Acid-free preparation and characterization of kelp (Laminaria japonica) nanocelluloses and their application in Pickering emulsions

Jiulin Wu; Wenjin Zhu; Xiaodan Shi; Qingxiang Li; Chenguang Huang; Yongqi Tian; Shaoyun Wang

doi:10.1016/j.carbpol.2020.115999

Acid-free preparation and characterization of kelp (Laminaria japonica) nanocelluloses and their application in Pickering emulsions

Carbohydr Polym. 2020 May 15:236:115999. doi: 10.1016/j.carbpol.2020.115999. Epub 2020 Feb 16.

Authors

Jiulin Wu¹, Wenjin Zhu², Xiaodan Shi², Qingxiang Li², Chenguang Huang², Yongqi Tian³, Shaoyun Wang⁴

Affiliations

¹ Institute of Biomedical and Pharmaceutical Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350002, China. Electronic address: wujiul590@126.com.
² Institute of Biomedical and Pharmaceutical Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350002, China.
³ Institute of Biomedical and Pharmaceutical Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350002, China. Electronic address: tian.yongqi@fzu.edu.cn.
⁴ Institute of Biomedical and Pharmaceutical Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350002, China. Electronic address: shywang@fzu.edu.cn.

PMID: 32172833
DOI: 10.1016/j.carbpol.2020.115999

Abstract

Cellulose nanofibers (CNFs) from kelp were prepared by cellulase treatment with lengths greater than 3 μm. CNFs were further oxidized by TEMPO-oxidized system, and the lengths of the oxidized CNFs (TEMPO-CNFs) were 0.6-1 μm. AFM and TEM images showed that intertwined CNFs fibers were divided into individual nanofibrils. The crystallinity of TEMPO-CNFs increased to 66.5 %. TGA analysis indicated that TEMPO-CNFs were more sensitive to temperature than cellulose and CNFs. FT-IR spectra revealed no changes in the basic cellulose structures of CNFs and TEMPO-CNFs. In the sunflower oil/water (20/80, v/v) model emulsions, the oil droplet sizes were less than 20 μm in CNFs emulsions, which became smaller in TEMPO-CNFs emulsions. Delamination was found in CNFs emulsions after three days of storage. Addition of NaCl increased the volumes of TEMPO-CNFs emulsions but enlarged the oil droplets sizes. TEMPO-CNFs emulsions had the largest volume with smallest and most homogeneous oil droplets at pH 3. TEMPO-CNFs emulsions showed good stability after storage for 30 days. Further, TEMPO-CNFs could also emulsify 50 % (v/v) of sunflower oil. All these results indicated that TEMPO-CNFs can be used in preparing Pickering emulsions.

Keywords: Cellulose nanofibers; Characterization; Kelp; Pickering emulsions; TEMPO-oxidation.

MeSH terms

Cellulose, Oxidized / chemistry*
Cyclic N-Oxides / chemistry
Emulsions / chemistry*
Kelp / chemistry*
Laminaria / chemistry*
Nanofibers / chemistry*
Particle Size
Sunflower Oil / chemistry

Substances

Cellulose, Oxidized
Cyclic N-Oxides
Emulsions
Sunflower Oil
TEMPO