WO2018056898A1

WO2018056898A1 - Aquaculture feed and method of producing same

Info

Publication number: WO2018056898A1
Application number: PCT/SG2016/050472
Authority: WO
Inventors: Luciaan Van Nieuwenhove
Original assignee: Pearl Aqua Co., Ltd.
Priority date: 2016-09-23
Filing date: 2016-09-23
Publication date: 2018-03-29

Abstract

An aquaculture feed (10) and a method (50) of producing the aquaculture feed (10) are provided. The aquaculture feed (10) includes a plurality of particles (12) of a feed mixture, the feed mixture including a protein source. At least a portion 5 of the protein source is denatured by an alcohol to bind the particles (12) of the feed mixture.

Description

AQUACULTURE FEED AND METHOD OF PRODUCING SAME

Field of the Invention

The present invention relates to aquaculture in general and more particularly to an aquaculture feed and a method of producing the same. Background of the Invention

As global populations increase, aquaculture is becoming an increasingly important source of food for growing numbers of people.

Live foods or feeds such as Artemia, algae, rotifers and other types of zooplankton are currently being used in aquaculture. However, there are various problems associated with the use of live foods such as, for example, availability, complexity and vulnerability of the live foods.

It is therefore desirable to provide an aquaculture feed that can help reduce dependency on live foods and a method of producing the same.

Summary of the Invention Accordingly, in a first aspect, the present invention provides an aquaculture feed. The aquaculture feed includes a plurality of particles of a feed mixture, the feed mixture including a protein source. At least a portion of the protein source is denatured by an alcohol to bind the particles of the feed mixture.

In a second aspect, the present invention provides a method of producing an aquaculture feed. The method includes providing a feed mixture, the feed mixture including a protein source, and forming a plurality of particles with the feed mixture. At least a portion of the protein source is denatured by an alcohol to bind the particles of the feed mixture. Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a magnified image of an aquaculture feed in accordance with one embodiment of the present invention;

FIG. 2 is a schematic flow diagram illustrating a method of producing an aquaculture feed in accordance with one embodiment of the present invention; and

FIG. 3 is a schematic view of a shrimp larva being fed a mixture of Artemia Naupiii and an aquaculture feed in accordance with one embodiment of the present invention.

Detailed Description of Exemplary Embodiments The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention, and is not intended to represent the only forms in which the present invention may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the scope of the invention.

Referring now to FIG. 1 , an aquaculture feed 10 is shown. The aquaculture feed 10 includes a plurality of particles 12 of a feed mixture. The feed mixture includes a protein source and at least a portion of the protein source is denatured by an alcohol to bind the particles 12 of the feed mixture. In the present embodiment, the aquaculture feed 10 includes a liquid media 14 in which the particles 12 of the feed mixture are dispersed. The denatured proteins of the feed mixture form new cross-links in the protein source that cause the particles 12 to coagulate. In this manner, the protein source serves as a binder for the particles 12 of the feed mixture. The protein source may be a source of globular proteins. The source of globular proteins may be one or a mixture of whole avian eggs, egg yolk, egg white and one or more milk derivatives such as, for example, yoghurt, cheese and cream. The feed mixture may include at least about 30 percent by mass (mass%) of the protein source, preferably at least 50 mass% of the protein source, and more preferably at least 70 mass% of the protein source. To increase nutritional value, medicinal value and/or acceptance levels of the aquaculture feed 10, the feed mixture may also include, for example, classic feed ingredients such as larval fish or shrimp formula, a nutritional supplement such as vitamins, minerals, docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA), a probiotic, a vaccine, a medicine such as an antibiotic or combinations thereof. Examples of suitable probiotics include, but are not limited to, Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Paenibacillus macerans, Lactobacillus acidophilis and Saccharomyces cerevisiae. Examples of suitable vaccines include, but are not limited to, a vibriosis vaccine and a furunculosis vaccine. Due to the effectiveness of the binding capability of the denatured proteins of the feed mixture, the components of the feed mixture are retained within the particles 12 and prevented from leaching out when the particles 12 of the feed mixture are introduced into water for feeding or when dispersed in the liquid media 14. Advantageously, this allows the particles 12 to function not only as a feed, but also as a carrier for nutritional supplements, vaccines, medicines and/or probiotics, thereby providing a simple and complete feed solution.

