Identification of aroma-active compounds in ‘wonderful’ pomegranate fruit using solvent-assisted flavour evaporation and headspace solid-phase micro-extraction methods

During the last few years, there has been a tremendous increase in consumption of pomegranate fruit and juice. Nevertheless, very little is yet known regarding the volatile constituents that determine the unique aroma of pomegranate fruit. We extracted aroma volatiles from fresh ‘Wonderful’ pomegranate juice using solvent-assisted flavour evaporation (SAFE) and headspace solid-phase micro-extraction (HS-SPME) methods, and applied gas chromatography–olfactometry (GC–O) (‘sniffing’) combined with gas chromatography–mass spectrometry (GC–MS) analysis, in order to identify volatile aroma-active compounds. In addition, we performed stir bar sorptive extraction (SBSE) of pomegranate aroma volatiles, coupled with GC–MS analysis, in order to assist in identifying aroma-active compounds. Overall, we tentatively identified 23 volatiles in the SAFE and HS-SPME extracts; they belonged to various chemical classes, including aldehydes, terpenes, alcohols, esters, furans and acids. Using the GC–O nasal impact frequency method, we tentatively detected 12 aroma-active peaks and identified the corresponding odourants by GC–MS. The aroma-active compounds of ‘Wonderful’ pomegranates were ethyl-2-methylbutanoate (fruity, apple), hexanal (green), β-pinene (pine, herbal), β-myrecene (woody, musty), cis-3-hexenal (green), limonene (fruity, musty), cis-2-heptenal (soapy, mushroom), cis-3-hexenol (earthy, grassy), 2-ethylhexanol (floral), β-caryophyllene (fruity, musty), 2(5H)-furanone (sweet, fruity) and β-sesquiphellandrene (terpene, almond). Overall, the flavour of ‘Wonderful’ pomegranate fruit derives from a mixture of various ‘green’, ‘woody’, ‘earthy’, ‘fruity’, ‘floral’, ‘sweet’ and ‘musty’ notes.     

The role of sour and bitter perception in liking,familiarity and choice for phenol-rich plant-based foods

Among factors influencing food preferences and choices, individual differences in taste perception play a key role in defining eating behaviour. In particular, sour and bitter responsiveness could be associated with the acceptance and the consumption of phenol-rich plant-based foods recommended for a healthy diet. The aim of this study was to investigate, in a large population sample, the associations among sour and bitter responsiveness and liking, familiarity and choice for plant-based foods characterized by these target tastes. Adults aged 18 to 60 years (n = 1198; 58% women) were tested for their sour and bitter responsiveness both in water solutions and in food models (pear juice-based beverages modified in citric acid content to induce different levels of sourness: 0.5, 2.0, 4.0 and 8.0 g/kg; chocolate pudding samples modified in sucrose content to induce different levels of bitterness: 38, 83, 119, 233 g/kg). Familiarity, stated liking and choice for fruit juices and vegetables varying for sour/bitter taste (high in bitter/sour taste: e.g. grapefruit juice and cauliflower; low in bitter/sour taste: e.g. zucchini and pineapple juice) were measured. Results showed a significant positive correlation between bitter and sour taste perception in water solutions and model foods, as well as a positive correlation between the perceived intensity of the two taste stimuli. Subjects characterized by high responsiveness to the two target stimuli were found to give lower liking scores to foods characterized by sour/bitter tastes and tended to choose less sour/bitter foods compared to less responsive subjects.Thus, food choice for phenol rich plant-based products could be associated with a reduced responsiveness to bitter and sour tastes and a consequent higher acceptance of food products characterized by these taste qualities.     

The flavor of pomegranate fruit: a review

Despite the increasing commercial importance of pomegranate, especially because of its recently discovered health‐promoting benefits, relatively little is yet known regarding its sensory quality and flavor preferences, or about the biochemical constituents that determine its sensory characteristics. The perceived flavor of pomegranate fruit results from the combination of various taste, aroma and mouthfeel sensations. The taste is governed mainly by the presence of sugars (glucose and fructose) and organic acids (primarily citric and malic acids). The aroma evolves from the presence of dozens of volatiles, including alcohols, aldehydes, ketones, and terpenes, which provide a mixture of various ‘green’, ‘woody’, ‘earthy’, ‘fruity’, ‘floral’, ‘sweet’ and ‘musty’ notes. In addition, the sensory satisfaction during the eating of pomegranate arils is complemented by various mouthfeel sensations, including seed hardness and astringency sensations. In the present review we will describe the sensory quality and flavor preferences of pomegranate fruit, including the genetic diversity in flavor characteristics among distinct varieties. In addition, we will describe the dynamic changes that occur in fruit flavor during fruit ripening and postharvest storage. © 2013 Society of Chemical Industry     

Aroma Characteristic and Volatile Profiling of Carrot Varieties and Quantitative Role of Terpenoid Compounds for Carrot Sensory Attributes

