苦味机理及苦味物质的研究概况

苦味是一种分布广泛、阈值极低的味感,而消费者往往拒食苦味食物,但苦味物质在食品风味和生理调节方面具有重要作用。简要论述了苦味呈味机理、几种苦味物质的功能特性以及苦味抑制剂方面的研究进展。     

阿魏酸苦味抑制效果研究

采用感官分析评定方法,对阿魏酸做了以下研究:1、不同浓度阿魏酸的酸味和涩味强度;2、不同浓度阿魏酸对糖精钠和咖啡因的苦味抑制效果;3、250mg/kg阿魏酸对其他四种基本口味的影;4、250mg/kg阿魏酸对3种甜味剂苦味的抑制效果。结果表明:阿魏酸浓度较高时具有酸味和涩味,没有甜味和苦味;阿魏酸是一种有效的苦味抑制剂,且对糖精钠的苦味抑制效果优于对咖啡因的苦味抑制效果;250mg/kg的阿魏酸对糖精钠、安塞蜜、甜菊糖的苦味均有抑制作用,但不会对其他4种基本口味造成影响。     

米甜酒苦味形成机理的研究

试验表明，米甜酒致苦的机理是由于酵母的厌气（酒精）发酵或产酸菌的活动所致，但对发酵液中游离氨基氮总量影响不明显，延长酵母的对数生长期，便可延迟米甜酒的变苦，定期移走发酵酒液或补充碳源，对延迟米甜酒的变苦有明显效果；补充碳源的效果与碳源的补给比例成正相关；同时与碳源的种类有关，蔗糖效果稍好于麦芽糖但两者明显好于糊化糯米粉；加碳源去米甜酒苦味的效果。蔗糖明显好于糊化糯米粉与麦芽糖。     

食品中的苦味及苦味物质

苦味在风味上来说,没有多大价值,但在调味和生理上却有其重要作用。苦味过多,就会影响水果、蔬菜的味道,而适量的苦味,反倒会带来独特的风味。柑桔的苦味就是这样。在生理上苦味对味觉感受器有强烈的刺激作用,对于消化道活动障碍,在味觉上出现衰退和减弱现象的人有重要的调节作用。     

复合苦味抑制剂对安塞蜜苦味抑制效果研究

探讨了在不影响安塞蜜溶液其他风味的前提下,阿魏酸、4-(2,2,3-三甲基环戊-3-烯基)丁-2-烯酸、乳酸锌对安塞蜜的苦味抑制效果.并在单因素实验的基础上,采用正交实验设计选出了最佳复配方案.同时,研究了此复合苦味抑制剂对咖啡苦味的抑制效果.结果表明:阿魏酸浓度为110 mg/L,4-(2,2,3-三甲基环戊-3-烯基)丁-2-烯酸浓度为140 mg/L,乳酸锌浓度为80 mg/L时,安塞蜜溶液苦味可从很苦降低到苦,而且此复合苦味抑制剂对咖啡具有有效的苦味抑制作用.     

白酒异味--苦味

大多情况下,苦味对白酒来讲属异味,适量的苦味对白酒的口感却是有益的。苦味的特征是阈值低,可达7.0×10-7;可变性小,不易区分单种苦味物质;感官灵敏度舌尖与舌根相差60倍左右;不同温度下显示出不同强度。苦味酒可用作调味酒,以增加酒的口感。常见苦味物质有杂醇油、醛类、氨基酸及无机盐类。(晓)     

苦味肽的形成机理及脱苦技术研究进展

蛋白水解物因具有良好的生物活性而备受关注。但因某些水解过程中会产生苦味物质,从而限制了其在现代食品工业中的广泛应用。本文综述了近年来国内外研究对苦味肽的形成机理及脱苦技术的最新研究进展,并指出了脱苦过程中产生的问题,旨在为蛋白水解物的脱苦提供技术支持。     

浓香型白酒中的苦味

酒的苦味主要来自原辅料、工艺和勾调过程。浓香型酒中的苦味物质主要有单宁类、多肽、氨基酸、杂醇、醛类和无机盐。苦味物质表现出阈值较低、在低温下较敏感、可变性小、可使浓香型酒风味复杂、舌各部位对苦味的敏感程度差异较大等特征。可通过对原辅料和工艺的控制及采用勾调等方法降低浓香型酒的苦味。（孙悟）     

植物苦味物质概况及其在食品工业的应用

苦味物质分布广泛,种类繁杂.大部分苦味物质存在于植物中,少部分来源于动物,还有一些苦味物质形成于食物加工、老化及变质过程中.植物中的苦味物质主要包括多酚、生物碱、皂甙、无机盐、氨基酸及多肽5类.苦味物质由味蕾感知,经苦味受体将其刺激转化为味觉信号并传输到大脑中枢,形成苦味感受.苦是一种不愉悦的感觉,在滋味调和与生理调节...     

