WO2009112608A1

WO2009112608A1 - Preparing and producing a fish similar in size and organoleptic properties to the transparent goby (aphia minuta)

Info

Publication number: WO2009112608A1
Application number: PCT/ES2009/000113
Authority: WO
Inventors: Jesús CANO PÉREZ
Original assignee: Universidad De Malaga
Priority date: 2008-03-04
Filing date: 2009-03-04
Publication date: 2009-09-17
Also published as: ES2330987A1; ES2330987B2

Abstract

A method for adapting individuals of a Gambusia sp freshwater fish species to increasing salt concentrations by selection and cross-breeding, breeding the adapted individuals, isolating the resulting broods and fattening them under predetermined salinity, temperature and feed conditions until they have a size, texture, colour and flavour similar to those of the transparent goby (Aphia minuta).

Description

Obtaining and producing a fish similar in size and organoleptic characteristics to the backgammon (Aphia minuta).

Technical sector

The present invention relates to the fields of aquaculture and fish farming and, in particular, to the adaptations and the means that enable reproduction and breeding, under optimal conditions for the achievement of an alternative to the cultivation of the piglet from species of fresh water.

Prior art

The backgammon is a fish of the family Gobiidae (Aphia minuta R.), of very small dimensions in adult state (2 - 4 cm), very commercially appreciated, and that has traditionally been consumed floured and fried in abundant oil. The frying of these fish really provides a low-medium protein ratio (fish mass) in relation to the flour used for their frying, which makes the taste of the meat of the piglet quite imperceptible. In fact, and due to the above, most of what is consumed as a backgammon actually comprises different larval, juvenile or juvenile phases of other species of marine fish such as sardines, anchovies, triglas, mujol, etc., without the average consumer there were differences from the gastronomic-qualitative point of view between the species mostly consumed with those of the backgammon itself. However, currently immature consumption of these "alternative" species is not allowed, mainly due to the decline in the production of commercial persian species (sardine, anchovy, horse mackerel, etc.) when their juveniles (immature) are caught ) and consumed as piglets.

Consequently, other fishing species, most of them imported, whose individuals are small, or fry of larger species, have been added to the market. However, in general, the organoleptic characteristics of these imported species do not meet the requirements of most consumers.

On the other hand, the possibility of producing analogues to the backgammon from different approaches has been investigated: Aggregation of muscle particles by fundamentally physical binding (EP 0234012), aggregation of particles by chemical bonds of their proteins (ES 2013965, ES 2047443, EP 0979616), particle aggregation by chemical bonds established by the action of transglutaminase (WO 193702).

A document specifically related to the backgammon is ES 2204323.

Finally, the cultivation of piglet has been described as such ["El Chanquete (Aphia minuta): background, biology and ^' experimental cultivation in Malaga", Reina Hervás and López Jaime: edited by: Provincial Council of Malaga, 2005], although it is not industrially applicable especially for the associated economic costs. There are no known references to crops of other similar fish species that may constitute alternatives to the consumption of pigtails or immatures of other species.

The present invention proposes and allows the cultivation of fish species not currently included in the catalog of cultivable species or of fish interest, or previously marketed, that may constitute an alternative to the breeding and / or consumption of the backgammon, and that by On the other hand, they contribute to reducing the illegal consumption of immatures.

Disclosure of the invention

The aim of the invention is an aquaculture product alternative to the cultivation of the pigtail, obtained by fish farming and characterized by being a food product with the characteristics of the species to which it is alternative, not only for its protein and lipid composition and contents in omega 3 and omega 6 fatty acids but also for its external appearance and texture, color, smell and taste, in addition to being suitable for human consumption (free of parasitosis) due to an exhaustive control in the aquaculture process. Obtaining said product requires the adaptation and regulation of various physical-chemical and biological parameters of the freshwater species to be used:

Color: Obtaining the pink bottom of the backgammon is achieved with a diet rich in beta-carotene through artificial and / or natural feeds rich in artemia, shrimp or equivalent.

Texture: Salinity conditions, and even the density of fish in the crop, allow to control the texture, size and number of the microscales. - Hardness of the endoskeleton: Adjustable according to the contribution of calcium in the diet and the culture temperature.

Taste and smell: Modifiable also depending on the food and salinity conditions. On the other hand it has been necessary to adjust parameters of reproductive biology to avoid uncontrolled reproduction (for example, due to the increase in the temperature of the cultivation water as a consequence, of the seasonality) at the same time as to enable its industrial production (for example, regulating the number of reproductive cycles, controlling the size dispersion).

