The texture and taste of food in the brain

Oral texture is represented in the brain areas that represent taste, including the primary taste cortex, the orbitofrontal cortex, and the amygdala. Some neurons represent viscosity, and their responses correlate with the subjective thickness of a food. Other neurons represent fat in the mouth, and represent it by its texture not by its chemical composition, in that they also respond to paraffin oil and silicone in the mouth. The discovery has been made that these fat-responsive neurons encode the coefficient of sliding friction and not viscosity, and this opens the way for the development of new foods with the pleasant mouth feel of fat and with health-promoting designed nutritional properties. A few other neurons respond to free fatty acids (such as linoleic acid), do not respond to fat in the mouth, and may contribute to some “off” tastes in the mouth. Some other neurons code for astringency. Others neurons respond to other aspects of texture such as the crisp fresh texture of a slice of apple versus the same apple after blending. Different neurons respond to different combinations of these texture properties, oral temperature, taste, and in the orbitofrontal cortex to olfactory and visual properties of food. In the orbitofrontal cortex, the pleasantness and reward value of the food is represented, but the primary taste cortex represents taste and texture independently of value. These discoveries were made in macaques that have similar cortical brain areas for taste and texture processing as humans, and complementary human functional neuroimaging studies are described.     

Human functional neuroimaging in nicotine and tobacco research: basics, background, and beyond.

Modern functional neuroimaging techniques allow nicotine and tobacco researchers to investigate the neurobiological basis of addiction in humans. We introduce the methods and measures of the following neuroimaging techniques: Electroencephalography and event-related cortical potentials, positron emission tomography, and functional magnetic resonance imaging. We outline strengths and limitations across modalities and describe new and emerging technologies. We provide summaries of recent neuroimaging findings in the field of nicotine and tobacco research for neurochemistry, smoking and nicotine administration, craving and cue-reactivity, cognitive and affective information processing, and tobacco withdrawal. We address limitations of studies to date and identify opportunities for future research.     

Variables Influencing Chewing Electromyography Response in Food Texture Evaluation

Food choice is linked to many characteristics, among which texture is one of the most important. As a consequence, texture is a quality parameter that needs to be understood on a global perspective, including physical and psychological aspects. Texture perception is gained from a complex process of chewing, and not from a single action. Thus, there is a need for techniques that consider the whole process of chewing. Among those techniques, electromyography (EMG) seems promising. Different variables influence the chewing response as registered through EMG. Some of those variables are linked to the experimental set-up, where there is a need for standardization as well as data processing procedures. Other variables are linked to subject characteristics, both physical (e.g., facial anatomy, age) and psychological (e.g., personality, cognitive processes). Experimental planning can also constitute a source of variability, the number of products and trials per session being important items. The way the EMG signals are processed (parameters from EMG records) also must be considered in order to extract reliable and consistent conclusions. Because no standard practices have been established for the use of EMG in food texture assessment, it is important to review how this technique has been used, the variables involved, and the meaning or concepts associated with the outputs.     

Mechanisms for sensing fat in food in the mouth: Presented at the Symposium "The Taste for Fat: New Discoveries on the Role of Fat in Sensory Perception, Metabolism, Sensory Pleasure and Beyond" held at the Institute of Food Technologists 2011 Annual Meeting, New Orleans, LA, USA., June 12, 2011

The brain areas that represent taste including the primary taste cortex and the orbitofrontal cortex also provide a representation of oral texture. Fat texture is represented by neurons independently of viscosity: some neurons respond to fat independently of viscosity, and other neurons encode viscosity. The neurons that respond to fat also respond to silicone and paraffin oil, indicating that the sensing is texture-specific not chemo-specific. This fat sensing is not related to free fatty acids such as linoleic acid, and a few other neurons that respond to free fatty acids typically do not respond to fat in the mouth. Complementary human functional neuroimaging studies show that the pleasantness of food texture is represented in the orbitofrontal cortex. These findings have implications for the design of foods that mimic the pleasant texture of fat in the mouth but have low energy content, and thus for the prevention and treatment of obesity.     

