Chemical and Biological Investigations with Black Sesame Seed Pigment

Sesame seeds are a well appreciated food ingredient all over the world. Black sesame seeds are widely used as spice, as source for edible oil and for functional ingredients (i.e., sesamin, sesamolin, sesaminol). Black sesame seeds contain also a black pigment with properties similar to melanins. Melanins are considered as the most ubiquitously distributed, the most chemically resistant and heterogeneous pigments in nature. The black pigment prepared and purified from black sesame seeds was characterized by analytical, chemical and biochemical methods. The purified pigment was investigated by quantitative UV-VIS, HPLC-MS, FT-IR, NMR as well as by chemical methods to define its main chemical properties and degradation products after chemical breakdown or artificial digestion. The sesame pigment was investigated in a series of in vitro test systems comprising of chemical and enzymatic assays. It displayed, amongst other tests, good antioxidant efficiency in the ferric ion-reducing assay, in a radical scavenging assay, in an induced LDL oxidation assay and yielded potent anti-nitrosating and heavy metal chelating effects. In a series of enzymatic tests, it could be shown that the black pigment has promising activities in the inhibition of acetylcholinesterase, butyrylcholinesterase, ß-secretase-1 and amyloid ß-42 self-aggregation.