EP2597965A1

EP2597965A1 - Food for aquacultural feeding

Info

Publication number: EP2597965A1
Application number: EP11737957.8A
Authority: EP
Inventors: Alain Guyonvarch; Bernard Devresse
Original assignee: INVIVO NSA
Current assignee: INVIVO NSA
Priority date: 2010-07-30
Filing date: 2011-07-28
Publication date: 2013-06-05
Also published as: FR2963208A1; CN103096729A; FR2963208B1; MX2013001196A; ECSP13012464A; WO2012013753A1; BR112013002174A2

Abstract

The invention relates to an extract of Artemia cysts and to an aquacultural food containing said extract.

Description

Food for aquaculture feed

The invention relates to an extract for aquaculture feed.

Because of their ontogeny, fish and shellfish larvae must actively feed before the development of their digestive system is complete. For most marine species, the proposed inert foods are not suitable for the early stages of larval life. It is therefore necessary to feed these larvae with live prey from the first intake of food (larvae 0.2 to 0.4 mg depending on the species) to a post-larval stage (more than 50 mg). During this short period, growth is fast.

In intensive farming, it was necessary to create an artificial food chain with the production of unicellular algae, which feed on the animals themselves, intended to serve as prey for the fish larvae. However, the costs of these solutions remain high.

In the wild, larvae feed on plankton. One of the solutions is therefore to reconstitute a medium that promotes the development of phytoplankton and zooplankton and to introduce the larvae.

The species used most often as live prey are Artemia and rotifers.

Rotifers are used for their exceptional productivity based on a parthenogenetic multiplication.

Artemia (Artemia spp.) Is adapted to overheated environments. They produce cysts in large quantities in salt marshes and other expanses of overwashed water. Easy to harvest, these dormant cysts ("eggs of duration") are preserved in the dried state under vacuum. Their use in hatcheries is technically easy: it is enough to reactivate them by rehydration and oxygenation to obtain in 24 to 28 ° C the hatching of larvae at the nauplius stage. The nauplii can be used directly as prey. Breeding a few days allows to obtain larger prey.

Artemics are irreplaceable today, essentially from a physiological point of view.

However, this live prey is very expensive to produce in hatcheries and, like all living prey, can carry pathogens and transmit them to the larvae. In In addition, the nutritional qualities of Artemia decrease rapidly in breeding ponds because they can not eat and must therefore draw on their own reserves to survive. Living Artemia must therefore be renewed frequently (new Artemia, elimination of older Artemia).

There is therefore a need for a feed for aquaculture feed, in particular fish and shellfish larvae, which is less expensive and easier to use than Artemia but equally nutritious.

It has therefore been proposed to replace the Artemia with their cysts, ie their eggs, which are available in an indefinite quantity, which would avoid the hatching process.

However, the inventors have surprisingly observed that the cysts of Artemia contain in their wall a quantity of semi-carbazide (SEM) which does not conform to the European legislation in force (Coppens et al., European Regulations on Nutraceuticals, Dietary Supplements and functional foods: A framework based on safety, Toxicology, 221 (2006) 59-74).

It has therefore been proposed to replace the cysts of Artemia by decapsulated cysts, that is to say cysts whose wall has been removed by chemical decapsulation.

Methods for decapsulation of cysts are described in "Manual on the Production and Use of Live Food for Aquaculture", Food and Agriculture Organization of the United Nations, section 4.2.3 "Decapsulation", http://www.fao.org/ These methods use hypochlorite and caustic soda.

However, the inventors have again surprisingly observed that Artemys cysts decapsulated by these methods also include an amount of semicarbazide (SEM) which is not in accordance with the European legislation in force because the chemical decapsulation reaction produces SEMs by alkaline oxidation.

The inventors have therefore sought to develop a particular method for providing a content extract of cysts of Artemia without SEM as nutritious as Artemia in aquaculture feed.

