I G. Suranaya Pandit *, N. T. Suryadhi, I. B. Arka, N. Adiputra **
Faculty of Agriculture, Warmadewa University *
Postgraduate Udayana University **
        Frigate mackerel fish is one of the food sources consumed by the community, and if left in room temperature, will easily putrefy.  Fish that have been through putrefaction process, if consumed by the community can cause histamine fish poisoning. This poisoning is due to pathogenic bacteria contamination with decarboxylase amino acid histamine by decarboxylase histidine enzyme resulting in histamine.  These bacteria are commonly found in parts of unhygienic human body, excrement, fish entrails, gills, and insanitary equipments.
        This is an experimental study with factorial method, i.e factor P referring to two levels of dressing (with and without dressing), and T factor refer to storage temperature with 3 level, 30oC, 15oC and 0oC.
        The statistical analysis on chemical quality such as histamine level, total volatile bases level (TVB), trimethylamine content (TMA), shows a significant different (P<0.05) to the effect of dressing and storage temperature.  There was an increase in histamine, TVB and  TMA contents and a decrease in water content during observation.  In additions,  an increase of bacterial colony and number of Coliform was also noted, except for Vibrio parahaemolyticus which was negative.  Dressing and 0oC storage temperature treatment has the best chemical and microbiological qualities up to day 10 and were still accepted by the panelist.
        There was a strong correlation between histamine and number of bacteria, showed by r value ≥ 0.7 except histamine level which has weak correlation of r ≤ 0.5.
       Frigate mackerel treatment using appropriate technology, with and without dressing combined with 30oC storage temperature is only safe to be consumed until day 0.  Treatment without dressing combined with 15oC storage temperature is safe until day 4, while with dressing safe until day 6.  Frigate mackerel treated with and without dressing and 0oC storage temperature is safe to be consumed until day 10.
Key words: frigate mackerel fish, dressing, and storage temperature.
        Fish is one of the food sources needed by community, before consuming fish, the community needs to know that fish are perishable food, due to some factors such as high protein content and environmental condition favorable for the growth of putrefying bacteria. The environmental condition includes temperature, pH, oxygen, length of storage, sanitary tools and equipments.
        Frigate mackerels belong to Scombroidae family, if left in room temperature, will promptly decrease its quality, become putrefied and if consumed, can cause fish poisoning. The poisoning is due to pathogenic bacteria contamination such as Escherichia coli, Salmonella, Vibrio chloreae, Enterobacteriaceae and others.  One type of poisoning frequently occurs with frigate mackerel is histamine poisoning (Scromboid fish poisoning), because this type of fish contains histidine amino acid which is contaminated by bacteria, by excreting histidine decarboxilase enzyme and producing histamine. This histamine producing bacteria are commonly found in parts of unhygienic human body, excrement, fish entrails, gills, and insanitary equipments.
        Poisoning cases due to fish consumption often occurred.  Therefore, efforts to handle frigate mackerel during storage using application of appropriate technology including dressing fish entrails and gills and storage at low temperature need to be  done.
Materials and Discussions
        This experimental research applied Randomized Blocked Design with 2 factors (Nazir, 2003), including dressing factor with 2 levels, i.e  with and without dressing (gills and entrails) and storage temperature factor with 3 levels: (30oC ± 2); (15oC ± 2); (0oC ± 2).
Chemical Quality
        The results of the experiment shows that the treatment of dressing and 00C storage temperature that had histamine level of 6.25 mg/100g, increased to 23.68 mg/100 g at day 10 compared to without dressing that was higher, reaching 7.74 mg/100g to 35.35 mg/100 g.  The same condition occurred on the treatment of dressing and 150C storage temperature day 0, with histamine level of 14.88 mg/100 g that became 62.13 mg/100 g, while the treatment without dressing at day 0, with histamine level of 19.43 mg/100 g  became 93.45 mg/100 g.  Histamine level of day 0 with dressing and storage temperature 300 amounting to 27.10 mg/100 g became 423.20 mg/100 g, while the treatment without dressing day 0 with 30.73 mg/100 g increased to 502.17 mg/100 g.
        Analysis of variance resulted in that storage temperature and dressing has significant effect (P<0.05).  According to Rickenbacker (2006), the main cause of bacterial  putrefaction comes from gills, skin surface and entrails, and therefore fish need to be dressed and cleaned with cold water.  A study made by Chytiri et al. (2004) revealed that histamine level and biogenic amine were lower on fillet rainbow trout (Onchorynchus mykiss) compared to whole fish at 5oC temperature after 12 days storage.