Description of the figures

Figure 1. Schematic view of a possible covered greenhouse installation (a) with a tank excavated in the ground (b) and with a central channel for collecting organic remains (c).

Figure 2. Schematic model of biological filtration system: Biofiltration system (wet and semi-humid) mounted in a greenhouse (Still system of fresh water production by evaporation) with bacterial rope nesting support (d). Cultivated water pumped to the top of the ropes slowly falls by gravity on them keeping them always moist. To the maintenance of the humidity and contribution of nutrients to the nested bacteria also contributes the arrival of water from the tank (in the opposite direction) by capillarity. The condensation of the water vapor (e) produced inside the greenhouse due to the high temperature generated by solar radiation (í), condenses on the walls and ceiling asking to collect and obtain, in this way, fresh water (g ) that is reintroduced into the general circuit to maintain the initial salinity, and it is even possible to increase the fresh water (desalination of the environment) by means of the rain-falling water (h) at certain times of the year through the collectors of roof pickup. The effect of lowering the temperature by the evaporation process, inside the filter, allows to obtain an optimum temperature for the bacterial cultures nested in the fixing ropes and the increase of the temperature of the cultivation water.

Figure 3. General scheme of the process representing the reproduction unit (i) and the filtration unit (j), both under greenhouse; the fattening or production unit (k), outside (without cover) and with seawater; the juvenile storage unit (1), and an additional biological filtration unit (m), for the elimination of nitrogen compounds.

Ways of carrying out the invention Preferred embodiments of the object of the invention are now described, without limitation, that is, of the process of reproduction and breeding in aquatic environment of a kind of poecidid {Gambusia sp), as well as of the device that allows it to be put into practice, for obtaining very similar specimens, both in morphology and in size, composition and texture of meat, to the species Affia minuta (backgammon), for use as a food alternative to it; all this preferably water recirculation conditions (closed circuit), which allow production without neglecting environmental criteria that could be affected, as well as controlling the physicochemical conditions of water, mainly temperature. Recirculating water allows the removal of feces and other waste from the culture water, for example by means of a settling pond. Water rich in nitrogen compounds and other organic remains is filtered, for example by a battery of physical silica sand filters followed by biological filtration in pvc tanks with semi-wet filters, bioballs and porous material that facilitates nesting and proliferation of transforming bacteria of nitrogen compounds. The resulting waters, rich in nitrate, can be used for algae production, ending at this point the elimination of nitrogen compounds and reusing this water again. Produced biolods and undigested organic remains are removed from the settling and separation tank and can be used as organic fertilizer.

The culture tanks can be made of various materials (fiber, polyester, etc.), excavated in the ground and waterproofed with asphaltic cloth or equivalent, or directly with a waterproof clay bottom. Such cultivation facilities can allow intensive cultivation, with biomass loads of 20kg / m3, for example. A possible installation consists of a greenhouse with galvanized iron support, plastic cover and tank excavated in the ground with a capacity of 600 cubic meters waterproofed with pvc sheet and central channel for collecting organic remains. As far as the biological filtration system is concerned, a wet and semi-humid system, mounted for example in a Still type greenhouse (production of fresh water by evaporation) with bacterial rope nesting support (hemp), has proven experimentally to be more effective that large surface bio-balls, volcanic porous material and / or plastic or pvc pipes; also allowing the bacterial nesting surface to be exceeded per unit area with respect to other usable materials (pvc, plastic, ceramic material), being also easy to clean and maintain and favoring the oxygenation of the bacterial flora.

A preferred breeding and reproduction procedure is described below. Salinity adaptation

First, to generate fish as close as possible to the backgammon (Affia minuta), their selective adaptation to seawater is necessary. This adaptation improves the flavor of the meat of this fish and conditions a texture of the meat more similar to the species that it intends to replace both internally (muscle pack) and externally (microscales, more patent and similar to those of A. minuta in conditions of high salinity). In addition, adaptation to salinity favors the cultivation in marshland or marshland areas in the South-Atlantic region (estuaries, for example) making it possible to have abundant water and the possibility of accessory crops for natural food, the absence of pathogens of the freshwater species and, finally, improve the organoleptic properties derived from the maintenance of crop species in water with salinity close to that of seawater.

