New method allows production of premium caviar from live sturgeon
AWI is out-licensing a solution for sustainable caviar production
Through observation of natural processes during egg fertilization, a new process for caviar production from eggs that were stripped from live female sturgeons without killing the fish was developed at the Alfred Wegener Institute.
Through AWI research in the past years, the relevant signalling molecules for the treatment of naturally born sturgeon eggs were identified, by which the eggs are enabled to stabilize themselves for caviar processing. The appropriate terms of application were analysed and the process standardised to industrial scales. In the innovative process, signalling molecules in very small natural concentrations activate a machinery of enzymes which stabilise the eggs’ membranes within milliseconds. This new method has been patented in relevant countries.
The advantages of this technology are obvious: no denaturation and quality loss occurs, the eggs remain in their native state. Harvesting of eggs is harmless for the fish and, thus can be repeated many times, which reduces production costs for fish breeding considerably.
The method does require controlled conditions and methodical correct timing. If conducted correctly, the quality of the caviar is superb. The caviar produced according to the AWI method is also particularly clean and pure as has been shown in high-resolution microscopy images (see below). There are no blood vessels and follicle cells sticking to the eggs’ surface (which occurs when rubbing the immature eggs out of the gonads). Thus, the caviar does not need any preservatives (Borax), has a long shelf life of up to 9 months (salted malossol) and exhibits a fine fresh marine taste.
License requests can be directed to AWI.
Sturgeons are fish that exist on this planet for more than 200 million years. Today, there are 27 species of sturgeon living in rivers, lakes and along the coastlines of Eurasia and North America. Sturgeons are long-lived, slow-growing and late-maturing fish that can reach an age between 60 to 120 years depending on the species.
Most of the sturgeon species are seriously endangered by overfishing and poaching, habitat loss due to dam building and pollution. As this trend persists, particularly some of the Caspian sturgeon populations are predicted to be extinguished within a few years. Consequently, trading sturgeon products is strictly controlled by CITES (Washington Treaty). No wild catches are permitted in most areas of the globe. Accordingly, caviar production from wild caviar massively decreased over the past decades.
Today, nearly all legal caviar is produced in sturgeon aquaculture.
Conventional Caviar Production
Conventional caviar is harvested by killing the sturgeon. Although sturgeons grow relatively fast in aquaculture, they require a minimum of 6 to 8 years and more to mature until caviar can be harvested for the first and only time. Therefore several attempts have been undertaken to produce caviar without killing the sturgeons to make aquaculture caviar production economically more viable and less cruel to the animals.
Only immature eggs harvested by opening the fish´s body cavity are stable enough to sustain the harsh procedure of making caviar. Therefore the conventional method of killing the fish is still the procedure commonly applied.
Earlier attempts of non-mortal caviar production faced the following difficulties, which could not be solved in the past:
Contact to water made the mature, released eggs stick together. Subsequent salt addition burst the eggs thus forming an amorphous mass without the characteristic caviar texture.
Another method often used until now is heat treatment and use of chemicals to harden the matured sturgeon eggs, but this method also leads to disadvantageous changes in the eggs’ structure through the denaturation of valuable proteins and the loss of liquid.
Advantages of the AWI process
- Kill-free production from live sturgeon
- Massive cost reduction in aquaculture, as the release of the eggs is harmless for the female sturgeons which can, therefore, produce caviar many times
- The treatment of the eggs is carried out with an inexpensive substance approved for food production, also produced by the egg itself
- Applied correctly, the method yields excellent caviar
- The caviar produced is purer than classical caviar (no blood vessels or cell fragments adhere to the eggs from the gonads), thus the caviar has a longer shelf live without treatment
- The fine pearl texture and fresh taste makes it highly suitable for star gastronomy and can be served even in warm arrangements