Thesis-1980-Santoso.pdf (3.77 MB)
Prevention of microbial deterioration in salted dried fish
thesis
posted on 2018-11-29, 11:28 authored by Ir SantosoThe reduction of microbial deterioration in salted
dried fish by application of the food preservatives, sodium
sorbate, sodium benzoate, sodium propionate and sodium
bisulphite was assessed using Aspergillus niger and
A.penicillioides, Halobacterium salinarium and
Staphylococcus sp as test organisms. The two bacteria were
grown on complex halophilic medium (CHM) and salted dried
fish homogenate (SDFH), whilst the moulds were grown in
Czapek Yeast Medium/Malt Extract Medium and 10 % salt-Czapek
Yeast Medium. Effectiveness of the food preservatives was'
also tested on one or two-dimensional gradient diffusion
systems and on salted dried fish samples.
Sodium sorbate was most effective in controlling growth
of A.niger. Growth on both 10 % salt-CYA and 10 % salt-CYB
prevented growth at a level of 0.1 % (w/v). Visible growth
of the mould was delayed for 3 days when 0.2 % sodium
benzoate was combined with 10 % salt. Total dry weight
increase was zero, when 10 % salt-CYB was supplemented with
a concentration of 0.15 % sodium benzoate.
Initiation of A.penicillioides grown on/in 10 % saltMEA
or 10 % salt-CYB, was delayed by sodium bisulphite,
sodium propionate and sodium benzoate at the highest levels
tested (0.04 %, 0.3 %, and 0.2 % respectively). Growth was
significantly inhibited using 0.1 % sodium propionate and
0.1 % sodium benzoate in these systems. Sodium sorbate at a
level of 0.1 % prevented growth of A.penicillioides on 10 %
salt-MEA and in 10 % salt-CYB.
H.salinarium grown on CHM and SDFH was not sensitive to
sodium propionate and sodium bisulphite at the highest
levels tested 0.3 % and 0.03 %, respectively, but sodium
benzoate at a a level of 0.10 % was lethal to the bacterium
grown in the two media. The lag phase was extended for 7
days, in CHM but no growth was observed in SDFH. Salted
dried fish previously dipped in a 1 % solution of either
sodium benzoate or sodium sorbate showed no sign of spoilage
by H.salinarium after 17 days incubation. Sodium sorbate was
also effective against the bacterium grown on SDFH when
growth remained in lag phase until the end of the incubation
period of day 7.
Growth of Staphylococcus sp was totally inhibited
using either 0.05 % sodium sorbate, 0.03 % sodium
bisulphite or 0.15 % sodium benzoate. At the highest level
of 0.3 %, sodium propionate did not significantly inhibit
growth of this bacterium.
Funding
School of Food and Fisheries Studies, Humberside College of Higher education
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Publisher
© Ir SantosoPublisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
1980Language
- en