WO1997019600A1

WO1997019600A1 - Protein substance production from earthworms

Info

Publication number: WO1997019600A1
Application number: PCT/AU1996/000324
Authority: WO
Inventors: Richard Laurance Lewellin
Original assignee: Richard Laurance Lewellin
Priority date: 1995-11-27
Filing date: 1996-05-29
Publication date: 1997-06-05

Abstract

The method of processing worms for providing or recovering valuable products from the worm bodies (10), includes the steps of exposing the insides of the digestive tracts (11) of the worms along substantially the entire lengths thereof and cleansing the worm bodies to remove ingested matter and/or the exposed digestive tracts. Exposure of the insides of the digestive tracts (11) either comprises eversion of the worm bodies on a pin (61) or splitting each worm body lengthwise so as to open the digestive tract. A slitting blade (21) is used to split each worm body longitudinally as it is drawn by a vacuum (17) along a tube (16).

Description

PROTEIN SUBSTANCE PRODUCTION FROM EARTHWORMS

This invention relates to the processing of worms for providing or recovering valuable products from the worm bodies, e.g. for production of protein rich food substances for human food supplements, or for use as animal food or food supplements, or for other uses.

Protein for human and animal consumption is usually obtained from products including the flesh of fish, birds or quadrupeds and it usually consumed in a relatively natural state or

after mixing with other food ingredients. Such creatures need to be either caught or raised in captivity and the slaughtering and processing adds substantially to the cost of the final food

product. Worms could provide a source of protein for use as an animal food or food

supplement, but before the bodies of worms could be used as a protein source, it would be

desirable to be able to cleanse the worm bodies of ingested matter and/or remove the digestive tract. Also cleansing the digestive tract would be desirable if the worm bodies are to be

processed for recovery of substances therefrom e.g. essential oils, acids, etc.

Evisceration processes used for fish, birds and quadrupeds are clearly unsuitable for use with worms.

It is an object of the present invention to provide a method of processing worm bodies

to enable production of or recovery of valuable products from the worm bodies.

It is also an object of the present invention to provide a valuable product made from or

recovered or processed from worm bodies.

According to the present invention there is provided a method of processing worms for providing or recovering valuable products from the worm bodies, the method including the

steps of exposing the insides of the digestive tracts of the worms along substantially the entire

lengths thereof and cleansing the worm bodies to remove ingested matter and/or the exposed

dieestive tracts.

SIΓBSTΓTUTE SHEET (Rule 26 The term "worm" includes an earthworm or marine worm (Chaetipoda), flat-worm

(Platyhelminthes), a round-worm (Nematoda), and other suitable invertebrates.

In one possible embodiment a method the step of exposing the insides of the digestive

tracts comprises eversion of the worm bodies. The eversion of the worm bodies may comprise drawing each worm body onto a pin located concentrically within a passage through

which the worm body is fed longitudinally so that the pin partially enters the digestive tract

but resistance to continued relative penetration of the pin into the digestive tract preferentially

causes the worm body to evert so that the digestive tract is exposed on the outside of the

worm body. The worm body may be split lengthwise after eversion so as to enable removal

of the worm body from a processing zone where eversion has taken place.

In an alternative embodiment the step of exposing the insides of the digestive tracts

comprises splitting each worm body lengthwise so as to open the digestive tract of the worm

lengthwise. Preferably in a first embodiment each worm body is split longitudinally

substantially to the centre of the worm body in cross section along which the digestive tract

extends. The worm body after having been split substantially to the centre thereof is

preferably spread out to fully expose the inside of the digestive tract for cleansing thereof. In

an alternative second possible embodiment each worm body is split completely through the

body generally diametrically so as to divide the worm body into two longitudinal halves with

the digestive tract also being split so as to be exposed along its length with part in each half of

the worm body.

