religious reasons. 16 Thanks to the utilization of fish bones, the amount of
wasting can be reduced, and environmental friendly producing can be done. New
type of gelatin can be produced without fishy odour. Peoples from all religions
can consume this gelatin without worrying about religion.
3. Objectives of
In this study, we aimed to use a fish
bones obtained from the fish species that have not been use before for gelatin
production. The acid-threated method will be used for gelatin production, so
the gelatin will be named as Type A. The selected fish species will be “Trout”
(Rainbow Trout, Oncorhynchus mykiss).
The reason for choosing this fish species is the most hunted and grown bony fish
in Turkey. 15
For gelatin production, there are two
main methods available in the literature. 11, 13 There is a method in
literature which is nearly accepted as main method belong to Muyonga et all.
11 In addition, there is an optimization method that belongs to Mahmoodani in literature. 13 In
this study, two methods will be used and evaluated based on their yield.
Whichever provides the highest yield will be our chosen method.
The aim of the study is using the
fish waste for producing added value product that is gelatin. First of all, two
types of gelatin will be produced by using Muyonga’s method and Mahmoodani’s method. 11, 13
After producing the gelatins, they will be compared according to their yields.
After that, the gelatin with high yield will be selected to analyze. This
gelatin and commercial gelatin will be analyzed for nutritional composition, pH,
gel strength, viscosity, turbidity, melting point, gelling temperature, color
and sensory properties. Lastly, these two gelatins will be compared to results
of the analysis.
There might be production extra added
value product after gelatin production from bones of fish. After the gelatin
extraction from fish bone, there will be a new waste which is fish bone without
gelatin. This fish bone without gelatin can be used for hydroxyapatite
production so the fish bone will be used as much as possible. If the time permits,
this part of experiment will be done, if the time does not remain, this idea can
be explored in future studies.
4. Scope of The
In this study, there will be two main
steps which are production and analyzing steps. Firstly, the gelatin will be extracted
from specific type of fish bone, and then the gelatin is analyzed for only
yield. 11 The gelatin with highest yield is selected and analyzing for other
features and it will be compared with commercial gelatin.
The selected extracted gelatin which
has highest yield will be analyzed for nutritional composition, pH, gel
strength, viscosity, turbidity, melting point, gelling temperature, color and
The nutritional composition is
analyzed to determine the moisture content, ash content, crude protein and fat
content. Moisture, ash, and fat contents of dried gelatin of fish bone will be measured
with the methods of the AOAC. 17 The determination of crude protein will be
done by using Kjeldahl method. 17
The pH of gelatin solution was measured
using the British Standard Institution method. 14 A 1% (w/v) gelatin solution
will be prepared in distilled water. Then cooled to 25 ?C in a water
bath. After standardization of the pH
meter with 4 and 7 pH buffers, the pH will be measured with a glass electrode.
The gel strength will be determined
by the British Standard 757:1975 method (BSI 1975) on a 6.67% gel (w/v), which
will be prepared by dissolving the dry gelatin in distilled water at 60 ?C, and
cooling the solution in a refrigerator of 7 to 8 ?C (maturation) for 16±18 h.
Viscosity will be determined by using
Turbidity The turbidity of FSG
solution (6.67% w/v) at different pH levels (3–10) will be determined using the
preferred method. 18 The samples will be dissolved in distilled water at 60
°C and the pH solution will be adjusted with either 6 N NaOH or HCl. The
turbidity will be determined by measuring the absorbance at 360 nm using
The melting point and
gelling temperature of gelatin will be determined as Muyonga’s method. 11
Color will be
determined with a colorimetry. 5