In one embodiment, the feed mixture may include up to about 50 percent by mass (mass%) of a lipid supplement, preferably up to about 30 mass% of a lipid supplement, and more preferably up to about 5 mass% of a lipid supplement. The lipid supplement may be an emulsion of highly unsaturated fatty acids (HUFA) containing high levels of omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Advantageously, the lipid supplement provides a nutritional lipid boost and the high oil content also results in a neutrally buoyant particle that is more readily consumed by aquatic organisms. Such formulations with high oil inclusions may be used to replace conventional enriched live foods that are difficult to produce and that may be of the wrong size. The enriched feed particles may be directly fed to shrimp or fish larvae in combination with rotifers or Artemia.

The particles 12 are the feed mixture in a subdivided state and the size of the particles 12 may thus be controlled. Each of the particles 12 may be formed to a uniform size of between about 10 micron (pm) and about 2000 pm. This allows the particles 12 to be sized to suit the aquatic organisms at specific periods of their life cycles. This flexibility in turn allows targeted delivery of the necessary nutrients at various stages of the life cycle of the aquatic organisms. In one embodiment, the particles 12 may be of a uniform size of 150 pm for Artemia substitution. In another embodiment, the particles 12 may be of a uniform size of 50 pm for rotifer substitution.

The alcohol serves as a denaturing agent in the process of producing the aquaculture feed 10. In their natural state, proteins, for example, from egg and milk are soluble in water with most of their hydrogen bond forming parts locked inside the folded structure of the protein, making them unavailable for forming bonds with other molecules. Denaturing of the proteins destroys these properties and a denatured protein becomes unfolded as many of the hydrogen bonds that preserve the three- dimensional structure of the protein are broken. The unfolded molecules of the denatured proteins have more bond forming areas exposed on the outside, forming cross-links or bonds with one another, and coagulating the particles 12 of the feed mixture in the process to become insoluble in water. The alcohol may be one or more of methanol, ethanol, propanol and butanol.

In one embodiment, the denaturing agent may be an aqueous alcohol solution having at least about 30 percent by volume (vol%) of ethanol, and more preferably between about 60 vol% and about 70 vol% of ethanol. In such an embodiment, the feed mixture may be pre-formed into a desired particle size before being dispersed in the aqueous alcohol solution where gelification or gelation takes place to form gellified particles 12 of the feed mixture bound with the alcohol- denatured proteins of the feed mixture. Alternatively, the feed mixture may be formed into a gel in the aqueous alcohol solution before being cut up into smaller particle sizes. The use of the aqueous alcohol solution as a denaturing agent allows the feed mixture to undergo gelification at room temperature without heating. This is advantageous as heat may affect the quality of the nutrients in the feed mixture. Further advantageously, the aqueous alcohol solution also serves as a disinfectant for the particles 12 of the feed mixture, thereby helping make the aquaculture feed 10 safe for consumption by aquatic organisms.

The liquid media 14 serves to keep the beads or particles 12 in a liquid preservative. The liquid media 14 may be one or more of water, an alcohol and an antimicrobial. Examples of suitable alcohols include, but are not limited to, ethanol, methanol, propanol and butanol. Examples of suitable antimicrobials include, but are not limited to, propylene glycol, glycerol, propionic acid, a water soluble salt of propionic acid, sodium chloride, calcium chloride and mixtures thereof. In one embodiment, the denaturing agent and the liquid media 14 may both be the same aqueous alcohol solution. Advantageously, because the gelification reaction of the feed mixture occurs in the same sterile environment in which gellified particles 12 of the feed mixture bound with the alcohol-denatured proteins of the feed mixture are stored, the finished feed particles are sterile and remain sterile during storage in the liquid media 14. Although described as being dispersed in a liquid media 14 in the present embodiment, it should be understood that the present invention is not limited to such an embodiment. In an alternative embodiment, the particles 12 of the feed mixture may be dried for storage. Advantageously, the aquaculture feed 10 may be stored in containers at room temperature.

