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，通过改变乳化脂肪被感官感知的方式来掩盖某些食物类型中的（低）脂肪含量。我们希望通过这一途径来提高消费者对更健康、低脂肪食品的接受度。许多食物含有分散的油滴，称为乳液，以赋予理想的味道和质地。这些食物，包括牛奶，奶油，酸奶，蛋黄酱，汤，酱汁等，估计占我们膳食脂肪摄入量的25%左右。我们的目标是通过控制油滴的外部稳定层来改变乳剂中脂肪含量的感官知觉。我们将制作模型食物，这些食物将在类似于口腔中的条件下流动时进行三维成像，以便我们能够理解所涉及的基本过程。这些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个主要挑战，预计NHS每年将花费20亿英镑，预计还会上升。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略多的能量，以备食物短缺时使用。这导致我们的身体质量指数（BMI）随着年龄的增长而稳步上升，因此55-65岁年龄段的肥胖率最高。因此，长期少量减少能量摄入可以显著降低肥胖水平。食品乳剂中脂肪的感官知觉是复杂的，因此许多低脂食品不太容易被消费者接受。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少量能量过剩。脂肪必须乳化成小滴（乳液），以保持其均匀分布在食物中。蛋白质和其他乳化剂等成分在乳液液滴上形成一层，以稳定它们并防止分离。这一层会影响液滴彼此之间以及与其他食物之间的相互作用，从而影响我们在口中感知它们的方式。我们之前已经表明，与其他类型的乳化剂相比，由蛋白质稳定的乳液具有增加的脂肪含量的感官知觉。在更多的受控实验中，我们还表明，蛋白质包被的液滴可以增加整个乳液的粘度。我们认为这是因为蛋白质在乳化液滴上形成了一个更坚固的固体层，而乳化剂形成了一个类似液体的层。我们的目的是确定乳化液滴上的层如何增强乳化食品中脂肪含量的感官知觉。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各种强度的表面层的乳液系统。- 在剪切流下使用高速共焦（3-D）成像了解复杂粘度和流动行为。- 通过这些表面层稳定的具有增强粘度的食品乳剂的设计模型。- 测量这些模型食品的脂肪含量的感官知觉-确定消费者对新模型食品与现有减脂食品相比的偏好。食品研究所（IFR）将开发和设计一系列具有明确表面特性的控制良好的乳液。莱瑟黑德食品研究将确定感官和消费者对这些食品的反应。爱丁堡大学将使用最先进的共聚焦成像技术，以3D方式可视化乳液液滴在类似于口腔中发现的流动条件下的行为。这将使人们更准确地了解所涉及的机制，这将使人们有可能在未来设计出更好的消费者偏好的减脂食品。这应该会增加对更健康，减少脂肪的食物的摄取，从而有助于解决长期体重增加的问题。

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.