Design of complex microstructures and processes for advanced salt reduction in foods

整个研究项目是关于复杂微结构（及其制造工艺）的设计，以实现食品中的盐减少。我们的目标不仅仅是减少盐，或者用人造材料代替盐，而是仔细地建立盐的输送曲线，不会对消费者的口味造成影响。因此，最小量的盐被递送给消费者，以帮助食品工业通过向消费者提供盐减少的加工食品的选择来实现减少盐摄入量的政府指导方针。加工食品中的盐与风味密切相关，事实上，盐通常作为增味剂添加。因此，非盐释放曲线的递送以及可接受的总体风味递送曲线的递送是本研究的主题。实验方法将包括在体内测量模型流体和食物中挥发性和非挥发性化合物的动态释放和感知以及由此产生的唾液流速。实验工作之后将进行建模（由财团领导者联合利华支持），以提供适当的目标，以纳入由另一个财团合作伙伴（伯明翰大学）开发的食品微结构的设计规则。模型流体最初将由氯化钠（“盐”）和氯化钾的简单水溶液混合物组成。氯化钾，而不是氯化钠，不会对消费者带来任何健康风险，因为它是钠离子与冠心病等问题有关。事实上，有报道说一般饮食中缺乏钾。它增强了咸度的感知，然而，当以太高的浓度递送时，它也被感知为苦的。需要仔细评价适当的混合物和输送情况。作为下一步，将添加香料，以确保提供的风味特征仍然是消费者可接受的。口味将是鸡肉、牛肉、蘑菇和大蒜等商业咸味口味，因为整个项目可能会在最后交付阶段将酱料或调料作为演示食品。真实的食品的物理化学性质比盐水溶液复杂得多，因此，所研究的模型流体或模型食品的微观结构、材料组成和流变学的复杂程度也会增加。我们的科学目标是推动与该项目相关的感官科学参数之间的理解，即，感知的咸味和风味，以及食品成分/材料行为。系统地改变模型流体的流变行为，包括剪切流变和拉伸流变。作为下一步，将引入第二食物相，其可以是固相或液相。第二液相可以是油基或水基的，并且分别在乳液体系或相分离的生物聚合物混合物中进行研究。感兴趣的固相包括凝胶颗粒和淀粉颗粒，这两种颗粒通常存在于食品中。后者最近被证明会影响盐的感知（诺丁汉大学的John Mitchell教授）。我们的团队还将负责测试初始微结构、模型食品以及最终真实的食品的感官特性。然后将确定感官特性，以确保为模型系统开发的设计规则可以应用于真实的食品。

The overall research project is about the design of complex microstructures (and processes for their manufacture) to achieve salt reduction in foods. The aim is, not simply to reduce salt, or replace it by man-made materials but to carefully establish salt delivery profiles that present no taste compromise to the consumer. Thereby, a minimum amount of salt is delivered to the consumer to help the food industry work towards government guidelines of reducing the salt intake by offering the consumer a choice of salt reduced processed foods. Salt in processed foods is closely linked to flavour, indeed, salt is often added as a flavour enhancer. Hence, the delivery of not salt release profiles as well as the delivery of acceptable, overall flavour delivery profiles are subjects for this research. The experimental approach will consist of in-vivo measuring of the dynamic release and perception of volatile and non-volatile compounds in model fluids and foods as well as the resulting saliva flow rate. The experimental work will be followed by modelling (supported by the consortium leader Unilever) to deliver appropriate targets to feed into the design rules for the food microstructures to be developed by another consortium partner (University of Birmingham). Model fluids will initially consist of simple aqueous mixtures of sodium chloride ('salt') and potassium chloride. Potassium chloride, as opposed to sodium chloride, does not carry any health risks to the consumer since it is the sodium ion that is linked to problems such as coronary heart desease. Indeed, a lack of potassium in the general diet has been reported. It enhances the perceived perception of saltiness, however, it is also perceived as bitter when delivered in too high concentrations. Appropriate mixtures and delivery profiles need to be carefully evaluated. As a next step, flavours will be added to ensure that the delivered flavour profiles will still be acceptable to the consumer. The flavours will be commercial savoury flavours such as chicken, beef, mushroom, and garlic since the overall project is likely to target a sauce or dressing as the demonstrator food product in its final delivery stage. Real foods are more complex in their physical-chemical properties than aqueous solutions of salt, hence, model fluids or model foods studied will be chosen with increasing degreees of complexity in their microstructure, material composition and rheology. Our scientific ambition is to push forward the understanding between the sensory science parameters related to this project, i.e., perceived saltiness and flavour, and food composition/material behaviour. In a systematic way, we will change the rheological behaviour of the model fluids including shear rheology and extensional rheology. As a next step, a second food phase, which can be a solid phase or a liquid phase, will be introduced. A second liquid phase can be oil-based, or aqueous based and studied in an emulsion system, or phase-separated biopolymer mixtures respectively. Solid phases of interest include gel particles and starch granules, both of which are often present in foods. The latter have recently been demonstrated to influence salt perception (Prof. John Mitchell, University of Nottingham). Our group will also be responible for testing the sensory properties of the initial microstructures, the model foods, and finally, a real food product. The sensory properties will then be determeind to ensure that the design rules developed for the model systems can be applied to real foods.