Microwave drying offers many advantages for processing dried sardine fishes. So let’s find the effects of microwave power on drying kinetics, specific energy consumption and modelling of drying of sardine fish through this study. Link: http://fooddryingoven.com/drying_ideas/drying-sardine-fishes-by-microwave-drying.html E-mail: info@food-machines.org

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Drying Sardine Fish by Microwave Drying Machine
Abstract ： Microwave drying offers many advantages for processing dried sardine
fishes. So let’s find the effects of microwave power on drying kinetics, specific energy
consumption and modelling of drying of sardine fish through this study.
1. Why Fresh Sardine
Fishes Need to Be Dried
by Microwave Drying
Machine?
Sardine fish is an important
source of high-quality
protein required in human
diet, but it has not yet been
fully utilized, due to the
limited storage period and,
sometimes, their strong
fishy odor. Fresh sardine
fish contains up to 80% of
water, and it is a highly perishable material and having a short storage life. Cooling is
a widely used, and the simplest method of cooling fish is icing which can maintain
quality and prevent the spoilage. However, the frozen sardine fish is not utilized by
consumers and converted into finished product, then it still remains surplus and goes
waste. Therefore, to improve their preservation quality and acceptance by consumers,
more innovative processing techniques need to be applied.
Dried fish fillets are conventional processed products of sardine fish, because they can
be stored for a long time and conveniently used. Conventional drying processes have
significant limitations of uneconomical energy consumption and long processing
time. However, microwaving changes electricity into high-frequency microwaves that
water can absorb, causing water molecular vibration, and results in drying of food.
And microwave drying offers many advantages in processing, including less startup
time, faster heating, energy efficiency, space savings, precise process control,
selective heating and final products with improved nutritive quality.
2. Optimum Parameters for Drying Sardine Fish by Microwave Drying Oven

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Drying is a complex caloric process, and unsteady heat and moisture transfer occur
simultaneously in this process. One of the most important aspects of sardine fish
drying technology is the modelling of the drying process. It is important to develop a
better understanding of the controlling parameters of this drying process from. So let’s
find the effects of microwave power on drying kinetics, specific energy consumption
and modelling of drying of sardine fish through this study.
2.1 Raw material handling and setup
The fresh sardine fish samples are used in this study. And the fresh sardine fish should
be cleaned by water to ensure the sardine fish free from foreign materials. In order to
preserve its original quality, the sardine fish was stored in a refrigerator until drying
experiments. The average initial moisture contents of the sardine fish samples were
found to be 2.76 on dry basis. The microwave was set temperature about 103 °C.
The microwave oven was operated by a control terminal which could control both
microwave power level and emission time. The sardine fish samples were put into the
microwave container. Drying experiments were carried out with 200, 300, 400 and
500 W microwave power levels to investigate the effects of microwave power on
drying of sardine fish. Moisture loss of the sardine fish was recorded by means of the
balance at 15s intervals until no discernible weight change was observed.
2.2 The analysis of moisture ratio, drying time and drying rate.
Through the contrast of date record in the drying process, and we found that the
moisture content was effected by the microwave power input and drying time of the
sardine fish was significantly reduced from 9.5 to 4.25min, as the power input
increased. It was also clear that increasing the power output resulted in shortened
drying times up to 51%. The results indicated that mass transfer within the sample
was more rapid during higher microwave power heating, because more heat was
generated within the fish creating a large vapor pressure difference between the center
and the surface of the product due to characteristic microwave volumetric heating.
The changes in moisture ratio with drying time of sardine fish in microwave drying
were presented in the following chart.
What’s the changes of moisture content and drying rate with the drying continuing? In
fact, the changes were similar with open sun drying of prawn and chela fish. The

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moisture content of the material was very high during the initial phase of the drying
which resulted in a higher absorption of microwave power and higher drying rates due
to the higher moisture diffusion. As the drying progressed, the loss of moisture in the
product caused a decrease in the absorption of microwave power and resulted in a fall
in the drying rate. Higher drying rates were obtained at higher microwave output
powers. The drying rate rapidly increased and then slowly decreased as drying
progresses. It was observed that drying rate reduces with time or with the reduction of
moisture content generally.
2.3 The changes between microwave power and energy consumption in the
drying process
Statistical analyses showed that microwave power in the range of 200–500 W was not

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significant on the specific energy consumption values of sardine fish. However, it was
noted that the lowest specific energy consumption occurred in 500 W. Drying energy
consumption at 500 W was 3.78 MJ/kg water. the microwave specific energy
consumption values at different amounts of microwave powers for the drying of
sardine fish were showed as this following chart.
Finally, we could find the drying of sardine fish samples took place in the falling rate
period and was governed by moisture diffusion in the drying process. And no
significant differences were observed about the specific energy consumption of
microwave drying sardine fish. However, minimum specific energy consumption
(3.78 MJ/kg water) was obtained at 500 W microwave levels. Besides that, we also
found microwave could penetrate through the sardine fish affecting its inside and
outside simultaneously, rapid drying speed, short drying time, uniform heating, good
product quality. To be honest, microwave drying method is very suitable for drying
fish because of its features and advantages.
3. Tips and Hints for Microwave Dried Sardine Fish Recipes
Sardines pack an awesome nutritional punch. A single serving has around 23 grams of

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protein and is loaded with omega-3 fatty acids, calcium, iron and potassium, and only
200 calories. It’s an important component of a healthy diet. Dried sardine fish can be
used in a variety of ways from being served as a snack to adding flavor to other dishes.
Dried sardine fish can be crumbled over salads and pastas, added to soups and is a
staple of many recipes.