NZ272338A

NZ272338A - Shellfish feedstuff; includes processed seaweed

Info

Publication number: NZ272338A
Application number: NZ272338A
Authority: NZ
Inventors: William John Courtney; Paul Allister Reeve Dryer; Kathleen Ann Coopey; Fevre Mark Le
Original assignee: Coast Biolog Ltd
Priority date: 1995-06-19
Filing date: 1995-06-19
Publication date: 1997-12-19
Also published as: WO1997000021A1; AU6141496A

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number £72338 272338 \ PATENTS FORM NO. g Fee No. 4: $260.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 272338 Dated: 19 June 1995 IMPROVEMENTS IN AND RELATING TO FEEDS FOR MARINE LIFE WE Coast Biologicals Limited, a New Zealand company of 260 Roscommon Road, Wiri, Auckland, New Zealand hereby declare the invention for which We pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: 272338 IMPROVEMENTS IN AND RELATING TO FEEDS FOR MARINE LIFE TECHNICAL FIELD The present invention is directed to foodstuffs for marine matter. In particular the feeding of shellfish such as abalone shall be considered though the present invention may be applied in other areas. BACKGROUND ART The present invention arose due to problems with the farming of abalone (known in New Zealand as paua). Abalone represent a group of shellfish which comprises many different species. As a group, abalone are of commercial importance in the luxury food market, while their shells are often sought after in other industries. Abalone, and other shellfish, may be caught wild or farmed. However, when farming, providing a suitable diet can be difficult. For abalone in particular, fresh (ie. wild) or farmed seaweeds can be used, which is usually some species of Gracillaria. Unfortunately in many areas providing seaweed, either wild or farmed, is not practical. This may be for reasons of cost and convenience, or because the preferred seaweeds are not present in the desired location in which case transporting fresh seaweed is not practical. As a consequence the applicant's have investigated the use of processed feeds. In doing so, they have concentrated on using the mass of seaweed that remains after commercial processing for agar extraction. Traditionally, the debris from the extraction process has been considered waste material, and discarded. However, the applicants have recognised that the "debris" comprises a useful natural base for feeds for marine organisms, 272338 particularly shellfish. ' However, it is to be appreciated that using any form of processed seaweed, not just that resulting from agar extraction, is within the scope of the present invention. Most existing feeds are not suitable for use for feeding marine life such as shellfish. Marine directed foodstuffs have typically been for fish, such as present in fish farms. Most of these feeds will break up in water though this is not a significant problem as fish tend to consume foodstuff as soon as it reaches the surface of the water. In contrast, shellfish are sluggish and must seek their food. Foodstuffs which break up and dissolve are generally unsuitable as they i) become unavailable for abalone or non-filter feeders to graze, and ii) cause turbidity or fouling of the water which is unacceptable to the abalone or shellfish. Accordingly, it is desirable that a foodstuff suitable for use with shellfish such as abalone should have either or both the following properties: good stability in water - it should be resistant to rapid dissolution or breaking down, and it should be able to promote the rapid growth of the abalone or shellfish giving a good feed conversion, in terms of weight food converted to weight abalone flesh. It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. 3 272338 msrxosTiRF. of invention According to one aspect of the present invention there is provided a feed, characterised by being resistant to rapid break up or dissolution in water, (either or both fresh water or seawater) and which includes a processed (as herein defined) seaweed. According to another aspect of the present invention there is provided a feed, substantially as described above, in which 'processing' of seaweed comprises cooking or heat treatment. According to another aspect of the present invention there is provided a feed, substantially as described above, in which 'processing' of seaweed includes digestion by at least one of acids, bases, enzymes, fungi, bacteria, or other micro-organisms. According to another aspect of the present invention there is provided a feed, substantially as described above, which includes at least one substance falling within the group comprising: minerals, vitamins, and lipids. According to another aspect of the present invention there is provided a feed, substantially as described above, which includes nutrient protein material. According to another aspect of the present invention there is provided a feed, substantially as described above, in which said nutrient protein material comprises at least one of: plant material, fish based material, casein, dairy products and/or by-products, and animal derived material. 