TECHNOLOG

FISH PACKAGING

TECHNOLOGYMODIFIED ATMOSPHERE PACKAGING (MAP)

TECHNOLOGY OF FISH

ABSTRACT

Modified atmosphere packaging, MAP, means replacing the air in a pack of fish with a different mixture of gases, typically some combination of carbon dioxide, nitrogen and oxygen.

FIRST GROUP

SYAFRI NURKHALISH ARHASTUTI. HSARDIANADARMAWATIWA ODE NUR WAHIDAWAHIDA. GSRI MARIA ULFASRI HERLY JUSNIANTYSILVIA SULISTIAWATI

ACKNOWLEDGEMENT

Praice to Allah SWT who has given taufiq, guidance, and inayah, so

we all can move as usual as well as the authors so we can complete tha

paper entitled “FISH PACKAGING“ and sub title “Modified Atmosphere

Packaging, (MAP) Of Fish”. Peace and salutation be upon to our prophet

Muhammad SAW, he is greatest man in this earth.

This paper contains about definiion, prinsiple, advantages and

disadvantages, and all about of Modifiend Atmosphere Packaging

Technology of fish products.

The authors also wish to express thanks to teammates and teacher

who have guided the authors of paper in accordance with the provisions in

force so that it become a paper is good and right.

The authors apologizes for any shortcomings and msitakes of this

paper, please qritique and suggestons for perfection of next paper. Thank

you.

Pangkep, 9th September 2013

Authors

I. INTRODUCTION

A. Background

This note defines modified atmosphere packing, and summarizes the

advantages and disadvantages of the method for fish products. Advice is

given on the selection of fish for packing, the appropriate gas mixture, and

on packaging materials and equipment. The importance of chilled storage

is stressed, and some indication is given of storage life and safety of

packs.

Modified atmosphere (MA) packaged foods have become

increasingly more available, as food manufacturers have attempted to

meet consumer demands for fresh, refrigerated foods with extended shelf-

life. The use of an MA with an enhanced carbon dioxide level has been

shown to extend the shelf-life of foods by retarding microbial growth

(Stiles, 1991). Fish and shellfish are highly perishable and their

deterioration is primarily because of bacterial action (Colbyet al., 1993).

Typical shelf-life under current icing and refrigerated storage conditions

ranges from 2 to 14 days (Stammen et al., 1990).

Modified atmosphere packaging (MAP) of fishery products has been

shown to inhibit the normal spoilage flora and increase shelf-life

significantly. However, the possibility that Clostridium botulinum type E

and non-proteolytic type B strains will grow and produce toxin in low-

oxygen atmospheres at refrigerated temperatures has caused great

concern in studies on MAP of seafood (Church, 1994). This review

examines the effect of the MAP technology used for fresh fishery products

on the spoilage microbiological flora and on the food-borne pathogens that

may be present in these products

B. Purpose

The purpose of this paper is people can know:

1. Definision of Modified atmosphere packing (MAP);

2. Principle of MAP;

3. Advantages and disadvantages of MAP

II. DISCUSSION

A. Definition of Modified atmosphere packaging (MAP)

Modified atmosphere packaging, MAP, means replacing the air in a

pack of fish with a different mixture of gases, typically some combination

of carbon dioxide, nitrogen and oxygen. The proportion of each

component gas is fixed when the mixture is introduced, but no further

control is exercised during storage, and the composition of the mixture

may slowly change. Modified atmosphere packing is often incorrectly

called controlled atmosphere packing, CAP. Controlled atmosphere

packing means packing in an atmosphere whose composition is

continuously controlled throughout storage; such control is possible in

large storage units, but not in small packs.

B. Principle of MAP

The principle of MAP is the replacement of air in the package with a

different fixed gas mixture. Once the gas mixture is introduced, no further

control of the gas composition is performed, and the composition will

inevitably change. CO2 is the most important gas used in MAP of fish,

because of its bacteriostatic and fungistatic properties. It inhibits growth of

many spoilage bacteria and the inhibition is increased with increased

CO2-concentration in the atmosphere. The use of CO2 to inhibit bacterial

growth is not a new technology. In 1877 Pasteur and Joubert observed

that Bacillus anthracis could be killed by CO2 (Valley, 1928) and 5 years

later the first article on the preservative effect of carbon dioxide on food

was published (Kolbe, 1882), showing extended storage life for ox meat

placed inside a cylinder filled with a carbon dioxide atmosphere.