The aroma characteristics and volatile profiles of 14 carrot varieties were investigated by sensory evaluations and gas chromatography–mass spectrometry volatile analyses. The sensory map obtained by principal components analysis showed that the sensory attributes comprised 3 categories: sour/green, overall carrot/harsh/ink‐like, and fruity/fresh/sweet. The Kuroda type is characterized by lower intensities of overall carrot/harsh/ink‐like and fruity/fresh/sweet notes. Furthermore, volatile profiling indicated that this type did not have significantly higher amounts of volatiles. Partial least squares regression analysis determined the quantitative contributions to ink‐like, harsh, and fruity carrot aromas; monoterpenes had significant positive correlations with these attributes, while bisabolene isomers had negative correlations. The aroma attribute intensity and contents of volatiles and nutritional compounds are relatively low in the Kuroda type than in other carrot types. This type may be useful for reducing carrot harshness during the development of new carrots with good eating qualities.     

番茄果实降异戊二烯类香气物质合成与代谢调控研究进展

番茄中的类胡萝卜素及其由类胡萝卜素降解产生的降异戊二烯类芳香物质是果实风味的重要组成部分。其中，降异戊二烯类香气物质阈值极低，是番茄果实花香、果香的主要贡献者。近年来，番茄果实类胡萝卜素合成途径已经形成较为清晰的通路，但对其降解产物降异戊二烯类香气物质的研究多在产物分析的层面。该研究综述了番茄中降异戊二烯类芳香物质的组成和生物合成途径，以及影响降异戊二烯积累的因素及转录调控因子，以期为番茄风味品质的提升提供参考。     

碧香早夏季鲜叶加工乌龙茶过程中品质成分动态变化

以碧香早夏季三四叶鲜叶为原料,按照萎凋、摇青、杀青、揉捻、干燥等工艺加工乌龙茶,对加工过程中的样品和干茶样进行生化成分分析及采用固相微萃取-气质联用(SPME/GC-MS)检测香气成分,并结合感官审评探讨碧香早鲜叶加工乌龙茶过程中品质成分动态变化及品质形成分析。感官审评结果表明,乌龙茶滋味醇和,香气带花香。品质成分分析表明,茶多酚、儿茶素、咖啡碱、可溶性糖、黄酮、水浸出物等成分总体呈现下降的趋势,从鲜叶到干茶分别下降了5.32%、3.96%、0.48%、0.38%、22.35%、2.77%,游离氨基酸的含量总体呈现上升的趋势,相较于鲜叶干茶的含量升幅为12.88%。挥发性成分分析结果表明,碳氢类、酮类、醛类及其他类物质总体含量呈现上升的趋势,而醇类、酯类、酚类物质含量总体呈现下降趋势。其中,反式-橙花叔醇、苯乙醇、二氢芳樟醇、苯甲醛、β-紫罗酮、吲哚、α-法呢烯、α-依兰油烯、香叶基丙酮等成分可作为夏季碧香早乌龙茶的特征香气成分。乌龙茶加工促使具苦涩味及青气物质逐渐减少、甜醇及花果香类物质逐渐增加,有利于茶汤滋味及香气的形成,为夏季茶资源利用提供科学的参考。     

中国黄酒风味感官特征及其风味轮的构建

首次对中国黄酒的风味轮进行绘制,由国家黄酒评委组成的品评小组结合消费者品评小组,对6种不同类型、不同特点的典型黄酒进行风味感官品评,给出黄酒风味感官基本描述语,对描述语进行筛选整理后,参照啤酒、葡萄酒及清酒风味轮,对描述语进行归类,绘制出中国黄酒风味轮。从黄酒风味轮描述语中,运用多元统计方法及ISO 11035感官描述语选择方法的国际标准,选择确定重要的、而且具有典型差异性的味觉和嗅觉描述语：甜味、苦味、涩味、酸味、鲜味、醇香、焦糖香、果香、药香、烟气香、曲香及蜂蜜香12个作为构成黄酒风味轮廓的主要描述语。这些描述语分别经由国家黄酒评委和消费者应用于黄酒描述分析,表明可以表征中国黄酒主要的基本风味感官特征,可用于黄酒基本描述性感官分析。     

中国酿造食醋风味轮的构建及应用

利用建立的食醋感官评价小组,对中国主要的酿造食醋进行了风味评价。首次构建了中国酿造食醋的风味轮,其中包括16个类别共45个描述词。运用方差分析、主成分分析等方法筛选出了16个能够描述中国酿造食醋风味差异的词汇,其中味觉描述词包括酸味、甜味、鲜味、咸味、涩味、苦味6个,嗅觉描述词包括酸气、甜香、焦香、酱香、果香、麸皮香、烟熏香、米香、酒香、花香10个。对选择的酿造食醋样品进行感官描述性分析,发现不同类型的酿造食醋风味有明显差异。     

The ability of 10–11-year-old children to identify basic tastes and their liking towards unfamiliar foods