4 272338 According to another aspect of the present invention there is provided a feed substantially as described above in which resistance to rapid break up or dissolution in water is achieved by at least one of: forming the feed into a gel; including a substance forming a skin in seawater; forming the feed into a compacted block, and including a hydrophobic substance. According to another aspect of the present invention there is provided a feed substantially as described above in which skinning is achieved by including at least one of: an alginic acid, an alginate salt and/or a polysaccharide; each of a type which gels in the presence of certain metal cations. According to a further aspect of the present invention there is provided a feed, resistant to rapid dissolution in seawater, and which includes at least one of: an alginic acid, an alginate salt and/or a polysaccharide; each of a type which gels in the presence of certain metal cations. According to another aspect of the present invention there is provided a feed substantially as described above which is further characterised by being self-skinning when surface portions contact seawater. According to another aspect of the present invention there is provided a feed substantially as described above which includes at least one of: vitamins, minerals, nutrient proteins, and lipids. One set of embodiments of the present invention are characterised by including cooked seaweed. Previously raw, or fresh seaweed was fed to shellfish though there are present the usual problems associated with storing and transporting fresh produce. Drying the seaweed is a possible 5 272338 solution though this adds an extra step and dried seaweed may not always be as palatable to the shellfish as is the fresh material. Accordingly, in one set of embodiments of the present invention there is provided a foodstuff which relies on a processed seaweed. By the term "processed seaweed" is meant a seaweed which has been cooked or heat treated, or otherwise subjected to conditions which produce an effect similar to heating. Digestion steps such as digestion by acids, alkalines, enzymes etc. are several examples. The use of fungi, bacteria and micro-organisms to break down or partially digest the seaweed are also envisaged. The processed seaweed will form a significant, if not major, proportion of any foodstuff for the embodiments being described. It is envisaged that other substances shall also be included and these may include: vitaiiins, minerals, lipids, nutrient protein sources, and other substances which may be required by the animal life to which a foodstuff is fed. Much of this material might already be present in tha seaweed, though additional components may be provided to provide what is considered to be a balanced or a required diet. Additional nutrient protein may be derived from a variety of sources. In some instances this may be derived from plant based material (the seaweed will provide a substantial proportion of required protein) though non-marine plant material may also be considered for inclusion. Animal based protein sources (both marine and non-marine) may also be considered. Examples include protein rich waste from many animal processing industries - for instance, fish waste, waste from meat processing works, dairy bi products such as casein and whey, etc. 6 272338 As the animals to which the foodstuffs are to be fed may not be accustomed to these other sources of protein (which are alien to their environment), consideration may need to be given to the tolerance and acceptance of these alternative protein and nutrient sources. It is possible that these alternative sources need to be supplementary rather than main nutrient sources - in preferred embodiments of the present invention it is envisaged that the processed seaweed will still form a dominant proportion of the resulting foodstuff. When the foodstuff is to be used in a marine environment it is preferred that whatever the form the foodstuff takes is resistant to rapid breakdown or dissolution in the water. There are several methods of providing this feature, and one in particular will be discussed with reference to a second set of embodiments of the present invention. One method of conferring resistance to the rapid breakdown of a foodstuff is to form foodstuff into pellets or articles which have been compacted. In some instances the solubility of the individual components is relatively low. Compacting an article generally reduces the overall surface area, and the integrity of the internal structure of the article - both surface area and integrity generally being factors affecting the rate of dissolution and breakdown of any article in a liquid. In general compacted articles dissolve or breakdown more slowly than their non-compacted counterparts and thus this technique may be relied upon to produce blocks and briquettes (etc.) which have relatively good stability in water. The inclusion of hydrophobic substances