天然苦味抑制剂的研究与应用

苦味抑制荆是一类能降低或消除苦味物质苦味的化合物。目前已发现多种天然的苦味抑制剂，如苯乙烯酸衍生物、单磷酸腺苷、磷脂酸等。简要论述了天然苦味抑制荆的种类、效果及其应用。     

Evaluation of bitterness in Ragusano cheese

The appearance of undesirable bitter taste in Ragusano cheese was investigated by comparing the composition of 9 bitter cheeses with that of 9 reference cheeses of good quality by means of chemical, electrophoretic, and chromatographic analyses. Rates of proteolysis were significantly affected in cheeses of different quality. Primary proteolysis, as measured by pH 4.6-soluble N, was significantly greater in bitter cheeses compared with reference samples. Urea-PAGE profiles showed an almost complete breakdown of caseins in bitter cheeses and the further degradation of primary peptides into smaller compounds not detectable by this technique. Cheeses with defects had significantly lower levels of secondary proteolysis as reflected by the percentage of pH 4.6-soluble N soluble in 12% trichloroacetic acid and the amounts of total free amino acids. Peptides separated by reversed phase-HPLC revealed that the large and significant differences in peptide profiles of the soluble fractions between bitter and reference cheeses were mainly due to a much higher proportion of hydrophobic peptides in the former. The occurrence of bitterness in Ragusano cheese was therefore attributable to unbalanced levels of proteolysis and peptidolysis. Extensive degradation of caseins and primary peptides by activities of proteases produced large amounts of small- and medium-sized hydrophobic peptides that were not adequately removed by peptidases of microflora and therefore accumulated in cheese potentially contributing to its bitter taste. The presence of these compounds in bitter cheeses was related to high salt-in-moisture and low moisture contents that limited the enzymatic activities of microflora important in secondary proteolysis. Combining salt-in-moisture and the ratio of hydrophobic-to-hydrophilic soluble peptides resulted in the best logistic partial least squares regression model predicting cheese quality. Although bitterness is known to be rarely encountered in cheese at salt-in-moisture levels >5.0, all of the bitter cheeses analyzed in this study had salt-in-moisture levels much greater than this value. According to the logistic model, a risk of bitterness development may exist for cheeses with a midrange (5 to 10%) salt-in-moisture content but with an inadequate level of secondary proteolysis.     

苦瓜系列产品的研制

苦瓜具有良好的食用和药用价值,但由于其带有明显的苦味,而不容易被消费者所接受。采用新鲜苦瓜为原料,通过控制苦瓜成熟度及采用酶处理、调配、热烫等加工方法,解决了苦瓜明显苦味所带来的口感缺陷,保持了苦瓜特有的清香,研制出多种风味独特的苦瓜系列产品。     

高收率低苦味值大豆低聚肽的制备

以大豆分离蛋白为原料,以酶解收率为指标对最优的酶解工艺进行研究。在单酶水解的基础上,用复合碱性蛋白酶,中性蛋白酶,胰蛋白酶进行水解,通过正交试验确定了复合酶的最佳水解条件为:碱性蛋白酶/中性蛋白酶/胰蛋白酶加酶1∶2∶3,温度50℃,酶解时间4.5h,在此最佳条件下,酶解收率为86.76%,大豆低聚肽含量为93.49%,苦味值比单酶水解明显降低。     

Ultrafiltered milk reduces bitterness in reduced-fat Cheddar cheese made with an exopolysaccharide-producing culture

