Four
types of kale-based snacks were investigated on the basis of polyphenol content
and composition, glucosinolates amount, and antioxidant activity. The amount of
polyphenols resulted to be higher than that of raw material, fresh kale (0.57 ±
0.03 mg GAE). The antioxidant activity turned out indeed very effective,
resulting sufficient just from 0.72 mg to 2.1 mg to dishearten the activity of
1 ml DPPH to 50%. Glucosinolates present in kale-based snacks ranged from 1.17
mg/gr to 1.52 mg of sinigrin equivalent/gr. Polyphenol profile, obtained by
UPLC-DAD analysis allowed us to identify gallic acid, chlorogenic acid, and
catechin common in all samples. Other polyphenols, that is caffeic acid,
p-coumaric acid, and ferulic acid, were found in almost all samples, almost all
more abundant than fresh kale, representing a precious source of beneficial
metabolites. Our results suggest that such snacks could represent an effective
functional dietary supplement also if compared to fresh vegetable.
Manufacturing of kale-based snacks does not negatively affect the beneficial
effect of the raw material; indeed, such snacks could positively meet people’s
expectation, mainly children and young, well known consumers of snacks, which,
also in such manner, could be addressed towards a healthier dietary regime.