Programmed emulsions for reduced levels of salt or sugar in liquid and semi-liquid foods

点击翻译按钮获取中文摘要

This project will deliver rapidly a formulation engineering route to salt or sugar reduction in sauces, dressings, soups and milk shakes. It will also provide non-chemically modified starches as food emulsifiers. The novelty lies in programming one of the formulation ingredients, starch, for dual purpose: product stabilisation and taste experience using ingredients acceptable to consumers.There are a range of novel strategies to reduce salt and sugar content in dry/solid foods, but these are not practical in liquid foods due to the high solubility of salt and sugar in water. Therefore this project specifically targets the salt or sugar levels of liquid and semi-liquid foods where salt or sugar is primarily added for taste rather than preservation, a particular challenge for the food industry. We hypothesise that the formulation levels of these undesirable nutrients can be reduced without taste compromise by encapsulation in a fashion that, while the delivery vehicles remain stable during shelf life, they break down in the mouth, close to the taste receptors to deliver the tastant right where it will be perceived. Currently salt or sugar is delivered to the taste receptors through the bulk of the food and taste intensity correlates to concentration. Delivery of pockets of sufficiently high concentrations of salt or sugar near the taste receptors will enable lowering their overall concentration in the bulk of the food that is swallowed without contributing to taste. The proposed approach is to use water-in-oil-in-water emulsions (wow/s) to encapsulate the salt or sugar, which will be protected by a starch based shell. This starch will be designed to break down when brought into contact with saliva, thus releasing high concentrations of salt or sugar close to taste receptors in the mouth.wow emulsions are oil-in-water (o/w) emulsions where the oil droplets are filled with water droplets. Although wow/s have been talked about for some time, they can be very difficult to stabilise to give a long shelf life and therefore are not found in commercial foods or drinks. What happens is termed emptying out: the internalised water diffuses through the oil into the external water phase slowly converting the wow into a simple o/w. There have been different approaches to reduce emptying out, but perhaps the only practically relevant method for this project is through particle stabilisation of the external o/w interface. This has recently been demonstrated to be possible with OSA starch (a chemically modified starch) that is well known to be a good emulsifier. Native starches with small granules have also been reported to show emulsifying ability although our own attempts have shown limited stability. It can be predicted that native starches will not be widely functional across the broad spectrum of emulsion based foods and drinks. Chemical modification of food ingredients is not desired by consumers, so we will explore physical modification via extrusion processing and milling to program starches as emulsifier & for break down delivery of salt or sugar near the taste receptors during consumption. As salivary amylase will be the tastant release trigger, individuals' or consumer groups' amylase levels will be considered in developing this pathway for salt or sugar reduction.We have proof-of-concept sensory data indicative of the potential success of the proposed technology based on formulating with a commercial OSA starch. Emulsion stability was excellent although encapsulation efficiency was not optimised for product storage. The internal water phase was stabilised with polyglycerol polyricinoleate (PGPR) as in most researches despite the limitations for use of PGPR in processed foods. In this research alternative approaches to stabilise the internal water phase, e.g., by a fat crystal network (which is known to be successful), extremely hydrophobic starches or other food particles not requiring chemical modification will be applied.