Aquafarming of artemia using salty by-products from the dairy industry

Abstract

The present invention relates to a process for producing Artemia biomass by aquafarming, comprising (i) cultivating Artemia in an aquafarming environment, and (ii) feeding to the Artemia salty whey under conditions that facilitate Artemia growth and / or reproduction. The present invention further relates to Artemia biomass or cysts that can be produced by said process.

Description

[0001] Aquafarming of Artemia using salty by-products from the dairy industry

[0002] The present invention relates to producing Artemia biomass by aquafarming as well as to Artemia biomass thus produced.

[0003] BACKGROUND OF THE INVENTION

[0004] Artemia is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. Species include Artemia franciscana, Artemia monica, Artemia persimilis, Artemia gracilis, Artemia parthenogenetica, Artemia tunisiana, Artemia salina, Artemia sinica, Artemia tibetiana, Artemia urmiana, Artemia amati and Artemia sorgeloosi. The ability of Artemia to produce dormant eggs, known as cysts, has led to extensive use of Artemia in aquaculture. The cysts may be stored indefinitely and hatched on demand to provide a convenient form of live feed for larval fish and crustaceans. Nauplii of the brine shrimp Artemia constitute the most widely used food item, and estimated 3500 to 4000 tons of Artemia cysts was used to support 900 billion crustaceans and fish fry as of 2021 .

[0005] Presently, Artemia cysts are harvested from the wild (mainly from the Great Salt Lakes in USA) and artemia biomass is collected as a by-product of the harvest of the cysts. Artemia are also grown to adulthood and used as a high value biomass for shrimp broodstock. Artemia is fed with high value resources such as microalgae / fish oils, as well as by-products from agricultural industries e.g. rice bran, to grow biomass. The biomass can be used fresh or processed into dry powder and has the potential to increase the availability of marine ingredients currently harvested from the wild. Biomass production of Artemia has been trialled on land with a variety of feedstock including by-products from agriculture. Current literature regarding feeding agricultural by-products to Artemia identify rice bran, wheat flour, yeasts, soy proteins and microalgae being fed in varying proportions. However, these by-products can be used to produce valuable products for human and / or animal consumption and consequently competition exists. Dairy products such as whey powder, milk powder, baby formula and liquid unspecified whey have also been fed to Artemia in small scale research, but have not made it to an industrial scale. One of the challenges of Artemia production in a farmed environment is the importance of feeding them products which lead to Omega-3 bioaccumulation. Currently only feeding microalgae can induce significant levels of Omega-3 in Artemia biomass, rendering the culture system complex (need to grow or use microalgae) as well as expensive.

[0006] The dairy industry is one of the largest producer of liquid byproducts, some of which can be utilised but other are currently representing a significant strain on the environmental impact as well as financially as they need to be disposed through sewer systems. Due to their high organic load, higher temperatures, inorganic salt content and large volume (among other factors) they require processes like chemical conversion using activated sludge. Such waste processes are energy intensive and costly. For example, salt content is a limiting factor to feed inclusion and high organic load is challenging to microbial digesters. This is also compounded by the large volume of these aqueous wastes. Therefore, there are no widely applied methodologies to upcycle these waste products. This results in the loss of valuable nutritional resources from the food chain.

[0007] An object of the present invention is to secure the sustainable development of aquaculture, providing technologies to domesticate and farm Artemia with a high level of Omega-3 without using microalgae for both production of cysts and biomass which can then be processed, for example, into hydrolysate or meal, and at the same time relieve municipal waste system from dairy by-products.

[0008] Another object of the invention is to efficiently upcycle dairy by-products into aquafarming, especially of Artemia.

[0009] DESCRIPTION OF THE INVENTION

[0010] According to a first aspect of the present invention, this object is achieved by a process for producing Artemia biomass by aquafarming comprising the following steps: cultivating Artemia in an aquafarming environment, and feeding salty whey to the Artemia under conditions that facilitate Artemia growth and / or reproduction.

[0011] Preferably, the Artemia is chosen from Artemia franciscana, Artemia monica, Artemia persimilis, Artemia gracilis, Artemia parthenogenetica, Artemia tunisiana, Artemia salina, Artemia sinica, Artemia tibetiana, Artemia urmiana, Artemia amati and Artemia sorgeloosi. Preferably, the Artemia is Artemia franciscana.

