2. Materials and methods2.1. Materi

2. Materials and methods
2.1. Materials and samples preparation
Live Japanese sea bass used in this study were purchased from
an aquatic market in Jinzhou, China. The mean weight and length of
fish were 640
20 g and 28.5
0.43 cm, respectively. Fish were
transported to the Aquatic Products Processing Laboratory of Bohai
University within 0.5 h and kept alive before being processed. The
sea bass were decapitated andfilleted by hand, and twofillets were
obtained from eachfish. A cryogenic temperature of55

C has
been suggested as ideal storage conditions for frozen meat to
prevent quality changes (Zhou, Xu, & Liu, 2010). So we packedfillets
in polyethylene bags and randomly separated fillets into three
groups. Three different freezing treatments were used: (T1) frozen
at18

C and kept for up to 3 months; (T2) frozen at55

Cbyan
ultra-low temperature freezer (MDF-382E, Sanyo Co., Ltd., Dalian,
China) for 24 h and then moved to a refrigerator at18

C (as a
typical frozen storage temperature) and kept for up to 3 months;
(T3) frozen at55

C and kept for up to 3 months. After that, the sea
bassfillets were stored in refrigerated chambers at 0
1

C during
20 days for subsequent quality analysis. Fresh sea bassfillets were
obtained and then stored at 0
1

C as control. For each group, 18
sea bassfillets were used, and subsequently every 4 days, microbial
characteristics, biogenic amines and quality changes from each
group were analyzed.
2.2. Microbiological characteristics
All samples were analyzed for mesophilic bacteria, psychrophilic bacteria, Enterobacteriaceae, and Shewanella putrefaciens
counts as described byLi, Li, & Hu (2013). The samples were homogenized for 2 min with a BagMixer (Model 400, Interscience,
France). Mesophilic bacteria counts were determined on plate
count agar (PCA, Aoboxing Bio-Tech, Beijing, China) by counting the
number of colony-forming units after incubation at 35

C for 48 h.
Psychrophilic bacteria were enumerated on plate count agar (PCA,
Aoboxing Bio-Tech, Beijing, China) after incubation at 7

C for 10
days and expressed as log10 CFU/g. Enterobacteriaceae were
enumerated in violet red bile glucose agar (VRBGA, Aoboxing BioTech, Beijing, China) with a double layer at 30

C for 24 h.S.
putrefacienswere counted from the black colonies grown on iron
agar (Lyngby, Aoboxing Bio-Tech, Beijing, China) at 20

C for 72 h
and a representative number of colonies were confirmed by using
API 20NE (Biomerieux, France)

Hasil (Bahasa Indonesia) 1:

2. bahan dan metode2.1. bahan dan sampel persiapanHidup bass laut Jepang yang digunakan dalam kajian ini dibeli daripasar akuatik di Jinzhou, China. Rata-rata berat dan panjangikan yang 640 20 g dan 28.5 0.43 cm, masing-masing. Ikan-ikandiangkut ke perairan produk pengolahan laboratorium dari BohaiUniversitas dalam 0,5 h dan terus hidup sebelum diproses. Thebass laut memenggal leher andfilleted dengan tangan, dan twofilletsDiperoleh dari eachfish. Suhu kriogenik 55C memilikitelah diusulkan sebagai kondisi penyimpanan ideal untuk daging beku untukmencegah perubahan kualitas (Zhou, Xu, & Liu, 2010). Jadi kami packedfilletspolietilena tas dan fillet secara acak dipisahkan menjadi tigakelompok-kelompok. Tiga perawatan pembekuan yang berbeda digunakan: (T1) bekudi 18C dan terus hingga 3 bulan; (T2) beku pada 55Cbyanultra-rendah suhu lemari es (MDF-382E, Sanyo Co, Ltd, Dalian,Cina) selama 24 jam dan kemudian pindah ke kulkas 18C (sebagaisuhu penyimpanan beku khas) dan terus sampai 3 bulan;(T3) beku pada 55C dan terus hingga 3 bulan. Setelah itu, lautbassfillets tersimpan dalam bilik-bilik yang didinginkan 0 1C selama20 hari berikutnya kualitas analisis. Bassfillets laut segar yangDiperoleh dan kemudian disimpan di 0 1C sebagai kontrol. Untuk setiap grup, 18bassfillets laut yang digunakan, dan kemudian setiap 4 hari, mikrobaKarakteristik, biogenic amina dan perubahan kualitas dari masing-masingkelompok dianalisis.2.2. mikrobiologis karakteristikSemua sampel dianalisis untuk mesophilic bakteri, psychrophilic bakteri, Enterobacteriaceae, dan Shewanella putrefaciensdihitung sebagai byLi dijelaskan, Li, & Hu (2013). Sampel yang homogen 2 min dengan BagMixer (Model 400, Interscience,Prancis). Mesophilic bakteri hitungan bertekad di piringHitung agar-agar (PCA, Aoboxing Bio-Tech, Beijing, Cina) dengan menghitungjumlah koloni membentuk unit setelah inkubasi di 35C selama 48 jam.Psychrophilic bakteri yang disebutkan pada piring hitungan agar (PCA,Aoboxing Bio-Tech, Beijing, Cina) setelah inkubasi 7C 10hari dan dinyatakan sebagai log10 yang Enterobacteriaceae CFU g.disebutkan dalam violet merah empedu glukosa agar-agar (VRBGA, Aoboxing biotek, Beijing, Cina) dengan lapisan ganda pada 30C untuk 24 h.S.putrefacienswere dihitung dari koloni-koloni hitam yang tumbuh di besiagar-agar (Lyngby, Aoboxing Bio-Tech, Beijing, Cina) di 20C untuk 72 hdan sejumlah perwakilan koloni dikonfirmasi dengan menggunakanAPI 20NE (Biomerieux, Perancis)