Microbial study of pH sensitive starch based film using agar diffusion method (zone inhibition assay)

International Research Advancement Network 2019

Khairuddin, Nozieana^1 ; Muhamad, Ida Idayu^2 ; Abdul Rahman, Wan Aizan Wan^2 ; Mobin Siddique, Bazlul^3

Department of Engineering, Faculty of Agriculture Science and Technology, Universiti Putra Malaysia Bintulu Sarawak Campus, Bintulu Sarawak

97008, Malaysia^1

Department of Bioprocess and Polymer Engineering, School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor Bahru

81310, Malaysia^2

School of Engineering, Swinburne University of Technology Sarawak Campus, Kuching Sarawak

93350, Malaysia^3

关键词: Antimicrobial films;    External stimulus;    Hydroxyethylcellulose;    Inhibition assays;    Microbial growth;    Microbial inhibition;    Pathogenic microorganisms;    Solution-casting method;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/607/1/012007/pdf
DOI  :  10.1088/1757-899X/607/1/012007

来源: IOP

【 摘 要 】

Active and smart packaging is a promising form of food packaging that offers a great economical potential due to consumer demand for a packaging that accommodate a hectic way of life. An antimicrobial film with pH colour indicator (pHF) can be made by incorporating suitable antimicrobial (AM) agent and colour indicator into food package matrices whilst applying a bio switch concept to inhibit the pathogenic microorganisms and respond automatically to changes (external stimuli) in the environment. The present work aimed to study the developed formulation of hydroxyethylcellulose (HEC)/wheat-starch based pHF film in which the active compound, thymol (0.5, 1, 1.5, 2, and 2.5% w/w) and 50:50% w/w bromothymol blue and methyl red (as the colour indicator) against microbial growth. A solution casting method was used in the film preparation while thymol and colourant were incorporated prior to casting. The effect of thymol showed a range of microbial inhibition zones of 16.3-26.4% and 22.1-39.9% towards E. coli and B. subtilis, respectively. Whilst, a lower inhibition zone of 0.4-5.1% was demonstrated for fungus A. niger.