CO2 is highly soluble in water and fat, and the solubility increases

greatly with decreased temperature. The solubility in water at 0°C and 1

atmosphereis 3.38g CO2/kgH2O, however, at 20°C the solubility is

reduced to 1.73 g CO2/kg H2O (Knoche,1980). Therefore, the

effectiveness of the gas is always conditioned by the storage temperature

with increased inhibition of bacterial growthas temperature isdecreased

(Haines,1933; Gill&Tan, 1980; Ogrydziak & Brown,1982).The solubility of

CO2 leads to dissolved CO2 in the food product (Knoche,1980)

The concentration of CO2 in the food is dependent on the product’s

water and fat content, and of the partial pressure of CO2 in the

atmosphere, according to Henry’s law (Ho et al., 1987). Devlieghere et al.

(1998a, 1998b) have demonstrated that the growth inhibition of

microorganisms in MA is determined by the concentration of dissolved

CO2 in the product. After the packaging has been opened, the CO2 is

slowly released by the product and continues to exert a useful

preservative effect for a certain period of time, referred to as CO2’s

residual effect (Stammen et al., 1990).

The action of CO2 on the preservation of foods was originally thought

to be caused by displacement of some or all of the O2 available for

bacterial metabolism, thus slowing growth (Daniels et al., 1985). However,

experiments with storage of bacon and pork showed a considerable

increase in shelf-life under 100% CO2 compared with storage in normal air

atmospheres (Callow, 1932), but the preservative effect was not because

of the exclusion of O2, as storage in 100% nitrogen offered no advantage

over normal air storage. The same results were also seen on pure cultures

of micro-organisms isolated from spoiled pork.

A drop in surface pH is observed in MA products because of the

acidic effect of dissolved CO2, but this could not entirely explain all of

CO2’s bacteriostatic effect (Coyne, 1933). It was shown that CO2 was

more effective at lower temperatures and that the change in pH caused by

the CO2 did not account for the retardation of growth. In a study on

several pure cultures of bacteria isolated from fish products, CO2

atmospheres were found to inhibit the growth of bacteria markedly,

whereas normal growth patterns were observed under air or N2

atmospheres (Coyne, 1932). It was also observed that bacterial growth

was inhibited even after the cultures were removed from the CO2

atmosphere and transferred to an air environment, interpreted as a

residual effect of CO2 treatment. Bacterial growth was distinctly inhibited

fewer than 25% CO2 and almost no growth was observed under higher

CO2 concentrations for 4 days at 15 °C. The results obtained could neither

be explained by thelackofO2 northepHeffect.Coynesuggested the

possibility that intracellular accumulation of CO2 would upset the normal

physiological equilibrium in other ways, i.e. by slowing down enzymatic

processes that normally result in production of CO2. Thus, the effect of

CO2 on bacterial growth is complex and four activity mechanisms of CO2

on micro-organisms have been identified (Parkin & Brown, 1982; Daniels

et al., 1985; Dixon & Kell, 1989; Farber, 1991).

1. Alteration of cell membrane function including effects on nutrient

uptake and absorption;

2. Direct inhibition of enzymes or decreases in the rate of enzyme

reactions;

3. Penetration of bacterial membranes, leading to intracellular pH

changes;

4. Direct changes in the physico-chemical properties of proteins.

5. Probably a combination of all these activities account for the

bacteriostatic effect.

A certain amount (depending on the foodstuff) of CO2 has to dissolve

into the product to inhibit bacterial growth (Gill & Penney, 1988). The ratio

between the volume of gas and volume of food product (G/P ratio) should

usually be 2:1 or 3:1 (volume of gas two or three times the volume of

food). This high G/P ratio is also necessary to prevent package collapse

because of the CO2 solubility in wet foods. Dissolved CO2 takes up much

less volume compared with CO2 gas, and after packaging a product in

CO2 atmosphere, under-pressure is developed with in the package and

package collapse may occur. The CO2 solubility could also alter the food–

water holding capacity and thus increase drip (Davis, 1998). Exudate from

MAP fish can be reduced significantly by dipping fillets in NaCl solution

prior to packaging (Bjerkeng et al., 1995; Pastoriza et al., 1998). In fishery

products eaten without prior heating, such as crab and cooked fish, an

acidic, sherbet-like flavour can be observed when high partial pressures of

CO2 is used.

