Air is great stuff for breathing and inflating basketballs, but a genuine nuisance when you are adding dry powder to a liquid. More and more powders are entering the food processing mix, a by-product of delivering more nutrient- and flavor-packed products to the health-minded masses. Beverage formulations in particular are becoming more complex.
"We are able to reduce the air in our mix by going to equipment that brings powder in under the liquid via vacuum," says one processor whose company has profited from a co-packing relationship to produce a major brand of isotonic beverage. The equipment is of recent vintage, he notes, and he wonders why the solution took so long to come to the fore.
Reducing the amount of air that enters the mix may not sound like a Nobel Prize-worthy accomplishment, but don't tell processors that. The latest generation of mixers is answering some of the longest running nuisances in processing.
The challenges of mixing are as familiar to the kitchen counter chef in your home as they are to the processor of mass quantities of food and beverage products. Traditional mixing incorporates air into the powder/liquid mix causing foaming, clogging and lumps. If the ingredients contain fat, separation of that fat can be a problem as well.
Difficulties with drinks
Always an issue in beverage mixes incorporating powders, solubility has become a more serious challenge as processors attempt to add a wide range of complex ingredients such as aspartame and other sweeteners, vitamins, minerals, amino acids and new waves of healthful ingredients into small quantities of liquid.
"In some nutritional drinks, such as isotonic beverages, it is often difficult to dissolve the ingredients," says Jean Pierre Berlan, director of sales and marketing for Tetra Pak (www.tetrapak.com), Vernon Hills, Ill. "Today's beverages are more and more complex, and you need different techniques to incorporate powders."
Improving the shear rate may have been sufficient with more traditional mixing applications but shear rate alone may not be enough with today's complex beverages, which have inspired entirely different design approaches. Ingredients such as carboxy methyl cellulose (CMC) change the thickness and mouthfeel of a mixture and can be difficult to dissolve in water. Maltodextrin, sucralose, aspartame and other complex carbohydrates and sweeteners are putting equipment and mixing talent to test. Creating a vacuum keeps air entry to a minimum.
"Our Flex Mix Instant draws powder under the liquid via vacuum," explains Jim LeClair, regional product director for Lake Mills, Wis.-based APV/Invensys (www. apv.com). "It actually minimizes the amount of air that enters the mix."
Like everything, the improvement comes at a price, he notes. The mechanical and automation systems are more complex and, correspondingly, more costly. The latest generation of equipment represented by Flex Mix requires a better educated operator due to the demands of the vacuum system and automation additions. "But the total cost of ownership is less because there is less operator intervention," LeClair adds.
"A good way to deal with air and clogging is with a vacuum high-shear mixer," agrees Berlan. "It is the new name of the game when you are dealing with highly complex ingredients."