title: Using Defatted Rice Bran as a Bioadsorbent for Carrying Tea Catechins.
abstract: The potential of rice bran as a bioabsorbent for tea catechins was examined. Defatted rice bran had the highest adsorption capacity for tea catechins and the best selectivity for (-)-epigallocatechin gallate over total catechins among water-washed rice bran and untreated rice bran. The adsorption characteristics of tea catechins onto defatted rice bran were determined over a range of concentration (0.5 to 2.5 g/L) and temperatures (10, 25, and 45 °C). The adsorption of tea catechins onto defatted rice bran showed excellent fitness with the pseudo-second-order model at different temperature. Both the Langmuir and Freundlich models adequately describe the isothermal adsorption of tea catechins onto defatted rice bran. The adsorption of total catechins on rice bran decreased from 10 to 25 °C, whereas was greatly enhanced at 45 °C. The adsorption system of bioadsorbent with multiconstituents may not be as simple as the single-force-driving adsorption system. Protein and cellulose are the main contributors to the adsorption of tea catechins on defatted rice bran.
  
  
  CONCLUSIONS
  Rice bran is regarded as a good fibre source that can be added to various food products and health supplements, which is a potential biocarrier for bioactives. Our study showed that defatted rice bran had a high affinity for tea catechins but caffeine, and provided a promising way for selective enrichment of catechins on defatted rice bran under practical condition. Protein and cellulose are the main contributors to the adsorption of tea catechins on defatted rice bran.
authors.affiliation: Zhejiang Univ. Tea Research Inst, Hangzhou, P.O. 310058, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Shi
authors.affiliation: Zhejiang Univ. Tea Research Inst, Hangzhou, P.O. 310058, China.
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Yang
authors.affiliation: Zhejiang Agricultural Technical Extension Center, Hangzhou, P.O. 310000, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.affiliation: Zhejiang Univ. Tea Research Inst, Hangzhou, P.O. 310058, China.
authors.forename: Long-Yue
authors.initials: LY
authors.lastname: Huang
authors.affiliation: Zhejiang Univ. Tea Research Inst, Hangzhou, P.O. 310058, China.
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Ye
authors.affiliation: Zhejiang Univ. Tea Research Inst, Hangzhou, P.O. 310058, China.
authors.forename: Yue-Rong
authors.initials: YR
authors.lastname: Liang
mesh_terms: D000327:Adsorption; D002110:Caffeine / Q000737:chemistry; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D004043:Dietary Fiber; D002523:Edible Grain / Q000737:chemistry*; D005503:Food Additives / Q000737:chemistry; D006801:Humans; D012275:Oryza / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry; D013662:Tea / Q000737:chemistry*; D013696:Temperature
chemical_list: D004043:Dietary Fiber; D005503:Food Additives; D010936:Plant Extracts; D010940:Plant Proteins; D013662:Tea; D002110:Caffeine; D002392:Catechin; D002482:Cellulose; C045651:epigallocatechin gallate
keywords: adsorption; catechins; isotherms; kinetics; rice bran