New research signals new avenues for growth in the ever-topical protein market. With developments emerging in the soy, wheat and hemp markets, and nanotechnology entering the protein world, Mark J Tallon, PhD, discusses the issues that may lead to the next fiscal resurgence

For some time, the leading milk-based protein has been whey, followed by casein. The greater bioavailability and amino-acid profile of whey has held it at the No. 1 spot regarding protein supplementation. However, of late its competitors, including plant proteins and isolated milk-protein bioactives, are leading the way in protein research and novelty. Following is an overview of the latest advancements in trade and academia within the protein markets.

Nano-encapsulation
Nanotechnology is often thought of as a next-generation technology, although issues regarding its safety as a food-delivery system are still in question.1 Technology moving toward that of the nano scale is now being applied via the utilisation of protein-based technology to encapsulate vitamins, minerals and enzymes.

Alpha-lactalbumin is protein extracted from milk and is widely used as a food and dietary-supplements ingredient. This protein also has important nutritional values as a calcium ion binder and a rich source of the amino acid L-tryptophan. The amino acid is mostly used in the animal-feed industry, but also has a number of food applications including clinical nutrition (infant formulas) and supplements designed for bodybuilders. Danish firm Arla Foods, the leading alpha-lactalbumin producer, has begun to exploit the unique abilities of this protein to form nanotubes (8.7nm pore size). These nanotubes have the potential to be used in an encapsulation format (controlled delivery), and, based on recent literature, are stable during freeze-drying and certain heating conditions (ie, pasteurisation), as well as being clear when formed into a gel.2 Innovative techniques for food design are becoming increasingly important for food manufacturers — alpha-lactalbumin-based nanotubes are one such application.

Milk fractions
The next step in the infant-formula fortification process may have arrived in the long-touted milk-protein fraction lactoferrin.3 Lactoferrin has an array of biological activities that include growth, immune modulation, and antimicrobial effects.4^,5 However, in recent years it has struggled to keep its head above water due to companies' inability to provide significant evidence to achieve acceptance for 'health-claim status,' and even 'acceptable for use in' from a selection of regulatory authorities across the globe. Although there is evidence and many of these issues could be resolved with the right package, it seems only blunt science facts are going to kick the potential of this ingredient back on track.

One new study examined the effect of bovine lactoferrin supplementation in infant formula.3 Healthy, formula-fed infants (>or=34 weeks gestation and

Those infants receiving lactoferrin-enhanced formula had significantly fewer lower respiratory-tract illnesses compared with the 26 regular formula-fed infants. In a first, we have evidence of what I like to call the Tour de France effect, where supplementation actually increased the oxygen-carrying capacity of these infants, and without the aid of altitude training. Following the 12 months of supplementation, hematocrit (ratio of red to white blood cells) levels were significantly higher at nine months in the lactoferrin-supplemented group compared with those on the control formula. These results provide some great insights into the benefits of lactoferrin fortification, and with the right industry backing can raise the profile of this milk bioactive.

Soy gets sporty
Over the years soy has played second fiddle to whey as a protein source, especially in the sports-supplement market. One of the main factors in the success of whey has been the belief that a more complete amino-acid composition provides a more effective protein source than soy for muscle building and recovery. However, research from Indiana University's School of Medicine and State University of New York may change this perception.6

This investigation compared the early response of skeletal-muscle protein synthesis following supplementation with soy + carbohydrate (SC), whey + carbohydrate (WC), or carbohydrate only (CO) after endurance exercise. Rats were split into either nonexercised controls or treadmill exercised for two hours at approximately 75 per cent VO2max. Following exercise, rats were then supplied with one of the three dietary interventions (SC, WC, CO).

