitability for minimal processing of non‐melting clingstone peaches

Clingstone non‐melting peach cultivars (Prunus persica L. Batsch) are used primarily for canning, but their processing as fresh‐cut products is also of interest. Four clingstone peach cultivars (‘Andross’, ‘Babygold 8′, ‘Calante’ and ‘Romea’) were evaluated for their suitability for minimal processing (washing, peeling and slicing) followed by storage for 9 days at 4 °C in a modified atmosphere using microperforated films. Romea cultivar, which has low polyphenol oxidase (PPO) enzymatic activity, proved to be the most suitable cultivar for minimal processing, given its lower degree of browning as well as the results from a sensory evaluation. Maturity indicators varied slightly during storage at a different degree depending on cultivars. We have found that PPO activity and browning potential are adequate indicators for surface browning in fresh‐cut non‐melting peaches.     

国内市售果醋饮品的感官品评及营养价值分析

对市售27种果醋饮料进行色泽、澄清度、口感、香气四个方面的感官品评和总酸、总糖、游离氨基酸、维生素C、多酚、黄酮、有机酸七种营养成分分析,并利用主成分分析法对市售果醋饮料的口感和营养进行综合分析并对样品进行归类。结果显示77%样品的感官品评得分在70分以上;果醋酸、糖的适宜搭配范围分别为3～10g/L和20～110g/L;果醋饮料中四种主要有机酸为乙酸、柠檬酸、乳酸、苹果酸。主成分分析结果表明所测定的27种果醋样品中,22%的样品口感优异、营养丰富,为优质饮料。      

电子舌对相似味型的分析研究及感官评价

糖醋味、鱼香味、荔枝味是从酸甜味衍生而来的3种相似的味型.通过文献了解这3种味型常用的调味料配比,每种味型选取3种配方进行感官评价并运用电子舌对3种味型9种配方进行主成分分析.结果显示:电子舌能够较好地区分相似味型.     

泡椒牛皮感官评价指标体系的构建

本实验旨在建立泡椒牛皮感官评价指标体系,以泡椒牛皮和市售泡椒猪皮为实验对象征集描述词,采用M值法对征集到的泡椒牛皮感官评价描述词进行初次筛选,得到辣味、硬度、泡椒味、弹性、有嚼劲等12个主要的感官评价描述词。结合主成分分析和相关性分析对初次删减的描述词进一步分析,得到泡椒味、硬度、淡黄色、表面脂肪含量、弹性、有嚼劲和余味等7个感官评价描述词,能较准确描述泡椒牛皮的感官品质。这说明筛选得到的泡椒牛皮感官评价描述词具有可行性,为保证泡椒牛皮产品的质量一致性提供理论依据。      

Sensory and chemical characteristics of trans‐resveratrol‐fortified wine

Background and Aims: trans‐Resveratrol (tR) is a grape‐derived polyphenolic that is believed to confer considerable health benefits to humans. Its concentration in wine, however, is highly variable, and thus direct fortification of wine with tR has been proposed to create a high‐value, health‐promoting wine product. This study determines the sensory and chemical characteristics of tR fortified white and red wine. Methods and Results: Riesling and Cabernet Sauvignon wines were enriched with 20 mg/L and 200 mg/L tR. Basic chemical and sensory indicators of wine quality, trans‐ and cis‐resveratrol concentrations, and antioxidant capacity were assessed at bottling and at 6, 18, 31, 44 and 58 weeks post‐bottling. tR concentrations in bottled wine remained relatively stable throughout the 58‐week period of this study. In addition, tR‐enriched wines had a significantly higher antioxidant capacity compared with control wine, and Cabernet Sauvignon fortified at both tR concentrations had greater colour intensity. Basic chemical indicators of wine quality were not affected by tR fortification, and sensory changes were minimal, with higher bitterness intensity in Riesling fortified at 200 mg/L tR the most consistent finding. Conclusions: tR is relatively stable in wine during bottle aging, and tR enrichment up to 200 mg/L results in minimal change to wine quality, particularly with red wine. Significance of Study: This is the first study to investigate the chemical and sensory characteristics of tR‐enriched wines. Results indicate that these products may have considerable potential for the functional food market.     