The splitting of the worm body longitudinally may comprise relatively moving the

worm body past a slitting member, the slitting member slitting the worm body longitudinally

as it passes by. For example the worm body may be located on a support member so that the

worm body is oriented in a straight line in a longitudinal direction and is moved on the support member relative to the slitting member in the longitudinal direction so that the slitting member cuts longitudinally along the worm body. The support member may comprise a

support conveyor having a longitudinal channel in which the worm body is oriented, the

support conveyor relatively moving the worm body past the slitting member which has a cutting edge facing along the channel. The worm body may be held oriented in the channel by

application of a vacuum to the base of the channel.

In an alternative embodiment the worm is passed through an aperture or along a

passage having the slitting member projecting into the aperture or passage so that the slitting

member slits the worm body longitudinally as it passes by. In this embodiment the aperture

may comprise a portion of a tube through which the worm body is passed, the worm being a

close fit within the tube and the worm body being drawn through the tube by application of a

vacuum to the tube downstream of the slitting member which projects into the tube, whereby

as the worm body is drawn along the tube by the vacuum, the worm body is oriented

longitudinally and is slit as it passes by the slitting member. The worm body may be slit

longitudinally to at least its centre in cross section, but not completely diametrically through

the worm body, the body being opened out to a generally flat condition after having been slit

by means of one or more profiled blades past which the slit worm body travels and which are

shaped to open out and lay substantially flat the slit worm body.

The cleansing of the worm bodies having the insides of the digestive tracts exposed

preferably includes washing the worm bodies by immersing and agitating the worm bodies in a

washing medium so as to loosen ingested matter enabling separation thereof from the bodies.

The method may include the further step of drying the worm bodies after exposure of

the insides of the digestive tracts and cleansing thereof, the drying being carried out to an extent that the bodies become leathery in texture. The worm bodies after the exposure and cleansing steps may be frozen to a temperature so that the bodies become brittle, the method including the further step of

fracturing the worm bodies while brittle to produce a particulate substance. The particulate

substance may be dried after the fracturing step so as to reduce the moisture content and

inhibit coalescing of the particles. There may also be the further step of treating the

particulate substance prior to packaging, storage or use so as to sterilise or disinfect the

substance.

The present invention also provides a processed substance derived from worm bodies,

the substance having been produced by a method according to the present invention.

Possible and preferred features of the present invention are shown or illustrated in the

accompanying drawings. However it is to be understood that the features illustrated in and

described with reference to the drawings are not to be construed as limiting on the scope of

the invention. In the drawings:

Fig. 1 is a schematic view of an apparatus for processing worm bodies according to

the present invention,

Fig. 2 is a schematic perspective view of a worm body (in partially sectional view)

being slit and flattened,

Fig. 3 is a cross section through the passage along line III - III,

Fig. 4 is a perspective view, partly in section, of an alternative apparatus according to

the invention, and

Figs. 5a to 5c are schematic cross sectional views of a third possible embodiment.

The method of the present invention includes the step of exposing the insides of the

digestive tracts 1 1 of worm bodies 10. In the embodiments of Figs. 1 to 4, each worm 10

may be slit longitudinally either substantially to the centre of the worm body along which the digestive tract 1 1 of the worm extends or completely through the body generally diametrically so as to open the gizzard along the entire length thereof.

In Figs. 1 to 3, cutting of the worm longitudinally is achieved by passing the worm

body 10 through an aperture 15 or along a passage having a slitting member 20 projecting into

the aperture or passage, the slitting member slitting the worm body longitudinally as it passes

by. The aperture 15 may be comprised by a portion of a tube 16 through which the worm is

passed. Preferably the worm body 10 is a close fit within the tube 16 and preferably the worm

is drawn through the tube having the slitting member 20 projecting into the tube, the slitting

member 20 extending generally radially into the tube, either by a distance substantially equal to

half the diameter of the tube 16 (as illustrated in Fig. 1) or across the entire diameter of the

tube. Preferably the diameter of the tube is slightly less than the expected relaxed diameter of

the worm to be processed so that the worm body is a close fit within the tube. The worm

body 10 is drawn through the tube 16 by applying a vacuum 17 to the tube 16 downstream of

the slitting member 20, the worm being introduced into the tube upstream of the slitting

member and being drawn into the tube by the applied vacuum. Because of the restricted

diameter of the tube 16, the worm body 10 is closely confined within the tube, thereby

allowing a vacuum applied to the tube to draw the worm body through the tube.

