Repository logo
  • English
  • 中文
Log In
Have you forgotten your password?
  1. Home
  2. College of Bioresources and Agriculture / 生物資源暨農學院
  3. Food Science and Technology / 食品科技研究所
  4. Effect of Media Milling on Physical Characteristics and Enzymatic Hydrolysis of Chitin
 
  • Details

Effect of Media Milling on Physical Characteristics and Enzymatic Hydrolysis of Chitin

Date Issued
2009
Date
2009
Author(s)
Lee, Yu-Hsuan
URI
http://ntur.lib.ntu.edu.tw//handle/246246/182215
Abstract
Being abundant polysaccharides in nature and multi-applications such as biological, biocompatible and biodegradable functions, chitin and its derivatives are useful biopolymers and taken a lot of attentions by scientists and researchers in decades. They are present mainly in exoskeletons of invertebrates and the cell walls of fungi. The water insolubility constrains the application of chitin, however, the hydrolytic products of chitin such as N-acetyl chitooligosaccharides and chitooligosaccharides are water soluble and get lots of employments. The objective of this study was to investigate the influence of media milling on the particle sizes and physical properties of chitin as well as the enhancement of media milled chitin on the enzymatic hydrolysis. The volume mean diameter of purchased chitin was 224.50 ± 13.44 μm. It was processed by media mill to reduce the particle size to micron and submicron scales. Physical properties such as particle size distribution, pH, deacetylation, rheology and morphology were compared between the unmilled and milled chitin. Finally the yield of N-acetyl diglucosamine ((GlcNAc)2) was applied to explore the effect of milling on chitin hydrolysis. Chitin (5 or 12.5 g) was blended with 500 g deionized water to prepare a 1% or 2.5% slurry for media milling, where 0.8 mm YTZ (yttria-stabilized tetragonal zirconia) beads was selected as the milling media. After 30-, 60- and 120-min milling, the volume mean diameters were reduced to 76.08, 58.45 and 7.13 μm, respectively, for 1% solution and 82.40, 52.40 and 23.80 μm for 2.5% one. The particle size distribution and SEM morphology showed the presence of submicron chitin particles for 120-min milled products. The rheological studies of the milled chitin-suspension showed the viscosity was increased with the increase of concentration, and, however it decreased with increase of shear rate; i.e., the milled chitin-suspension appeared to be a shear-thinning fluid. The degree of deacetylation of chitin evaluated by FTIR was increased from 30.5 to 43% by media milling. The chitinase obtained from Streptomyces griseus was applied to proceed the hydrolysis of milled chitin. It showed that a longer milling product resulted in a higher yield of (GlcNAc)2 as the same hydrolytic duration was considered (8 hr). The yield of (GlcNAc)2 from unmilled chitin-suspension was 16.04%. For the hydrolysis of 30-, 60-, 90-min milled 1% chitin suspension, the yield of (GlcNAc)2 was 33.73, 34.09 and 41.35%, respectively; while for the hydrolysis of 30-, 60-, 120-min milled 2.5% chitin suspension, the yield of (GlcNAc)2 was 31.51, 34.15 and 44.28%.
Subjects
chitin
enzymatic hydrolysis
media milling
Streptomyces griseus
N-acetyl chitobiose
Type
thesis
File(s)
Loading...
Thumbnail Image
Name

ntu-98-R95641028-1.pdf

Size

23.53 KB

Format

Adobe PDF

Checksum

(MD5):8a24f399da670b94b286d06f4afeb53f

臺大位居世界頂尖大學之列,為永久珍藏及向國際展現本校豐碩的研究成果及學術能量,圖書館整合機構典藏(NTUR)與學術庫(AH)不同功能平台,成為臺大學術典藏NTU scholars。期能整合研究能量、促進交流合作、保存學術產出、推廣研究成果。

To permanently archive and promote researcher profiles and scholarly works, Library integrates the services of “NTU Repository” with “Academic Hub” to form NTU Scholars.

總館學科館員 (Main Library)
醫學圖書館學科館員 (Medical Library)
社會科學院辜振甫紀念圖書館學科館員 (Social Sciences Library)

開放取用是從使用者角度提升資訊取用性的社會運動,應用在學術研究上是透過將研究著作公開供使用者自由取閱,以促進學術傳播及因應期刊訂購費用逐年攀升。同時可加速研究發展、提升研究影響力,NTU Scholars即為本校的開放取用典藏(OA Archive)平台。(點選深入了解OA)

  • 請確認所上傳的全文是原創的內容,若該文件包含部分內容的版權非匯入者所有,或由第三方贊助與合作完成,請確認該版權所有者及第三方同意提供此授權。
    Please represent that the submission is your original work, and that you have the right to grant the rights to upload.
  • 若欲上傳已出版的全文電子檔,可使用Open policy finder網站查詢,以確認出版單位之版權政策。
    Please use Open policy finder to find a summary of permissions that are normally given as part of each publisher's copyright transfer agreement.
  • 網站簡介 (Quickstart Guide)
  • 使用手冊 (Instruction Manual)
  • 線上預約服務 (Booking Service)
  • 方案一:臺灣大學計算機中心帳號登入
    (With C&INC Email Account)
  • 方案二:ORCID帳號登入 (With ORCID)
  • 方案一:定期更新ORCID者,以ID匯入 (Search for identifier (ORCID))
  • 方案二:自行建檔 (Default mode Submission)
  • 方案三:學科館員協助匯入 (Email worklist to subject librarians)

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science