Gambusia sp. It is a freshwater species that tolerates salinity well, although salinities close to 36 g / 1 can significantly increase mortality and inhibit reproduction. In the present invention it is achieved after the selection (crossings) of different individuals at increasing salt concentrations so that they can be grown in seawater (35-36 g / 1, salinity). For this, salinity is increased from 5 to 5 g / 1, preferably once a week. The adaptation to high salinity conditions allows the reproduction process to be interrupted, thus achieving a maximum size and weight with lower consumable energy expenditure in reproduction and thus obtaining a better industrial assessment by presenting the most homogeneous sizes of fish independently that it is done at times of adequate temperature for reproduction (spring and summer months) and / or suitable photoperiod. From these individuals, the selection of males and females is carried out to obtain the Fl, thus having a line of reproducers suitable for salinity conditions. Due to the system of reproduction and laying (viviparous), it is advisable to isolate the parental population of newborns to avoid predation of these by the former. For this, the players can be kept in isolation in the mass of cultivation water in plastic mesh enclosures with a mesh light that prevents the passage of the breeders but allows the passage to newborns, who naturally look for the protection outside the enclosure of the players. The system thus configured allows continuous extraction of the offspring to a second tank where they accumulate, allowing adequate feeding to their size and avoiding their predation by larger specimens. Nutritional characteristics of the diet

Gambusia is a larvicidal species that can ingest any type of larvae (insects, fish, crustaceans, etc.) whose size allows it. It adapts well to artificial feeding and can be fed with commercial feed for other fish species. The ease of using dry food (pelletizing) allows the use of programmable automatic feeders. The composition of the diet is variable, although a preferred composition would consist of: 20-32% crude protein for adult feeding and 32-40% in juveniles. As for fats, the average values are made up of 3-6% polyunsaturated fats, and a carbohydrate ratio of 40%.

As for the minerals present in the diet, calcium is not included, or is included in a very low proportion (for example, 0.1 g / kg), in the diet, in order to weaken or soften the endoskeleton of Gambusia sp., More Rigid than that of a backgammon, the quantities for the other minerals being the following:

Phosphorus 6-12 g / kg

Magnesium 0.3-0.5 g / kg

Potassium 1.2 g / kg

Iron 30 mg / kg

Manganese 2 mg / kg

Copper 5.2 mg / kg

Selenium 0.1 mg / kg

Chrome 1.0 mg / kg

Depending on the phase of growth or cultivation, it is possible to distinguish: o Feeding of breeders: Live food {Artemia salina, tubifex, daphnia).

Artificial food: 20-32% protein; 3-6% fat, and vitamins. o Juvenile feeding: Live food (various stages of development of

Artemia salina). Artificial food: 32-40% protein; 6% fat, and vitamins. o Adult food: Live food (Artemia salina adults). Artificial food: 20-32% protein, 6% fat, and vitamins. Dose and frequency of feeding according to body weight: The amount supplied in the total rations ranges from 2% (adults) to 20% (juveniles) with respect to the fish's body weight.

Weight range (grams) Feeding frequency (portions / day)

<0.5 8 - 12 (20% Weight)

0.5 - 1.5 8 (15-10% Weight)

1.5 - 2.0 6 (10-5% Weight)

2.0 <3 - 4 (5 - 2% Weight)

Physicochemical characteristics (salinity, temperature and pH) of the crop

The eurihalina condition of this alternative species allows us to regulate the reproduction rate by controlling salinity conditions, even when the temperature of the medium is adequate for it (between 24-28 ⁰ C in natural conditions). In high salinities (above 20 g / 1) this species does not reproduce (although the temperature of the medium is adequate); which makes it possible to prevent the dispersion of sizes and uncontrolled reproduction in the culture tanks, with the consequent energy saving by the fish, saving that is used to promote faster growth of the fish.

Ideal temperature and salinity:

o For reproduction: 24-28 ⁰ C, salinity <20 g / 1. o For development and fattening: 15-28 ⁰ C (optimal, 22-25 ⁰ C), salinity> 20 g / 1.

On the other interested party select specimens with greater resistance at low temperatures (preferably with acceptable growth at temperatures below 15 ⁰ C), in order to obtain good growth even in winter months. To do this, the selection is made through crosses. As already mentioned, the temperature and the salt concentration have an influence, among others, on the hardness of the endoskeleton, the taste, the smell, etc., so it is intended to obtain the final product in saline concentrations close to the marine (36 g / 1) and at a temperature between 22 and 25 ⁰ C (fattening). With regard to other variables, the oxygen values are in the range 6-8 ppm, while the pH values are buffered by salinity in the range 7.5-8.4.

Finally, the particular cultivation conditions allow the industrial production of Gambusia sp. [adjusted to optimal species reproduction (24-28 ⁰ C), with 3 to 5 annual reproductive cycles (multiparity)]

Depending on the growth phase or the different cultivation phases, the following physicochemical characteristics can be distinguished:

o Players: 10-12 g / 1 salinity, 24 - 28 ⁰ C temperature; 7-8 ppm oxygen. or larval development (juvenile): 10 - 12 g / 1 of salt, 20 to 22 ⁰ C temperature, 8 ppm oxygen. o Fattening: 36 g / 1 salinity, 15-28 ° C temperature, 6 ppm oxygen.