The slitting member 20 comprise a blade 21 having a cutting edge 22 facing in the

direction from which the worm body is initially drawn so that as the worm body 10 is drawn

through the tube past the blade 21, the body 10 is slit completely from one end to the other.

As the worm body 10 passes the slitting blade 21 or emerges from the tube 16, if the slitting

has been to half way through the body, the body can be spread out and laid flat to enable

washing and/or removal of the gizzard 12. The body can be laid flat by means of one or more

profiled blades 23 past which the slit worm body travels so that the body is opened out and laid substantially flat. Two profiled blades 23 can be located immediately downstream of the slitting blade 21. If the worm body 10 is completely slit across its width, the two halves are

already suitable for flushing since the gizzard is divided longitudinally and the two divided sections are exposed. Downstream of the slitting blade 21 and the profiled blades 23, the

passage may be flattened at 30 so as to continue to allow the split and opened worm bodies

travel along the passage under the applied vacuum 17. Water may be injected at inlets 31 into

the flattened passage 30 to further assist the continued movement and to commence washing.

The passage 30 may be grooved or fluted at 32 to allow water to travel past the worm bodies

thus lubricating their movement and washing ingested matter.

In Fig. 4 there is an alternative apparatus in which the worm body 10 is oriented in a

straight line on a support member 35 which is moved past slitting blades 21 to split the worm

body. The support member 35 is a support conveyor 36 having multiple longitudinal channels

37 in which worm bodies can be oriented longitudinally and into which the slitting blades 21

project. The worm bodies 10 may be held oriented in the longitudinal channels by application of a vacuum 38 through port 39, manifold 40 beneath the conveyor 36, and through holes 41

along the bases of the channels 37. The initial orientation of the worm bodies in the channels

37 may be achieved by vibration of worm bodies fed onto the corrugated conveyor in

conjunction with running water directed along the channels 37. Of course manual orientation

of worm bodies is also possible.

Although slitting blades 21 are described and illustrated in Figs. 1 to 4, other splitting

means could be used to split the worm bodies to expose the insides of the digestive tracts such

as lasers or high pressure water jets.

In Figs. 5a to 5c the worm body 10 is drawn, e.g. by vacuum and/or positive pressure

fluid behind the body 10, through a passage 60 onto a pin 61 located concentrically within the passage so that the pin 61 partially enters the digestive tract 1 1 (Fig. 5a). However, resistance to continued relative penetration of the pin 61 into is provided by shoulder 62 (Fig.

5b). The continued application of vacuum preferentially causes the worm body 10 to evert as

is shown occurring in Fig. 5c by the body 10 peeling back on itself. This causes the gizzard

12 to be exposed on the outside of the body 10 for facilitating cleansing. Cleansing can take

place inside the passage 60 by flushing water through inlets 63 onto the outside of the everted

body while on the support rod 64 for the pin 61. As the body moves further along the passage

60, blade 65 can split the body so that it separates from the rod 64 and passes out through the

passage 60.

After exposing of the insides of the digestive tracts, the worm bodies are cleansed to

remove ingested matter and/or remove the exposed digestive tracts. The bodies 10 may be

discharged into a washing means 45, such as a vessel 46 where the bodies are immersed and

maintained suspended in a washing medium 48 and simultaneously agitated to loosen ingested

matter which will be denser and fall to the bottom for removal through outlet 47 together with

excess water. The medium 48 may be a liquid having a sterilising or disinfecting action. For

example, water with chlorine dissolved therein can be used to at least partially sterilise or

disinfect the body, e.g. by killing organisms such as Salmonella bacteria.

The bodies can be continuously recovered, after a suitable residence time for effective

washing, e.g. by means of an elevating conveyor 50 spaced from the point 49 where the bodies

are admitted. The bodies can then be discharged from the conveyor 50 through a metering

vaive 51. The vacuum 17 can be supplied to the head space in the washing vessel 46.

