Scientists from the University of Minnesota and Robertet Flavors, NJ report that emulsions stabilised with commercial sources of gum arabic achieved better stability that modified starch-stabilised beverages, when stored at three days to 25 or 35 Celsius.
The champion and the challengers
Gum arabic (acacia gum) is used widely by food and beverage formulators; particularly in confectionery categories, where it is included to delay or prevent sugar crystallisation and to emulsify fat.
Wherever film-forming and emulsifiying properties are required – without affecting taste or viscosity – gum arabic can often be found. Further, the emulsification properties of gum arabic are also used in various flavour emulsions.
Food and drink makers do have alternatives available in the form of gelatine and modified starches. Working in an increasingly tough environment, impacted by squeezed margins and growing consolidation, a new level of competitiveness appears to be opening up as starch and gelatine suppliers push to compete with gum arabic.
Price and properties are pivotal, with both gelatine and starch products undercutting gum arabic in price. But for gum arabic suppliers, their ingredient has 'value-added' strengths compared to the alternatives on the market.
Indeed, according to background in the Journal of Food Science, gum arabic from Acacia senegal is “generally being considered the industry ‘gold standard’ for stabilizing beverage emulsions”.
Formulation tests
Led by Gary Reineccius, Professor and Head of the Department of Food Science and Nutrition at U of M, the researchers tested the stability of emulsions prepared using three commercially available gum arabic (FCC powder & Bev-101 GR, both TIC Gums; Eficacia, CNI), one modified gum arabic (Ticamulsion, TIC Gums), and three modified starches (Purity R Gum 1773 & 2000, National Starch; Mira Mist, Tate & Lyle).
Emulsions were based around one of two oil phases –orange terpenes or Miglyol. The choice of oil was found to influence the emulsion stability.
“Overall, results showed that all gum acacia products investigated yielded superior emulsion stability in comparison to that achieved using the modified starches,” wrote Reineccius and his co-workers.
“Eficacia (at a usage rate of 16 per cent) and A. Senegal [FCC powder] were the best performing gum acacias in both oil systems,” they added.
However, the potential of modified starches to act as gum arabic replacements was shown in the Miglyol-based beverages, with National Starch’s Purity Gum 2000 deemed “the better performer”, and equal to the gum arabic-stabilised beverages.
More is better?
Prof Reineccius and his co-workers also found that when Eficacia and Ticamulsion were used at a level of 16 per cent – more than twice the recommended level of 7 per cent – the beverage emulsion stability increased.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2010.01625.x
“A Comparison of the Stability of Beverage Cloud Emulsions Formulated with Different Gum Acacia- and Starch-Based Emulsifiers”
Authors: S.J. Reiner, G.A. Reineccius, T.L. Peppard