Physicochemical Changes in Hemerocallis coreana Nakai After Blanching, Drying, and Fermentation

Abstract

To promote the utilization of wild edible plants, this study examined blanching, drying, and fermentation as methods for enhancing the functionality of Hemerocallis coreana Nakai. Specimens fermented for 24 hours at a fermentation temperature of 50°C, with a relative humidity of 65%, contained the highest amount of organic acid (18,109.82 mg/100 g). For the blanched; specimens, total organic acid content decreased about 30% compared with the freeze-dried specimens. The main organic acid of Hemerocallis coreana Nakai was confirmed as succinic acid. After fermentation, free sugars decreased; in particular, specimens fermented at a relative humidity of 80% showed a 32～75% reduction in free sugar compared with the freeze-dried specimens. In terms of amino acid content, Hemerocallis coreana Nakai was mainly composed of valine, isoleucine, and phenylalanine. In fermented specimens the total amino acid content was highest in a moderately fermented (17 hr) specimen, (1,010.71 mg/100 g fresh wt.), but decreased in the maximally fermented (24 hr) specimen. The longer the fermentation, the higher the decrease in non-essential amino acids content, while the content of more essential amino acids consistently increased. In conclusion, since seasoned Hemerocallis coreana Nakai contains a considerable amount of glutamine and asparagine, it has a fresh sour and sweet taste; thus, it will likely be a highly preferred wild edible plant. Also, with an increase of essential amino acids after fermentation, Hemerocallis coreana Nakai is excellent in terms of nutrition. Thus, it may be possible to utilize fermented Hemerocallis coreana Nakai in the development of diverse products.