The aquaculture feed 10 provides soft feed particles for larval shrimp, larval fish and/or other aquatic organisms and may serve as a partial or complete Artemia Nauplii, rotifer, other zooplankton or algae replacement or substitute and/or as a carrier for other feed ingredients or feed supplements such as, for example, specific nutrients, vitamins, oils, pro-biotics, vaccines, medicines, heat sensitive ingredients, water soluble ingredients and classic feed ingredients. The aquaculture feed 10 may also be used to replace conventional dry feeds.

Referring now to FIG. 2, a method 50 of producing the aquaculture feed 10 will now be described. The method 50 begins at step 52 by providing a feed mixture. The feed mixture includes a protein source and may be provided in the form of a wet paste or a liquid to facilitate mixing of components of the feed mixture and formation of the particles 12 in specific sizes.

At step 54, a plurality of particles 12 is formed with the feed mixture. This may be, for example, by atomizing the feed mixture via a dropping method or a spray, cutting or use of a mold. Depending on feed requirements, each of the particles 12 may be formed to a uniform size of between about 10 micron (pm) and about 2000 pm.

At least a portion of the protein source is denatured at step 56 with an alcohol to bind the particles 12 of the feed mixture. This may be by contacting the particles 12 of the feed mixture with an aqueous solution of the alcohol. When the particles 12 of the feed mixture contact the denaturing agent, the protein source in the feed mixture becomes at least partially denatured by the denaturing agent and new cross-links that bind the particles 12 are formed in the protein source of the feed mixture. A plurality of digestible beads or particles 12 is thus formed due to the crosslinking of the proteins or binders in the feed mixture. Advantageously, the reaction with alcohol is fast and does not require heating, the latter making the aquaculture feed 10 a suitable carrier for heat sensitive ingredients. The aqueous solution of the alcohol may include at least about 30 percent by volume (vol%) of ethanol, and more preferably between about 60 vol% and about 70 vol% of ethanol. At step 58, the particles 12 of the feed mixture may be dispersed in a liquid media 14. The aquaculture feed 10 may thus be stored in a liquid medium of one or more of water, an alcohol and an antimicrobial until use. Advantageously, this helps to keep the aquaculture feed 10 sterile until the aquaculture feed 10 is fed to aquatic organisms.

Examples

Exemplary compositions of the feed mixture are provided in Tables 1 and 2 below. The figures given below are expressed in percentage by mass (mass%).

Table 1

Tocopherol acetate powder 50% 0.10 0.09 0.07 0.06 0.04 0.03 0.01

Inositol 0.04 0.04 0.03 0.02 0.02 0.01 0.01

Capsoquin 0.03 0.02 0.02 0.02 0.01 0.01 -

Egg yolk 13.50 18.00 22.50 27.00 31.50 36.00 40.50

Egg white 13.50 18.00 22.50 27.00 31.50 36.00 40.50

Fish oil 3.00 4.00 5.00 6.00 7.00 8.00 9.00

Table 2

Experimental Data

Referring now to FIG. 3, an experiment was performed to evaluate the effectiveness of the aquaculture feed 10 as an Artemia Naupiii replacement or substitute. In the experiment, various mixtures of the aquaculture feed 10 and Artemia Naupiii 16 were fed to larval shrimp 18 and the growth of the larval shrimp 18 was measured at post-larval stage 5 (PL5). In the first control sample, the larval shrimp 18 were fed only with Artemia Naupiii 16. In the second sample, the larval shrimp 18 were fed with a mixture of 50% Artemia Naupiii 16 and 50% of an oil- enriched aquaculture feed 10. In the third sample, the larval shrimp 18 were fed only with the aquaculture feed 10. The results of the experiment are shown in Table 3 below.