can also delay the dissolution or breakdown of an article in water. Some of the envisaged additional nutrient sources (see above) are hydrophobic in nature. Examples include many of the lipids, dairy by products and fatty or oily animal and 7 272338 fish wastes. Hydrophobic substances if dispersed throughout a feed matrix will typically make the feed article water repellent, or wetting resistant, depending of course on the proportion and nature of hydrophobic substance included. Hydrophobic substances may be included in compacted embodiments. Envisaged is a compacted block comprising a matrix of substantially dry components. Such a block impregnated with an oily or fatty substance is also envisaged. Other embodiment? of the present invention may take the form of a gel. This gel may be of type resistant to rapid dissolution in water. Many gels comprise a 3-dimensional network of linked molecules and comprise substantially water. Often such gels are resistant to dissolution in water, or can be prepared in a form where such resistance exists. Many gelling agents are known, and many of these are non-toxic and used in the food industries. Such gelling agents may be used in various embodiments of the present invention to provide a gelled embodiment of a foodstuff. Solid nutrients and components may be dispersed throughout the gel while soluble components may be present in the water encased within the gel network. Some examples of gelling agents include gelatines, agars, and many polysaccharide materials. 'Non-organic' gelling agents, such as some silicone compounds, may be considered in some instances. It is envisaged that most gelled embodiments of the present invention will comprise relatively stiff gels so as to be resistant to the effects of dissolution and breakdown in water. It is also envisaged that some gels may be more resistant to dissolution in salt water than in fresh water 8 272338 and vice versa. Accordingly, the intended application of the resulting foodstuff will have a bearing on the gelling agent included. It is also envisaged that some foodstuffs may find use for non-marine applications. Examples could be snail farming, and even domestic pets. Here, resistance to drying out may be a consideration and stiffer or more rigid gels may be used. It is also envisaged that there will not be an excess of water within a resulting feed product as this not only increases the bulk of the product but also the weight for shipping and transport. In some instances additional water may be desirable or required for the particular application, though attempting to reduce the proportion of water will be a consideration in many instances. In another set of embodiments according to the present invention the foodstuff is also substantially a gelled product though the gel is of a type which increases in gel strength or viscosity in the presence of certain metal cations. The alginates, such as alginic acid, and many alginate salts (eg. sodium alginate), are often able to be prepared into a gel which thickens in the presence of certain heavier metal cations (eg. calcium and above). This can be a useful quality in preparing a foodstuff as, firstly, it allows a way of rapidly promoting the setting of a prepared foodstuff mixture. Various components may be combined and, providing care is taken not to include any gel-promoting cations, the mixture could be relatively readily mixed and blended. Introducing a gel promoting substance can then be used to set the foodstuff. This may have inherent problems if the conditions are such that the gel sets while attempting to blend in the gel promoting substances (though for some embodiments this may be acceptable). It may be simpler, in some instances, to merely 9 272338 extrude, or introduce into a gel-promoting solution, portions of an animal foodstuff. The result would be a product having a fluid or lightly gelled centre but also possessing a skin of a more heavily gelled nature. The ability to form a skin when contacting solutions of heavier metal cations can be useful both for the manufacturing of a product, and the end use. Potentially realisable advantages in manufacturing have been described above, as it provides a useful method for forming a final product. It may also be advantageous during vise, especially where used in seawater which is rich in many gel promoting metal cations. Such embodiments will be useful when be grazed by marine life as they would in effect be self skinning as each new portion of the feed article is exposed by the grazing action of the shellfish or animal. This self skinning process would be a consequence of the inner portions being exposed to the seawater and the result is a product whose self skinning properties can resist its rapid dissolution or breakdown in water or marine conditions. It is noted however that such embodiments may not be as particularly suitable in fresh water environments where there may be an insufficient concentration of metal cations to promote the skinning process. In such