Why photo voltaic dried epipelagic fish has 70% protein, solely 12% salt and lengthy shelf life
If recent fish is already a wealthy supply of protein (17-19%) relying on the fish selection, dry fish with as much as 70% protein is a far superior supply of protein. Apart from excessive protein content material, dry fish can be a wealthy supply of omega-3 fatty acid, calcium and iron. Because the protein content material is excessive, a considerable quantity of protein requirement will be met by consuming simply 5 grams of dry fish. Epipelagic fish corresponding to mackerel, sardine, anchovy, and ribbon fish are chosen for fish drying.
“Dry fish is a superb supply of protein. It may be complement for Anganwadi and noon meals, particularly in coastal fish-eating communities,” says Dr. Soumya Swaminathan, Chairperson of MSSRF.
One of many main drawbacks of conventional drying of fish is the excessive salt content material of over 30%, far exceeding the FSSAI restrict of 15%. Along with excessive salt content material, historically dried fish is usually unhygienic by advantage of being dried within the open, and has a brief shelf lifetime of about two months. Researchers at M.S. Swaminathan Analysis Basis (MSSRF), Chennai and Fish for all Analysis and Coaching Centre at Poompuhar, Tamil Nadu, which is a MSSRF hub of innovation, have turned to photo voltaic drying to efficiently tackle these ache factors.
Chopping down salt content material
“The salt content material of solar-dried fish is about 12%. FSSAI has set a restrict of 10-15% salt content material for salted dried fish,” says Ms. N.A. Anbu Vahini, Lead, Coaching and Improvement at MMSRF, Chennai. “Solely about 3% salt is added to recent fish, which turns into 12% when the fish will get dried. Historically dried fish has over 30% salt content material.”
Recent anchovies from the ocean naturally include round 1-2% salt. After drying, even when no salt is added, the pure salt focus within the fish will increase to round 5-7% as a result of moisture loss. “Now we have additionally studied the shelf lifetime of unsalted fish dried beneath hygienic circumstances and packed in aluminium foil. This technique has supplied a shelf lifetime of as much as 9 months. Nevertheless, in response to FSSAI and CODEX requirements, dried fish should have a minimal salt content material of 12% to satisfy compliance necessities,” she says.
Doubling the protein content material
If the protein content material in historically dried fish is about 35-40%, it goes as much as 70% in photo voltaic dried fish. “The low protein content material in historically dried fish is due to excessive moisture content material,” Ms. Vahini says. The principle purpose why the moisture content material is excessive in historically dried fish is as a result of the fish isn’t dried totally to scale back the moisture content material beneath 16% as specified by FSSAI. The moisture content material is lowered from about 70% to about 35-40% throughout summer season and over 45% in winter in historically dried fish. In distinction, moisture content material in photo voltaic dried fish is 5-15% to realize greater shelf life. However as much as 16% moisture is permissible.
“When the moisture content material is excessive the shelf life is brief. That is the rationale why historically dried fish has a brief shelf lifetime of about two months,” Ms. Vahini says. “The photo voltaic dried fish has a shelf lifetime of 9 to 12 months when moisture content material is 5-7, and 9 months when the moisture content material is about 10-15%.”
Even throughout peak summer season, it takes about 22 hours to dry anchovy fish with 18% moisture utilizing open solar drying, whereas photo voltaic drying takes solely 9 hours and reduces the moisture to simply 6%. The open sun-drying technique depends on ambient circumstances of 34 diploma C and a relative humidity of 54%, whereas photo voltaic drying will increase the temperature to 55-60 diploma C and reduces the humidity to about 17%. This quickens the drying course of, she says. In winter, it takes a couple of day to dry utilizing a photo voltaic drier, attaining 23% moisture content material, in comparison with three days with 39% moisture content material within the case of conventional open solar drying. “The photo voltaic drying technique is 1.2 to 2.4 instances quicker in contrast with conventional solar drying, relying on the climate circumstances,” Ms. Vahini says.
Significance of packaging
Shelf life relies upon not solely on the moisture content material but in addition on how the dry fish is saved post-drying. Whereas no packaging materials is used to retailer dried fish within the conventional technique, individuals utilizing photo voltaic driers use aluminium foil pouches or HDPE tray bins to pack the dry fish. “Photo voltaic dried fish is saved within the containers after which packed utilizing aluminium foil pouches. Vacuum packaging will make it hermetic however then we don’t advocate it as a result of it’s expensive for small-scale fishers. Aluminium foil solves the issue when it’s correctly sealed. When appropriately packed, the moisture content material is about 5-7% and now we have achieved 12 months of shelf life,” Ms. Vahini says. Correct number of recent fish, thorough cleansing utilizing potable water, photo voltaic drying, and packaging utilizing aluminium foil be certain that the dried fish is hygienic
One other key purpose conventional open solar drying ends in inferior dried fish is the usage of leftover or unsold recent fish, relatively than fish particularly chosen for drying. In some instances, even poor high quality or spoiled fish is used. Fisherwomen have now been educated on all elements of the method, together with the significance of utilizing recent, high-quality fish for drying, she says.
Dry fish has a stronger odor than even recent fish however will be lowered if care is taken at each step of the drying and packaging course of. “The odor is vastly lowered when fish is washed correctly previous to drying, following the right salting course of, sustaining hygienic circumstances throughout the drying course of, by growing the speed of drying, decreasing the quantity of moisture within the dried fish, and correct packaging post-drying,” Ms. Vahini says. “Scent will be additional lowered if the dry fish is powdered.”
Photo voltaic drying not solely accelerates the drying course of but in addition ensures superior product high quality, decrease moisture content material, lowered microbial contamination, and enhanced dietary retention.
Greater earnings
In keeping with Dr. S. Velvizhi from Fish for All Analysis and Coaching Centre, MSSRF, Poompuhar, historically dried anchovy sells at Rs.200-250 per kg, whereas photo voltaic dried anchovy sells for Rs.450-600 per kg. If the historically dried anchovy fish is larger in dimension, it sells for Rs.300-400 per kg, whereas photo voltaic dried fish sells for Rs.750-800 per kg.
MSSRF has educated the fishing group in Tamil Nadu across the Poompuhar area, Nagapattinam, Cuddalore, and Rameshwaram on each side of fish drying beginning with deciding on fish for drying to packaging. Apart from housing a big photo voltaic drier at its centre in Poompuhar, MSSRF has additionally equipped 50 mini, moveable photo voltaic dryers with a capability of 25-30 kg per day to ladies in Mudasalodai in Cuddalore district to allow them to dry fish in their very own place as a substitute of coming to the centre. Dr. Velvizhi says the Tamil Nadu authorities needs MSSRF to copy the venture in some fishing villages within the State.
Revealed – July 29, 2025 02:00 am IST
