a proposal on study on the histamine content of dried fish in some districts of nepal

7/28/2019 A Proposal on Study on the Histamine Content of Dried Fish in Some Districts of Nepal

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STUDY ON THE HISTAMINE CONTENT ANDHYGEINIC QUALITY OF DRIED FISH IN SOME

DISTRICTS OF NEPAL

BY

Prashanta PokhrelFood Research Officer

Food Quatantine Laboratory

Submitted to

Planning, Management & Evaluation section

Department of Food Technology and Quality Control

Babarmahal, kathmandu

2013


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1. IntroductionHistamine is a biogenic amine produced during microbial decomposition ofscombroid fish such as mackerel as well as non scombroid fish such as

sardines. Consumption of spoiled fish results in the outbreaks of foodpoisoning and histamine fish poisoning is one such type of foodpoisonings. Scombroid poisoning is usually a mild illness with a variety ofsymptoms including rash, urticeria, nausea, vomiting, diarrhea, flushing,tingling and itching of the skin.Fish is a rich source of protein and provide a means to compensate thenutritional difficulties of man. Fisheries can contribute as a low costsupplementary source of protein. According to a report 100gm of table fishprovides 17.0gm of protein. The percentage of protein varies from 15-20in fishes. This protein is relatively of high digestibility, biological andgrowth promoting values for human consumption. Nutritional studies have

proved that fish proteins rank in the same class as chicken protein and aresuperior to milk, beef protein and egg albumin. Fish protein comprises ofall the ten essentials amino acids in desirable strength for humanconsumption. It is also rich in minerals and vitamins. Besides, protein fishcontains Potassium, Calcium and Phosphorus in few amounts. The fishliver is well known as a source of vitamin A and D essential for thedevelopment of children. Fishes also contains vitamin B and B12 in thesame degree as in meat. Fish flesh contains negligible quantity ofcarbohydrates.Fish is a quickly perishable commodity and is spoiled if it is not properlypreserved. The place of consumption is generally at a distance from the

landing or catching point, and fish if it is to be markettted fresh it needsfast transport and cooling facilities. During peak period, large quantities offish are caught and need proper preservation so as to be available in leanperiod, and have to be transported to market at long distances forconsumption.When alive in water, fish carries large number of bacteria on its body, gillsand in the gut. Soon after the death of fish, these bacteria startreproducing and attack various organs so that the preservation of the fishhas to be done without loss of time.The principal aim of fish preservation is to delay, reduce or inhibit themicrobial spoilage. In the case of fatty fish, the preservation may also aim

at reducing or inhibiting oxidation and other undesirable changes in thefish oils, which are highly unsaturated and capable of going rancid atvarious stages of processing.Some fish preservation methods such as canning and curing change thecharacter of the fish substantially, while the sequence of freezing, coldstorage and thawing normally aims at retaining the fresh fish character asmuch as possible (Timilsina, 2007).


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Histamine ProductionHistidine exists naturally in many types of fish, and at temperatures above16C (60F) on air contact it is converted to the biogenic aminehistamine via the enzyme histidine decarboxylase produced by entericbacteria including Morganella morganii (this is one reason why fish should

be stored at low temperatures). Histamine is not destroyed by normalcooking temperatures, so even properly cooked fish can be affected.Histamine is a mediator of allergic reactions, so the symptoms producedare those one would expect to see in severe allergic responses.The production of histamine on fish can be fairly rapid. In one outbreak,threshold toxin levels were reached after only three to four hours ofstorage at room temperature. The greater the temperature abuse, thehigher the level of histamine that can be expected.Levels in excess of 50 mg/100 g fish tissue are considered potentially

dangerous. In Canada, imported fish is rejected if it contains more than 10mg of histamine per 100 g of fish.

