472
R. Berka
Frozen semi—products compose the greater part of processed carp, products
due to their technological feasibility of production (Skricil, 1976; Jilek,
1978; and Bojcic et al. 1982). Halves or portions of freshly processed carp
are
packaged in polyethylene bags and/or shrinkaged foil, stowed in flat
cardboard boxes and frozen in plate freezers. Freezing lasts 2 hours at tempe—
ratures
from —35°C —40°C. Frozen carp is stored 5 months maximum at temperature
—18°C (Skricil, 1976). A weight loss of 2 % is calculated for the storage
period. The field of low temperature preservation of fish was reviewed by
Ronsivalli and Baker (1981). Changes in lipids and proteins of carp muscles
during freezing and storage in the cooling plant were studied by Bastavizi
and Smirnova
(1972) who found that the freezing treatment has no substantiel
effect on muscle lipids. Na1etov et al. (1982) studied ultrastructural changes
in muscle tissue of carp during freezing and proved that fast freezing, utili—
zing liquid nitrogen, preserves the structure of muscle fibres and the ultra—
structural components of cells better than air freezing. The optimum freezing
rate for carp in a vapour—liquid mixture of liquid nitrogen is 5°C/min. till
a
final temperature of —80°C. The storage of carp at temperature of —20°C was
examined by Wagenknecht and Runge (1982) and did not change the fish protein
content
and quality. Fish glazing was more effective from the point of view of
weight loss due to drying, than packaging in polyethy1ene foid. The authors
recommend 13 weeks as the maximum.storage period for carp utilized directly in
making dishes, and a period of 6 months for frozen carp used as a raw material
for sterilized tinned products and/or hot—smoked products. The effects of
3—month—storage at —18°C and —25°C on bacteriological conditions were studied
by Oluski et al (1984) and Tumbas and Svrizic (1980) who proved that most of
the microflora was destroyed during the freezing process; nevertheless, some
fungi and bacteria, particularly Achromobacteriacae, isolated on the surface
of carp body survived at both temperatures. From a bacteriological point of
view, the quality of carp stored 3 months was Within the limits of food standards and no differences between both storage temperatures (—18°C and —25°C)
were
reported. Standards for freezing and cool storage of carp, valid in the
German Democratic Republic, were published by Anwand (1973, 1975).
The smoking of carp is part of to standard technology of hot smoking of
fish (Sbieschni, 1974; Bojcic et
1982; Zaitsev et al., 1969). After the
processing, the carp is immersed in salt brine at 12°C maximum. Carp saltiness
should not exceed 12 %. After soaking, the carp is dried and smoked in a kiln
at
70—130°C for 0.5—3 days, depending on the size of fish and kiln temperature.
The smoked product is removed from the kiln and cooled. The quicker it is
cooled, the lower the infection by microorganisms and the losses (average loss
is
10—12 % of raw material weight).
Carp can also be marinaded. All marinades fall into two groups: cold or
salt, and warm marinades prepared for pre—fried, pre—cooked, or pre—smoked
fish. Cold marinades are extensively used because they keep well and are
easier to prepare. Warm marinades are in fact made—up cooked dishes, and they
will not be discussed here. Informations on marinaded carp products are presented by Menzel et al. (1978a), Zaitsev et al. (1969) and Bojcic et al. (1982)Portions of carp are boiled with a vinegar and salt solution at 80—100°C
for
7 min.
After air—drying and cooling to 20—50°C, the carp is put into conta1ners.
Vegetab1e filling and pre—prepared marinade is added. A carp reprosents
40—60 % of the total weight of product which is sterilized at 100—118°C
for 35—50 min. These products can be stored for 12 months.