青稞品种对青稞发酵酒营养与感官品质的影响

本研究以7种西藏特有的青稞品种及相应发酵青稞酒为对象,基于理化性质、营养、风味和感官等指标,采用典范对应分析（canonical correspondence analysis,CCA）和主成分分析（principal component analysis,PCA）等探究青稞品种与其发酵酒品质的关系。研究表明,与青稞原粮相比,青稞酒体氨基酸中必需氨基酸占比增加,可能是酿造过程中非必需氨基酸转化形成了必需氨基酸。CCA结果显示不同品种青稞原粮在总氨基酸、γ-氨基丁酸、β-葡聚糖和总多酚含量等方面具有一定相似性,但其营养结构的差异经微生物生物化学转化得以放大,为筛选青稞酒的优质品种提供了可能。通过青稞原粮及相应青稞酒中的蛋白质、氨基酸、γ-氨基丁酸和总多酚水平等营养指标分析初步优选出‘藏青2000’为酿酒青稞品种,其次是‘隆子黑’‘芶芝黑’‘藏青25’。结合青稞酒营养、风味和感官等多维度指标,最终确定‘藏青2000’为最佳酿酒青稞品种,其次为各具特色风味的‘芶芝黑’‘隆子黑’‘藏青25’。本研究可为我国青稞酒领域的发展提供参考。     

南瓜的感官品质、质构及生化分析

在对127份南瓜材料进行感官鉴定的基础上,选取10份口感明显不同的南瓜材料为研究对象,分别测定其质构指标及生化指标,并分析感官属性和质构指标以及感官属性和生化指标的相关性。结果表明：南瓜的感官属性可以分为3个主成分,第1主成分为粉质、干湿情况和甜度,第2主成分为面度和纤维度,第3主成分为硬度和脆性;南瓜的质构指标也分为3个主成分,第1主成分为硬度、回复性和剪切力,第2主成分为内聚性,第3主成分为黏附性和弹性。感官属性与质构指标及理化指标不同项目之间具有不同的相关性。南瓜感官评价的关键指标为粉质,干湿情况和甜度。     

Physico‐chemical and sensory attributes in conjunction with multivariate analysis of two potato (Solanum tuberosum L.) cultivars after 90 days of storage: an exploratory authentication study

Two cultivars of potato (Spunta and Agria), were studied in terms of their physico‐chemical and sensory characteristics. These cultivars were cultivated in three geographical regions of Greece (Macedonia, North Greece; Thessaly, Central Greece; Peloponnese, South Greece) and were stored for 90 days after harvesting. The physico‐chemical characteristics of the tubers determined, were pH, total acidity, firmness, dry matter and content in Ν, in Κ, P, Cu, Mn, Zn and Fe. The sensory characteristics measured for raw tubers of potato after storage, were skin colour, skin brightness, internal colour, surface roughness, odour intensity, moistness, surface wrinkling and stains while the sensory characteristics measured for the boiled tubers of potato were odour intensity, moistness, special taste, sweet taste, aftertaste persistence, metal taste, pastiness, mastication, flavour intensity, elasticity and overall acceptability. The application of multivariate analysis (principal component analysis, cluster analysis and discriminant analysis), revealed a variety of relations between the various parameters and resulted in satisfactory grouping either per geographical region or per cultivar.     

Characteristics of olive fruits and extra‐virgin olive oils obtained from olive trees growing in Appellation of Controlled Origin ‘Sierra Mágina’

Olives and olive oils from Appellation of Controlled Origin (ACO) ‘Sierra Mágina’ have been analysed during the 1997/98 harvest. The territory of this ACO has been subdivided into four zones of different characteristics. The olives were harvested on two occasions (November 1997 and January 1998). Various parameters were analysed, such as the ripening index, the average volume, the average weight of 100 olives and 100 stones, the pulp/stone ratio, the industrial yield, etc. From these olives, olive oils were extracted using an Abencor system, and the free acidity, the peroxide index, the coefficients K₂₇₀ and K₂₃₂ and the fatty acid composition were determined. The analysis of the results obtained, as well as principal component analysis, demonstrates a marked variability in the fruits, but the corresponding olive oils show fairly homogeneous compositions that are difficult to distinguish by sensory analysis. The olive oils from this ACO are extra‐virgin olive oils characterised by low acidity, a high content of oleic acid and a high ratio of unsaturated to saturated fatty acids. The most important sensory attributes are fruity, woody‐fig, green, bitter and pungent. Copyright © 2003 Society of Chemical Industry     