As shown schematically in Fig. 1 preferably the method includes the step of drying the

worm bodies after splitting and cleaning. The drying may be carried out to eliminate moisture

to the extent that after subsequent preferred steps of freezing, fracturing and warming of the substance to ambient temperature, the particles do not substantially coalesce as a result of free

moisture. Alternatively, the drying may be sufficient to allow freezing and fracturing but

further drying after fracturing may be desirable. The step of drying may be carried out by solar drying or by heating the worm bodies artificially, in either case the worm bodies being

preferably dried to an extent that the bodies become leathery in texture.

The worm bodies with or without preliminary drying may be frozen by using

conventional refrigeration equipment, such as ammonia refrigeration plant, or by cryogenic

process. For example, the worm bodies may be frozen by immersing, spraying or exposing the

bodies to gas from boiling liquid nitrogen. Preferably the worm bodies are frozen to a

temperature so that they become brittle.

The process preferably further includes the step of fracturing of the worm bodies while

brittle to produce a particulate substance. For example, the frozen bodies may be pulverised,

e.g. in a hammer mill to which the bodies are fed immediately after freezing. The hammer mill

components that contact the products may be stainless steel for hygienic purposes. The

particulate substance produced may comprise a fine granular free flowing substance suitable

use as a food supplement or animal food or for blending with other food substances, or for

processing to manufacture or recover valuable products therefrom.

Particularly if use as a food or food supplement is intended, preferably the particulate

substance is treated prior to storage or use so as to generally sterilise or disinfect at least

partially the substance prior to packaging, storage or use. The particulate substance for

example may be passed in the form of substantially separate particles through a sterilising

radiation flux, e.g. an ultra violet radiation flux. The particulate substance may be pulverised

to a fine powder consistency and entrained in air so as to create an aerated suspension of the

particuiate food substance. The suspension may be passed through a zone in which the particles are exposed to a sterilising radiation flux, or the suspension may be passed to a deaerating means such as a cyclone deaerator, the deaerating means having an outlet at the

bottom arranged so that the particles fall gently through the output, the falling particles then

falling into an irradiation zone. The process and apparatus of sterilising or disinfecting the

particulate substance may be generally as described in Australian Patent Specification

No. 59352/86 and the description of the process and apparatus in that specification is

incorporated herein by reference. The disinfected substance will be expected to have a greater

storage life due to the disinfecting process.

Preferably the particulate material is subjected to further drying action after fracturing

so as to further reduce the moisture content and thereby inhibit coalescing of the particles.

This may be achieved by providing a heated air stream contacting the particles at the outlet

of the hammer mill.

It will be seen that the process and apparatus for exposing the insides and cleansing the

worm bodies according to the present invention can commence with worms grown in any

suitable growing medium on an intensive scale. When the worms have reached an optimum

size they can be readily separated from the growing medium, e.g. by sieving. The worms can

then be fed to the slitting and cleaning system to remove matter from the digestive tracts.

After collection of the worms they can be dried to reduce the moisture content after

which the worm bodies can be frozen and pulverised while brittle to produce the particulate

substance. This substance will be very high in protein content and can be readily stored as a

dry animal feed or human or other food supplement. The substance for example can be used

as or in pet food, or as a food in raising of fish, birds or animals. The substance is

substantially odourless and tasteless so that it can be used as a human food (with suitable

flavouring) or as a human food supplement. The paniculate substance can be used as a raw material for further processing, e.g. for recovery of oils, acids, peptides, enzymes, and/or other valuable substances, or for use as a feed or starter for manufacture of valuable substances.

The growing, harvesting and processing of worms according to the present invention can be an intensive operation and the growing, collecting and processing of the worms can be

carried out with little human intervention or direct control thus minimising labour associated

costs of the kind involved in processing of animal flesh from fish, birds or quadrupeds.

It is to be understood that various alterations, modifications and/or additions may be

made to the features of the possible and preferred embodiment(s) of the invention as herein

described without departing from the scope of the invention as defined in the claims.

Claims

The claims defining the invention are as follows:

1. A method of processing worms for providing or recovering valuable products from the worm bodies, the method including the steps of exposing the insides of the digestive tracts of

the worms along substantially the entire lengths thereof and cleansing the worm bodies to

remove ingested matter and/or the exposed digestive tracts.

