Amid pressure over reformulating beverages due to challenges from dairy protein prices, and under pressure to correct the dietary deficiency of protein for consumers, formulators are increasingly looking at soy.
Although dairy prices have begun to soften compared top last year's record levels, formulation of soy-based foods is increasing since they are deemed "suitable vehicles for fortification to meet known deficiencies of essential nutrients," wrote the researchers in the International Journal of Food Science & Technology .
"Besides providing an alternative to traditional dairy products, soy protein is also being incorporated into many nutritious meal-replacement beverages offering convenience to 'on-the-go' consumers," wrote Rashmi Deshpande, Manjeet Chinnan and Robert Phillips from the Department of Food Science and Technology at the University of Georgia.
"Currently, consumer enthusiasm for soy protein-based beverages is growing as attempts to combine flavours and ingredients are on the rise," they added.
Peanuts plus chocolate equals success To tap into this enthusiasm, and cancel out some of the limiting factors associated with soy, including masking the beany flavour, as well as boosting the protein profile, the researchers formulated a chocolate-flavoured, peanut-soy beverage.
Development was extended to the pilot-scale phase.
Deshpande, Chinnan and Phillips used medium-roasted peanut flour and chocolate flavour to improve the flavour profile of the beverage, while the peanut-soy combination was intended to enhance the protein profile.
Beverage development, which involved the processing steps of filtration, homogenisation and pasteurisation, used peanut, soy and chocolate syrup with optimal ranges of 31 to 59 per cent, 28 to 44 per cent, and 13 to 26 per cent, respectively.
Comparing with a commercial chocolate milk (Hershey's creamy chocolate milk shake), the researchers reported similar viscosity levels, and also found that the visual stability index (VSI) was also of a similar to the commercial beverage.
"The chocolate-flavoured, peanut-soy beverage thus developed is expected to have improved nutritional and sensory properties because of the combination of peanut protein with high-quality soy protein and popular chocolate flavour," wrote the researchers.
"Further study on consumer acceptability and nutritional characteristics of the chocolate-flavoured peanut-soy beverage will help ensure the success of the new product developed in this study.
"Hence, the future work of this study will be to conduct a sensory evaluation of the new product developed and study its consumer acceptability," they concluded.
Economic advantages While soy isolate cost €5.50 to €6.50 per kg protein in November 2007, skimmed milk powder cost between €8 and €9 per kg protein.
Based on these rates - which can, of course, fluctuate depending on a variety of factors - manufacturers could save 15 to 20 per cent of their protein costs by taking the soy route.
Source: International Journal of Food Science & Technology May 2008, Volume 43, Issue 5, Page 886-894, doi: 10.1111/j.1365-2621.2007.01537.x "Process development of a chocolate-flavoured peanut-soy beverage " Authors: R.P. Deshpande, M.S. Chinnan, R.D. Phillips