Soya beverages are harder to homogenize than milk. Cow’s milk is essentially the same the world over, but soya beverages come in a multitude of recipes that make differing demands on the homogenization process. “Soya particles are large proteins that can aggregate together and you need to break these up through effective homogenization. Quite often you homogenize downstream to break up these clusters,” says Nicole Uvenbeck, Line Product Manager at Tetra Pak.
If the soya milk is extracted by grinding and the protein level is higher than 3.0%, the homogenizer should be placed downstream of the heat treatment. Downstream (aseptic) homogenization generally reduces sedimentation.
Abrasion is another factor. While milk’s smooth texture makes it kind to stainless steel and other food processing surfaces, soya drinks are more abrasive because they frequently contain fibres and husk traces.
Like any plant product, soya mixtures may contain abrasive fibres. Though often invisible to the naked eye, these particles create wear on the homogenizer. Typically, a soya homogenizer needs to operate at equal pressure to a milk homogenizer in order to achieve the desired level of homogenization. It also needs to have a wear-resistant configuration. “You need a homogenizer with wear-resistant options, especially for those parts in contact with the product, notably the pistons but also the homogenizer device itself and the pump block valves,” Uvenbeck says.
Tetra Pak has two full-time food technologists that help customers to optimize soya beverage recipes and minimize abrasion. Expert input can range from mouth feel and colour to how to tackle sedimentation and achieve the desired level of viscosity in the beverage. “Maybe the client needs to add a filter to the homogenizer to avoid abrasive particles entering the process. Or maybe they need help getting their soya milk recipe right,” Uvenbeck says.
Collaboration is the byword here and Tetra Pak works closely with customer R&D centres to help them develop the end product they need.