Nitrofurans include a group of antibiotics that has been used extensively in intensive pastures of pigs, poultry and fish. In the late 1980s, they were shown to be metabolized rapidly after administration and to form persistent residues. Nitrofurans and their metabolites have therefore been classified in genotoxic compounds. Semi-carbazide (SEM) is the characteristic metabolite of one of these nitrofurans, 5-nitrofurazone. SEM is a member of the family of hydrazines that are carcinogens. In 2003, SEM was detected in foods of non-animal origin and then detected in marine products that were not treated with antibiotics such as lobsters (L. Saari et al., Novel source of semicarbazide: levels of semicarbazide in cookd crayfish samples determined by LC / MS / MS, Food Additives and Contaminants, Vol 21, No 9, pp. 825-832).

There is therefore a need for a food for aquaculture feed based on Artemia without SEM.

The present invention proposes to provide such a food.

The inventors have developed a decapsulation process for cysts of Artemia which makes it possible to obtain an extract of cysts of Artemia without SEM.

Therefore, the object of the invention relates to an extract of cysts of Artemia cies lacking semi-carbazide (SEM), preferably as a nutritional supplement of an aquaculture feed.

It has thus been shown that this extract is particularly advantageous when used in fish and crustacean larvae feed since these foods are likely to replace the supply of live Artemia.

The concentrate of the invention is intended for all areas of aquaculture nutrition, in particular the feeding of fish larvae or crustaceans.

It is particularly advantageous for feeding shrimp larvae.

According to one embodiment, the extract according to the invention is an intact vitelline platelet concentrate.

Artemia cysts include vitelline platelets.

The term "vitelline platelets" is understood to mean membrane-bound egg storage organelles derived from vitellogenesis and present in the cytoplasm of the oocyte.

They are part of the "vitellus". "Yolk" means all of the egg reserve substances

The term "intact vitelline platelet" means an isolable vitelline platelet whose contents can spontaneously hydrolyze in less than two hours under the following physiological conditions: in sea water at pH 8.5-9.0 and 28.0-30.0 ° C. If the wafer is not intact, it remains in the form of a granule with its outer membrane under these same conditions. Another subject of the invention relates to the use of an extract of the invention for feeding fish or crustacean larvae in aquaculture.

Another object of the invention relates to an aquaculture feed comprising an intact vitelline platelet extract of the invention.

Another object of the invention relates to the use of an extract of the invention for preparing an aquaculture feed.

Another object of the invention relates to a process for preparing an extract of the invention.

The process of the invention is particularly advantageous since it does not require expensive hatching processes and because the starting material, eggs, is easily accessible.

The cysts of Artemia are very abundant in salty areas whereas the number of viable cysts is sometimes very low. The food of the invention is therefore particularly advantageous compared to live prey.

The l ^st step of the method (i) is to break and remove the membrane of the cyst.

The rupture is done mechanically after rehydration. Preferably, the mechanical rupture of the membrane of the cyst is performed by a turbine provided with knives.

The term "cyst membrane" means the set of cell layers separating the embryo from the outside, namely the alveolar layer, the outer and inner cuticular membranes and the embryonic cuticle (FAO, CYST BIOLOGY, Gilbert Van Stappen).

This excludes the l ^st step of the process is carried out by a conventional method of chemical-encapsulation that does not break the embryonic cuticle and cuticular internal membrane.

The membrane of the cyst can be removed by mechanical separation and / or centrifugation (for example, centrifuge with decantation).

For example, the mixture of contents of cysts and broken cyst membranes obtained in the previous step is decanted on a series of sieves of less than 300 μιη then 150 μιη, then 70 μιη.

Preferably, these steps of the process of the invention are carried out at a pH of between 4 and 10, preferably between 5 and 8.5, particularly preferably between 6 and 7. Preferably, all the steps of the process of the invention are carried out at a temperature of between 0 and 60 ° C., preferably between 0 and 40 ° C., particularly preferably between 0 and 20 ° C.