芦荟黄瓜复合饮料的研制

研究了以芦荟和黄瓜为原料加工生产复合饮料的生产工艺及操作要点，通过正交试验和对饮料的品尝鉴定，确定了饮料的最佳配比，即白砂糖12％，黄瓜汁30％，芦荟汁10％，VC 004％，并提出了该饮料的质量指标，所研制出的芦荟黄瓜复合饮料具有多种保健功能。     

Psychophysiological effect of odor

Techniques to measure the activity of the taste and odor molecules at the olfactory epithelium, taste bud, and brain response levels are now being used to determine and measure the actual transduction of the chemical information to the brain waves. We studied a number of methods of measuring brain wave responses to odorants and we settled on an electroencephalographic method of measuring the slow brain waves {>13 Hz} at the frontal location on the scalp. This technique known as contingent negative variation (CNV) measures the early component {at 400 to 1000 ms} of the beta wave variation, which can be negative, positive, or neutral depending on the odorant being presented to the subject. This component is almost independent of the subject's psychological state, degree of arousal, or level of consciousness and is known as the external component. The experimental paradigm creates a reproducible result in which odorants may be classified as stimulating, sedating, or neutral. These psychophysiological effects of odors on man appear to offer a means to determine precognitive responses directly related to the effect of the chemical messenger. There does not appear to be any bias as to sex, national origin, or race. At this point in our research efforts, we do not see evidence that there is a bias related to age. It is proposed that some of the problems of classical sensory evaluation can be helped by the use of psychophysiological recording techniques, such as CNV, as a measurement of brain activity and response to flavor and aroma.     

TASTE PERCEPTION, FOOD QUALITY AND CONSUMER ACCEPTANCE

Consumer acceptance is a more measurable parameter than the ill defined concept of quality. Thus, it is better to consider how the taste, and indeed all the sensory characteristics, of foods can be manipulated to improve consumer acceptance. If tastes are to be manipulated, it is necessary to understand something about taste mechanisms so that the researcher can avoid the all too common artifacts and biases involved in gustatory measurement. Discussed here are some aspects of sensory information processing in the brain, the problems of crosssensory confusion, sensory adaptation and taste categorization.     

Biomimetic-based odor and taste sensing systems to food quality and safety characterization: An overview on basic principles and recent achievements

The appreciation of food is based on the perception of many senses; in fact for a total estimation the human senses are involved. Biomimetics as the ‘abstraction of good design from nature’ is to analyze and tap nature’s huge reservoir of potential innovative solutions. These biological solutions are cost-efficient, multi-functional and environmentally friendly. Human sense inspired sensor technologies such as multi arrays of sensors are of interest to food industry for food control and sensory evaluation. These systems mimic the human sense to provide a decision on final food quality and safety. Nanotechnology techniques and biosensors are the recent advances in these systems. Odor and taste sensors are interestingly under consideration to food engineers and scientist for application in food processing tasks such as drying, packaging, sorting and so on. Soft computing together with computer development is the promising outlook to enhance the performance of these sensing systems to food quality and safety characterization. This paper deals with some aspects of such systems (odor sensor and taste sensor) and some of more recent applications and advances for food control in food research and technology are discussed as well.     

Is the taste of British milk chocolate different?

The flavour of a piece of chocolate can be affected by the type and amount of ingredients present, as well as by the processing techniques used. This article reviews the factors that alter the taste of milk chocolate and considers whether a unique British flavour exists. Chocolate varieties with a wide range of flavours are currently being sold throughout the world and most are available within the UK. It is concluded that the existence of a unique British milk chocolate flavour may be due to the widespread use of chocolate crumb as an ingredient, which introduces a cooked taste into the final product.     

肉品中的寡肽及其呈味机制研究进展

呈味肽是从食物中提取或由氨基酸合成的,能够丰富、改善、掩盖肉品感官特性的肽类组分。呈味肽分为多肽和寡肽两类,其中赋予肉品滋味的主要是分子质量小于3000 Da的寡肽。此外,寡肽还具有多种生理功能,在参与人体免疫调节和生理代谢等方面具有重要意义。本文介绍了几种寡肽在肉品中的作用,综述了其在味觉生理学和受体等呈味机制的新进展,并从pH、加工方式、微生物和其他因素等角度阐述了影响寡肽呈味的因素,以期为肉制品滋味研究、新型健康食品的开发提供参考依据。     

