Reduction of Bitterness and Tartness in Grapefruit Juice with Florisil

Treatment of commercial grapefruit juice with Florisil (activated magnesium silicate) simultaneously reduced the content of citric acid and the bitter compounds limonin and naringin. Ascorbic acid concentration and °Brix (total soluble solids) were not altered by the Florisil treatment. Experienced taste panelists were able to differentiate between the nontreated and Florisil-treated juice on the basis of bitterness and tartness (acidity). The panelists indicated a preference for the Florisil-treated juice.     

胡柚汁益生菌发酵挥发性风味特征

利用筛选到的2株乳酸菌植物乳杆菌L1（Lactobacillus plantarum）和发酵乳杆菌L2（L. fermentum）对胡柚汁发酵,研究其挥发性风味成分及其变化特征。采用静态-顶空固相微萃取和气相色谱-质谱联用分析方法,测定胡柚汁经此2种乳酸菌发酵后挥发性风味物质组分和相对含量,运用主成分分析法对发酵胡柚汁样品挥发性风味成分进行分析,并采用电子鼻对乳酸菌发酵胡柚汁的香气进行检测。结果表明,胡柚汁经发酵后共鉴定出79种挥发性风味物质,其中醇类20种、烯烃类15种、烷烃类12种、酮类10种、醛类5种、酯类2种、其他类15种,挥发性风味物质分别为59、36种和35种。经乳酸菌发酵后,胡柚汁挥发性风味化合物种类均增加,并检测到了胡柚汁中未被检测到的酯类、醇类、酮类和烷烃类相对含量显著提高,醛类物质相对含量大量降低。主成分分析找出了影响4个样品特征风味组分在主成分中的差异,表明主成分分析法可实现对乳酸菌发酵胡柚汁特征风味差异性的评价。电子鼻分析表明胡柚汁经不同乳酸菌发酵后风味差异显著。研究结果揭示了胡柚汁乳酸菌饮料的风味特征并为产品质量评定等提供依据。     

Reduction of Bitterness in Grapefruit Juice with β-Cyclodextrin Polymer in a Continuous-Flow Process

Levels of the bitter components naringin and limonin were reduced an average of 50% or more in clarified grapefruit juice by treatment of about 16 bed volumes of juice with β-cyclodextrin polymer in a continuous flow process. Dilute alkaline solution regenerated the column effectively, ethanol was only about half as effective as dilute alkali. Cloudy grapefruit juice was also debittered in the same column using reversed flow to prevent column plugging. This process was less efficient because liquid flow was inadequate to maintain a fluid bed. A preliminary batch process showed ability of the polymer to be regenerated at least 19 times with no loss in ability to adsorb bitter components.     

提高芝麻香酒质量工艺试验

介绍了提高芝麻香型白酒的窖底酒质量及提高其酱香、焦香香气试验的工艺过程、操作步骤和参数。通过制作窖底及窖底醅,提高了酒的浓香,增加了酒体的醇甜感和圆润度;通过添加酸性蛋白酶,增加了酒的酱香成分,使酒体更加完善;通过增加麸皮及延长发酵期,提高了酒的焦糊香和酱香。     

Quality of Florida-Packed Retail Grapefruit Juices as Determined by Consumer Sensory Panels and Chemical and Physical Analyses

Six samples of each of 5 types of Florida-processed grapefruit juice obtained from the U.S. retail market during 1983 were evaluated for overall flavor and other quality attributes by 108-member consumer sensory panels. Grapefruit juice consumers found overall flavor acceptable and color about right, aroma and sweetness lacking (P < 0.01) and tartness and bitterness excessive (P < 0.01). Juices were measured for content of furfural, naringin, limonin, Brix and acid with Brix:acid ratio being calculated. Most factors varied according to type of product. Many correlation coefficients, although mostly low, were found significant between factors (P < 0.05). Panelists perceived bitterness to a measurable extent as tartness or lack of sweetness and did not clearly differentiate between these two sensory attributes.     

