Enhancing the consumer perception of reduced fat foods through interfacial design and rheological behaviour

我们的目标是开发一种策略，通过改变感官对乳化脂肪的感知方式来掩盖某些食物类型中的(低)脂肪含量。通过这一途径，我们希望提高消费者对更健康、更低脂肪食品的接受度。许多食物含有分散的小油滴，被称为乳状液，可以提供令人满意的味道和质地。这些食物包括牛奶、奶油、酸奶、蛋黄酱、汤、调味汁等，估计约占我们膳食脂肪摄入量的25%。我们的目标是通过控制油滴的外部稳定层来改变感官对乳状液中脂肪含量的感知。我们将制作模型食品，在类似于口腔中的条件下，在流动时进行三维成像，这样我们就可以了解涉及的基本过程。研究结果将与人类志愿者对这些食物的感官知觉和可接受性相关。肥胖是英国人口健康面临的一大挑战，据估计，NHS每年要花费2b GB，预计这一数字还会上升。这被归咎于饮食和生活方式的结合。我们习惯性地消耗比我们需要的稍多的能源，在食物短缺的情况下积累储备。这导致我们的身体质量指数(BMI)随着年龄的增长而稳步增加，因此55-65岁年龄段的肥胖率最高。因此，长期小幅减少能量摄入可以显著降低肥胖水平。食品乳状液中脂肪的感官感知是复杂的；因此，许多低脂食品不太被消费者接受。提高这些食物的可接受性有助于减少导致长期体重增加的小能量过剩。脂肪必须被乳化成小滴(乳状液)，以保持其在食物中的均匀分布。蛋白质和其他乳化剂等成分在乳液滴上形成一层，以稳定它们并防止分离。这一层影响液滴相互作用的方式以及食物的其他部分，这反过来又影响我们在嘴里感觉它们的方式。我们之前已经证明，与其他类型的乳化剂相比，由蛋白质稳定的乳状液对脂肪含量的感官感受更强。在更多的对照实验中，我们还表明，包有蛋白质的液滴可以增加整个乳状液的粘度。我们认为这是因为蛋白质在乳液滴上形成了一个更坚固的层，而乳化剂形成了一个类似液体的层。我们的目标是确定乳液滴上的这一层如何增强对乳化食品中脂肪含量的感官感知。我们的主要目标是：-开发使用蛋白质、乳化剂、颗粒和加工方法形成具有广泛强度的表面层的乳液系统。-在剪切流动下使用高速共聚焦(3-D)成像了解复杂的粘度和流动行为。-设计由这些表层稳定的具有增强粘度的食品乳状液模型。-测量这些模型食品的脂肪含量的感官感知-确定与现有减脂食品相比，消费者对新模型食品的偏好。食品研究所(IFR)将开发和设计一系列具有明确表面特性的受控乳剂。Leatherhead食品研究将确定消费者对这些食品的感官和反应。爱丁堡大学将使用最先进的共焦成像技术在3D中可视化乳化液液滴在类似于口腔中发现的流动条件下的表现。这将使人们更准确地了解其中涉及的机制，从而使未来有可能设计出更具消费者偏好的低脂食品。这应该会增加人们对更健康、更低脂肪食物的摄取，从而有助于解决长期体重增加问题。

We aim to develop a strategy to disguise the (low) fat content in certain food types by changing the way emulsified fats are perceived by the senses. By this route we hope to improve the consumer acceptability of healthier, reduced fat foods. Many foods contain small dispersed droplets of oil, known as emulsions to impart desirable tastes and textures. These foods, include milk, cream, yoghurts, mayonnaise, soups, sauces etc, and are estimated to form around 25% of our dietary fat intake. We aim to change the sensory perception of fat content in emulsions by controlling the outer stabilising layer of the oil droplets. We will make model foods that will be imaged in 3 dimensions whilst flowing, under conditions similar to those in the mouth, so that we can understand the fundamental processes involved. The results will be correlated with sensory perception and acceptability of these foods in human volunteers. Obesity is a major challenge facing the health of the UK population and costs the NHS an estimated £2b each year which is forecast to rise. This is blamed on a combination of diet and lifestyle. We habitually consume slightly more energy than we require, building up reserves in case of times of food shortage. This leads to a steady increase in our body mass index (BMI) with age, so that the 55-65 age range has the highest obesity rates. Small reductions in energy intake over long periods could therefore significantly reduce obesity levels. The sensory perception of fat in food emulsions is complex; thus many low fat foods are less acceptable to consumers. Improving the acceptability of these foods could help to reduce the small energy excess responsible for long term weight gain. Fat has to be emulsified into small droplets (emulsion) to keep it evenly distributed within the food. Ingredients such as proteins and other emulsifiers form a layer on the emulsion droplets to stabilise them and prevent separation. This layer affects the way the droplets interact with each other and the rest of the food, which in turn affects how we sense them in the mouth. We have shown previously that emulsions stabilised by proteins have an increased sensory perception of fat content, compared to other types of emulsifier. In more controlled experiments, we have also shown that the protein-coated droplets can increase the viscosity of the whole emulsion. We think this is because proteins form a stronger, solid layer on the emulsion droplets, whereas emulsifiers form a fluid-like layer. Our aim is to determine how the layer on the emulsion droplets enhances the sensory perception of fat content in emulsified foods. Our key objectives are:- - Develop emulsion systems that form surface layers with a wide range of strengths using proteins, emulsifiers, particles and processing methods. - Understand the complex viscosity and flow behaviour using high speed confocal (3-D) imaging under shear flow. - Design model food emulsions stabilised by these surface layers with enhanced viscosity. - Measure the sensory perception of fat content of these model foods - Determine consumer preference of new model foods compared to existing reduced fat foods. The Institute of Food Research (IFR) will develop and design a range of well controlled emulsions with defined surface properties. Leatherhead Food Research will determine the sensory and consumer response to these foods. The University of Edinburgh will use state of the art confocal imaging techniques to visualise in 3-D how the emulsion droplets are behaving under flow conditions similar to those found in the mouth. This will give more precise understanding of the mechanisms involved that will make it possible in the future to design reduced fat foods with better consumer preference. This should increase the uptake of healthier, reduced fat foods and thus help to address long term weight gain.