[0012] By “Artemia biomass”, it is meant any form of Artemia along its lifecycle. Artemia biomass thus refers to Artemia cysts (i.e. eggs), nauplii, meta-nauplii, asexual adults and / or sexual adults.

[0013] By “whey”, it is meant the aqueous liquid remaining after milk has been curdled and strained. It is a by-product of the manufacturing of cheese. Whey generally presents a total solids of around 5-6.5% by weight of the total whey weight. Whey is typically rich in carbohydrates (60 to 86% of the dry weight, mainly lactose) but poor in proteins (i.e. less than 1 % by weight of the total whey weight) and in fats (see https: / / www.dairyforall.com / whey.php).

[0014] The term “salty whey” as understood herein generally denotes a source of whey having a salt (NaCI) level higherthan 0.5% by weight, relative to the total weight of the whey source. Preferably, the salt (NaCI) level in the whey source is higher than 0.5% by weight, relative to the dry mass of the whey source. Moreover, the salty whey is preferably a source of whey (having a salt level as specified above) produced as a byproduct of the manufacturing of cheese after adding salt to the manufacturing. The form of salty whey is not particularly limited and can be liquid or solid depending on preferences. During manufacturing of cheese the salty whey is formed as liquid. In liquid form, the salty whey can be easily added directly into the aquafarm. Dehydration I drying of the liquid gives solid salty whey. The salty whey can be provided into the aquafarming environment in liquid form, or in solid form blended with other feedstocks.

[0015] Preferably, the salty whey is a source of whey having a NaCI level higher than 0.5% by weight, relative to the total weight of the whey source. Said total weight of the whey source is aqueous, i.e. not dried. A level of 0.5% corresponds to 5 g / l of NaCI in the whey source. Preferably, the salty whey is a source of whey having a NaCI level higher than 1 % by weight, relative to the total weight of the whey source, preferably higherthan 2% by weight, preferably higher than 3% by weight, preferably higher than 4% by weight. Preferably, the NaCI level in the source of whey is comprised between 1 % and 15% by weight, relative to the total weight of the whey source, preferably between 2% and 12% by weight, preferably between 3% and 11 % by weight, preferably between 4% and 10% by weight.

[0016] The present invention is based on the unexpected finding that salty whey is an outstanding resource for Artemia feed. Feeding Artemia with salty whey while aquafarming results in biomass enriched with Omega-3 fatty acids, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Moreover, increased levels of arachidonic acid, C18:2n-6 linoleic acid and C18:3n-3 linolenic acid can be found in the produced Artemia biomass. Therefore, Artemia biomass produced by the process of the present invention reflects a nutrition-rich feedstock for fish and crustaceans.

[0017] Moreover, salty whey is a by-product of the dairy industry. It is currently entering the waste stream in large quantities. In 2018 an estimated 95.250 million litres of salty whey was lost to waste streams in the UK alone. This creates a challenge for the dairy industry and municipal waste systems due to the high organic load, higher temperatures, inorganic salt content and large volume of liquid dairy wastes (among other factors), which is addressed by the present invention. The present invention enables the upcycling of currently costly byproducts, turning them into a revenue stream. The ability of Artemia sp. to withstand hypersaline environments (amongst other conditions) also answers the difficulties introduced by the high salt levels etc. of dairy liquid waste byproducts.

[0018] In a preferred embodiment of the invention, the salty whey makes up between 5% and 100% by weight, preferably 10 to 90%, more preferably 30 to 90%, most preferably 50 to 90% by weight, relative to the total daily feed weight of the Artemia.

[0019] While not being limited to a particular feeding regimen, a preferred regimen involves a first feeding phase and a second feeding phase, wherein the amount of salty whey relative to the total mass of the Artemia biomass is higher in the first phase than in the second phase. In the first phase, 45 to 75% of salty whey relative to the mass of Artemia biomass may be fed, and in the second phase, 20 to 40% of salty whey relative to the mass of Artemia biomass may be fed. The first phase may range from 3 to 5 days and the second phase may range from 5 to 50 days.

[0020] Preferably, the regimen involves a first feeding phase and a second feeding phase, wherein the amount of salty whey relative to the total mass of the Artemia biomass is lower in the first phase than in the second phase. Preferably, in the first phase, 10 to 30% of salty whey relative to the total daily feed weight of the Artemia is fed, and in the second phase, 40 to 90% of salty whey relative to the total daily feed weight of the Artemia is fed. The first phase may range from 1 to 5 days, preferably 3 to 5 days, preferably 4 to 5 days, and the second phase may range from 5 to 100 days, preferably 5 to 50 days.