利用单宁酶改善绿茶滋味品质的研究

为了利用外源单宁酶改善夏茶滋味品质成分和组成,实验设计了在传统绿茶加工工艺的揉捻工序中,添加不同浓度的外源单宁酶,比较不同处理的成品茶在多酚类物质、儿茶素和氨基酸含量方面的差异,分析单宁酶提高夏季绿茶品质的效果。结果表明:单宁酶处理和对照相比,茶叶中茶多酚总量无显著性差异,但儿茶素的组成变化很大,其中表没食子儿茶素没食子酸酯(EGCG)明显下降;氨基酸总量有所增加,其中谷氨酸等一些低阈值氨基酸含量增加更为明显。这些成分变化对改善夏季绿茶滋味有积极意义,在夏茶加工中添加外源单宁酶可以在一定程度上降低苦涩味,从而提高茶汤的鲜醇度。     

低盐接种发酵辣椒对其风味品质的提升作用

由于高盐辣椒加工脱盐后产生大量的盐渍辣椒水,不仅污染了环境,还造成了辣椒本身营养物质的损失,中低盐度发酵辣椒是辣椒加工技术发展的方向和重点。该实验选用植物乳杆菌（Lactobacillus plantarum）和季也蒙迈耶氏酵母（Meyerozyma guilliermondii）进行低盐发酵8%(m/m)盐度,测定pH值、总酸、还原糖、氨基酸态氮等理化指标和感官评价,利用高效液相色谱测定发酵后的有机酸含量,顶空固相微萃取-气相色谱-质谱联用技术测定挥发性物质,运用聚类分析和主成分分析对室温自然发酵辣椒、32℃自然发酵辣椒、X公司提供的发酵辣椒产品18%(m/m)盐度、32℃接种发酵辣椒的风味品质进行差异性分析。结果表明,X公司发酵辣椒和接种发酵辣椒整体感官评分较高,分别为90.81、88.80分,它们的总酸分别达0.62、0.74 g/100 g,X公司发酵辣椒产品中有机酸含量较低,接种发酵辣椒中乳酸含量较高。不同发酵辣椒之间挥发性物质存在较大差异（P<0.05）,自然发酵组中含量占比最高的是烷烃类（31%）、酯类（16.29%～18.10%）,X公司发酵辣椒中是酯（33.46...     

Irradiation and Fumigation Effects on Flavor, Aroma and Composition of Grapefruit Products

Effects were evaluated on grapefruit treated to meet quarantine restrictions against Caribbean fruit fly infestation. Differences were found in flavor of fresh sections, fresh juice, and aroma of peel oil when obtained from fruit irradiated with x-rays, as compared with products from nonirradiated fruit. Flavor differences were found in all pasteurized juices from fruit irradiated at 50–60 krad. Vitamin C levels were significantly lower in juice from most irradiated fruit. Flavor differences were found in fresh and pasteurized juice from fruit treated with methyl bromide, and in pasteurized juice from fruit treated with ethylene dibromide. Aroma differences were found in peel oil from fruit treated with phosphine.     

Chemical and Instrumental Analyses of Warmed-Over Flavor in Beef

Raw, freshly cooked, stored and recooked beef muscle samples were assessed by chemical, instrumental and sensory methods of analyses for flavor quality, with particular emphasis on warmed-over flavor (WOF). The character notes used by a trained sensory panel to describe WOF were cardboardy, rancid, stale, and metallic. Samples analyzed by direct gas chromatography utilizing either packed or fused silica capillary columns showed that compounds usually associated with lipid oxidation reactions could be used as marker compounds to follow the development of WOF. Of the many compounds that appeared to be markers, hexanal and 2,3-octanedione as well as total volatiles showed a highly significant degree of correlation when compared to sensory scores and 2-thiobar bituric acid (TBA) numbers. Many of the volatile compounds that were identified in WOF meat samples were also found in the distillates prepared for the TBA reaction.     

葡萄酒风味修饰研究进展

葡萄与葡萄酒中香气成分以游离态和结合态存在.作者阐述了大量存在的结合态香气,即风味前体物的结构、含量及其研究方法,并论述了葡萄酒中风味修饰机制;介绍了关键酶,即β-D-葡萄糖苷酶的相关特性及其来源,并对风味前体物的研究前景做了展望.     