applications it is likely that embodiments which are substantially gelled throughout the entire article are relied upon, unless the foodstuff was formed into articles of a size which would each be substantially consumed by a grazing animal or shellfish etc. In another embodiment of the present invention there is provided a method of producing a seaweed based foodstuff for marine organisms comprising the steps of: (a) processing a quantity of seaweed; 10 272338 (b) optionally adding additional nutrients to said processed seaweed to produce a mixture, and (c) forming said mixture into an administrable form suitable for use in an underwater environment. The administrable form so produced may either be in gelled form or in substantially solid form, although any other form which will sink to the area of grazing by the marine organism is within the scope of the present invention. According to another aspect of the present invention there is provided a method of producing a seaweed based foodstuff for marine organisms comprising the steps of: (a) processing a quantity of seaweed; (b) drying said quantity of seaweed; (c) milling said quantity of seaweed; (d) optionally adding additional ingredients to said milled seaweed to produce a mixture; (e) extruding and cutting said mixture into the desired form and (f) optionally again drying the formed mixture. It is envisaged that the seaweed will be dried in hot air driers. Once extruded the mixture may be in a semi dry condition. Accordingly, the mixture can be dried again into an administrable form, such as chips or pellets or similar. 11 272338 BEST MODES FOR CARRYING OUT THE INVENTION Example I This is an embodiment which includes, as a source of protein and carbohydrate, a processed seaweed. A seaweed such as Pterocladia lucida, and/or Pterocladia capillaceae is initially cooked. A variety of heating methods may be relied upon, such as steam heating, pressure cooking, etc. to produce a softened or partially digested material which is more readily consumed or digested by a shellfish or animal. Other seaweeds and marine plant matter may be considered, including various species of Gelidium, Gracillaria, and Ahnfeldtia. These three families, and other members of the Rhodophycaea group are, in particular, preferred foodstuffs of abalone. Other plant based matter may be included to supplement the seaweed. Cooking of the seaweed also has the effect of partially extracting substances, such as agar, which are able to contribute to the gelling of a product. In many instances, depending upon the seaweeds chosen, the addition of other gelling substances may not be required. It is noted however that to extract a sufficient level of gel forming substances from the included seaweed may be too time consuming or energy intensive and thus other commercially available sources of gelling substances may be relied upon to supplement those which are extracted from the nutrient seaweed/plant matter sources. To the cooked seaweed fraction are included other nutrient substances. By way of example there follows a formulation for a nutrient additive which may be added in various proportions to the cooked seaweed base as required. The following formulation which has been optimised for 12 27 2 3 abalone but is also applicable to many other types of animal life, would typically be sufficient to treat the base material from between 100 -1000 kg of seaweed: NaCl 0.04 kg MgS047H20 0.6 kg NaH2P04.2H20 1.0 kg KH2P04 1.28 kg Ca(H2P04)22H20 0.8 kg Fe-citrate 0.1kg Ca lactate 0.14 kg ZnS04.7H20 0.333 kg MnS04.4H20 0.162 kg CuS04.5H20 0.031kg CoC12.6H20 0.001kg KIO3 0.003 kg Choline Chloride 0.5 kg Thiamine HC1 6 gm Riboflavine 5 gm Pyridoxine HC1 2gm Niacin 40 gm Ca Pantothenate 10 gm Inosital 200 gm Biotin 0.6 gm Folic Acid 1.5 gm PABA 20 gm Menadione 4 gm B12 0.009 gm Ascorbic Acid 200g Vitamin A 5000IU Vitamin D 100IU Vitamin E 0.05 kg Optionally, to the preparation prepared thus far, may be added additional nutrient or protein sources. By way of example this could include fish waste and offal, fish oils (cod liver oil and halibut oil), protein rich meats, processing plant waste, milk powders, casein, whey, etc. The resulting product is formed into pieces of gelled material. As previously mentioned, there may be sufficient agar and gel forming 13 27 2 3 38 substances extracted from the seaweed to result in a gelled product though additional gelling agents may be included. The resulting product may be slowly stirred as the gel forms so that the result is a vat of broken gelled lumps of irregular size and shape. Alternatively the product may be allowed to solidify into blocks or shapes which can be further cut or processed as desired. Another alternative is to extrude or mould a product into variously sized or shaped articles. Example 2 Essentially the same as Example 1, there is also included the preparation at least one alginate material capable of gelling, or forming a thicker gel, in the presence of certain metal cations. Such substances may be extracted