inf0rîïîïËâëzîî îäîned caäp
includes a broad spectrum
of products. SuffiCient
ferent ingredients sî
pro ucâs
(from carp soup, tinned carp fillets with difMenzel et al
(1978, %
spreads
made from manced meat) are presented by
are
prepared from Ê6il,dc’
:
Za1tsey
et
al., 1969; Lantz, 1966). Carp soups
ve
etable (20—25 7
e
meat
and ed1ble v1scera (18—40 % of the total),
g
.) and milk or cream (12 %) are added contingently. After
R. Berka
Frozen semi—products compose the greater part of processed carp, products
due to their technological feasibility of production (Skricil, 1976; Jilek,
1978; and Bojcic et al. 1982). Halves or portions of freshly processed carp
are
packaged in polyethylene bags and/or shrinkaged foil, stowed in flat
cardboard boxes and frozen in plate freezers. Freezing lasts 2 hours at tempe—
ratures
from —35°C —40°C. Frozen carp is stored 5 months maximum at temperature
—18°C (Skricil, 1976). A weight loss of 2 % is calculated for the storage
period. The field of low temperature preservation of fish was reviewed by
Ronsivalli and Baker (1981). Changes in lipids and proteins of carp muscles
during freezing and storage in the cooling plant were studied by Bastavizi
and Smirnova
(1972) who found that the freezing treatment has no substantiel
effect on muscle lipids. Na1etov et al. (1982) studied ultrastructural changes
in muscle tissue of carp during freezing and proved that fast freezing, utili—
zing liquid nitrogen, preserves the structure of muscle fibres and the ultra—
structural components of cells better than air freezing. The optimum freezing
rate for carp in a vapour—liquid mixture of liquid nitrogen is 5°C/min. till
a
final temperature of —80°C. The storage of carp at temperature of —20°C was
examined by Wagenknecht and Runge (1982) and did not change the fish protein
content
and quality. Fish glazing was more effective from the point of view of
weight loss due to drying, than packaging in polyethy1ene foid. The authors
recommend 13 weeks as the maximum.storage period for carp utilized directly in
making dishes, and a period of 6 months for frozen carp used as a raw material
for sterilized tinned products and/or hot—smoked products. The effects of
3—month—storage at —18°C and —25°C on bacteriological conditions were studied
by Oluski et al (1984) and Tumbas and Svrizic (1980) who proved that most of
the microflora was destroyed during the freezing process; nevertheless, some
fungi and bacteria, particularly Achromobacteriacae, isolated on the surface
of carp body survived at both temperatures. From a bacteriological point of
view, the quality of carp stored 3 months was Within the limits of food standards and no differences between both storage temperatures (—18°C and —25°C)
were
reported. Standards for freezing and cool storage of carp, valid in the
German Democratic Republic, were published by Anwand (1973, 1975).
The smoking of carp is part of to standard technology of hot smoking of
fish (Sbieschni, 1974; Bojcic et
1982; Zaitsev et al., 1969). After the
processing, the carp is immersed in salt brine at 12°C maximum. Carp saltiness
should not exceed 12 %. After soaking, the carp is dried and smoked in a kiln
at
70—130°C for 0.5—3 days, depending on the size of fish and kiln temperature.
The smoked product is removed from the kiln and cooled. The quicker it is
cooled, the lower the infection by microorganisms and the losses (average loss
is
10—12 % of raw material weight).
Carp can also be marinaded. All marinades fall into two groups: cold or
salt, and warm marinades prepared for pre—fried, pre—cooked, or pre—smoked
fish. Cold marinades are extensively used because they keep well and are
easier to prepare. Warm marinades are in fact made—up cooked dishes, and they
will not be discussed here. Informations on marinaded carp products are presented by Menzel et al. (1978a), Zaitsev et al. (1969) and Bojcic et al. (1982)Portions of carp are boiled with a vinegar and salt solution at 80—100°C
for
7 min.
After air—drying and cooling to 20—50°C, the carp is put into conta1ners.
Vegetab1e filling and pre—prepared marinade is added. A carp reprosents
40—60 % of the total weight of product which is sterilized at 100—118°C
for 35—50 min. These products can be stored for 12 months.
inf0rîïîïËâëzîî îäîned caäp
includes a broad spectrum
of products. SuffiCient
ferent ingredients sî
pro ucâs
(from carp soup, tinned carp fillets with difMenzel et al
(1978, %
spreads
made from manced meat) are presented by
are
prepared from Ê6il,dc’
:
Za1tsey
et
al., 1969; Lantz, 1966). Carp soups
ve
etable (20—25 7
e
meat
and ed1ble v1scera (18—40 % of the total),
g
.) and milk or cream (12 %) are added contingently. After