2. A method as claimed in claim 1 wherein the step of exposing the insides of the

digestive tracts comprises eversion of the worm bodies.

3. A method as claimed in claim 2 wherein the eversion of the worm bodies comprises

drawing each worm body onto a pin located concentrically within a passage through which

the worm body is fed longitudinally so that the pin partially enters the digestive tract but

resistance to continued relative penetration of the pin into the digestive tract preferentially

worm body.

4. A method as claimed in claims 2 or 3 wherein the worm body is split lengthwise after

eversion so as to enable removal of the worm body from a processing zone where eversion

has taken place.

5. A method as claimed in claim 1 wherein the step of exposing the insides of the digestive tracts comprises splitting each worm body lengthwise so as to open the digestive

tract of the worm lengthwise.

6. A method as claimed in claim 5 wherein each worm body is split longitudinally

extends.

7. A method as claimed in claim 6 wherein the worm body after having been split

substantially to the centre thereof is spread out to fully expose the inside of the digestive tract

for cleansing thereof.

8 A method as claimed in claim 5 wherein each worm body is split completely through

the body generally diametrically so as to divide the worm body into two longitudinal halves

with the digestive tract also being split so as to be exposed along its length with part in each half of the worm body

9 A method as claimed in any one of claims 5 to 8 wherein the splitting of the worm

body longitudinally compπses relatively passing the worm body by a slitting member, the

slitting member slitting the worm body longitudinally as it passes by.

10 A method as claimed in claim 9 wherein the worm body is located on a support

member so that the worm body is oπented in a straight line in a longitudinal direction and is

moved on the support member relative to the slitting member in the longitudinal direction so

that the slitting member cuts longitudinally along the worm body

1 1 A method as claimed in claim 10 wherein the support member compπses a support

conveyor having a longitudinal channel in which the worm body is oπented, the support

conveyor relatively moving the worm body past the slitting member which has a cutting edge

facing along the channel

12 A method as claimed in claim 1 1 wherein the worm body is held oπented in the

channel by application of a vacuum to the base of the channel

1 A method as claimed in claim 9 wherein the worm is passed through an aperture or

along a passage having the slitting member projecting into the aperture or passage so that the

slitting member slits the worm body longitudinally as it passes by

14 A method as claimed in ciaim 13 wherein the aperture compπses a portion of a tube

through which the worm body is passed, the worm being a close fit within the tube and the

worm body being drawn through the tube by application of a vacuum to the tube downstream

of the slitting member which projects into the tube, whereby as the worm body is drawn along the tube by the vacuum, the worm body is oriented longitudinally and is slit as it passes by the

slitting member.

15. A method as claimed in claim 14 wherein the worm body is slit longitudinally to at

least its centre in cross section, but not completely diametrically through the worm body, the body being opened out to a generally flat condition after having been slit by means of one or

more profiled blades past which the slit worm body travels and which are shaped to open out

and lay substantially flat the slit worm body.

16. A method as claimed in any one of the preceding claims wherein the cleansing of the

worm bodies having the insides of the digestive tracts exposed comprises washing the worm

bodies by immersing and agitating the worm bodies in a washing medium so as to loosen

ingested matter enabling separation thereof from the bodies.

17 A method as claimed in any one of the preceding claims and including the further step

of drying the worm bodies after exposure of the insides of the digestive tracts and cleansing

thereof, the drying being carried out to an extent that the bodies become leathery in texture.

18. A method as claimed in any one of the preceding claims wherein the worm bodies after

the exposure and cleansing steps are frozen to a temperature so that the bodies become

brittle, the method including the further step of fracturing the worm bodies while brittle to

produce a particulate substance.

19. A method as claimed in claim 18 and including the further step of drying the particulate

substance after the fracturing step so as to reduce the moisture content and inhibit coalescing

of the particles. 20 A method as claimed in claim 18 or 19 and including the further step of treating the particulate substance prior to packaging, storage or use so as to sterilise or disinfect the substance.