from materials included in the initial plant material being processed, though it is also possible that the alginate materials may be included from a separate source. The resulting products may still resemble a gel and may be formed into articles according to many of the ways described above. Depending on the exact process tLe formed articles may be subjected to a solution of gel promoting cations to form or toughen any skin around each article. It is also possible that gel-promoting cations may be incorporated into the base, or subsequent, preparations. Esampte 3 Similar to Examples 1 and 2, this example relies upon alternative digestion processes to supplement or replace heat treatment or cooking. For instance, a mineral, or organic, acid may be relied upon to at least partially digest the seaweed.. The strength of the acid will influence the rate by which digestion occurs, and is largely a matter of user choice. 14 Alkalis could also be relied upon and again the concentration, as well as nature of, the alkaline solution will influence the rate of digestion. Enzymes, fungi, bacteria and other micro-organiems are often also used in other fields for digestive processes and it is envisaged that these techniques may be used to assist in the processing of the seaweed. Example 4 In this method similar components are used to form a substantially dry foodstuff. Preferably cooking or heat treatment of the seaweed and plant matter fraction is performed, primarily as a means for reducing, or limiting, the proportion of moisture in the final product. To the resulting base portion are added any remaining components, also in a non-liquid (or at least non aqueous) or relatively dry form. The components are blended into a substantially homogeneous blend and then compacted into articles of the preferred size and shape. Additional components which possess hydrophobic properties may be included. Various nutrient substances which possess hydrophobic properties have been previously discussed. Non-nutrient hydrophobic substances may also be included. Examples include many minerals, organometallic substances such as zinc stearate etc., mineral oils, and also oils of other origins (which may also be considered to be a partial nutrient source in some instances). Consideration would need to be given that the included substances are not toxic to the targeted animal for which the foodstuff is being prepared. 15 272338 Different targeted animals will require different components though percentage breakdowns (dry weight equivalents) of some preferred examples according to the present invention are as follows: Vitamin/Mineral mixture 6% Lipid blend # 5 % Sodium alginate 7% Pterocladia+ 32% (NaP03)6 3% Fish meal * 47% 100% Vitamin/Mineral mix 4-8% Lipid Blend 2-8% Sodium alginate 2 - 20% Pterocladia + 5 - 80% Fish meal * 5 - 60% (NaP03)6 1-4% 100% * or other suitable protein source or casein or soy protein + or other pre-processed seaweed where the pre-processing consists of cooking in an aqueous system, with or without pressure, carried out at pH values which may be varied between 2-11 with mineral acids or bases or other suitable buffering or pH controlling compounds # fish and seed oils blended in proportions between 1: 0.5 and 1: 4. Example 5 "In this method any of the foregoing embodiments may be dried to a low residual moisture level to aid long term stability. Such dried products will rehydrate, at a greater or lesser rate depending on formulation, when placed in water until they are of a sufficiently soft consistency to be eaten by the shellfish." 16 272338 Example 6 The applicants conducted growth trials investigating the effect of using processed (or "treated") seaweed in abalone diet on abalone weight increase over 100 days. 300 animals were divided into five tanks with 60 animals in each tank. All 300 animals had been fed on a commercial, casein based diet for 4 weeks prior to the start of the trial. Each animal was individually identified with a numbered tag and individually weighed and measured at the start of the trial, and after 100 days on the test diets. The total number of diets in each tank was kept constant by replacing any missing or dead animals with untagged abalone of a similar size. Animals were randomly assigned to the different diets. Diet Initial weight (g) Weight after 100 days A Commercial pre-mix + treated weed 4.4 8.0 B Applicant's pre-mix + treated weed 4.4 8.7 C Commercial pre-mix + untreated weed 4.2 7.6 D Applicant's pre-mix + untreated weed 4.0 8.2 E Control diet: no weed 4.5 7.9 SED 0.24 0.19 p-value 0.31 <0.001 Unbalanced ANCOVA was used to analyse the data. The abalone weights were adjusted at the trial measurement dates to allow for initial differences in the abalone size. An effect of this adjustment is an assumption that all abalone in every treatment had a 17 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 272338 constant initial mean weight of 4.3g. Another effect is the reduction in Standard Error of differences between the means. Results