味觉感知的人体肠-脑轴信号传导机制研究进展

味觉是人类感知生物摄取能的重要环节,胃肠道亦存在味觉感知现象。本文从胃肠道味觉受体、胃肠道味觉感知通路及肠-脑轴味觉信号传导机制等方面进行了分析,胃肠道中味觉感知表明胃肠道中存在味觉受体第一家族亚型（taste receptor type 1 member,T1R）1、T1R2、T1R3、味觉受体第二家族亚型（taste receptors type 2,T2Rs）等味觉受体,且肠道味觉物质刺激肠内分泌细胞分泌胆囊收缩素（cholecystokinin,CCK）、肽YY（peptide YY,PYY）等脑肠肽激素,与味觉信号在神经元的传递有关;肠道中鲜味物质谷氨酸钠显著激活大脑缰核、杏仁核和下丘脑亚核的神经网络,表明肠-脑轴味觉感知是基于胃肠道受体及脑肠肽、神经元和大脑中枢神经系统之间的共同调控,从而提出肠-脑轴味觉信号传导机制假说,认为甜味受体T1R2/T1R3和鲜味受体T1R1/T1R3具有相似的信号传导通路,味觉物质作用于肠道后,与肠道中相应的味觉受体结合,激活磷脂酶-β2（phospholipase C-β2,PLC-β2）,释放Ca2＋,引起肠道内环境的变化,刺激肠内分泌细胞分泌PYY、CCK等激素,被肠神经元突触特异性识别,将味觉信号传导至大脑神经中枢;而谷氨酸代谢型受体4（metabotropic glutamate receptor 4,mGluR4）和苦味受体T2Rs信号传导通路则是通过激活磷酸二酯酶（phosphodiesterase,PDE）,使细胞质内3’,5’-环腺苷酸（3’,5’-cyclic adenylic acid,cAMP）浓度降低,从而解除环核苷酸（cyclic nucleotide,cNMP）的抑制作用,从而释放Ca2＋。基于肠-脑轴味觉偏好,为味觉发生改变的患者开发治疗新药物、寻找新的药物靶点提供了新的方向。对肠-脑轴味觉信号传导机制的研究将为胃肠道生理的神经控制提供分子框架、精准控制人体对味觉营养物质的生理反应,并对味觉物质在肠-脑轴中的摄入、代谢、调节等及开发新的味觉感知途径提供新的理论依据。     

A critical review on the use of artificial neural networks in olive oil production,characterization and authentication

Artificial neural networks (ANN) are computationally based mathematical tools inspired by the fundamental cell of the nervous system, the neuron. ANN constitute a simplified artificial replica of the human brain consisting of parallel processing neural elements similar to neurons in living beings. ANN is able to store large amounts of experimental information to be used for generalization with the aid of an appropriate prediction model. ANN has proved useful for a variety of biological, medical, economic and meteorological purposes, and in agro-food science and technology. The olive oil industry has a substantial weight in Mediterranean's economy. The different steps of the olive oil production process, which include olive tree and fruit care, fruit harvest, mechanical and chemical processing, and oil packaging have been examined in depth with a view to their optimization, and so have the authenticity, sensory properties and other quality-related properties of olive oil. This paper reviews existing literature on the use of bioinformatics predictive methods based on ANN in connection with the production, processing and characterization of olive oil. It examines the state of the art in bioinformatics tools for optimizing or predicting its quality with a view to identifying potential deficiencies or aspects for improvement.     

油脂的风味及感知

油脂是一种重要的营养物质。随着我国经济水平的发展,居民越来越多地关注油脂的风味品质。油脂原料本身的差异以及加工制备过程中的脂肪氧化降解、热分解、美拉德反应等是影响油脂形成不同风味品质的主要因素。口腔加工中油脂及其制品经过味觉、嗅觉、三叉神经感觉等方面相互作用,在大脑特定区域形成风味的认知。目前有研究证明脂肪酸转位酶（CD36）、G蛋白偶联受体（GPCR）等受体参与到一个专门用于感知脂质的感官系统。因此,有人提出脂肪可能是第6种味道。复杂的多感官交互依赖于人类所有感官的反应,未来关于脂肪感知以及脂肪参与多感官交互方面还需要进一步研究。     

植物多肽的制备及在食品中应用的研究进展

植物功能多肽是植物来源的蛋白通过加工后形成的肽链片断,具备独特的生理功能以及较高的营养价值而在食品中得到广泛应用。植物功能多肽在制备、分离、应用与产业化方面均取得了显著进步。植物多肽的制备技术有酸碱水解法、酶水解法、微生物发酵法,其中酶解前对植物蛋白进行预处理可改善植物功能多肽。靶向酶水解法可减少或消除苦味肽的产生,解决了多肽食品应用难题;不同酶解条件得到不同类型的植物功能多肽,并具有营养、呈味、乳化等多种功能,可用于改善食品的产品品质与功能。针对近年来功能多肽在食品方面的研究新进展,综述了植物多肽的制备、脱苦技术和功能特性,并对其产业现状和前景也进行了分析和探讨。     

