Health and wellness have become main drivers for new product developments in food and beverages. As consumers increasingly expect a natural taste and a high quality product, we are seeing more and more different types of particles being introduced. Juices with pulp and fibers, such as in orange juice, are already very common, but in the last 5-10 years’ demand for the inclusion of larger particles has increased. This is because mixing particles into beverages creates a similar experience as eating fruit itself, but in liquid form, with the added benefits of having whole pieces of the fruit in juice. This also has the advantage of being more filling for the consumer, than a beverage without particles.
With these exciting opportunities for new and innovative products come challenges for manufacturers as they seek to perfect flavor and provide authentic textures, while maintaining food safety levels.
Food safety is achieved by ensuring that the particles reach the required sterilization and pasteurization temperature in the coldest spot, whilst simultaneously preserving the particle’s taste, color, texture and nutrients. It takes time for the heat to penetrate into the center of particles, however, the longer a liquid is subjected to heat the more degraded it gets. This degradation lowers the overall quality and integrity of the liquid and particles, which can impact the taste and texture of the product. And of course, too little heat treatment will jeopardize food safety, and so the challenge becomes how to get the balance right. Tetra Pak has identified a formula which calculates and ‘cracks the code’ on the optimum time for heat treatment and processing. Due to this discovery, manufacturers are able to protect particle integrity, achieve the highest quality product and deliver a natural experience for the consumer, whilst guaranteeing food safety.
Protecting particle integrity can also be affected by the handling of raw materials. The various processes that the particle has to go through will inevitably affect its quality. Larger particles are particularly sensitive to mechanical shearing or tearing during the heating, holding and cooling phases so again, shorter retention time is crucial.
In addition, consistency and even distribution of added particles needs to be ensured to give the consumer a “natural” experience. If the formulation and recipe are not optimised for the density difference between particles and the carrier liquid, the particles will separate from the carrier liquid, resulting in an uneven distribution in the product.
These challenges are further complicated by the wide variety of particle characteristics, thanks to differences in particle size, shape and composition. The specific composition of particles, such as water and carbohydrate content, affects physical properties such as density, thermal conductivity and specific heat capacity. Liquids may go through several steps in a traditional process that particles cannot withstand, thereby further jeopardising the quality and integrity of the particles.