[0021] The process of the invention may further comprise one or more of the following: recovering Artemia biomass and / or Artemia cysts from the aquafarming environment; optionally drying Artemia biomass recovered from the aquafarming environment; and / or optionally biochemically analyzing the Artemia biomass.

[0022] The Artemia biomass and / or cysts may be recovered from the aquafarming environment by any suitable technique. For instance, filtration can be used. Here, the biomass containing culture water may be passed through a filter comprising netting or meshes of suitable size. The biomass is retained on the filter, whereas the culture water passes through. The culture water can be actively moved (pumped) or passively moved, e.g. by gravity.

[0023] The recovered biomass may be dried by the application of heat and / or movement of air.

[0024] As mentioned above, a key advantage of the process described herein is that the Artemia biomass is enriched in valuable fatty acids. Hence, according to another aspect of the present invention, Artemia biomass produced or producible by the process specified herein, comprises, by weight relative to its total lipid mass: at least 0.2%, preferably at least 1 %, preferably at least 1.2%, preferably at least 2.2% arachidonic acid, and / or at least 1 .0%, preferably at least 2.0%, preferably at least 4.0%, preferably at least 4.5% eicosapentaenoic acid (EPA).

[0025] Preferably, Artemia biomass produced or producible by the process specified herein, comprises, by weight relative to its total lipid mass: at least 0.2% arachidonic acid, at least 1 .0% (preferably at least 2.0%) eicosapentaenoic acid (EPA), and at least 2.0% (preferably at least 2.2%) C18:3n-3 linolenic acid.

[0026] A preferred embodiment of the Artemia biomass comprises, by weight relative to its total lipid mass, one or more of the following: at least 4.5% C18:2n-6 linoleic acid; at least 2.0%, preferably at least 2.2% C18:3n-3 linolenic acid; at least 0.3% docosahexaenoic acid (DHA), preferably at least 1 .0%, preferably at least 2.0%.

[0027] A further embodiment of the Artemia biomass and / or Artemia cysts described herein comprises, by weight in dry matter:

[0028] 50% or above, preferably 62 to 79%, preferably 72 to 79 %, preferably 68 to 78%, preferably 72.5 to 78%, more preferably 70 to 76%, preferably 72.5 to 76%, most preferably 72 to 75%, preferably 73 to 75%, crude protein; and / or 8.8 to 13.0%, preferably 8.9 to 12.0%, more preferably 9.0 to 11 .0%, most preferably

[0029] 9.1 to 10.0%, crude lipid; and / or

[0030] 0.5 to 3.5%, preferably 1.0 to 3.0%, more preferably 2.0 to 3.0%, more preferably

[0031] 1 .5 to 2.8%, most preferably 1 .8 to 2.5%, crude fibre; and / or

[0032] 10.0 to 15.0%, preferably 10.1 to 14.0%, more preferably 10.2 to 13.0%, most preferably 10.5 to 1 1 .5%, crude ash.

[0033] The Artemia biomass and / or Artemia cysts described herein may be further characterized by the following profile of essential amino acids, by weight of the total protein weight:

[0034] Arginine: 5.20 to 5.75%;

[0035] Histidine: 1 .20 to 1 .70%;

[0036] Isoleucine: 3.00 to 4.10%;

[0037] Leucine: 5.00 to 6.30%;

[0038] Lysine: 6.30 to 6.90%;

[0039] Methionine: 1 .50 to 2.00%;

[0040] Phenylalanine: 3.00 to 3.90%;

[0041] Threonine: 3.50 to 4.10%;

[0042] Tryptophan: less than 0.50%;

[0043] Valine: 4.33 to 4.60%; or has a profile overlapping in at least three, four, five, six, seven, eight, nine or all ten of said essential amino acids.

[0044] The Artemia biomass and / or Artemia cysts described herein may be further characterized by the following profile of non-essential amino acids, by weight of the total protein weight: Cysteine: 0.91 to 1.20%;

[0045] Tyrosine: 2.00 to 2.28%;

[0046] Glutamic acid: 11 .05 to 11 .80%;

[0047] Aspartic acid: 8.00 to 8.40%;

[0048] Glycine: 4.25 to 4.55%;

[0049] Serine: 3.80 to 4.17%;

[0050] Alanine: 5.20 to 5.80%;

[0051] Proline: 3.75 to 4.00%;

[0052] Taurine: 0.50 to 1 .50%, or has a profile overlapping in at least three, four, five, six, seven, eight or all nine of said non-essential amino acids.