Origin of Histamine poisoning/ Scombroid toxicityScombroid toxicity, also known as histamine poisoning, results from

ingesting fish incorrectly held at warm temperatures after capture orduring subsequent handling and storage. Histamine is formed by bacterialdecomposition of free histidine. Histidine is a naturally occurring aminoacid found in the muscle tissue of fish harvested in tropical and temperatemarine waters. The fish species most often implicated with histamineillness include mahi mahi, marlin, bluefish, mackerel, bonito and tuna.

Fish Production in Nepal

In Nepal the fish production per capita is 1676 gm. (MOA, Directorate ofFisheries Development 2004/2005). There are about 122 species of fishesin Nepal. The commonly cultivated are Labeo rohita, Catla catla. Theexotic species are Cyprinus carpio, Hypopthalmichthys moltrig,Aristichthys nobility and Oncorhynchus mykiss (trouts). They areconsumed fresh (Niroula, 2010) In many districts, ethnic grups, mainly theTharus, Pode, Maghim, Danuvarm, Darai and Damaihas have beencapturing fish from lakes, swamps, rivers and streams (Bhusal, 2011).They generally sell the fish fresh if the fish are big enough, while dry tomake sidra. Even big fishes are dried when the fished quantity is big(Timilsina, 2007).

Fish drying technology in NepalSmall fishes after washed to remove dirt and sand. After draining they arelaid spread over bamboo mats, plastic mats gunny bags. Then they are leftfor sun drying for 2-3 days with a drying time of 8-10 hours daily. Thedried fish are stored in plastic bags or gunny bags. The dried fish have amoisture content of 10-12 %. Regarding big fishes, bamboo skewer isinserted into the big fishes after degutting and dried over sunlight.
http://en.wikipedia.org/wiki/Histidinehttp://en.wikipedia.org/wiki/Histaminehttp://en.wikipedia.org/wiki/Histidine_decarboxylasehttp://en.wikipedia.org/wiki/Morganella_morganiihttp://en.wikipedia.org/wiki/Histaminehttp://en.wikipedia.org/wiki/Histidine_decarboxylasehttp://en.wikipedia.org/wiki/Morganella_morganiihttp://en.wikipedia.org/wiki/Histidine


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Alternatively removing the gut and cleaning, 25 % salt is rubbed and leftfor few hours. After that they are sundried (Kharel et al, 2007). The fishprocessing technology is traditional (Timilsina, 2007).

Fish Marketing in Nepal

Dried indigenous fish species in Nepal are kept in the market for selling inbackground Malekhu Bazzar, Koshi Barrage, Khadichour, and so on whichare attached with highway. These places are near big rivers which are richsource of indigeous fish species. Big fishes are sold fresh while excess offish and small fishes are sundried and kept in the market for selling. Fishspecies used for drying are Nakata (Garra gotyla), Buduna (Garraannandalei), Kabre (Glyptothorax sps,), Sahar (Tor putitora), Faketa(Barilius sps,) and Sidra (Puntius sps) ( Bhusal, 2011 ).

Fig 2: Dry fish being kept for selling in Nepal

2. Objective of the study

To study the histamine content of dried fish found in different

districts of Nepal.

To study the hygienic condition of dried fish.

To find the proximate composition of dried fish.


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Dried Fish Sample Collection

(30 samples, 3 species)

Data Analysis

Histamine content analysis

SunsariBagmatiChitwanDhadingSindhupalchok

Microbiological and proximate

analysis

Data Collection

Result Interpretation, ReportWriting and Submission

3. Problem Statement

Fish have formed an important item of human diet from the time manappeared on the earth, and are primarily caught for this purpose. Fish diet

provides proteins, fats and vitamins A and D. A large amount ofphosphorus and other elements are also present in it. They have a goodtaste and are easily digestible. Fishes are eaten in various ways, eithercooked or even raw. Some are dried, while some are salted or cured topreserve. In Nepal fresh and dried fish are available in the market.The processing aspect of fish in Nepal is traditional and unhygienic. Takinginto account, the small fish, the gut is not removed /cannot be removed,and dried over sunlight. Similarly in the processing of big fishes, thecleaning water used is not potable. Hence the condition is very muchfavorable for the enteric bacteria to decompose free histidine intohistamine.

