Inclusion of piperine in β-cyclodextrin complexes improves their bioaccessibility and in vitro antioxidant capacity

Abstract Piperine (PIP) is a nitrogenous substance; despite its beneficial properties, its application in food is still limited due to the low solubility in water, low bioavailability and high pungency. β-cyclodextrin (BCD) might be a suitable choice as a nanoencapsulation system to preserve the bioactive properties of PIP. The objective of this study was to evaluate the formation of BCD/PIP inclusion complexes and to study their bioaccessibility, pungency and antioxidant capacity during in vitro gastrointestinal digestion and simulated colonic fermentation. The effect of the BCD/PIP molar ratios of 1:1, 2:1, 3:1 and 4:1 on the loading efficiency (LE) and formation of inclusion complexes, by FTIR analysis, were assessed. The LE increased with the BCD/PIP molar ratio (>54%) and in all cases there was formation of the BCD/PIP inclusion complexes evidenced through the BCD and/or PIP shifted bands. The inclusion complexes of BCD/PIP 4:1 and 1:1 with the highest and lowest LE of PIP, 18.61% and 73.50%, respectively, were subjected to simulated gastrointestinal conditions. PIP was highly retained at the non-digestible fraction (up to 353.1 mg L −1 ). The bioaccessibility was higher for BCD/PIP 4:1 in the colon, whereas for BCD/PIP 1:1 in the small intestine. The antioxidant capacity of all samples increases significantly along the gastrointestinal tract. This means it is convenient to encapsulate PIP in BCD to increase its bioaccessibility. However, there is a lack of effectiveness in masking the pungent flavor.