The method of the invention comprises a 2 ^nd optional step (ii) drying the resulting extract.

This drying step can be done by atomization, the hot air entering the atomization tower to be at a temperature below 200 ° C, preferably between 160 and 180 ° C; or by true lyophilization at a temperature below -15 ° C

The method of the invention optionally comprises the addition during step (i) of ingredients and additives conventionally used by those skilled in the art in aquaculture feed, such as vitamins, lipids, antioxidants.

Another subject of the invention relates to an SEM-free Artemia cyst extract that can be obtained according to the preparation method of the invention.

Another subject of the invention relates to a process for preparing the food according to the invention comprising a step of agglomeration of an extract of the invention. Agglomeration makes it possible to obtain particles of a size compatible with that of the larvae for which they are intended. The equipment for agglomeration on an industrial scale consists, for example, of a fluidized bed, a continuous fluidized bed, a mixer with eccentric arm type "high shear Colette ™", a drum or drum granulator type "tumble growth, pin mixer or pelletizing say, etc ... "

The following examples illustrate the invention without limiting its scope.

Example 1: Measurement of the amount of SEM on different cyst preparations

The amount of SEM was measured on the following preparations by LC-MS / MS chromatography:

Code

ND YP cysts (<100 μιη) jCystes not decapsulated. These whole cysts are cut by a jturbine equipped with knives. The contents of the cyst and its membrane are suspended in water. Fraction collected by sieving passing through the mesh of a sieve of 100 μπι. iiCystems D YP (<100 μηι) Decapsulated cysts. These decapsulated cysts are cut by an

turbine equipped with knives. The contents of the cyst and its membrane are suspended in water. Fraction collected ii by sieving passing through the mesh of a sieve of 100 μπι. ii Non-decapsulated cysts membranes (> 100 non-decapsulated cysts.) These whole cysts are cut by a ii

! μ · ") turbine equipped with knives. The membranes are collected on ii

a sieve of ΙΟΟμπι (refusal of the sieve). ii ijCystes decapsulated membranes (> 100 μιη) Decapsulated cysts. These decapsulated cysts are cut by an

turbine equipped with knives. The membranes are collected by him on a sieve of ΙΟΟμπι (refusal of the sieve). i cysts ND read II Complete cysts ii

"Decapsulated cysts" means cysts decapsulated by a conventional decapsulation process.

Conventional process for decapsulation of cysts of Artemia used:

The cysts are rehydrated for 1 hour in water at 25 ° C.

They are then collected on a 125 μπι sieve, rinsed and transferred into a solution of hypochlorite at 15-20 ° C comprising 0.5 g of active hypochlorite product per gram of cysts, 0.15 g of sodium hydroxide (NaOH) per gram of cysts and seawater up to 14 ml per gram of cysts.

The cysts are removed and rinsed when they turn orange.

The results are as follows.

The contamination of Artemia cysts is about 4 μg SEM / kg (ppb).

Example 2 Process for the Preparation of a Content Extract of Artemia Cysts In a tank of 5000 liters, 1000 kg of Artemia cysts are suspended with 4000 liters of fresh water running at room temperature, not exceeding 20 ° C. Artemia cysts are left in suspension with agitation for one hour to allow complete hydration. The pH is controlled and if necessary adjusted to 6.5.

The hydrated cysts are then pumped to a turbine with knives that will individually cut each of these cysts.

The cysts thus opened are passed on a vibrating screen of 300 μπι, then 150 μπι and finally 70 μπι. The membranes are rejected on the three successive screens and the contents of the cyst are collected free of membranes.

This cyst content is then passed through a decanting centrifuge to separate the vitelline platelets from the rest of the yolk sac contents.

The entire process takes place at room temperature, not exceeding 20 ° C and in an optimum pH range of 6.5 to 7.0. The process is executed in less than two hours.

