Enhancing the bioaccessibility and stability of curcumin through the formation of curcumin-piperine complexes in delivery systems based on nanoemulsions stabilized with phospholipids and whey protein

Abstract

Curcumin is a phenolic compound with multiple health benefits and limited use due to its low bioaccessibility and bioavailability, which can be improved by the addition of alkaloid piperine and the use of nanoencapsulation systems such as nanoemulsions (NEs). The impact of the addition of piperine on the stability and bioaccessibility of NEs loaded with curcumin and stabilized with krill oil phospholipids and whey protein was investigated. The findings indicated that curcumin was successfully encapsulated within the NEs. All NEs showed initial particle sizes < 200 nm; however, curcumin-piperine complex nanoemulsion (without whey protein) presented the smallest particle size (108.85 ± 5.88 nm), being the one that showed the best physicochemical stability during storage and accelerated stability test. The curcumin and astaxanthin bioaccessibility, antioxidant capacity, and fatty acid release were also evaluated in both the gastric and intestinal phases using an in vitro model. The addition of whey protein to curcumin-piperine complex NEs significantly improved the bioaccessibility of curcumin and astaxanthin, and this improvement increased with the increase in added protein, reaching values of 88.61 % and 93.33 %, respectively. Furthermore, adding 5 % whey protein to the curcumin-piperine complex nanoemulsion also released a higher level of free fatty acids (43.88 %). It provided the most significant antioxidant capacity in the intestinal phase (4.88 μM TE/mg of curcumin).