Fish hydrolysate, in its simplest form, is ground up

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

transformed into a liquid phase, where the cleavage of molecular bonds occurs through various biological processes. Raw material choice; either whole fish or by-products, depends on the commercial sources of the fish. In some cases, the fillet portions are removed for

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

consumption, the remaining fish body (generally the

guts The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

bones A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, a ...

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck ...

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

and remaining

meat Meat is animal flesh that is eaten as food. Humans have hunted, farmed, and scavenged animals for meat since prehistoric times. The establishment of settlements in the Neolithic Revolution allowed the domestication of animals such as chic ...

) is put into water and ground up. Some fish hydrolysate is ground more finely than others so more bone material is able to remain suspended.

Enzymes Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. ...

may also be used to dissolve bones, scale and meat. If the larger chunks of bone and scales are screened out,

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

content may be lacking in the finished product form. If purchasing fish hydrolysate for

agricultural Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

applications, one should look at the label carefully for the concentration of mineral elements in the liquid. Some fish hydrolysates have been made into a dried product, increasing the potential for inclusion as an ingredient in other food or feed products. The

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

is separated out in this process, which means the

Omega 3 Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

fatty acid would remain with the oil and not the hydrolysate.Critical Reviews in Food Science and Nutrition, Volume 40, Issue 1 January 2000, pp. 43-81.

Uses of fish hydrolysate

There are many uses of fish hydrolysate - from fish-based

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

, to its use as an animal food, or even for human consumption applications which are developing. A number of scientific journals have cited the

antiproliferative Cytostasis (cyto – cell; stasis – stoppage) is the inhibition of cell growth and multiplication. Cytostatic refers to a cellular component or medicine that inhibits cell division. Cytostasis is an important prerequisite for structured multic ...

activity of fish protein hydrolysate, which makes it eligible for listing as a nutriceutical.Picot, L, et al., 'Antiproliferative activity of fish protein hydrolysates on human breast cancer cell lines', Process Biochemistry. Vol. 41, no. 5, May 2006.

Bycatch

New technologies that have increased fishing efficiency have also resulted in the taking of species or sizes not suitable for market, known as

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

. An increased catch of unsaleable whole fish has resulted from the increased bycatch of the

fishing industry The fishing industry includes any industry or activity concerned with taking, culturing, processing, preserving, storing, transporting, marketing or selling fish or fish products. It is defined by the Food and Agriculture Organization as including ...

. These fish are often dumped overboard at sea, but are also brought into port in the holds of

fishing boats A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. The total number of fishing vessels in the world in 2016 was e ...

. This has spurred an incentive to find a market for the bycatch in order to lower the cost of production.

Stabilizers

The liquid fish hydrolysate process minces the whole fish, then enzymatically digests, then grinds and liquifies the resulting product, known as gurry. Because it is a cold process, gurry putrefies more rapidly than

fish emulsion Fish emulsion is a fertilizer emulsion that is produced from the fluid remains of fish processed for fish oil and fish meal industrially. Production The process of creating fish emulsion begins with whole fish, or with carcass products of fish, ...

and needs to be stabilized at a lower pH, requiring more acid. Researchers have tried

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Est ...

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

, and others. Formic acid had phytotoxic effects on plants. Phosphoric acid is the preferred stabilizer.Brian Baker, ''Plant Nutrition from the Sea'', Farmer to Farmer 16 (Sept./Oct. 1996), available online a

.

Comparison with fish emulsion

If fish hydrolysate is heated, the oils and certain proteins can be more easily removed to be sold in purified forms. The complex protein,

carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may o ...

and

fat In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. The term often refers specifically to triglycerides (triple est ...

s in the fish material are denatured, which means they are broken down into less complex foods. Overheating can result in destruction of the material as a food to grow beneficial organisms. Once the oils are removed and proteins denatured and simplified by the heating process, this material is called a

. The hydrolysate process has substantially lower capital and production costs compared to fish emulsion production.

References

External links