1. The effect of treated weed versus untreated weed ie. the mean of diets A and B (8.4g) versus the mean of diets C and D (7.9g) shows increased weight of 6.3% over 100 days with treated weed. Diets with treated weed accordingly provide superior weight gain to those with untreated weed.

2. The effect of the applicant's pre-mix over commercial pre-mix ie. the mean of diets B and D (8.4g) versus the mean of diets A and C (7.8g) shows increased weight of 7.7% over 100 days with the applicant's pre-mix. The applicant's pre-mix is superior to commercial premix regardless of weed used. Diet Initial weight (g) 100 days (g) B 4.4 8.7 E 4.5 7.9 SED .24 .19 p-value .44 <0.001 A comparison of diet B in comparison with the no-weed control diet E provides a very statistically significant increase in weight of 10.1% in weight over 100 days with diet B. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as claimed in the appended claims. 18 19 WHAT WE CLAIM IS;

1. A seaweed based foodstuff for marine organisms characterised in being resistant to rapid breakdown or dissolution in water and having as a seaweed base a quantity of seaweed that has been processed to soften and/or partially digest same.

2. A foodstuff as claimed in claim 1 wherein additional nutrients are added to said seaweed base to produce a mixture.

3. A foodstuff as claimed in claim 1 or claim 2 wherein the marine organisms are shellfish.

4. A foodstuff as claimed in claim 3 wherein said shellfish are abalone.

5. A foodstuff as claimed in any one of above claims 1 to 4 wherein the seaweed is of any one or more of the Pterocladia. fle1idinmr Gracillaria and Ahnfeldtia families.

6. A foodstuff as claimed in any one of claims 1 to 5 wherein the processing of the seaweed to produce a seaweed base comprises heat treatment.

7. A foodstuff as claimed in any one of claims 1 to 5 wherein the processing of seaweed to produce a seaweed base comprises partial or complete digestion by the action of any one or more of acids, bases, enzymes, fungi, bacteria or other micro organisms.

8. A foodstuff according to any one of claims 1 to 7 wherein additional nutrients added to the seaweed base comprise any one or more of minerals, vitamins, lipids and proteinaceous material. N.Z. PATENT OFFICE 1 13 OCT W7 272338

9. A foodstuff according to claim 8 wherein said proteinaceous material comprises any one or more of fish based material, casing, dairy products and or by-products and animal material.

10. A foodstuff according to claim 9 wherein the seaweed base mixture is formed into a gelled foodstuff.

11. A foodstuff according to claim 10 wherein, to form the mixture into a gelled foodstuff, one or more further gelling agents are added to the base or mixture to supplement the gelling agents released from the seaweed upon processing of same.

12. A foodstuff according to claim 11 wherein the supplementary gelling agents are capable of causing the mixture to thicken upon contact with certain metal cations in water.

13. A foodstuff according to claim 12 wherein the supplementary gelling agent may be any one or more of alginic acid, alginate salts and or polysaccharides.

14 A foodstuff as claimed in any one of claims 1 to 9 wherein the seaweed base or mixture is compacted into a substantially solid foodstuff.

15. A foodstuff as claimed in claim 14 wherein the substantially solid foodstuff additionally contains hydrophobic substances coating, or dispersed throughout, same.

16. A foodstuff according to claim 15 wherein the hydrophobic substances may be any one or more of lipids, dairy products, and oily fish or animal wastes. 20 r • 21

17. A foodstuff as claimed in any one of claims 1 to 16 wherein the seaweed based foodstuff is dehydrated.

18. A method of producing a seaweed based foodstuff for marine organisms comprising the steps of: a) processing a quantity of seaweed, b) optionally adding additional nutrients to said processed seaweed to produce a mixture, and c) forming said mixture into an administrable form suitable for use in an underwater environment.

19. A method of producing a seaweed based foodstuff for marine organisms comprising the steps of: a) processing a quantity of seaweed; b) drying said quantity of seaweed; c) milling said quantity of seaweed; d) optionally adding additional ingredients to said milled seaweed to produce a mixture; e) extruding and cutting said mixture into the desired form; f) optionally drying the formed mixture.

20. A seaweed based foodstuff as claimed in claim 1 substantially as described herein with reference to any one of the examples.

21. A seaweed based foodstuff when produced by the method of claims 18 °r 19* N.Z. PATENT OFFICE 13 OCT 1997 RECEIVED 22 A method as claimed in claim 19 of producing a seaweed based foodstuff substantially as described herein with reference to any one of the examples. COAST BIOLOGICALS LIMITED By its Attorneys END OF CLAIMS N.2. PATENT OFF-. - 13 OCT 1997 RECEIVED </div>