Nitrogen (N2) is an inert and tasteless gas, and is mostly used as

filler gas in MAP, because of its low solubility in water and fat (Church &

Parsons, 1995). N2 is used to replace O2 in packages to delay oxidative

rancidity and inhibit growth of aerobic micro-organisms, as an alternative

to vacuum packaging. The use of oxygen in MAP is normally set as low as

possible to inhibit the growth of aerobic spoilage bacteria. Its presence is

reported to increase oxidative rancidity (Chen et al., 1984), although

others claim that rancidity caused by presence of O2 in the atmosphere is

no problem (Haard, 1992). However, for some products oxygen could or

should be used. High levels of oxygen are used in red meat and red fish

meat (tunas, yellowtails, etc.) to maintain the red colour of them eat, to

reduce and retard browning caused by formation of metmyoglobin

(Oka,1989).O2 in MA-packages of fresh fish will also inhibit reduction of

TMAO to TMA (Boskou & Debevere,1997).

C. Advantages of MAP

The storage life of sonic chilled products, notably white fish can be

extended by packing in a modified atmosphere. The appearance of the

pack is attractive and, since the transparent packaging is not in close

contact with the contents, the buyer can clearly see the product. Modified

atmosphere packs have the advantages common to most forms of

prepacked fish; they are odourless, easy to label and convenient to

handle. In addition they are leakproof and robust.

D. Disadvantages of MAP

Modified atmosphere packing is relatively expensive, currently about

twice the cost of vacuum packing. Continuous production of rigid packs

entails the purchase of expensive packaging machinery and the use of

expensive thermoformable film. Modified atmosphere packs are commonly

two or three times bulkier than other forms of pack, and therefore are

costlier to carry and store.

The walls of a pack may collapse when the enclosed atmosphere

contains a high proportion of carbon dioxide, which is highly soluble in fish

tissue. As the carbon dioxide dissolves, a partial vacuum is created, the

pack may collapse onto the product, and in some instances the contents

may be squashed. The problem can be avoided by correct choice of gas

mixture.

Unsightly drip may form inside the pack when too high a proportion of

carbon dioxide is used. The problem can be minimized by choosing the

right gas mixture and by introducing an absorbent paper pad beneath the

fish.

Any extension of storage life attributable to modified atmosphere

packing may be lost if the additional safeguard of chilled storage is

ignored; the packs must be kept at or close to 0°C throughout distribution

if the full benefits of a modified atmosphere are to be maintained.

E. Gas Mixture

Carbon dioxide retards bacterial spoilage of fish, but too high a

proportion in the mixture can induce pack collapse, excessive drip and, in

products that are eaten without further cooking, for example brown crab

meat, an acidic, sherbet-like flavour. Oxygen can prevent colour changes

and bleaching that would otherwise occur in some products. Nitrogen is an

inert gas that is used to dilute the mixture. The following mixtures are

recommended, based on an assumed ratio of 3 parts gas mixture to 1 part

fish by volume in the pack.

For white fish, scampi shrimp and scallops a mixture of 40 per cent

carbon dioxide, 30 per cent nitrogen and 30 per cent oxygen gives the

best results. For salmon, trout, fatty fish such as herring and mackerel,

and for smoked fish products, a mixture of 60 per cent carbon dioxide and

40 per cent nitrogen is recommended. Smoked salmon packed in this

mixture may sometimes show a green discoloration during storage, the

extent of the greening being dependent on the strength of the smoke cure;

where greening is likely to occur, the mixture recommended for white fish

should be used.

F. Machinery And Materials

The simpler and cheaper machines pack the product in a flexible bag

or on a tray inside a bag to form what is termed a pillow pack. At the more

expensive end of the available range are sophisticated machines that

continuously form packs with rigid bases from rolls of thermoformable

plastics film. Some of these machines have a dual purpose and can be

converted to vacuum packing when required, although the changeover

can take up to 3 hours. Modified atmosphere packs can be produced at a

rate of more than thirty a minute on the fastest machines. Packaging films

must have low gas permeability, and be to the machine maker's

specification.

