Functional beverages: a complicated concept

A functional beverage is hard to define. In this discussion, it is defined as a liquid or semi-liquid product designed to deliver particular food components with the intent of having an impact on health, says David Welsby,Food Applications Specialist, DuPont Nutrition and Health

It may be supposed that one of the original functional beverages is cow’s milk, long promoted as a source of protein and minerals for healthy bone development for children. However, during the past 20 years or so, the marketing of particularly formulated products for a variety of uses and invoking a variety of hard and soft claims, has exploded.

Infant and Follow-On Formulae

These products are controlled by a specific Directive (Commission Directive 2006/141/EC of 22 December 2006 on infant formulae and follow-on formulae and amending Directive 1999/21/EC) that controls all aspects of the composition of products designed to be consumed by infants 0–6 months and 6–12 months old. In Europe, the vast bulk of product sold is in the form of spray dried powders, although a small quantity is in the form of ready-to-feed (RTF) products.

The permitted sources of protein in these categories are from dairy and soy (and specifically isolated soy protein, for example Supro 1751 IP). Although a discussion on the use of carrageenans by SCF in 2003 concluded that “it remains inadvisable to use carrageenan in infant formulae that are fed from birth, including those in the category of foods for special medical purposes, the Committee had no objection to the use of carrageenan in foods for older infants, such as follow-on milks and weaning foods”.

Directive 2006/141 lists phospholipids as a nutritional ingredient with a maximum level (2 g/L). E471, E472c and E473 are allowed at different levels and lecithin is also on the list (E322) of permitted emulsifiers at 1000 mg/L of the final mix. Food additives allowed in infant formulae and follow-on formulae are regulated in Regulation (EC) No. 1333/2008 and in this regulation several of DuPont’s emulsifiers are allowed. Some of DuPont’s hydrocolloids are also allowed (many in the follow-on formulae). Similarly, the industry requested permission to incorporate locust bean gum (LBG) in infant formula to increase viscosity to avoid gastro-oesophageal reflux. According to Regulation 1333/2008, LBG can be used in formulas falling under the Foods for Special Medical Purposes (FSMP) for infants and young children. It can be used from birth onwards for the reduction of gastro-oesophageal reflux. In this case, GRINDSTED LBG 860 could be used.

Technical Considerations: The primary technical concern is the formation of a stable emulsion in the processing steps leading to the production of the feed to the dryer. Correct processing of both dairy and soy-based systems produces stable emulsions that can withstand spray drying intact and reconstitute to produce stable formulas in the bottle with no separation after overnight, refrigerated storage.

Products Designed for Young Children

Older children have different, nutritional requirements after the age of 12 months. These products are produced in a manner very similar to that of infant formula and similar technical issues apply.

Clinical Nutrition and Foods for Special Medical Purposes

This category includes enteral nutrition products that are liquid and RTD (Ready-to-Drink), either by mouth (sip feed) or by nasogastric tube. RTD products are sold through retail channels and also through institutions (hospitals, nursing and retirement homes). They are formulated to meet the special nutritional needs of particular groups in the population and have become increasingly disease specific as time has gone by. Commission Directive 1999/21/EC controls their vitamin and mineral compositions. However, in June 2011, the Commission published a proposal to establish rules applicable to foods intended for both infants and young children and to foods for special medical purposes. An agreement is expected later this year on this proposal.

Technical considerations: These products are almost universally shelf-stable products (either UHT processed or retorted). Specific formulations are governed by end-user requirements.

  • Standard formulas: This category comprises the range of products used most often for tube or sip feeding. Their nutrient composition is calculated according to the requirements of a healthy individual.
  • Fibre-containing formulas: Patients fed with these products for any length of time require fibre enriched formulas to maintain normal gut function.
  • Disease specific formulas: For example, renal disease, hepatic disease, diabetes, pulmonary disease, allergy, all have requirements for a specialized nutritional composition.

Most manufacturers do not wish to manufacture two separate SKUs, one for sip feeding and another for tube feeding. Therefore, viscosity control for optimised flow through the tube is of prime importance. Also, having a restriction point on the tube often controls flow. These points of restriction can produce complete blockages as incompletely dispersed particles accumulate to create blockages, a major inconvenience, if not a hazard. For these products, proteins to use would be Supro 1500 IP or, if low sodium levels are needed, Supro 1611 IP. Supro XT 34N IP is another option, especially at higher protein concentrations. It has the added benefit of being made by using proprietary calcium phosphate technology. When incorporated into a beverage, it provides a source of both calcium and protein.

Fibrim 2000 IP is a source of insoluble fibre that has been used for many years, but its use should be limited to 1% in products for use in tube feeding. A suitable carrageenan (such as GRINDSTED Carrageenan CL 235) or stabiliser system (Recodan CM 226) may be added to improve the suspension of Fibrim particles, together with some of the minerals. Litesse polydextrose is an excellent source of soluble fibre with high digestive tolerance, high solubility with minimal impact on viscosity and a neutral flavour and can make up the fibre concentration to the desired level. Polydextrose is permitted in Foods for Special Medical Purposes (category 13.2) as mentioned in Regulation 119/2011.