[0053] The Artemia biomass and / or Artemia cysts described herein may further have: an iron content ranging from 200 to 1200 mg / kg, preferably 400 to 1200 mg / kg; and / or a copper content ranging from 10 to 150 mg / kg, preferably 50 to 150 mg / kg; and / or a zinc content ranging from 150 to 800 mg / kg, preferably 300 to 800 mg / kg; and optionally may have one or more of the following, in dry matter: a calcium content ranging from 0.10 to 0.40%, preferably 0.22 to 0.40%; a phosphorus content ranging from 1.10 to 1.50%; a sodium content ranging from 1 .50 to 5.0, preferably 11 .50 to 1 .90%; a potassium content ranging from 0.80 to 2.0, preferably 0.80 to 1.10%; a magnesium content ranging from 0.20 to 0.50, preferably 0.24 to 0.30%.

[0054] Another aspect of the present invention pertains to the use of salty whey for increasing Omega-3 fatty acid level and / or arachidonic acid level in Artemia. Preferably, the Omega 3 fatty acids are selected from the group consisting of DHA and EPA.

[0055] In the following, the invention is explained in more detail with reference to a representative example.

[0056] EXAMPLE 1

[0057] Artemia was grown in an aquafarming system including three tanks. As a feed, 50% salty whey by weight of the daily feed weight was used. Said salty whey comprises 6.5% NaCI by weight of the total whey weight. About 90 ppt sea salt was added for product stabilization at 28°C. The feed was provided at intervals of 1 min throughout the day. Cysts were hatched over a 24hr period in marine and / or artificial marine water (30 to 120 ppt of NaCI) within hatching tanks of various dimensions. Cysts were seeded in said water at a density up to 2g / L. Water temperature was maintained between 25 and 30°C. Water is illuminated using artificial lighting to stimulate the hatching process.

[0058] After 10 days of cultivation, Artemia biomass was recovered and dried, followed by biochemical analysis of the thus obtained Artemeal. The results are shown below.

[0059] 1 . Biomass composition

[0060] 2. Fatty acid composition

[0061] Salty whey Artemeal has higher % of beneficial Omega-3 fatty acids than control diets. In particular, salty whey fed Artemeal has enrichment of EPA and arachidonic acid.

[0062] 3. Amino acid composition % by weight of the total protein weight

[0063] Roughly comparable ratios of essential and non-essential amino acids is found in Artemeal fed with salty whey.

[0064] 4. Amino acid profile

[0065] 4.1 Essential amino acids

[0066] % by weight of the total protein weight

[0067] 4.2 Non-essential amino acids

[0068] % by weight of the total protein weight

[0069] 5. Mineral composition

Claims

CLAIMS1. Process for producing Artemia biomass by aquafarming, comprising the following steps: cultivating Artemia in an aquafarming environment, and feeding to the Artemia salty whey under conditions that facilitate Artemia growth and / or reproduction, wherein the salty whey is a source of whey having a NaCI level higher than 0.5% by weight relative to the total weight of the whey source.

2. Process of claim 1 , wherein the salty whey is a source of whey having a NaCI level higher than 1 % by weight relative to the total weight of the whey source, preferably higher than 2% by weight, preferably higher than 3% by weight, preferably higher than 4% by weight; preferably the NaCI level in the source of whey is comprised between 1 % and 15% by weight relative to the total weight of the whey source, preferably between 2% and 12% by weight, and preferably between 3% and 1 1 % by weight, preferably between 4% and 10% by weight.

3. Process of claim 1 or 2, wherein the salty whey makes up between 5 and 100% by weight, preferably 10 to 90%, more preferably 30 to 90%, most preferably 50 to 90% by weight, relative to the total daily feed weight of the Artemia.

4. Process of any one of claims 1 to 3, wherein the feeding involves a first phase and a second phase, wherein the amount of salty whey relative to the net weight of Artemia biomass is lower in the first phase than in the second phase.

5. Process of claim 4, wherein in the first phase 10 to 30% of salty whey relative to the total daily feed weight of the Artemia is fed, and in the second phase 40 to 90% of salty whey relative to the total daily feed weight of the Artemia is fed, preferably the first phase is 1 to 5 days, preferably 4 to 5 days, and the second phase is 5 to 100 days, preferably 5 to 50 days.

