辣椒素的分析方法及辣度分级

对国内外在辣椒果实中的辣椒素类物质化学组成、结构及辣椒素类物质的定性、定量分析方法等方面的研究进行了综述,并进一步阐述了辣椒及制品辣度分级的方法,并对该领域的发展前景进行了展望。     

基于模糊聚类分析的辣椒制品表观辣度分级研究

借助模糊聚类分析方法,选取辣椒制品的总酸、氨基酸态氮、食盐、总糖、脂肪、辣椒素6项分类指标,对辣椒制品的表观辣度进行分级,辣椒制品表现出明显的模糊聚类特征。与运用感官评定方法的结果相比基本一致。     

辣椒制品模糊辣度的表示与测定

以新鲜辣椒为原料,通过单因素试验可知辣椒制品中食盐、白糖、食用油、总酸含量是对感观辣度有减弱作用的影响因素,采用四元二次正交旋转组合设计研究这4个因素对剁辣椒制品感观辣度的影响,并获得了其减弱程度的线性关系:单因素含量越高,对感观辣度的减弱作用越大,并且有交互影响.据此,以斯科维尔(Scoville)指数为基础,根据传统辣度概念“不辣、微辣、轻辣、中辣、很辣、猛辣”相对应的“0度(表示为0°M)、1度(表示为1°M)、2度(表示为2°M)、3度(表示为3°M)、4度(表示为4°M)、5度(表示为5°M)”模糊辣度分级来表示辣椒制品的感观辣度,获得0～5°M的模糊辣度指数的计算公式,从而排除了感观辣度确定时人为因素的影响和消除了以辣椒素计算辣椒制品辣度的片面性.     

我国首次制定辣度国家标准

受国家标准委委托，湖南农业大学食品科技学院正在制定辣椒素测定及辣度表示方法的国家标准，这是我国首次针对辣椒和辣椒制品制定辣度国家标准。     

Scoville感官评定法测定辣椒辣度

对辣椒中辣味成分的组成、辣椒素的性质及功能、国内外辣椒辣度的研究概况以及评价方法等进行了综述。主要研究了辣度的Scoville感官评定法,并与HPLC法测定的辣度结果进行比较,结果表明,用感官评定法测得干辣椒样品的辣度与HPLC法结果在同一辣度级别。     

辣白菜的辣度测定与分级研究

辣白菜是以白菜、辣椒为主要原料经发酵制得的一类调味品,其风味独特,味道鲜美,是餐桌上的调味佳品。通过控制辣椒添加量,制作多种辣味程度的辣白菜。当辣白菜总酸含量达到0.4%时测定其辣度,品评人员依照所制定的辣度分级标准对辣白菜的辣味进行感官评价。最终根据辣度值与感官评价结果,将辣白菜辣度划分为3个级别:微辣0SHU900、中辣900SHU1600、辣1600SHU2500。     

川菜菜品的辣味物质分析与辣度分级

采用高效液相色谱法测定部分川菜菜品中辣味物质（辣椒素及二氢辣椒素）的含量,根据高效液相色谱分析结果结合感官评价进行辣味分级。根据辣度的强弱分为5级（特辣,辣椒素类物质含量≥0.291 8 g/kg）、4级（辣,辣椒素类物质含量0.092 4～0.291 8 g/kg）、3级（中辣,辣椒素类物质含量0.019 5～0.092 4 g/kg）、2级（微辣,辣椒素类物质含量0.001 95～0.019 5 g/kg）、1级（不辣,辣椒素类物质含量＜0.001 95 g/kg）5 个等级。在123 个样品中,1级样品占39.84%,2级样品占18.70%,3级样品占26.83%,4级样品占12.20%,5级样品占2.44%。实验还分析了辣椒及其制品对样品辣味的影响,样品的辣味不仅与辣椒及其制品的种类和使用量有关,还与加工方式、原料大小、加工温度、调味料等密切相关。     

辣味食品辣度量化分级技术研究

本文针对贵阳地区消费人群对辣味食品辣度的感官评价进行了调查,定量分析了不同辣度辣味食品中辣椒碱的含量,依据感官辣度和辣味食品中辣椒碱的含量,对辣味食品的辣度进行了量化,并分为4级:1级(微辣;辣椒碱含量<0.30%)、2级(中辣;辣椒碱含量0.30%～0.50%)、3级(辣;辣椒碱含量0.50%～0.70%)、4级(很辣;辣椒碱含量>0.80%)。在考虑辣椒原料综合利用的基础上,设计了定量添加辣椒精以生产不同辣度辣味食品的工艺路线。     

