Effects of tannic acid on proteins and fat in cream

The addition of polyphenols to ice cream mix has been shown to cause a decrease in melting rate of that ice cream, although the mechanisms of this effect are not well understood. To better understand this phenomenon, the objective of this study was to understand the effects of a polyphenol, tannic acid (TA), on dairy cream. TA was added to cream at 0.75%, 1.5% and 3% (wt/wt) concentrations. An increase in complex viscosity was seen as TA% increased. The effect of pH on protein aggregation was minimal since the pH values of the resulting TA-cream samples were generally above the isoelectric point of milk proteins. Microscope images and particle size distributions confirmed the presence of fat globule clusters in these samples, creating a network at 3% TA. Using sodium dodecyl sulfate (SDS) and ethylenediaminetetraacetic acid (EDTA) to disperse both fat and protein, average particle size and microscope images suggested that milk protein-TA interactions helped create the clusters. No evidence of partial coalescence was observed. These findings can help optimize the complex effect of polyphenols in the dairy matrix to create higher quality products. Graphical Abstract