Table 3 Sample Sample Content Larval Percentage Dry Weight Biomass No. Development Survival (%) per 100 (g)

Index Organisms

1 100% Artemia Nauplii 6.78 87.6 316.33 26.7

2 50% Artemia Nauplii + 50% 6.80 84.2 321 .67 28.7 Oil-Enriched Aquaculture

Feed

3 100% Aquaculture Feed 6.78 73.7 287.00 22

As can be seen from the experimental data provided in Table 1 , the larval shrimp 18 were able to grow and develop as well as in the control sample when fed wholly or partially with the aquaculture feed 10. This demonstrates that the aquaculture feed 10 is an effective replacement or substitute for Artemia Nauplii 16. As is evident from the foregoing discussion, the present invention provides an aquaculture feed that can help reduce dependency on live foods and a method of producing the same. Advantageously, the aquaculture feed of the present invention may be produced without heat with a denser structure that is better able to retain water soluble nutrients. Further advantageously, the particles of the aquaculture feed of the present invention may be sized accordingly to suit specific aquatic organisms. The aquaculture feed of the present invention is also easily produced in large quantities to meet the growing needs of the aquaculture industry. Furthermore, it is possible to provide with the aquaculture feed of the present invention a complete feed that includes nutritional supplements, pro-biotics, vaccines and/or medicines.

While preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not limited to the described embodiments only. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art without departing from the scope of the invention as described in the claims. Further, unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising" and the like are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims

1 . An aquaculture feed, comprising:

a plurality of particles of a feed mixture, the feed mixture comprising a protein source, wherein at least a portion of the protein source is denatured by an alcohol to bind the particles of the feed mixture.

2. The aquaculture feed of claim 1 , wherein the protein source is a source of globular proteins.

3. The aquaculture feed of claim 2, wherein the source of globular proteins comprises one or more of egg yolk, egg white and a milk derivative.

4. The aquaculture feed of claim 1 , wherein the feed mixture comprises at least about 30 percent by mass (mass%) of the protein source.

5. The aquaculture feed of claim 1 , wherein the feed mixture further comprises one or more of a nutritional supplement, a vaccine, a medicine and a probiotic.

6. The aquaculture feed of claim 5, wherein the feed mixture comprises up to about 50 percent by mass (mass%) of a lipid supplement.

7. The aquaculture feed of claim 1 , wherein the alcohol is one or more of methanol, ethanol, propanol and butanol.

8. The aquaculture feed of claim 1 , wherein each of the particles has a uniform size of between about 10 micron (pm) and about 2000 pm.

9. The aquaculture feed of claim 1 , further comprising a liquid media in which the particles of the feed mixture are dispersed.

10. The aquaculture feed of claim 9, wherein the liquid media comprises one or more of water, an alcohol and an antimicrobial.

1 1 . A method of producing an aquaculture feed, comprising:

providing a feed mixture, the feed mixture comprising a protein source;

forming a plurality of particles with the feed mixture; and

denaturing at least a portion of the protein source with an alcohol to bind the particles of the feed mixture.

12. The method of claim 1 1 , wherein the protein source is a source of globular proteins.

13. The method of claim 12, wherein the source of globular proteins comprises one or more of egg yolk, egg white and a milk derivative.

14. The method of claim 1 1 , wherein the feed mixture comprises at least about 30 percent by mass (mass%) of the protein source.

15. The method of claim 1 1 , wherein the feed mixture further comprises one or more of a nutritional supplement, a vaccine, a medicine and a probiotic.

16. The method of claim 15, wherein the feed mixture comprises up to about 50 percent by mass (mass%) of a lipid supplement.

17. The method of claim 1 1 , wherein each of the particles is formed to a uniform size of between about 10 micron (pm) and about 2000 pm.

18. The method of claim 1 1 , wherein the step of denaturing the at least a portion of the protein source with the alcohol comprises contacting the particles of the feed mixture with an aqueous solution of the alcohol.

19. The method of claim 18, wherein the alcohol is one or more of methanol, ethanol, propanol and butanol.

20. The method of claim 18, wherein the aqueous solution of the alcohol comprises at least about 30 percent by volume (vol%) of ethanol.

21 . The method of claim 20, wherein the aqueous solution of the alcohol comprises between about 60 vol% and about 70 vol% of ethanol.

22. The method of claim 1 1 , further comprising dispersing the particles of the feed mixture in a liquid media.

23. The method of claim 22, wherein the liquid media comprises one or more of water, an alcohol and an antimicrobial.