In the Terai belt of Nepal people are suffering from Allergic reactions andhistamine poisoning due to the consumption of such fish. Even due to theirnegligence, severe cases of blurred vision, swelling of tongue, respiratoryproblems have arosed. In this context study on the histamine content andsanitary condition of dried fish marketed in Nepal is of value.

4. Expected output

This study will find the histamine content of dried fish markted inNepal.

It will show the hygienic condition of the fish.

Help the planning agencies and DFTQC to develop new fishprocessing methods

Help DFTQC to develop ways to reduce histamine poisoning in Nepal

5. Materials and Methods

Experimental design:

The whole study will be conducted at Food Quarantine Laboratory, Tatopani, Sindhupalchok.

A total of 30 dried fish samples will be collected from 5 districts of Nepal. At least 3 species

of fish will be included in the study. The histamine content of the fish will be analyzed.Similarly, the hygienic condition of fish will be studies through microbiological count.


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Fig 1: Methodology of the study.

Materials

Fish sample collection: Dried Fish Saples will be collected from 5different markets of 5 districts of Nepal. They will be Sunsari, Chitwan,Dhading, Bagmati and Sindhupalchok. From each district 6 samples (atleast 3 different species of fish) will be collected.

Chemical Equipment and glassware requirements

Chemicals Glasswares and equipments1. Benzene 1. Spectrophotometer (475nm)

2. Butanol 2. Vacuum oven

3. Sodium acetate 3. Refrigerator

4. Succnic anhydride 4. High speed Centrifugemachine

5. Acetic acid 5. High Speed Blender

6. Sulphuric acid 6. Polyethylene bottle

7. Hydrochloric acid 7. pH meter

8. p-nitroaniline 8. Ice bath

9. Sodium metaborate 9. Water bath


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(NaBO2)10.Sodium carbonate 10. Erlenmeyer flask11.Sodium barbital 11. Oswald pipette12.Dry histamine

dihydrochloride12. Centrifuge tubes

13.4-methyl-2-pntanone(methyl isobutylketone)

13. Volumetric flasks

14.Benzaldehyde (chlorinefree)

14. Beakers

15.Sodium borate 15. pipettes16.Absorbent Cotton17.Ethyl alcohol absolute18.NaOH19.Methanol20.Oxalic acid

Methods

Histamine content analysis:Histamine content will be analyzed according to AOAC, 2005.

Microbiological analysis:Total plate count was determined by pour plate method according to Harriganand McCane (1979) using plate count agar and distilled water as diluents.

Proximate analysisProximate constituents crude protein, crude fat, ash, calcium and

phosphorous content will be done according to K.C and Rai, 2005.

Budgetary Distribution

Particulars Amount (NRs.) Remarks

Sample collection and Transportation 50,000.00 -

Chemical and equipments 100,000.00 -

Report writing 10,000.00 -

Stationery and others 10,000.00 -Total 1,70,000.00

ReferencesBhusal D. (2011).Dried indigenous fish kept in the market for selling inNepal. Available at http://fishconsult.org/?p=1694 Accessed on 4 April,2013.
http://fishconsult.org/?p=1694http://fishconsult.org/?p=1694


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Niroula S. (2010). Fish Farming in Nepal, Available athttp://www.scribd.com/doc/31497481/Fish-Farming-in-Nepal Accessed on 4April, 2013.

Kharel G.P., Acharya P.P, Rai, B.K, 2007. Handbook of Traditional Foods ofNepal. 2007.

Timilsina A (2007). Comparative study on the hygienic quality oftraditionally dried fish dried with lab dried fish. B. Tech dissertationpresented to Central department of food technology, CCT, TU, Dharan,Nepal.
http://www.scribd.com/doc/31497481/Fish-Farming-in-Nepalhttp://www.scribd.com/doc/31497481/Fish-Farming-in-Nepal

a proposal on study on the histamine content of dried fish in some districts of nepal

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