        The result of putrefaction in the form of histamine was optimum at 300C temperature and decreased at cold temperature 0-50C (Lehane and Olley, 2000).  Kose et al. (2003) reported that histamine production was 80.96 mg/100 g on mackerel fish which was stored at 150C, RH 70% for a week.  Aflak et al. (2005) found histamine level of 77.7 mg/100 g in sardine which was stored at 300C for 24 hours.
        The lowest total volatile bases (TVB) of 8.60 mg/100 g was found on treatment with dressing and 0oC storage temperature on day 0, to become 109.29 mg/100g, compared to without dressing 12.96 mg/100g increased to 127.94 mg/100 g at day 10.  Increasing level occurred on treatment with dressing and 15oC storage temperature and increase more at 30oC storage temperature.  This TVB level was affected by number of bacteria that stayed alive after treatment, so that bacterial metabolism product in the form of TVB were also different.  According to Kerr et al. (2002); Anon., (2006b), TVB is an indicator for fish quality, at an maximum level of 200 mg/100g, a proper limit that is safe for consumption including trimethylamine, dimethylamine, ammonia and other nitrogen bases which were products of bacterial activities and autolytic enzyme during putrefaction process. 
        Analysis of variance revealed that treatment of storage temperature and dressing     was significantly different (P<0.05). The difference in TVB level was caused by difference in bacterial population, therefore amount of metabolism in the form of TVB was also different and increased during observation time.  TVB is the result of protein decomposition by bacterial activities and enzyme.  Protein division resulted in 95% ammonia and CO2, besides as a direct results, protein was broken into total N non protein of fish became base with pH 7.1 – 7.2.  Results of protein degradation were volatile  causing bad smell such as ammonia, H2S, mercaptane, phenol, kresol, indol and skatol (Aurand et al., 1987).  Based on Antoine et al. (2004) research, mahi-mahi fish cutlets stored at 5oC, then observed on day 3, it was found TVB level achieved 30 mg/100 g.
        Trimethylamine (TMA) on treatment without dressing and 30oC storage temperature and treatment with dressing on day 0, TMA level was 33.91 mg/100 g and 28.98 mg/100 respectively and then increased rapidly until day 10 to become 332.62 mg/100 g and 288.70 mg/100 g.  When storage temperature decreased to 15oC and then 0oC on day 0, TMA level became lower, due to the number and population of bacteria that produced TMA became lesser, and then increased during observation time, followed by an increase in bacterial number.
        Analysis of variance showed that dressing and storage temperature treatment have significant effect (P<0.05). The difference in TMA level is caused by the difference in bacteria population.  TMA is a result of degradation product, specific to fish that contains trimethylamine oxide compound (TMAO) and other non protein nitrogen compound, and then were reduced into TMA (Ilyas, 1983).  TMA level on each treatment highly correlated with the number of bacteria.  According to Kerr et al (2002), trimethylamine level on marine product is safe to consume if it is not more than 100 mg/100 g.
Microbiology Quality
        On day 0 frigate mackerel with dressing and 0oC storage temperature, the lowest number of bacteria was found, 1.2 x 102 colony/g, compared to without dressing and 0oC storage temperature with 3.2 x 102 colony/g.  This circumstance kept rising until end of observation time on day 10, became 4.4 x 104 colony/g and 6.2 x 104 colony/g respectively.  The same circumstance happened on with and without dressing treatment with 15oC and 30oC storage temperature with different pattern of increase.
        Analysis of variance showed significant different (P<0.05). This number of bacterial colony greatly determined fresh frigate mackerel quality, such as chemical and organoleptic quality.  Application of low temperature 0 – 5oC on preservation process, could slow down bacterial growth, and some bacteria died, while others had a slow growth by forming spore (Gaman and Sherrington, 1994).  Furthermore, application of low temperature resulting in a decrease in chemical process and the number of bacteria related to degradation, but application of low temperature could not kill all the bacteria.  According to Anon. (2003), based on maximum temperature and optimum growth, bacteria can be divided into 3 groups, thermophiles, mesophiles and psychrophiles.  Thermophiles microbes are bacteria that grow best on temperature 40 – 65oC. Mesophiles microbe, mostly saphrophyte bacteria grow on temperature ranging 15 – 45oC, while psychrophiles microbe are bacteria that grow on low temperature 0-20oC, bacteria types that are commonly found on stored product at low temperature are Pseudomonas, Aerobacter, Streptococcus and Proteus.