Potential effects of umami ingredients on human health: Pros and cons

Abstract

Umami taste is the most recent confirmed basic taste in addition to sour, sweet, bitter, and salty. It has been controversial because of its effects on human nutritional benefit. Based on the available literatures, this review categorized 13 positive and negative effects of umami taste on human health. On the positive side, umami taste can improve food flavor and consumption, improve nutrition intake of the elderly and patients, protect against duodenal cancer, reduce ingestion of sodium chloride, decrease consumption of fat, and improve oral functions. On the other hand, umami taste can also induce hepatotoxicity, cause asthma, induce migraine headaches, damage the nervous system, and promote obesity. Due to its novelty, there are many functions and effects of umami taste waiting to be discovered. With further investigation, more information regarding the effects of umami taste on human health will be discerned.     

Interactions among salty, sour and bitter compounds

The human gustatory system is capable of responding to and processing the taste of solitary compounds in water. However, the taste system rarely contacts solitary compounds outside the laboratory and has surely evolved to process complex mixtures of sapid chemicals, such as occur in virtually all foods. This review will focus primarily on the lesser-studied interactions between pairs of salty, sour and bitter compounds. Pair-wise interactions among these three taste qualities should be of interest because they constitute a significant proportion (∼30–50%) of possible binary taste interactions. In general, salts and acids enhance each other at moderate concentrations but suppress each other at higher concentrations. Bitter compounds and acids can either enhance or suppress each other depending on the concentrations, the food stimuli and the experimental methods involved. Sodium salts and bitter compounds generally interact so that bitterness is suppressed to some variable degree and the saltiness is unaffected. As will be described below, there are exceptions to all of these generalities.     

出口腌渍蘑菇的余料利用研究

文章以出口腌渍蘑菇的余料为主要原料对其进行开发利用研究,提出了一种加工美味蘑菇食品的加工技术,主要对其生产工艺、操作技术要点及相关工艺参数进行了探讨。该工艺加工的蘑菇产品,营养丰富、风味鲜美,为出口腌渍蘑菇的余料综合利用提供了新的途径,具有较好的发展前景。     

松花鸡腿的制作工艺

松花鸡腿是以松花蛋和鸡肉为主要原料,借鉴灌制品的加工工艺和配方对传统制作方法进行改进,经过绞制、斩拌、煮制、烟熏、包装、杀菌等工艺制成的新产品。加工后的制品切片平整不散,色香味俱全,并且具有较高的营养价值。此方法解决了传统松花鸡腿制品在切片时一切就散的问题,为应用现代化技术制作松花鸡腿提供了新的方法依据。     

玉米饮料的研究现状与发展前景

玉米被称为"黄金食品",具有多种营养成分及生理功能。将玉米加工成饮料,使吃玉米变成"喝玉米",不但保留了玉米中的营养成分,而且饮用方便,口感清新自然,风味独特,更易于人体吸收。近年来,将玉米与水果、蔬菜等复合而成的复合型的玉米饮料,因其营养价值高,符合目前消费者和市场的需求,成为玉米饮料发展的新机遇。本文综合分析了相关文献的研究现状,对玉米饮料从加工工艺、分类、稳定性研究等方面进行了综述,旨在为以后玉米饮料的研究与发展提供较为全面的参考。     

Cognitive factors affecting taste intensity judgments

The mean sensory response is often considered to represent the perceived intensity for a stimulus on the specified attribute. However, a momentary judgment is the outcome of a number of physical, physiological, and psychological processes. Four types of cognitive variables are discussed, that can affect the outcomes of an intensity scaling experiment.

First of all, the role of cognitive algebra and concept formation in tasks varying with regard to the number of stimuli to be compared, and with regard to the type and number of response scales used, is discussed. Subsequently, the effects of stimulus set characteristics on context and sequence effects are reviewed. Thirdly, temporal changes in responses during the time course of an experimental session are related to fatiguing and learning. Finally, the role of subjects' expectations is discussed.