Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013
Palembang, South Sumatra -Indonesia, 24-25 October,2013
138
3.2. Texture elasticity
The research results showed that fish formulation produced pempek with lower value of texture elasticity. High temperature had effect on higher value of texture elasticity. Initial measurement of
pempek texture gave average value in the range of 317.2 to 811.6. The values of pempek texture were decreased after 48 hours storage in the range of 216.2 to 586.2. The effect of formulation, temperature and
shelf life on the change of pempek texture elasticity was described by the following model :
Y = - 17,417 + 109,892 X
1
+ 3,710 X
2
– 4,301 X
3
R
2
= 0,977.............................................. 4 Texture is an important characteristics in evaluation of pempek quality. Higher addition of tapioca flour
would increased starch gelatinization capacity due to availability of water and heat which results in elastic texture of pempek. Tapioca flour has function as binder agent that capable to improve texture, but excessive
addition of tapioca flour will results in elastic texture. Protein content has significant effect on pempek texture. Protein content within fish flesh that has effect on texture is actomiosin. Prevention of actomiosin
denaturation is one of the most important factor to take into account. One method to prevent actomiosin denaturation is by using highly fresh fish as raw material Wang, 2011 and maintaining constant low
temperature during handling Astawan
et al
., 1996. Starch has two fractions which consisted of amylose and amylopectin. Amylose has effect on gel hardness, whereas amylopectin has effect on gel elasticity.
3.3. Total Volatile Nitrogen mg100g
The research results showed that fish formulation produced pempek with higher value of total volatilenitrogen. High temperature had effect on lower value of total volatilenitrogen. Measurement results
of total volatilenitrogen of pempek were in the range of 6.11 to 8.52. The values of total volatilenitrogen of pempek were increased after 48 hours storage in the range of 12.89 to 19.76. The effect of formulation,
temperature and shelf life on the change of total volatilenitrogen of pempek was described by the following model :
Y = 3,501 + 0,70X
1
– 1,030 X
2
+ 0,409 X
3
R
2
= 0,992........................................................... 5 Total volatile nitrogen is one of parameter to determine quality deterioration of fish and fish derived
products. TVN measurement on pempek was conducted to determine the rottenness indication of protein containing in food product. The increase of TVN concentration on pempek during storage was due to protein
degradation and its derivatives by proteolytic bacteria activity that decompose protein into simpler protein coumpounds which consisted of highly volatile bases such as ammonium, trimethylamine, histamine, indole,
H
2
S andskatol as well as breakdown of TMAO Trimethyl Amine Oxide into TMA TrimethylAmine. The acceptable maximum concentration of TVN for food products was 20 mg100 gram Castro
et al.
, 2012 and about 30-35mg100gramin case of fish flesh Huss.1988
in
Kaba, 2006 ., Amegovu
et al.,
2012. Pempekthat had been stored for 24 hours was still consumable because it hasTVN maximum concentration of 18 mg100
gram material, whereas 36 hours storage was in the range of 20 to 24 mg100 gram material and 48 hours storage was in the range of 25 to 29 mg100 gram material. Therefore, it can be concluded that pempek
stored for 48 hours was started to deteriorate and no longer consumable.
3.4. pH
