Sains
Malaysiana 41(3)(2012): 325–331
Penilaian Kaedah Pengiraan Escherichia
colidalam Masakan Ayam
(Evaluation of Escherichia coli Enumeration
Methods in Poultry Dishes)
Ratna Dewi Abdul Rahman & Norrakiah
Abdullah Sani*
Program Sains Makanan, Pusat Pengajian
Sains Kimia dan Teknologi Makanan
Fakulti Sains dan Teknologi, Universiti
Kebangsaan Malaysia
43600 Bangi, Selangor D.E. Malaysia
Abdul Aziz Jemain
Program Statistik, Pusat Pengajian Sains
Matematik, Fakulti Sains dan Teknologi
Universiti Kebangsaan Malaysia 43600
Bangi, Selangor D.E. Malaysia
Diserahkan: 21 Julai 2011 / Diterima: 19
September 2011
ABSTRAK
Kajian ini bertujuan untuk memilih kaedah terbaik
daripada sebelas kaedah pengiraan Escherichia coli dalam masakan ayam. Kaedah-kaedah tersebut
adalah piring curahan, piring sebaran, piring titisan, PetrifilmTM, tiga jenis
pemiringan terus dan empat jenis kaedah bilangan paling mungkin (MPN).
Perbandingan kaedah dijalankan mengikut prosedur ISO 16140. Setiap strain E.
coli (ATCC 25922, IMR 1/3 107B dan IMR
E243) telah diinokulasikan ke dalam lima jenis masakan ayam bagi mendapatkan
kepekatan bakteria sehingga 105 cfu/g. Perlakuan haba dibuat pada 55oC
selama 4-6 min bagi mewujudkan persekitaran yang seakan-akan sama seperti
makanan tersebut dihidangkan sebaik sahaja selepas dimasak. Analisis statistik
Regressi Kaedah Kuasa Dua Terkecil (KKDT) dijalankan bagi membandingkan sebelas
kaedah pengiraan E. coli. Nilai kecerunan (m) yang signifikan (p <
0.05) pada kesemua Graf KKDT membawa maksud kesemua kaedah adalah serupa
daripada segi kejituan, korelasi, dan ketepatan relatif. Oleh itu, penilaian
praktikal turut dipertimbangkan bagi menentukan tiga kaedah terbaik bagi
pengiraan E. coli dalam masakan ayam. Piring curahan,
PetrifilmTM dan piring titisan adalah lebih praktikal berbanding lapan kaedah
yang lain.
Kata kunci: Escherichia
coli; kaedah ISO 16140; masakan ayam; regresi KKDT
ABSTRACT
The purpose of this study was to select the best
from eleven methods for Escherichia coli enumeration in poultry dishes. The methods
were pour, spread and drop platig, PetrifilmTM, three types of direct plating
and four types of most probable number (MPN) methods. Method comparison was
carried out based on ISO 16140 procedure. Each type of E. coli strains (ATCC 25922, IMR 1/3 107B and IMR
E243) were inoculated into five types of poultry dishes to obtain 105 cfu/g
bacterial concentration. Heat treatment was done at 55oC for 4-6 min
to mimic the environment as these foods were served right after cooking. The
Ordinary Least-Squares (OLS) Regression statistical analysis was carried out to
compare eleven methods for E. coli enumeration. The significance
(p<0.05) of gradient value (m) for all OLS Graphs mean that all methods were
similar in term of accuracy, correlation and relative accuracy. Thus, practical
approaches were also considered in order to select the best from eleven methods
for E. coli enumeration in poultry dishes. Pour plating,
drop plating and PetrifilmTM methods were more practical than the other eight
methods evaluated.
Keywords: Escherichia coli; ISO 16140 method; poultry dishes; OLS
regression
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*Pengarang
untuk surat-menyurat; email: norrra@ukm.my
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