Effect of stevia supplementation of kale juice spheres on their quality changes during refrigerated shelf life.

Background: Kale is a vegetable that contains a high proportion of health-promoting compounds although its consumption as a beverage is very limited due to its bitter flavor. Nonetheless, the bitter flavor of Brassica may be masked by sweetening. The effects were studied of different stevia extracts (CTRL, S0.5 (g L ), S1.25 and S2.5) added to a kale beverage on the quality of kale juice spheres over a period of 7 days at 5 °C. Kale juice spheres were produced with a double-spherification technique, which allowed hydrogel spheres to be produced with high mechanical resistance.

Results: The addition of the stevia extracts did not affect the physicochemical quality of spheres. In particular, S2.5 spheres showed the least color changes after 7 days. All spheres showed good microbiological quality throughout storage, with loads < 7 log CFU g , regardless of the stevia concentration. The sulforaphane content of kale spheres was not affected by the stevia supplementation over the 7-day period.

Conclusion: The addition of stevia to the kale juice spheres led to a better flavor without altering product quality during refrigerated storage. © 2018 Society of Chemical Industry.