153
Natural sun drying has been used since ancient times for agricultural products.
Sun drying is the most convenient and the cheapest processing technique to preserve
fish and fish products particularly in tropical and subtropical countries, where solar
radiation is abundant, inexhaustible, and environmentally friend (Nguyen et al.
2014). The products are dried by spreading in the open air. The products are placed
on various materials such as trays, hangers, frames, etc. For this purpose, bamboo
frames are mostly preferred in tropical regions (Gokoglu 2002). However, a major
problem of open sun drying is the loss of quality due to contamination with dust and
excreta from birds and animals (Nguyen et al. 2014). Therefore, other drying techniques have been developed and various studies have been conducted on the use of
these techniques in drying mussels.
Recently innovative drying methods have been tried to dry mussel meat in some
studies. Spray drying is a unique technique which can produce powder of special
particle size. In a study, to produce dried powder from freshwater mussels, after
washing the mussels were deodorized by two different methods. In the first method,
0.3% sodium chloride, 1% citric acid and 0.1% yeast powder, in the second method
1% ginger and 0.5% cooking wine were used. The deodorized mussels were placed
in the meat grinder and the small pieces were transferred to the ultrafine grinder
with 20% water for the subsequent pulverization process and dried in a spray dryer
(Zhang et al. 2013). Freeze drying is an innovative drying process that uses ice sublimation as the main drying mechanism. This differs from conventional drying
methods in that it is based on capillary movement and evaporation of liquid water
for drying. In freeze-drying, water in the products is removed by sublimation at low
temperature and low pressure below the triple point. First, the water in the products
is frozen in the pre-freezing step and then removed by sublimation of ice in the
primary drying step (Nguyen et al. 2014). McCarron et al. (2007) have tried freezedrying process of mussel (M. edulis) with the aim of stabilizing shellfish toxins. In
this study, they used mussels naturally contaminated with domoic acid, okadaic
acid, dinophysistoxin-2, and azaspiracid-1, -2 and -3. Wet materials were used for
control purposes. The freeze-dried material containing domoic acid was stable over
the whole duration at all temperatures, while in the wet material domoic acid
degraded to some extent at all temperatures except −20 °C. In freeze-dried and wet
materials containing lipophilic toxins, okadaic acid, dinophysistoxin-2, azaspiracid1 and azaspiracid-2 were stable over the whole duration at all conditions, while
concentrations of azaspiracid-3 changed significantly in both materials at some storage temperatures. In another (Kipcak 2017) study, microwave drying have been
used for M. edulis. In this study, several microwave power levels (90, 180, 360, 600
and 800 W) were applied to mussel (Mytilus edulis) to determine their effect on
drying kinetics, rehydration characteristics and energy consumptions. At the end of
study, it was found that for microwave power levels of 90, 180 and 360 W optimal
drying times were found to be 16, 5 and 2 min, while they were 80 and 60 for 600
and 800 W respectively. The microwave power level of 360 W was found to be the
most effective, considering the minimum energy consumption.
Dried products which are rich in lipids and unsaturated fatty acids lose their flavour and oxidize easily during storage. Mussel (M. edulis) meat boiled and later
3.1 Bivalves
Natural sun drying has been used since ancient times for agricultural products.
Sun drying is the most convenient and the cheapest processing technique to preserve
fish and fish products particularly in tropical and subtropical countries, where solar
radiation is abundant, inexhaustible, and environmentally friend (Nguyen et al.
2014). The products are dried by spreading in the open air. The products are placed
on various materials such as trays, hangers, frames, etc. For this purpose, bamboo
frames are mostly preferred in tropical regions (Gokoglu 2002). However, a major
problem of open sun drying is the loss of quality due to contamination with dust and
excreta from birds and animals (Nguyen et al. 2014). Therefore, other drying techniques have been developed and various studies have been conducted on the use of
these techniques in drying mussels.
Recently innovative drying methods have been tried to dry mussel meat in some
studies. Spray drying is a unique technique which can produce powder of special
particle size. In a study, to produce dried powder from freshwater mussels, after
washing the mussels were deodorized by two different methods. In the first method,
0.3% sodium chloride, 1% citric acid and 0.1% yeast powder, in the second method
1% ginger and 0.5% cooking wine were used. The deodorized mussels were placed
in the meat grinder and the small pieces were transferred to the ultrafine grinder
with 20% water for the subsequent pulverization process and dried in a spray dryer
(Zhang et al. 2013). Freeze drying is an innovative drying process that uses ice sublimation as the main drying mechanism. This differs from conventional drying
methods in that it is based on capillary movement and evaporation of liquid water
for drying. In freeze-drying, water in the products is removed by sublimation at low
temperature and low pressure below the triple point. First, the water in the products
is frozen in the pre-freezing step and then removed by sublimation of ice in the
primary drying step (Nguyen et al. 2014). McCarron et al. (2007) have tried freezedrying process of mussel (M. edulis) with the aim of stabilizing shellfish toxins. In
this study, they used mussels naturally contaminated with domoic acid, okadaic
acid, dinophysistoxin-2, and azaspiracid-1, -2 and -3. Wet materials were used for
control purposes. The freeze-dried material containing domoic acid was stable over
the whole duration at all temperatures, while in the wet material domoic acid
degraded to some extent at all temperatures except −20 °C. In freeze-dried and wet
materials containing lipophilic toxins, okadaic acid, dinophysistoxin-2, azaspiracid1 and azaspiracid-2 were stable over the whole duration at all conditions, while
concentrations of azaspiracid-3 changed significantly in both materials at some storage temperatures. In another (Kipcak 2017) study, microwave drying have been
used for M. edulis. In this study, several microwave power levels (90, 180, 360, 600
and 800 W) were applied to mussel (Mytilus edulis) to determine their effect on
drying kinetics, rehydration characteristics and energy consumptions. At the end of
study, it was found that for microwave power levels of 90, 180 and 360 W optimal
drying times were found to be 16, 5 and 2 min, while they were 80 and 60 for 600
and 800 W respectively. The microwave power level of 360 W was found to be the
most effective, considering the minimum energy consumption.
Dried products which are rich in lipids and unsaturated fatty acids lose their flavour and oxidize easily during storage. Mussel (M. edulis) meat boiled and later
3.1 Bivalves