Bioaccessibility of carotenoids and antioxidant capacity of seed-used pumpkin byproducts powders as affected by particle size and corn oil during in vitro digestion process.

Powders made from seed-used pumpkin flesh (SUPF) are potential sources of carotenoids. In this study, unexplored effects of particle size and corn oil on bioaccessible amounts of carotenoids and antioxidant capacity of SUPF powders during in vitro digestion process were investigated. Overall, total carotenoid relative bioaccessibility (TCRB) of 100 mesh-sized powder (100 MP, 15.46%) was higher than that of 18 mesh-sized powder (18 MP, 12.94%). With the addition of 2% corn oil, TCRB increased 108.35% (18 MP) and 88.55% (100 MP), respectively. Lutein (≥27160 µg/100 g) and ß-carotene (≥5192 µg/100 g) were main carotenoid monomers in SUPF and significantly correlated with DPPH radical scavenging activity of digestive supernatant (p < 0.05). Notably, DPPH radical scavenging activity of 18 MP increased 96.54% with corn oil. These results implied that smaller particle size and oil addition could improve bioaccessible amounts of carotenoids and antioxidant capacity of SUPF powders.

Occurrence, biological activity and metabolism of 6-shogaol.

As one of the main bioactive compounds of dried ginger, 6-shogaol has been widely used to alleviate many ailments. It is also a major pungent flavor component, and its precursor prior to dehydration is 6-gingerol, which is reported to be responsible for the pungent flavor and biological activity of fresh ginger. Structurally, gingerols including 6-gingerol have a ß-hydroxyl ketone moiety and is liable to dehydrate to generate an α,ß-unsaturated ketone under heat and/or acidic conditions. The conjugation of the α,ß-unsaturated ketone skeleton in the chemical structure of 6-shogaol explicates its higher potency and efficacy than 6-gingerol in terms of antioxidant, anti-inflammatory, anticancer, antiemetic and other bioactivities. Research on the health benefits of 6-shogaol has been conducted and results have been reported recently; however, scientific data are scattered due to a lack of systematic collection. In addition, action mechanisms of the preventive and/or therapeutic actions of 6-shogaol remain obscurely non-collective. Herein, we review the preparations, biological activity and mechanisms, and metabolism of 6-shogaol as well as the properties of 6-shogaol metabolites.