基于感官模糊综合评价法与价值工程评价法的市售烤羊肉质量分析评价

基于5组市售烤羊肉样本采用烤羊肉的感官模糊综合评价法（fuzzy comprehensive sensory evaluation,FSE）以及价值工程评价法（value engineering evaluation,VEE）,在感官评分与气相色谱-质谱联用（gas chromatography-mass spectrometry,GC-MS）检测的基础上,以量化及直观的形式表征不同组分挥发性有机化合物（volatile organic compounds,VOCs）对烤羊肉感官属性贡献率的差异,通过主成分分析（principal component analysis,PCA）比较两种方法得到结果的差异,并探究感官模糊指标与价值功能得分之间的相关性,以获得综合评价排序。结果表明：以GC-MS为检测手段鉴定出烤羊肉的42 种VOCs,依据不同属性可以将所有VOCs大致分为Z1（萜烯类和醇类）、Z2（醛类和含硫含氮化合物）、Z3（醚类和酮类）、Z4（芳香类和其他）4 个价值功能组分,且5 组市售烤羊肉样品的功能指数排序为SS4（26.18%）＞SS1（22.53%）＞SS2（19.59%）＞SS3（17.26%）＞SS5（14.43%）;FSE与VEE对5 组样品的评价排序大致相同,通过FSE发现5 组样品综合得分排序为SS4＞SS1＞SS2＞SS5＞SS3;采用PCA对两种方法所得结果综合分析后发现评价排序与采用VEE得出结论一致。VEE的使用一定程度上弥补了FSE中由边界模糊带来的不足,可以作为食品品质监控的价值评判标准,同时采用两个模型能更好地对烤羊肉综合品质进行分析评价。     

泡椒牦牛黄喉感官评价描述词的建立

为研究泡椒牦牛黄喉感官评价描述词的建立方法,本实验以拉萨斯布牦牛黄喉为原料,青野山泡椒为主要辅料制作泡椒牦牛黄喉。采用感官剖面分析,首先对感官描述词利用M值法进行初次筛选,得到切面光滑的、有刺激性的、有光泽的、肉香的等19 个泡椒牦牛黄喉产品的感官品质描述词,并通过主成分分析法（principalcomponents analysis,PCA）对19 个初筛获得的描述词进行二次筛选,提取5 个主成分PC1（24.13%）、PC2（13.12%）、PC3（10.81%）、PC4（8.39%）、PC5（7.89%）,分别代表泡椒牦牛黄喉的外观、质地、风味、组分和色泽特征,再结合相关性分析从5 个主成分因子中分别筛选出能较全面评价泡椒牦牛黄喉感官品质的描述词,最终得到切面光滑的、有刺激性的、结实的、多汁的及乳白的5 个描述词作为泡椒牦牛黄喉感官评价的关键描述词,能较准确评价泡椒牦牛黄喉的感官品质。表明利用上述方法建立泡椒牦牛黄喉的感官描述词具有可行性,可为进一步建立泡椒牦牛黄喉产品的感官评价体系提供理论参考。     

Sensory characteristics of british sausages: Relationships with composition and mechanical properties

The appearance, texture and flavour of cooked British sausages were assessed by 11 trained panellists using their analytical profile of 19 attributes, each of which was rated on an unstructured line scale. Five independent components were isolated, accounting for 86% of the sensory variation. ‘Saltiness’ was the only independent attribute. A map of sausage quality showed that ‘skin toughness’, ‘firmness’ and ‘meatiness’ were related closely to the principal sensory axis, and ‘juiciness’ and ‘fattiness’ to the second principal axis. The attributes of appearance describing the degree of doneness, and those describing comminution in appearance and in texture, were related to both principal axes. Mapping instrumental measurements into the sensory space showed that puncture and compressive strengths and nitrogen content were the best measures of variation on the first principal axis, indicating a toughness/tenderness component influenced by lean meat content. Fat increased juiciness, but, as salt or rusk increased, sausages were drier and more cohesive. Adhesion and cohesion were assessed as ‘cohesiveness’. ‘Fattiness’ and ‘saltiness’ were related poorly to fat and salt contents, respectively. ‘Fattiness’ decreased in tough, dry sausages of low pH, and ‘saltiness’ decreased as pH, fat and ‘dryness’ increased. In commercial sausages, the effects of comminution on eating quality could override those of formulation.