Vitamin K2 reinforces the role of calcium and vitamin D for bone health and is easily incorporated into a wide range of beverage formulations

Products are often fortified with vitamins and minerals, again targeted at a specific application or health benefit. One such product is ActivK (vitamin K2), which is approved by the EU Commission for a health claim related to bone health: “Vitamin K contributes to maintenance of normal bone.” Vitamin K2 reinforces the role of calcium and vitamin D for bone health and is easily incorporated into a wide range of beverage formulations. Menaquinones (vitamin K2) are mentioned in the annex to Regulation 953/2009 relating to substances that may be added to foods for particular nutritional requirements (PARNUTS).

Some products are used for patients who suffer from dysphagia, or difficulty in swallowing normal liquid foods. For such patients, high viscosity food is the only solution and, except in the case of formulas with very high protein levels, this can only be accomplished by the judicious selection of hydrocolloids. The hydrocolloid must be easy to disperse, cold soluble and able to hydrate quickly in a number of different liquids (milk, water, juice). Xanthan gum is often used in this application — particularly GRINDSTED Xanthan NTJ-1 — that has been specifically developed for this application and has excellent dispersion and hydration to give the viscosity required in a transparent solution.

Weight Management Products

In the category of functional beverages, weight management products in Europe are dominated by dry blends, although RTD products have become more important because of their convenience. The composition of such products is still governed by Directive 96/8/EU, as amended by Directive 2007/29/EC controlling labelling aspects and claims. There are two types of product: those designed to constitute the total daily caloric intake and those formulated to be a meal replacer. Energy can vary between 800 and 1200 kcal/day for the total daily intake category, and between 200 and 400 kcal/serving for the meal replacer type.

Weight management products in Europe are dominated by dry blends, although RTD products have become more important because of their convenience

Protein levels are based on energy. For both categories, 25–50% of the energy must come from protein. A meal replacer could legally contain, therefore, between 12.5 and 50g of protein (50% x 400kcal/4kcal/g)! It is rather difficult to formulate products at the very high end of the permitted protein range, for either dry blended or RTD products, unless large serving sizes are used.

Technical considerations: For dry blended products at lower protein levels, consideration could be given to agglomeration of the whole blend using a fluidized bed and a lecithin, such as Solec 3F-UB IP, dissolved in oil. In formulas in which protein comprises a high proportion of the blend, a preinstantized protein, such as Supro XT219D IP, could be used. Often, mouthfeel in DBB products is compromised because the components do not have time to hydrate adequately — the powder blend is mixed with liquid (water, milk or juice), shaken or stirred, and consumed immediately. Mouthfeel may be improved by using hydrocolloids. A combination of cellulose gum (GRINDSTED Cellulose Gum BEV 350) and xanthan gum (Grindsted Xanthan BEV-SH) will produce a pleasant, smooth mouthfeel in dry blended beverages.

RTD products require correct processing if an emulsion that will remain stable during long shelf-lives is to be produced. Carrageenan (GRINDSTED Carrageenan CL220) can help to maintain shelf-life stability.

Products Designed for Sports Nutrition

This category can be divided into two main subcategories:

  • Isotonic drinks for the replacement of minerals lost during exercise, along with carbohydrates for energy.
  • Protein enriched products, usually in powder form (approximately 77% of market), to act as a source of amino acids for muscle protein synthesis.

Until recently, whey protein has been the standard for protein supplements used in sports nutrition. Recent discoveries indicate that, in fact, protein blends are more efficacious at promoting muscle protein synthesis after consumption than any single protein source. Researchers at the University of Texas Medical Branch led by Professor Rasmussen found that the consumption of a blend of proteins from soy, casein and whey provided an extended “window” of muscle protein synthesis when compared with whey protein alone. Products containing blends are becoming more common as a result of these discoveries. Supro XT219D IP is an example of an isolated soy protein that would work well in such blends, also.

Gut and Immune Health Products

Pre- and probiotic dairy based fermented drinks are often cited as the original functional beverages, dating, as they do, back to the 1930s in Japan. Probiotics can be described as live micro-organisms that, when administrated in adequate amounts, confer a health benefit on the host and represent one of the fastest growing sectors in the global functional food market with a range of health benefits. Differences between strains may be subtle from a genetic perspective, but can nevertheless cause substantial differences in both robustness and health effects.

The current refusal of health claims relating to gut health and other conditions by the European Food Safety Authority (EFSA), although controversial, seems to have done little to dampen their popularity among consumers. For manufacturers, the key requirement is the presence of strong clinical documentation that can back up described health benefits. HOWARU probiotics were awarded for excellence in science by Nutrition Business Journal, commenting: “DuPont Nutrition & Health has one of the most researched probiotic strains in the world and has really raised the bar when it comes to scientifically assessing what probiotics can do in humans.”

Energy Drinks

These are usually canned beverages, either carbonated or non-carbonated, that contain ingredients such as caffeine, taurine, glucuronolactone, B-group vitamins, sucrose and glucose and, in some cases, others. Claims for the products relate to the physiological functions of the ingredients. Overall, the products are promoted to provide mental and physical stimulation.