        Coliform are heterogen bacterial from Enterobacteriaceae family, in which the treatment without dressing with 0oC storage temperature on day 0, result in the growth of  bacteria, about 8 x 101 colony/g and the growth keep increasing until day 10 to 2 x 108 colony/g.  Based on SNI (Anon., 1994), fresh fish safety threshold for Coliform contamination is 1 x 104 colony/g.  Microbiology quality of specifically Coliform on Tilapia fish (Sarotherodun galiaenus) that have been frozen already for 10 days, was 3.0 x 103 colony/g – 7.5 x 106 colony/g (Arannilewa et al., 2005).
        Based on the variance analysis, the treatment of storage temperature and dressing gave significant effect (P<0.05).  Coliform are heterogen bacteria, stick shape, negative gram and facultative aerobic, or aerobic, fermenting lactose, forming acid and gas in 24 hours at 37oC.  This group of Enterobacteria  includes Eschericia, Edwardsiella, Citrobacter Salmonella, Shigella, Klebsiella, Enterobacter, Hafnia, Serratia, Proteus, Yersinia and Erwinia (Fardiaz, 1989).
        In this research, bacteria Vibrio parahaemolyticus was not found, because Vibrio parahaemolyticus belongs to sea flora mostly found in abundant on shellfish, crab, prawn, fish and sea plants, halophylic in nature (Desmarchelier, 1997); (Anon., 2003b), furthermore, stated that this bacteria was found lots in delta areas, coastline and sediment area.  Frigate mackerel are schooling fish and live on the water surface (pelagic fish) (Dahuri, 2003), so  it is very likely that frigate mackerel are not contaminated by bacteria Vibrio parahaemolyticus.
Organoleptic Quality
        At the end of observation time at day 10, treatment 0oC with and without dressing was still accepted by the panelist with average score 7.4 (with a little dull, reddish appearance).  The analysis of variance on frigate mackerel appearance revealed that storage temperature significantly (P<0.05) affects the appearance and it was very much determined by water content.  Besides, high number of bacteria will break protein to become simple compounds and using the free water content in the frigate mackerel that could change the appearance of fresh frigate mackerel from bright into dull.
        On day 10 treatment 0oC storage with dressing, odor was still accepted by the panelist with average score of 7.1 (fish odor is almost neutral).  Based on the analysis of variance the storage temperature and dressing affect significantly (P<0.05) on odor score.   Sharp change in odor score on treatment with and without dressing at 30oC was caused by very rapid and effective degradation process at 30oC, where bacteria and enzyme broke the macro components on fish, particularly protein, to become simple compounds and finally became odor compound such as ammonia, histamine, H2S, indol, skatol, etc until all materials are all degraded.  Treatment at 0oC showed that degradation process occurred very slowly, but a number of psicrophylic were still able to do minimum activities until the end of observation period and was still accepted by the panelist.
        For storage temperature 00C, with or without dressing treatment, there was a decrease on texture value.  Based on analysis of variance, storage temperature and dressing treatment affect significantly (P<0.05) on texture.  With dressing treatment and storage temperature 00C rigormortis process went very slow because glycogen degradation into lactic acid, until glycogen content ran out very much affected by temperature.  In this condition, frigate mackerel texture was still compact and elastic, and decrease slightly at the end of observation time at day 10 and was still accepted by the panelist.
        Correlation between histamine level with; total volatile bases; trimethylamine level,  number of bacteria, number of Coliform, appearance, odor, texture, was very strong, shown by value r = ≥ 0.7 except for histamine level with time which has low correlation r = ≤ 5.  This low correlation was due to the fact that histamine level did not affect directly on observation time, but histamine did directly affect the number of bacteria.
The best improvement of  fish safety on frigate mackerel (Auxis tharzard) through the application of appropriate technology from the view points of chemical, microbiology and organoleptic quality, was obtained on dressing treatment and 00C storage temperature, respectively followed by without dressing and storage temperature 00C, dressing and storage temperature 150C, without dressing and storage temperature 150C, dressing and storage temperature 300C, and the last was with no dressing and storage temperature 300C.
Novelty for this research is that dressing and without dressing and storage temperature 00C can increase storage time and safe for consumption until day 10, compared to treatment of dressing and storage temperature 150C only less than day 6, followed by without dressing at 150C under 4 days, and then dressing and without dressing at 300C storage temperature only safe to be consumed for less than 1 day.
There was a very strong and significant correlation between histamine level with  TVB level; TMA level; number of bacteria; number of Coliform bacteria; appearance; odor; texture, while histamine level with time (days) had low correlation but still significant.
Aflal, M.A., Daoudi, H. Jdaini, S., Asehraou., and Bouali, A.  2006.  Study of The Histamine Production in a Red Flesh Fish (Sardina pilchardus) and a White Flesh Fish (Dicentrarchus punctatus).  J. of Fish and Aquatic Sciences 6: 43-48.