近红外光谱技术快速无损测定干辣椒的辣度

采用高效液相色谱测定干辣椒样品中的辣椒碱和二氢辣椒碱含量,利用透反射模式采集干辣椒样品的近红外光谱,采用偏最小二乘法(PLS)建立干辣椒样品的辣度评价的校正模型,并对模型用于预测。结果表明,筛选出建模光谱波段为9000～4000cm-1;通过残余方差(RVV)分析,确定了最适主成分数为8;干辣椒的辣度PLS评价模型的定标集和验证集的相关系数(RC,RV)分别为0.9871、0.9104,定标集和验证集的标准差(SEC,SEP)分别为2445、3976。研究发现,近红外光谱法作为一种快速而准确的定量分析手段,在干辣椒及其制品的辣度评价方面有广阔的应用前景。     

辣椒及辣椒制品辣度分析研究进展

对辣椒及辣椒制品中辣味的物质基础和呈味机理、辣度的分类和影响因素、辣度评价方法和分级方法等方面进行了详细的阐述,并对该领域的发展前景进行了展望。     

Improved consistency in DNPH-mediated pyruvic acid analysis of onion juice by modifying the sample processing order

Onion pungency is commonly measured on absorbency of the wine pink color that results from adding NaOH to the heated mixture of dinitrophenylhydrazine (DNPH) and onion juice. However, significant variation exists among several modifications of the original Schwimmer and Weston (SW) method. We observed differences in pyruvic acid concentrations of 20%-30% between our automated method and a batch method with manual absorbency readings. To determine the source of the differences, we examined the heating time and waiting time of the sample-DNPH mixtures and found no differences. The differences were caused by differential color degradation between the pyruvic acid standards and onion juice samples. These differences could be minimized by reading the absorbency within 1 min of NaOH addition. Using this information, we devised the one-by-one method to control the reading time at 30 s. We compared 5 different analysis methods of 40 onion samples representing 4 onion colors. The automated, high-performance liquid chromatography, and SW methods had similar results, with only about a 5% difference. However, the batch method resulted in differences of approximately 24% as compared to the automated method. The one-by-one method produced very comparable results, within 5%, to the automated method. By modifying the procedure to ensure a uniform and fast reading time, we increased the consistency between the pungency analysis methods. Therefore, fast and uniform absorbency reading time is essential for an accurate measurement of pungency in undiluted onion juice.     

花椒麻度分级的改良斯科维尔指数法建立研究

针对辣椒辣度的斯科维尔指数（Scoville heat units,SHU）法存在对基质影响因素的忽略及检验结果缺乏统计学依据的问题,通过将单样品评价改为样品液与制备基质对照液的成对比较检验,以及增加评价小组人数或评价轮次改进实验设计等,建立了与辣味同为三叉神经感的花椒麻味感觉强度的间接测量方法--改良SHU法。应用新方法对花椒（Zanthoxylum bungeanum Maxim.）麻度进行测量与分级,并同时采用紫外分光光度计法对花椒中的酰胺含量进行了测定。结果表明：麻味感觉强度值与花椒酰胺的物理含量之间具有一定的一致性,但对某些品种而言,相近的或者较低的花椒酰胺含量表现出更强的麻感,较高的酰胺含量却能表现出较低的麻感。说明,花椒麻味感觉强度不仅与其所含的花椒酰胺总含量相关,也与花椒酰胺的构成及其结构相关。该方法的建立对花椒麻度相关研究以及应用麻度作为核心指标进行花椒及其制品质量评价与控制具有重要的理论和实践意义。     

Decrease of Pungency in "Radish Kimchi" during Fermentation

Acidity in radish kimchi increased with fermentation time, resulting in a gradual decrease in pH. Decrease of pungency was accompanied by a decrease in 4-methylthio-3-butenyl isothiocyanate (MTB-NCS) in the homogenate. Optimum flavor occurred on the third day of fermentation when MTB-NCS concentration was 6.6 × 2 μmoles/100g. The decrease in MTB-NCS concentration was accompanied by the gradual loss of 4-methylthio-3-butenyl glucosinolate (MTB-glu-cosinolate), which occurred more rapidly than the decline in total glucosinolates. Ascorbic acid-dependent myrosinase activity declined gradually until the third day of fermentation, although ascorbic acid content remained above that required for maximal enzyme activity.     