Example 3 Method for Preparing an Aquaculture Feed from the Extract Obtained in Example 1

The extract obtained in Example 2 is mixed with other ingredients and additives such as fish oil (minimum 3%), trace vitamins and minerals, natural antioxidants, etc.

This mixture constitutes the aquaculture feed and its final nutritional composition is then determined.

The mixture is spray-dried with an incoming air of 160 ° C. The water content of the powder obtained will be 4-6%, preferably 5.0%

The atomized powder is then agglomerated in a fluidized bed. The powder is agglomerated by spraying a solution containing an organic polymer such as alginates, carrageenans or gelatin. The solution is sprayed until a granulated powder having an average size of 200 to 250 μπι is obtained.

The granulated powder is subsequently dried in the same fluidized bed with an incoming air temperature of not more than 60 ° C. The final product is then sieved into three different fractions (1) <150 μπι, (2) 150-400μπι and (3) 400-600 μπι. These three fractions are used at different stages of larval development of fish or shrimp. Example 4: Comparative measurements in hatcheries (Venezuela)

Shrimp larvae are fed with the feed obtained in Example 3 vs. with living Artemia.

The results obtained are then compared in terms of survival rate, stress test, weight, number of post-larvae harvested.

The stress test consists of putting a certain amount of post-larvae in fresh, slightly saline water for 20-30 minutes and returning them to initial salinity conditions.

The survival rate is then calculated.

The bins are 15000 L.

The results are shown in Table 1.

Table 1.

S: Significant (P <0.05), NS: Not Significant

PL: post-larvae

From this study, it can be deduced that the average survival is greater with the concentrate of the invention giving more PL harvested.

Example 5: Comparative measures in hatchery (Ecuador)

The same measures as in Example 4 are carried out in another hatchery. The results are shown in Table 2.

Table 2.

From this study, it can be deduced that the average survival is greater with the concentrate of the invention giving more PL harvested. Example 6: Comparative Measurements in Hatchery (Mexico)

The same measures as in Example 4 are carried out in another hatchery. The results are shown in Table 3.

The bins are 20000 L.

Table 3.

From this study, it can be deduced that the average survival and growth are greater than the concentrate of the invention giving more PL harvested.

Example 7: Summary of Examples 4 to 6 The summary of results from the three hatcheries is presented in Table 4. Table 4.

Claims

claims

1. Artemia cyst extract lacking semi-carbazide (SEM).

2. Extract according to claim 1 as a nutritional supplement of an aquaculture feed.

3. Extract according to claim 2, the aquaculture feed being intended for feeding larvae of fish or crustaceans, in particular shrimp larvae.

4. Extract according to any one of claims 1 to 3, characterized in that it is an intact vitelline platelet concentrate.

5. Use of an extract according to any one of claims 1 to 4 for feeding fish or crustacean larvae in aquaculture.

An aquaculture feed comprising an extract of any one of claims 1 to 4.

7. Use of an extract according to any one of claims 1 to 4 for preparing an aquaculture feed.

8. Process for the preparation of an extract according to any one of claims 1 to 4 comprising the following steps:

(i) Mechanical rupture and removal of the rehydrated Artemia cyst membrane

9. Preparation process according to claim 8, the set of steps taking place at a pH between 4.0 and 10.0, preferably between 5 and 8.5, particularly preferably between 6 and 7.

10. The method of claim 8 or 9, the set of steps taking place at a temperature between 0 and 60 ° C, preferably between 0 and 40 ° C, particularly preferably between 0 and 20 ° C.

11. A method according to any of claims 8 to 10, comprising a subsequent step (ii) of drying, preferably at a temperature below 160 ° C.

12. Extract obtainable according to the process according to any one of claims 8 to 11.

13. Process for the preparation of an aquaculture feed comprising the agglomeration of an extract according to any one of claims 1 to 4 and 12.