Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013
Palembang, South Sumatra -Indonesia, 24-25 October,2013
136
The Decrease of Pempek Lenjer Quality During Storage at Room Temperature
Railia Karneta
1+
, Amin Rejo
2
, Gatot Priyanto
2
, Rindit Pambayun
2
1
Doctoral Program Student at Graduate School Program of Sriwijaya University and Lecturer at StiperSriwigama
2
Lecturers at Agricultural Faculty of Sriwijaya University
Abstract.
The research objective was to study the effects of temperature and formulation on shelf life of pempek lenjer at room temperature. Treatments in this study were four levels of pempek formulation X
1
, five levels of temperature X
2
and nine levels of shelf life X
3
. Data was analyzed by using multivariant regression through computer program of SPSS ver 17. The results showed that higher tapioca flour addition
results in higher values of texture, pH and color whereas total volatile nitrogen TVN and total microbes TPC were lower. Higher temperature at center point of pempek results in higher values of texture, pH,
color and total microbia but TVN value was relatively constant. Longer storage time results in lower values of texture elasticity, pH and color whereas TVN and total microbes were higher. The maximum shelf life of
pempek was 30 hours.
Keywords:
quality, shelf life, pempek
1. Background
Pempek is one of South Sumatra traditional food made from milled fish flesh, tapioca flour or sago palm flour, water, table salt and spices as flavour enhancement. Pempek can be developed into larger
industrial scale. The main problems for current pempek industry were diverse quality and short shelf life because the pempek producers, especially for small scale industry, were frequently changed the pempek
formulation and the optimum cooking duration and temperature were not yet developed which results in decreasing of quality especially in term of nutrients and deterioration due to excessive heat treatment that
gave impact on relatively short shelf life of pempek. Provision of food industry product should be accompanied by assurance of food safety and quality.
Pempek processing stages were consisted of fish flesh milling, ingredients mixing, pempek forming and cooking Karneta, 2010. Cooking stage boiling is one of important stage because heat and mass diffusions
were occurred at this stage as well as physicochemical reactions such as protein denaturation and starch gelatinization. Temperature increase of boiled product is affected by the heat transfer rate from boiling water
into product through convection process and heat transfer within product was occurred through conduction process Huang and Liu, 2009. Conduction heat transfer on heated product was located at the slowest
heating point cold point, i.e at center of product Jaczynski and Park, 2002; Opaku, 2006. Heat diffusivity characteristic was affected by product chemical composition, product structure and temperature
SilalahidanTambunan, 2005; Sun, 2006. The research objective was to study the effect of temperature and pempek formulation on pempek shelf life at room temperature.
2. Method
Materials used in this research were tapioca flour, snake head fish
Ophicephallusstriatus
Blkr, table salt NaCl and ice water. Snake head fish was bought from Cinde Market of Palembang with average
weight of 400 to 500 grams per fish. Treatments in this research were as follows: X
1
: Fish and flour formulation having ratios of : X
1.1
= 1 : 0,5 ; X
1.2
= 1 : 1,0 ; X
1.3
= 1 : 1,5 and X
1.4
= 1 : 2,0.
X
2
:Temperature treatments on center point of pempek :
+
Corresponding author. Tel.: -
E-mail address
: railiakarnetayahoo.com
Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013
Palembang, South Sumatra -Indonesia, 24-25 October,2013
137 X
2.1
= 75 C ; X
2.2
= 80 C ; T
2.3
= 85 C ; T
2.4
= 90 C and T
2.5
= 95 C.
X
3
= Storage time hours : X
3.1
= 0 hour control; X
3.2
= 6 hours ; X
3.3
= 12 hours ; X
3.4
=18 hours ; X
3.5
= 24 hours; X
3.6
= 30 hours; X
3.7
= 36 hours ; X
3.8
= 42 hours and X
3.9
= 48 hours. Procedure:
a. Pempek dough processing was based on their formulations by addition of water and 2.5 table salt.
Water addition was conducted according to the following formulation :75 dough weight – fish water
content x fish weight – flour water content x flour weight.
b. Weighing of 350 grams pempek dough followed by pempek molding in cylindrical form which was then
boiled within water bath at temperature of 100 C. Temperature measurement on pempek was conducted
by using thermocouple line of K-type chromel + and allumel - installed on sample container during boiling. The use of thermocouple line was to guarantee that sample temperature measurement was at
pempek center point. Samples that had achieved center point temperature of 75 C, 80
C, 85 C, 90
C and 95
C were raised and leaked through. c.
The cooked pempek based on its center point temperature was then leaked through and stored at room temperature. The pempek deterioration was observed every 6 hours through textural change elasticity
by using
texture analyzer
, color change by using Munsell system, pH AOAC, Total Volatile Nitrogen TVN by using AOAC method and Total Microbes TotalPlate Count. TPC.
3. Result and Discussion
