Microencapsulation may increase consumer acceptance of resveratrol in foods

March 24, 2016

A study published in the Journal of Food Science shows that encapsulating resveratrol in a sodium caseinate matrix may improve its stability, lessen its bitterness, and allow it to be incorporated into shelf-stable foods at biologically active levels. One major limitation of incorporating resveratrol into food products is the instability of the compound in the presence of light. In fact, about 90% of the bioactive form of resveratrol has been shown to convert to the bioinactive form after 100 min of light exposure. Another limitation is the bitterness associated with the compound.

The researchers’ prior study demonstrated that resveratrol encapsulated within a sodium caseinate matrix has a significantly higher stability and higher taste detection threshold in comparison to unencapsulated resveratrol. In this study, the researchers wanted to apply the resveratrol microcapsules to shelf-stable foods—in this case, bars and gummies.

The microcapsules used in the consumer testing contained 9.1% resveratrol and 90.9% sodium caseinate. For both bars and gummies, 10 mg and 40 mg resveratrol/serving were tested as these are effective levels that align with the therapeutic dosages. One-hundred panelists aged 18–65 participated in the two days of testing, in which they received the gummies on the first day and the bars on the second. Four different controls were used for both gummies and bars: 1) without any resveratrol and protein (plain), 2) unencapsulated resveratrol (resv), 3) sodium caseinate and unencapsulated resveratrol just mixed without encapsulation (P + R), and 4) sodium caseinate only (PRO).

The researchers found that the overall liking of bars with 10 mg of encapsulated resveratrol did not differ significantly from the control without any added resveratrol and protein (plain) or from the controls with equivalent protein and/or resveratrol concentrations. For the gummies, samples with both concentrations of microcapsules had a significantly lower overall liking in comparison to other samples with the equivalent concentration of protein and/or resveratrol. The addition of resveratrol microcapsules decreased consumer acceptance of gummies.

The researchers concluded that the study provides a basis upon which the food industry can add stabilized resveratrol into food products. However, future research should evaluate consumer acceptance of other food matrices utilizing additional resveratrol concentrations.