ISSN 2086-5953 The objective of this work is to chitosan
coating effect on noodle chemical, textural properties, sensorial acceptance and deterioration
delay related to chitosan antimicrobial activity. Furthermore, this research may provide basic
information
to develop
chitosan as
food biopreservatives.
2 MATERIAL AND METHOD
2.1 Material
Chitosan was made from shrimp shells by chemical processes, obtained from The Indonesian
Institute of Sciences LIPI. Noodle was made according to the method used by noodle local
producer in Yogyakarta, using wheat flour and food grade additives. All chemicals used were analytical
grade.
2.2 Preliminary
This process was conducted to determine noodle boiling time to obtain noodle with 55 as
standard moisture
content, acetic
acid concentration, and ratio between noodle and
dipping solution that sensorially accepted. To measure chitosan properties, proximat content,
solution viscosity, and deacetylation degree were also analyzed according to each standard analysis
[12].
2.3 Sample preparation
The experimental samples were prepared according to the basic formulation. They were
made from hard wheat flour and mixing with 35 water, 1 salt and 2 alkaline solution. The flour
was formed into dough sheets before cutting. The string-shaped noodle was then dipped into boiled
water for 1 minute.
Dipping solution were made by dissolving chitosan powder into 0.5 acetic acid in
concentration of 0, 0.5, 1, and 1.5 wv, using sterilized beaker glass. Samples were divided
and dipped 2 minutes into each solution in ratio 1:6 gml. After drained, samples were placed inside
sterile sealed polyethylene bags for room temperature incubation, prepared for triplicate
samplings, every 10 hours from 0 to 40 hours. Samples weight differences before and after
dipping were counted as retained chitosan on samples surface.
2.4 Chemical, physical and sensorial
properties analysis
Right after dipping process, samples properties were determined for pH using pH meter
and also for moisture, protein, fat and ash content according to AOAC 2000. Noodle physical
analysis as conducted in quantitative and qualitative measurement. The textural qualities of the cooked
noodles,
in strength
and break
distance extensibility, were measured on a Lloyd Texture
Analyser in triplicate at three random locations of noodle string. The noodles were tested individually.
The F
max
values recorded for freshly made sample and 45 hours incubated sample. Physical changes
during incubation were also observed. Samples were evaluated for sensory acceptability by 20
trained panelists. Scoring method in scale 1-10 1=unrecognizable, 10=extremely recognizable
was used to analyze whether chitosan application was recognizable in term of noodle taste and aroma.
While hedonic test in scale 1-7 1=dislike extremely, 7=like extremely was used to analyze
samples acceptability. The effect of cleansing after dipping was also sensorial analyzed.
2.5 Chitosan antimicrobial analysis