调味剂与食用油对辣度影响的研究

通过进行单因素试验和均匀试验,研究不同调味料(食盐,蔗糖,柠檬酸,硫酸奎宁,谷氨酸钠,食用油)对辣度的影响。实验结果表明,添加食用油和调味剂对辣度均有降低效用,其中食用油的影响是最大的,食盐(咸味)和谷氨酸钠(鲜味)的影响相对较小。     

Implications of spatial and temporal changes in concentration of pyruvate and glucose in onion (Allium cepa L.) bulbs during controlled atmosphere storage

BACKGROUND: Pungency and perceived sweetness are important quality assurance parameters for onion producers; however, there is still a paucity of information describing the spatial changes within the bulb of some taste‐related compounds during storage. Accordingly, onion bulbs of cultivars (cvs.), SS1 (low pungency, low dry matter) and Renate (pungent, high dry matter) bulbs, were divided into 12 sections and both spatial and temporal variations of pyruvate and glucose were recorded during standard controlled atmosphere storage. RESULTS: Pyruvate within cv. SS1 bulbs reached 8.3 µmol g^?1 fresh weight (FW) from pre‐storage levels of less than 3.4 µmol g^?1 FW, whilst pyruvate changes in cv. Renate remained in the ‘pungent’ category, between 12 µmol g^?1 FW and 15 µmol g^?1 FW; thus having fewer implications for marketing and quality assurance. Glucose concentrations were significantly higher for both cvs. in the neck region as compared to basal tissue. Higher glucose levels were recorded in the core of the bulb than in outer scales of cv. Renate. The opposite was found for cv. SS1. There was an inverse correlation of ? 0.69 and ? 0.87 between glucose and pyruvate for cvs. SS1 and Renate, respectively. CONCLUSION: In order to measure overall bulb flavour, it is recommended that sampling procedures, particularly for routine pungency determination, be carried out on bulb quarters or wedges rather than equatorial sections. Copyright © 2009 Society of Chemical Industry     

基于差别度的电子舌对花椒麻味物质的定量预测

以建立一套快速批量的电子感官麻度评价方法为目的。以干花椒麻味提取液为研究对象,基于感官评价对照差别检验的方法和原理,对未知样品与参比样采取对比平行测定,以欧氏距离作为参比与样品间电子舌区分的差别度,探索建立花椒麻味物质含量电子舌预测模型。结果表明：差别度能很好地反应麻味物质不同质量浓度之间的差异,该差异可用线性数学模型表示。采用该模型对样品的预测值与实际值之间的相对标准偏差小于20%,满足感官评价对风味属性量化评价的要求。本研究实现了对花椒麻味物质定量预测的突破,同时也对利用电子感官进行半定量和定量测定研究提供了方法借鉴。     

辣椒素类物质辣味的研究进展

辣椒素类物质是一类带有香草基团和中长链脂肪酰胺结构的生物碱,其中辣椒素和二氢辣椒素辣度最高。部分辣椒素类物质可激活相关受体,引起痛觉与热觉神经信号的传导,使人感到辣味。斯科维尔指数法是评价辣度最常见的方法,但评价结果仅与辣味物质的含量有关,无法真正反映样品的辣度,而时间-强度法可获得多个与辣度相关的定量指标,具有更高的参考价值。除增加辣椒素类物质的含量外,使用水基分散系、提高体系温度、增感作用的产生甚至其他感觉刺激均可显著提升辣椒素类物质辣味感知强度,在感官评价中应当特别注意。综上,本文总结辣椒素类物质的结构、分布,辣味呈现机制、评价方法以及影响辣味感知的因素等方面,以期为食品辣味强度预测和辣味食品的开发提供参考。     

Magnitude Estimation of Food Acceptance

A printed list of 50 various food items was evaluated to determine foods most favored by 236 enlisted Army personnel. Three groups, based on intergroup comparability, were formed to test several measurement procedures to determine which technique best evaluated overall food acceptance. Two variations of magnitude estimation procedures were compared to the standard nine-point category ratings. The category ratings and variations of magnitude estimation results were highly related. Benefits concerning the choice of method depend on the extent or magnitude of sensory information required.