The objectives were to reduce bitterness in reduced-fat Cheddar cheese made with an exopolysaccharide (EPS)-producing culture and study relationships among ultra-filtration (UF), residual chymosin activity (RCA), and cheese bitterness. In previous studies, EPS-producing cultures improved the textural, melting, and viscoelastic properties of reduced-fat Cheddar cheese. However, the EPS-positive cheese developed bitterness after 2 to 3 mo of ripening due to increased RCA. We hypothesized that the reduced amount of chymosin needed to coagulate UF milk might result in reduced RCA and bitterness in cheese. Reduced-fat Cheddar cheeses were manufactured with EPS-producing and nonproducing cultures using skim milk or UF milk (1.2×) adjusted to a casein:fat ratio of 1.35. The EPS-producing culture increased moisture and RCA in reduced-fat Cheddar cheese. Lower RCA was found in cheese made from UF milk compared with that in cheese made from control milk. Ultrafiltration at a low concentration rate (1.2×) produced EPS-positive, reduced-fat cheese with similar RCA to that in the EPS-negative cheese. Slower proteolysis was observed in UF cheeses compared with non-UF cheeses. Panelists reported that UF EPS-positive cheese was less bitter than EPS-positive cheese made from control milk. This study showed that UF at a low concentration factor (1.2×) could successfully reduce bitterness in cheese containing a high moisture level. Because this technology reduced the RCA level (per g of protein) to a level similar to that in the control cheeses, the contribution of chymosin to cheese proteolysis would be similar in both cheeses.     

Explaining tolerance for bitterness in chocolate ice cream using solid chocolate preferences

Chocolate ice cream is commonly formulated with higher sugar levels than nonchocolate flavors to compensate for the inherent bitterness of cocoa. Bitterness, however, is an integral part of the complex flavor of chocolate. In light of the global obesity epidemic, many consumers and health professionals are concerned about the levels of added sugars in foods. Once a strategy for balancing undesirable bitterness and health concerns regarding added sugars has been developed, the task becomes determining whether that product will be acceptable to the consumer. Thus, the purpose of this research was to manipulate the bitterness of chocolate ice cream to examine how this influences consumer preferences. The main goal of this study was to estimate group rejection thresholds for bitterness in chocolate ice cream, and to see if solid chocolate preferences (dark vs. milk) generalized to ice cream. A food-safe bitter ingredient, sucrose octaacetate, was added to chocolate ice cream to alter bitterness without disturbing other the sensory qualities of the ice cream samples, including texture. Untrained chocolate ice cream consumers participated in a large-scale sensory test by indicating their preferences for blinded pairs of unspiked and spiked samples, where the spiked sample had increasing levels of the added bitterant. As anticipated, the group containing individuals who prefer milk chocolate had a much lower tolerance for bitterness in their chocolate ice cream compared with the group of individuals who prefer dark chocolate; indeed, the dark chocolate group tolerated almost twice as much added bitterant in the ice cream before indicating a significant preference for the unspiked (control) ice cream. This work demonstrates the successful application of the rejection threshold method to a complex dairy food. Estimating rejection thresholds could prove to be an effective tool for determining acceptable formulations or quality limits when considering attributes that become objectionable at high intensities.     

水产品腥味物质形成机理及相关检测分析技术的研究进展

腥味作为影响水产品品质的重要因素,一直以来都是人们关注的热点。国外对此研究较早,而国内则鲜有报道。综述了水产品腥味物质的种类,从养殖环境、体表吸附及水产品本身生化反应等角度阐明了腥味物质形成的原因,介绍了近年来水产品腥味物质检测方法的研究进展,并就水产品腥味物质研究发展趋势进行了展望。     

Afrosimetric estimation of threshold saponin concentration for bitterness in quinoa (Chenopodium quinoa Willd)

Taste testings and saponin estimation by a simple afrosimetric method showed that quinoa containing 0·11% saponins or less (corresponding to foam heights of 1·0 cm or less) can be considered sweet. A variation of the standard afrosimetric method is described which reduces total analysis time from 73 to 7 min. Used with the proper precautions, this rapid method, in which quinoa producing foam heights of 1·3 cm or less is considered sweet, is suitable for selecting promising low-saponin varieties in field trials and for monitoring the efficacy of abrasive dehulling (polishing) as a debittering process.     

Hydroxycinnamates of Vitis vinifera: Sensory assessment in relation to bitterness in white wines

The bitter and astringent taste properties of hydroxycinnamoyl tartaric acids have been responsible for incorrect speculation that these compounds influence the taste of wine. The sensory contribution of the major hydroxycinnamates found in wine was evaluated by duo—trio difference tests in model wine solutions and in white wine. The major hydroxycinnamate compound, trans-caffeoyl tartaric acid, was not detectable when added at the highest level at which it has been found in wine, 150 mg litre^?1. Similarly, no significant difference in taste was produced when caffeic acid and p-coumaric acid were added at 120 mg litre^?1 and 30 mg litre^?1, respectively. Trans-2-S-glutathionyl caffeoyl tartaric acid, a product of oxidase activity in must, was not detectable at 50 mg litre^?1. It was concluded that the hydroxycinnamates do not play any direct role in the taste of wines.