Gases can be obtained either ready mixed, or separately for use in

machines that mix the gases before packing. Where gases are mixed in

the machine, the gas composition in the packs should be measured at the

start of a run, and monitored throughout the day, particularly when faults

are suspected or adjustments to the gas mix are made.

G. Quality of Fish

Only the highest quality fish should be used for modified atmosphere

packs, in order to gain the most benefit from any extension of storage life;

packing fish in a modified atmosphere is not a means of marketing

medium quality or poor quality fish.

White fish should be of a quality equivalent to 1-4 days in ice, and

should be free from blemishes and visible parasites. Herring and mackerel

should be of a quality equivalent to 1-3 days in ice, and should contain at

least 8 per cent fat. Smoked fish products should be made from fish of the

same initially high quality. Salmon and trout should be of a quality

equivalent to 1-3 days in ice.

H. Packing the Fish

Fish should be handled hygienically and kept chilled from the time of

capture or harvesting until they are packed; whole fish and fillets should be

kept in ice while awaiting processing, and smoked products should be held

in a chillroom at 0°C. Ideally an air blast chiller should be provided in the

processing line, either before or after the packing machine, since the fish

may warm significantly during the packing operation.

Layering of products within a pack should be avoided; a single fillet

or portion is more fully exposed to the action of the gases. Layering is

unavoidable when packing sliced smoked salmon, but the product does

not gain the full benefit of the modified atmosphere. Wet fish products that

are likely to exude drip can be laid on a pad of absorbent paper inside the

pack. Packs with faulty seals can be detected by pressing them with the

hands; faulty packs will collapse. Packs should be clearly labelled

according to existing regulations, and should be marked with a sell-by or

consume-by date.

I. Storage life of packs

Storage life will depend on the species of fish used, its initial quality

and fat content, the nature of the finished product, temperature of storage

and, in a modified atmosphere, the gas mixture. Temperature of storage is

of paramount importance in deriving the most benefit from a modified

atmosphere; packs should be stored at a temperature as near to 0°C as

possible, and never above 5°C. Any benefit from a modified atmosphere

will be much reduced when storage temperature rises above 5°C.

White fish fillets benefit most from packing in a modified atmosphere;

for example cod fillets of high initial quality, packed in the recommended

gas mixture, and with a ratio of gas to product in the pack of 3:1 by

volume, will keep up to 50 per cent longer at 0°C than when stored under

vacuum or unwrapped. Raw shell-on scampi and shrimp keep up to 30 per

cent longer at 0°C in a modified atmosphere pack than in other types of

pack, and the onset of black spot is inhibited. The storage life of herring,

mackerel, salmon, trout, and smoked fish products is not extended in a

modified atmosphere at 0°C.

J. Safety

Fishery products in the UK have a good record of safety with regard

to food poisoning, and products in modified atmosphere packs are no

exception. Some concern has been expressed about smoked products

that are eaten without further cooking, for example smoked salmon and

smoked mackerel, but the risk of an outbreak of botulism or of

scombrotoxin poisoning from these products is no greater when packed in

the recommended modified atmosphere than when packed in any other

form.

III. CONCLUSION

Only the highest quality fish and seafood products should be used to

benefit from the extended shel-flife advantages of MAP. The extended

shelf-life will depend on the species, fat content, initial microbialload, gas

mixture, the ratio of G/P, and most importantly temperature of storage.

The SSO of MAP cod at 0°C has been found to be P. phosphoreum.

Whether this bacteria is the general SSO for all marine fishes at different

storage temperatures and under various CO2/N2/O2 mixtures needs to be

resolved.

Without proper control of storage temperatures, the benefits of MAP

may be lost. Higher storage temperature will inevitably lead to loss of

dissolved CO2 in the product and consequently loss of inhibitory effect;

higher microbial and enzymatic activity; and uncertainties around the

microbial safety of the product.

REFERENCES

1. http://www.fao.org/wairdocs/tan/x5956e/x5956e01.htm

2. http://www.aseanfood.info/Articles/11025084.pdf