Encapsulation is sometimes an option, but difficult in beverages. “A highly effective alternative to mask unpleasant tastes and odors would be to coat the particles in a fluid-bed agglomerator,” Gutierrez adds. “Typical coatings consist of waxy or fatty substances with inert or desirable flavors. This process would best work in a product that is not soluble and is to be reconstituted into a thick suspension at the time of consumption.” However, this method is more suitable for beverages that come in powdered form. In ready-to-drink (RTD) beverages, the coating on the agglomerated particles would either dissolve before the product is consumed, or would cause the suspended particles to have an undesirable, gritty consistency. “You could make an RTD beverage that had an insoluble coating around the particles in something like a thick shake,” he says.
Solutions for solubility
The second most-important issue to address in formulating nutraceutical beverages is solubility. Often, solubility issues prevent manufacturers from adding enough of an ingredient to give a beverage the desired level of health benefit.
“In terms of processing, solubility remains a challenge, especially in clear beverages or clear packaging, which is a big part of the U.S. market,” says Jones. In the United States, he says, there are two schools of thought: those who are interested in clear products such as vitamin-fortified waters, and those looking for smoothie-type products, which can include some pulp. “While we work with both types of customers, our products are more suited to the pulpy products, which allow us to retain more-intense nutrient profiles, nicer colors and additional fiber in the product,” he says. “This simply isn’t possible in fully clarified products.”
However, keep in mind that the type of drink depends not just on the nutritional ingredients, but also “greatly upon the actual use that the consumer has intended,” observes Reid. “Both formats have a place: for example the nutritional shakes definitely are expected to be more viscous, thick, and creamy because they are loaded with protein and other functional ingredients that deliver healthy, sustained energy when consumed prior to a workout. However, on the other end of the workout, the recovery drinks need to be more water-like and refreshing with ingredients that replenish what was lost during exercise or enhance the ability to recover and quickly get back to the rest of their daily routine.”
When it comes to the ingredients, though, it’s difficult to drastically change a product’s solubility profile without using undesirable solvents or getting into serious chemistry at the molecular level, says Gutierrez. In many instances, a good dispersion will suffice, he explains, and this can sometimes be achieved by modifying particle size and surface area through milling; by emulsifying, in the case of oil-water dispersions; by spray drying; or by fluid-bed agglomerating with soluble carriers.
A stable environment
Stability enhancement is another important issue in beverage development. In the presence of water, Gutierrez says, you concern yourself much more with product stability, the need for preservatives and potential interaction between ingredients. The problems created range from reduced shelf life to off flavors and the loss of potency of the active ingredients. “In RTD beverages, product stability can sometimes be improved by carefully controlling and maintaining the product pH,” he says.
Some ingredients are naturally stable and thus withstand light, heat and pH―even some who have a reputation for needing special handling. For example, some natural probiotic ingredients can withstand the heat of hot beverages and the pasteurization process, and the acidic pH in the stomach. “For all probiotics, the toughest thing to create is a shelf-stable product. There are a couple of technologies that help that, but we mostly stay away from that,” says Mike Bush, vice president of business development, Ganeden Biotech, Mayfield Heights, OH. “With us, nature handled all of our engineering for us. We had to develop proprietary particle size, which involved beefing up the particle size so that it would stay inside of a tea bag. We didn’t need to worry about encapsulation.”
Taking the natural way
One of the more difficult decisions to make is whether to use natural vs. artificial ingredients. Being able to make a “natural” claim is desirable, especially on a beverage that purports to be “healthy,” but it’s becoming more and more difficult to figure out what exactly is, and is not, natural.