Treatment of Grapefruit Juice for Bitterness Removal by Amberlite IR 120 and Amberlite IR 400 and Alginate Entrapped Naringinase Enzyme

ABSTRACT: Treatment of grapefruit ( Citrus aurantium ) juice with Amberlite IR 400 resulted in 69.23% naringin removal after 5 min exposure with significant clarification and 89.41% tartness (acidity) reduction. Amberlite IR 120 removed only 9% naringin in 1 min with increased shelf life of the juice without any change in clarity, quality, and naringin content. Alginate entrapped naringinase treatment of the juice resulted in 83.84% naringin hydrolysis at 55°C and 220 rpm in 180 min with 1.98 enzyme units/mL of juice. The soluble enzyme hydrolyzed only 65.53% naringin under similar conditions. Kinetic constant values of the immobilized and soluble enzymes were found to be 9.75 mM and 20 mM, respectively.     

肉类食品的风味改良与开发

肉类食品风味因地域、国家、民族而异,呈现多样化。本文以肉类食品、肉类风味的形成以及影响因素为研究对象,通过对比研究,分析了国内外近年来在这些方面的研究进展。     

Quality Changes and Nonenzymic Browning Intermediates in Grapefruit Juice During Storage

Effects of storage temperature and time on the quality of commercially canned grapefruit juice were investigated. The most noteworthy and reproducible trend observed by HPLC was a significant increase in concentration of 5-hydroxymethylfurfural and furfural with increased storage temperature. During storage over 50% of sucrose was hydrolyzed after 6 wk at 30°C, and the reducing sugars increased in accordance with hydrolysis of sucrose. In the juice stored at 50°C, more than 98% of the ascorbic acid, and about 9% of total sugars were lost. Lightness value of juice decreased continuously during storage.     

风味葵花籽油品质和风味喜好的研究

本文旨在研究风味葵花籽油的产品品质和消费者风味喜好。通过研究色泽、酸价和过氧化值等理化指标,分析构成风味葵花籽油的小榨葵花籽油和精炼葵花籽油的品质。对营养素指标的分析发现,市售风味葵花籽油的主要营养素为维生素E和植物甾醇,均值分别达到63.93 mg(α-TE)/100g和4058.52mg/kg。对危害物指标的分析发现,各个品牌的葵花籽油中苯并[a]芘和多环芳烃的含量均低于国家限量,70%的风味葵花籽油中苯并[a]芘的含量低于欧盟限量2 μg/kg,90%的风味葵花籽油中多环芳烃的含量低于欧盟限量10 μg/kg。风味葵花籽油中的塑化剂检出量较低,国际前沿关注的缩水甘油酯类存在一定超标风险,而3-氯丙醇酯类的风险较低。在风味指标上,各个品牌的风味葵花籽油的风味属性差异较大,消费者对于葵花籽油的喜好度与“生瓜子味”呈显著负相关,与“甜味”呈显著正相关,与“熟瓜子味”和“焦糊味”正相关,与“油炸方便面味”负相关。     

提高酱香型云门陈酿酒质量的工艺技术措施

对酱香型酒在继承传统工艺的基础上,以提质限产为经济杠杆,从制曲、投料、堆积、入池、发酵、蒸馏、贮存等各个环节进行了大胆创新,提高了酱香型云门陈酿酒的质量。     

Bitterness in cheese: A review

Bitterness, the necessary consequence of proteolysis, has been under investigation from different perspectives. This review attempts to give more up‐to‐date information on the definition of some principal aspects, the relationship between the proteolytic activity and bitter peptide accumulation in cheese, and methods of isolation and detection of bitter peptides. Further knowledge on the physicochemical properties of bitter peptides in cheese as well as in synthetic peptides and the possible control methods for bitterness are discussed.

Particular interest in using some strains of lactobacilli or their enzymes as an adjunct in accelerated ripened cheese (ARC) and enzyme‐modified cheese (EMC) without bitterness is also described in detail.     

香料指纹图谱及其在烟用香精质量控制中的应用概述

简要介绍了指纹图谱的概念、要求、方法建立、数据处理及其在烟用香精香料质量控制上的应用研究进展。