The involvement of children in sensory evaluation and consumer research continues to increase and has become crucial in the food industry, as children sensory perceptions differ from adults. Research on basic taste sensitivity in children provides contradictory results, with most of the studies not considering the familiarity aspect of the food samples. Familiarity can lead children to memories of the food which are able to influence their taste perception and liking. This study aims to investigate the ability of 10 to 11-year old children in identifying sweetness, saltiness, sourness, and bitterness in unfamiliar food samples. The taste identification data was collected from 98 children using 19 food samples representing the four basic tastes of sweet, sour, salty, and bitter. For each food sample, the children evaluated their familiarity, the basic taste(s) they perceived using the check-all-that-apply (CATA) method and scored their liking. Their basic taste identification ability was investigated by comparing their results to trained panellists as a reference. The food samples were unfamiliar to most of the children (never tasted by 85% of the children on average). Correspondence Analysis (CA) showed that children were able to identify the basic tastes of sweet, sour, salty, and bitter in the unfamiliar foods, with a high congruency to the trained panellists. However, children’s identification ability was lower when combinations of dominant basic tastes occurred. Principal Component Analysis (PCA) demonstrated a positive correlation between the presence of sweet taste and the children’s liking while sour and bitter tastes showed the opposite.     

SENSORY AND PHYSIO‐CHEMICAL PROPERTIES OF MEMBRANE FILTERED APPLE JUICES1

Shelf‐stable apple juices were prepared using two ceramic and four polymeric tubular membranes of varying pore sizes and evaluated using color matching and triangle tests. Juices from 9 kDa and 20 kDa membranes were different in color and aroma/flavor from the other membranes, the characteristics of which did not differ from each other. A full sensory profile was obtained for experimental juices produced using a 0.02 μm ceramic membrane and from commercial pasteurized apple juice. Experimental juices were prepared from fresh and stored apples with and without ascorbic acid. Twelve judges evaluated color; cooked/caramelized, appley, fruity and green aromas and seven flavor attributes (cooked/caramelized, appley, fruity, green, sweet, sour, astringence). Analysis of variance and principal component analysis revealed that membrane filtered juices lacked the cooked/caramelized aroma and had a green flavor compared with the commercial apple juice. Membrane filtered juices prepared from freshly harvested apples had less appley and fruity aroma and flavor, but were more sour and astringent than juices prepared from stored apples. Ascorbic acid treatment significantly reduced the yellow color and increased the astringence of juices.     

The multisensory perception of hop essential oil: a review

Hops are a key ingredient to add bitterness, aroma and flavour to beer, one of the most consumed beverages worldwide. Essential oils from different hop varieties are characterised by similar classes of chemical compounds and complexity, but their contribution to sensory characteristics in beer differs considerably. Volatiles in hop oil are categorised into several chemical classes. These induce diverse aroma and flavour sensations in beer being described as ‘floral’, ‘fruity’ (e.g. contributed by alcohols, esters, sulphur-containing compounds), ‘spicy’, ‘woody’, ‘herbal’ (sesquiterpenes, oxygenated sesquiterpenoids), and ‘green’ (aldehydes). The perception of hop volatiles depends on their concentrations and combinations, but also on threshold levels in different beer matrices or model systems. Several studies attributed modified taste and mouthfeel sensations to the presence of hop volatiles contributing to a multisensory perception of hop flavour. Linalool is frequently observed to show additive and synergistic-type behaviour and to affect aroma perception if combined with geraniol. Linalool has also been found to be involved in aroma-taste interactions, modifying the perception of bitterness qualities in beer. Particularly oxygenated sesquiterpenoids are suggested to be responsible for an irritating, tingling sensation indicating the activation of trigeminal receptors. The majority of these sensory interactions have been discovered almost by accident and a systematic research approach is required to gain a broad understanding of these complex phenomena. This review provides an overview of factors affecting the perception of hop derived volatiles involved in different sensory characteristics of beer, while illustrating the latest advances and highlighting research gaps from a sensory science perspective. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling     

外源可发酵糖对葡萄酒挥发性化合物的影响

通过气相色谱-质谱法对4 种外源可发酵糖葡萄酒中的挥发性化合物进行定性定量分析。结果表明：添加外源可发酵糖,影响葡萄酒挥发性物质的特征;添加麦芽糖,葡萄酒中醇类、酮类、酸类、醛类、酚类和萜烯类的含量较高,酯类含量较低,而醇类和酯类的总含量在添加果糖和葡萄糖的条件下达到最大值。通过计算挥发性物质的香气活性值,确定20 种挥发性化合物为葡萄酒的关键香气物质。主成分分析和感官分析显示添加不同可发酵糖发酵葡萄酒的关键香气物质有显著差别,添加葡萄糖改善了葡萄酒的植物香和果香,风味强度最大,添加果糖和蔗糖改善了葡萄酒的青草香、花香、甜香和果香,添加麦芽糖改善了葡萄酒的花香、酯香、果香和甜香。