title: Effects of cellulase from Aspergillus niger and solvent pretreatments on the extractability of organic green tea waste.
abstract: As green tea is being consumed in larger amounts, more green tea waste is being produced. Following extraction, several bioactive compounds may exist in the waste including polyphenols and amino acids. It was found that an Aspergillus niger cellulase treatment of green tea waste increased the extractability of various nutritional and functional components after pretreatments with various extraction solvents such as cold water (CW), hot water (HW), sulfuric acid (SA), hydrochloric acid (HA), and methanol (Me). After the residue was treated with cellulase from Aspergillus niger, the amounts of polyphenols, total catechins, and reducing sugars in the HW extract were increased by 64.6, 941.2, and 350.9%, respectively. In particular, levels of epigallocatechin, epicatechin, and gallic acid were significantly enhanced compared to those in the nontreated control. However, protein extraction was not significantly affected, and cellulase treatment was not more efficient for caffeine extraction compared to phenolic extraction. Among the four extraction solvents, HW and SA showed relatively higher extractabilities as compared to the other groups (CW, HA, and Me). These results indicate that cellulase from A. niger can increase the extractability of green tea waste when combined with certain solvent pretreatments. Consequently, the residual functional compounds and essential nutrients from cellulase-treated green tea waste have the potential to be applied in the production of new functional foods.
authors.affiliation: Department of Food and Biotechnology, Korea University, Chunggnam 339-700, Korea.
authors.forename: Jae Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Pan
authors.forename: Wan
authors.initials: W
authors.lastname: Heo
authors.forename: Hyungjae
authors.initials: H
authors.lastname: Lee
authors.forename: Eung Gi
authors.initials: EG
authors.lastname: Kwon
authors.forename: Hong-Gu
authors.initials: HG
authors.lastname: Lee
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Shin
authors.forename: Rui Hai
authors.initials: RH
authors.lastname: Liu
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Kim
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000032:analysis; D002473:Cell Wall / Q000378:metabolism; D002480:Cellulase / Q000494:pharmacology*; D005419:Flavonoids / Q000032:analysis; D005511:Food Handling / Q000379:methods; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D010940:Plant Proteins / Q000032:analysis; D059808:Polyphenols; D012997:Solvents
chemical_list: D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D010940:Plant Proteins; D059808:Polyphenols; D012997:Solvents; D002392:Catechin; D002480:Cellulase