6. Process of any of the preceding claims, wherein the salty whey is provided into the aquafarming environment in liquid form, or in solid form blended with other feedstocks.

7. Process of any of the preceding claims, further comprising: recovering Artemia biomass and / or cysts from the aquafarming environment; optionally drying Artemia biomass recovered from the aquafarming environment; and / or optionally biochemically analyzing the Artemia biomass.

8. Artemia biomass and / or Artemia cysts produced or producible by the process of any of claims 1 to 7, comprising, relative to the total lipid mass: at least 0.2% arachidonic acid, and at least 1 .0%, preferably at least 2.0% eicosapentaenoic acid (EPA), and at least 2.0% C18:3n-3 linolenic acid.

9. Artemia biomass and / or Artemia cysts of claim 8, further comprising, relative to the total lipid mass, one or more of the following: at least 4.5% C18:2n-6 linoleic acid; at least 2.2% C18:3n-3 linolenic acid; at least 0.3% docosahexaenoic acid (DHA), preferably at least 1 .0%, preferably at least 2.0%.

10. Artemia biomass and / or Artemia cysts of claim 8 or 9, comprising, in dry matter of the total composition:50% or above, preferably 62 to 79%, preferably 72 to 79 %, preferably 68 to 78%, more preferably 72.5 to 78%, more preferably 70 to 76%, yet more preferably 72.5 to 76%, most preferably 72 to 75%, most preferably 73 to 75%, crude protein;8.8 to 13.0%, preferably 8.9 to 12.0%, more preferably 9.0 to 11 .0%, most preferably9.1 to 10.0%, crude lipid; and / or0.5 to 3.5%, preferably 1.0 to 3.0%, more preferably 2.0 to 3.0%, more preferably1 .5 to 2.8%, most preferably 1 .8 to 2.5%, crude fibre; and / or10.0 to 15.0%, preferably 10.1 to 14.0%, more preferably 10.2 to 13.0%, most preferably 10.5 to 1 1 .5%, crude ash.11 . Artemia biomass and / or Artemia cysts of any of claims 8 to 10, characterized by the following profile of essential amino acids, by weight ofthe total weight of the proteins:Arginine: 5.20 to 5.75%;Histidine: 1 .20 to 1 .70%;Isoleucine: 3.00 to 4.10%;Leucine: 5.00 to 6.30%;Lysine: 6.30 to 6.90%;Methionine: 1 .50 to 2.00%;Phenylalanine: 3.00 to 3.90%;Threonine: 3.50 to 4.10%;Tryptophan: less than 0.50%;Valine: 4.33 to 4.60%; or having a profile overlapping in at least three, four, five, six, seven, eight, nine or all ten of said essential amino acids.

12. Artemia biomass and / or Artemia cysts of any of claims 8 to 1 1 , characterized by the following profile of non-essential amino acids, by weight of the total weight of the proteins:Cysteine: 0.91 to 1.20%;Tyrosine: 2.00 to 2.28%;Glutamic acid: 11 .05 to 1 1 .80%;Aspartic acid: 8.00 to 8.40%;Glycine: 4.25 to 4.55%;Serine: 3.80 to 4.17%;Alanine: 5.20 to 5.80%;Proline: 3.75 to 4.00%;Taurine: 0.50 to 1 .50%, or having a profile overlapping in at least three of said non-essential amino acids.

13. Artemia biomass and / or Artemia cysts of any of claims 8 to 12, having: an iron content ranging from 200 to 1200 mg / kg, preferably 400 to 1200 mg / kg; and / or a copper content ranging from 10 to 150 mg / kg, preferably 50 to 150 mg / kg; and / or a zinc content ranging from 150 to 800 mg / kg, preferably 300 to 800 mg / kg; and optionally having one or more of, in dry matter: a calcium content ranging from 0.10 to 0.40%, preferably 0.22 to 0.40%; a phosphorus content ranging from 1.10 to 1.50%; a sodium content ranging from 1 .50 to 5.0, preferably 1 .50 to 1 .90%; a potassium content ranging from 0.80 to 2.0, preferably 0.80 to 1.10%; a magnesium content ranging from 0.20 to 0.50, preferably 0.24 to 0.30%.

14. Use of salty whey for increasing Omega-3 fatty acid level and / or arachidonic acid level in Artemia.

15. Use of claim 14, wherein the Omega 3 fatty acids are selected from the group consisting of DHA and EPA.

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