Allen, G. Green, D.P and Bolton, G.E.  2004.  Control of Histamine Production in Current Commercial Fishing Operations for Mahi-Mahi (Coryphaena hippurus) and Yellowfin Tuna (Thunnus albacares) in North Carolina.  Coresponding authors:
Anonimus, 1994.  Standar Nasional Indonesia.  Balai Bimbingan dan Pengujian Mutu Hasil Perikanan.  Dirjen Perikanan dan Kelautan.  Jakarta.
Anonimus, 2003.  Bakteriologi Medik.  Fakultas Kedokteran Universitas Brawijaya.  Bayumedia Publishing, Malang.
Anonimus,  2006.  Assessment of Fish Quality, Biochemical and Chemical Methods.  http://D:Ch16, Ch 18.htm.  Accessed 2/3/2006.
Antoine, F.R., Wei, C.I., Otwell, W.S., Sims, CA., Littell, R.C., Hogle,A.D., and Marshall, M.R.  2004.  Chemical Analysis and Sensory Evaluation of Mahi-Mahi (Coryphaena hippurus) during Chilled Storage.  J. of Food Protection: Vol 67, No. 10: 2255 – 2262.
Arrannilewa, S.T., Salawu, S.O., Sorungbe, A.A., and Olasalawu, B.B.  2005.  Effect of Frozen Period on the Chemical, Microbiological and Sensory Quality of Frozen Tilapia Fish (Sarotherodun galiaenus).  J. of Biotechnology: Vol. 4(8):852-855.
Aurand, L.W., Eoods, A.E., and Wells, M.R.  1987.  Food Composition and Analysis.  The Avi Published by Van Nostrand Reinhold Co. New York.
Chrytiri, S., Paleologos, E., Savaidis, I., and Kontominas, M.G.  2004.  Relation of Biogenic Amines with Microbial and Sensory Changes of Whole and Filleted Freshwater Rainbow Trout (Onchorinchus mykiss) Stored on Ice.  J. of Food Protection.  Vol 67. No. 5. 960-965.
Dahuri, R.  2003.  Keanekaragaman Hayati Laut.  Aset Pembangunan Berkelanjutan Indonesia.  Penerbit PT Gramedia Pustaka Umum.  Jakarta.
Desmarchelier, P.M. and Grau, F.H. 1997.  Escherichia coli.  Foodborne Microorganisms of Public Health Significance.  Australian Institute of Food Science and Technology Inc.  North Sydney. P: 159-231.
Desmarchelier, P.M.  1997.  Pathogenic Vibrios.  Foodborne Microorganisms of Public Health Significance.  Australian Institute of Food Science and Technology Inc.  North Sydney. P: 285-307.
Fardiaz, S.  1989.  Mikrobiologi Pangan.  Departemen Pendidikan dan Kebudayaan.  Direktorat Jenderal Pendidikan Tinggi.  Pusat Antar Universitas Pangan dan Gizi.  IPB.  Bogor. 5.
Gaman, P.M.  dan Sherrington, K.B.  1994.  Ilmu Pangan, Pengantar Ilmu Pangan dan Nutrisi dan Mikrobiologi.  2nd edition.  Fakultas Teknologi Pertanian. UGM,  Yogyakarta.
Ilyas, S.  1983.  Teknologi Refrigerasi Hasil Perikanan.  Penerbit CV. Paripurna.  Jakarta.
Kerr, M, Lawickim, P., Aguirre, S. and Rayner, C.  2002.  Effect of Storage Conditions on Histamine Formation in Fresh and Canned Tuna.   State Chemistry Laboratory, Werrbee.  Victorian Government Department of Human Sevices.
Kose, S., Quantick, P., and hall, G.  2003.  Changes in the Levels of Histamine during Processing and Storage of Fish Meal.  Animal Feed Science and Technology.  107:161-172.
Lehane, L. and Olley, J.  2000.  Histamine Fish Poisoning Revisites.  Intl. J. Food Microbiol. 58: 1-37.
Nazir, M.  2003.  Metode Penelitian.  Penerbit Ghalia IndonesiaJakarta.
Rickenbacker.  2006.  Spoilage of Fish.  http://Spoilage/of/fish.htm.  Accessed 2/3/2006.
Appreciate thanks to Profesor dr. N. T. Suryadhi, MPH. Ph.D.,  Profesor Dr. drh. Ida Bagus Arka, GDFT, Profesor Dr. dr. N. Adiputra, M.OH, as promotor and copromotor. Profesor Dr. Made Sukarsa, SE. M.S, Rector of Warmadewa University