Effect of sprouting on the chemical and nutritional qualities and phenolic alkaloid content of lotus (Nelumbo nucifera Gaertn.) seeds

Abstract

The chemical and nutritional qualities of lotus seeds sprouted in water at different temperatures (25 and 35°C) and water to seed ratio (1:2.5, 1:3.75, 1:5, 1:6.25 and 1:7.5), and their embryos’ phenolic alkaloids content were determined and compared to the non-sprouted lotus seeds (control). Sprouting of the seeds resulted to significant increases in the crude protein and crude lipid and decreases in protein solubility and moisture content (p<0.05). Meanwhile, no significant variations are observed on the fiber and ash contents. The sprouted seeds also exhibited significantly lower (p<0.05) total phenolics, tannins, and cathechins except phytic acid contents. Furthermore, both of the embryo of sprouted seeds extracted by 80% methanol and water demonstrated significant rise (p<0.05) in their total phenolics, flavonoids and phenolic alkaloids (neferine, liensinine and isoliensinine). Results show that sprouted seed at 35°C and water to seed ratio of 1:5.00 (w/v) has higher nutritional qualities of the seeds and higher phenolic alkaloids content of the embryos. Sprouting is a simple method which does not require intensive energy input and also yields chemically unvaried product. The previous results strengthen the use of lotus seed as food and lotus seed flour for the development of new food products and formulation. The embryo, a good herbal medicine, can be used as tea component. Key words: Lotus seed, sprouting, nutritional, phenolic alkaloids, embryo of lotus seed.