One hour after exercise, serum insulin concentrations in WC, SC and CO were greater than in the nonexercised controls. Serum concentrations of branched-chain amino acids in WC and SC were higher than in CO, but amino acids making headlines in the sports-nutrition and weight-loss categories (leucine and isoleucine) were higher in WC than in SC group. However, both WC and SC supplementation promoted the rate of skeletal-muscle protein synthesis and translation (mTOR; eIF4F) significantly more than CO, suggesting both soy and whey are effective for muscle-protein synthesis post-endurance exercise, at least in rats.

The protein high
Hemp isolates provide another useful protein source to give the industry a novel high. Hemp-seed extract delivers a good source of essential fatty acids and an excellent dietary source of easily digestible, gluten-free protein. Its overall protein content of 34.6g/100g is comparable to that of soybeans, and better than other high-protein sources.7 Given the surge of nitric oxide-based products in the personal-care and sports-nutrition markets, the high content of nitric oxide generating amino acids (arginine = 123mg/g protein and histidine = 27mg/g protein) may offer some additional marketing claims above that of other proteins.

In a recent study from South China University of Technology, China has evaluated the compositional properties of this nonobvious protein source.8 Hemp (Cannabis sativa L.) protein isolate (HPI) was compared with soy protein isolate (SPI). Edestin, a kind of hexameric legumin, was the major protein component. HPI had similar or higher levels of essential amino acids (except lysine), compared to the amino acids of SPI. The essential amino acids in HPI (except lysine and sulfur-containing amino acids) are sufficient for the FAO/WHO suggested requirements for two- to five-year-old children.

HPI contained much higher free sulfhydryl (SH) content than SPI, which affects its water holding; this will influence its application in some food groups. However, the data suggest that HPI can be used as a valuable source of nutrition for infants and children, but has poor functional properties compared with SPI. The message for those in the hemp field trying to make this a fully functional food is to remove a large amount of the free sulfhydryl groups that reduce its applications.

Protein still ISOLATE-d
Innovation and growth possibilities still exist within the protein market but many companies are not capitalising on that potential. This lack of confidence in growth potential is leaving specific segments of the protein market isolated and sales slowing. This has been especially evident in the RTD and MRP segment, where the only innovations are coming from taste and a few bioactives such as DMV's cysteine peption.

Should the industry commit to the R&D path, the recent surge of new protein sources — including wheat, rice, hemp and canola with its own unique bioactive profile — should turn this negative tide and open up the door for the next wave for the protein markets.

Mark J Tallon, PhD, is chief science officer of NutriSciences, a London-based consultancy firm specialising in health-claim substantiation, product development and technical writing. www.NutriSciences.net.
Respond: [email protected]

References
1. Lanone S, Boczkowski J. Biomedical applications and potential health risks of nanomaterials: molecular mechanisms. Curr Mol Med 2006; 6(6):651-63.
2. Graveland-Bikker JF, et al. Structural and mechanical study of a self-assembling protein nanotube. Nano Lett 2006;6(4):616-21.
3. King JC, et al. A double-blind, placebo-controlled, pilot study of bovine lactoferrin supplementation in bottle-fed infants. J Pediatr Gastroenterol Nutr 2007;44(2):245-51.
4. Ward PP, et al. Multifunctional roles of lactoferrin: a critical overview. Cell Mol Life Sci 2005; 62(22):2540-8.
5. Gifford JL, et al. Lactoferricin: a lactoferrin-derived peptide with antimicrobial, antiviral, antitumor and immunological properties. Cell Mol Life Sci 2005;62(22):2588-98.
6. Anthony TG, et al. Feeding meals containing soy or whey protein after exercise stimulates protein synthesis and translation initiation in the skeletal muscle of male rats. J Nutr 2007;137(2):357-62.
7. Silversides FG, Lefrancois MR. The effect of feeding hemp seed meal to laying hens. Br Poult Sci 2005;46(2):231-5.
8. Tang CH, et al. Physicochemical and functional properties of hemp (Cannabis sativa L.) protein isolate. J Agric Food Chem 2006, 54(23):8945-50.