Next Article in Journal
Anti-Inflammatory Compounds from Atractylodes macrocephala
Previous Article in Journal
Controlled Release of Biological Control Agents for Preventing Aflatoxin Contamination from Starch–Alginate Beads
Previous Article in Special Issue
Study on the Emulsifying Properties of Pomegranate Peel Pectin from Different Cultivation Areas
Article Menu
Issue 10 (May-2) cover image

Export Article

Open AccessArticle

Ultrasonic Degradation of Konjac Glucomannan and the Effect of Freezing Combined with Alkali Treatment on Their Rheological Profiles

1,2, 1,3, 1,2,* and 1,2
1
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
2
Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Ministry of Education, Wuhan 430070, China
3
Training Base of Army Logistics, University of PLA, Xiangyang 441000, China
*
Author to whom correspondence should be addressed.
Molecules 2019, 24(10), 1860; https://doi.org/10.3390/molecules24101860
Received: 21 April 2019 / Revised: 4 May 2019 / Accepted: 9 May 2019 / Published: 14 May 2019
(This article belongs to the Special Issue Natural Products Used as Foods and Food Ingredients)
  |  
PDF [5137 KB, uploaded 22 May 2019]
  |  

Abstract

The effect of freezing combined with alkali treatment on physicochemical property of konjac glucomannan (KGM) with different molecular weight was investigated in this work. The properties and structure of degraded KGM was characterized by means of intrinsic viscosity measurement, atomic force microscope (AFM) and Fourier transformation infrared (FT-IR). The results suggested that the intrinsic viscosity of KGM solution gradually decreased during the ultrasonic treatment. The AFM observation indicated that KGM with lower viscosity average molecular weight had smaller height and lateral diameter of molecules. The main repeating units of the KGM chain could not be destroyed no matter how long the KGM was sonicated. Rheometrical studies revealed that with increasing alkali concentration from 0% to 0.36%, both viscosities and shear stress of deacetylated konjac glucomannan (Da-KGM) system were increased and moduli G′ were substantially higher in either freezing or unfreezing samples. Da-KGM system performed a solid-like behavior (G′ > G′′) along the frequency range after freezing treatment. With increasing sonication time, both viscosity and shear stress of unfreezing samples were decreased while had an inverse effect for freezing treated samples. The modulus G′ and G′′ declined for unfreezing samples but rise significantly for freezing treated samples with increase of sonication time. View Full-Text
Keywords: konjac glucomannan; ultrasonic degradation; freezing treatment; rheological properties konjac glucomannan; ultrasonic degradation; freezing treatment; rheological properties
Figures

Figure 4

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Zhu, B.; Xin, C.; Li, J.; Li, B. Ultrasonic Degradation of Konjac Glucomannan and the Effect of Freezing Combined with Alkali Treatment on Their Rheological Profiles. Molecules 2019, 24, 1860.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top