Regarding the flow of water in the cutive (renewal in recirculation):

o Players: 100% per day o Pre-fat: 20 - 40% per day o Fattening: 50 - 100% per day

Claims

1. Method of obtaining and producing a commercial alternative to the backgammon from freshwater species characterized in that it comprises the following stages: a. Selection of individuals adapted to increasing salt concentrations through crossings. b. Reproduction of individuals adapted to increasing salt concentrations. C. Isolation of offspring resulting from the reproduction of individuals adapted to increasing salt concentrations. d. Development and fattening of isolated offspring to obtain adult individuals with optimal characteristics (color, texture, hardness, taste, smell).

2. Method according to the preceding claim characterized in that the reproductive individuals adapted to increasing saline concentrations are isolated from the offspring by a mesh or equivalent whose light allows the passage of the offspring but not of the breeders.

3. Method according to the preceding claim characterized in that it comprises water recirculation conditions that allow the reproduction and development of individuals, control the physicochemical conditions of the water, and remove feces and wastes.

4. Method according to any of the preceding claims characterized in that it comprises the use of the following facilities or compartments: a. Reproduction unit (i), in which individuals adapted to increasing saline concentrations cross. b. Juvenile storage unit (1), in which the offspring of the individuals located in the reproduction unit accumulate and are isolated by a mesh or equivalent whose light allows only the passage of the offspring and not of the breeders. C. Fattening unit (k), to which developing offspring are transferred to obtain adults with optimal characteristics. d. Filtration unit Q), in which the feces and waste accumulated in the recirculation water are generally removed. and. Filtration system (m), in which specific compounds, mainly nitrogen compounds, are removed.

5. Method according to the preceding claim, characterized in that the different units are constituted by separate tanks or compartments that allow the culture conditions and / or the physicochemical characteristics of the water to be regulated separately.

Method according to the preceding claim, characterized in that the filtration system preferably comprises a battery of physical filters of silica sand and a subsystem with semi-wet filters, of bio-balls and of porous material that facilitate the nesting and proliferation of transforming bacteria of nitrogen compounds ( d).

Method according to claim 5 or 6, characterized in that the filtration unit comprises a settling tank (b, c) for the removal of feces and other wastes.

8. Method according to any of the preceding claims characterized in that the species of fresh water used is of the genus Gambusia.

9. Method according to the preceding claim characterized in that the selection of individuals adapted to increasing saline concentrations is achieved by periodically increasing salinity, preferably from 5 in 5 g / 1 and once a week.

10. Method according to claims 8 or 9 characterized in that the individuals are fed by a diet of variable composition comprising, in percentage with respect to the composition of the feed, 20-40% of proteins, 3-6% of fats and 40% of carbohydrates

11. Method according to the preceding claim characterized in that the diet further comprises the following minerals, in percentage with respect to the composition of the feed: phosphorus (6- 12 g / kg), magnesium (0.3-0.5 g / kg), potassium (1.2 g / kg), iron (30 mg / kg), manganese (2 mg / kg), copper (0.1 mg / kg), selenium (0.1 mg / kg) and chromium (1 mg / kg).

12. Method according to the preceding claim characterized in that the diet further comprises, in percentage with respect to the composition of the feed, calcium (0.1 g / kg).

13. Method according to any of claims 10 to 12 characterized in that, depending on the growth or cultivation phase, the following are distinguished: a. Breeding feeding: Live food {Artemia salina, tubifex, daphnia). Artificial food: 20-32% protein; 3-6% fat, and vitamins. b. Juvenile feeding: Live food (various stages of development of Artemia salina). Artificial food: 32-40% protein; 6% fat, and vitamins. C. Adult food: Live food (adults of Artemia salina). Artificial food: 20-32% protein, 6% fat, and vitamins.

14. Method according to any of claims 10 to 13, characterized in that the amount of food supplied in the total rations is, in percentage with respect to the individual's body weight, from 2% to 20%; and because the number of food rations per day ranges from 3 to 12 doses

15. Method according to the preceding claim characterized in that, depending on the weight or the development phase, a distinction is made: a. Individuals of less than 0.5 g body weight (fry): 8 - 12 food rations, representing a total of 20% with respect to the individual's body weight. b. Individuals between 0.5 and 1.5 g of body weight: 8 food rations, representing a total of 10-15% with respect to the individual's body weight. C. Individuals between 1.5 and 2 g of body weight: 6 portions of food, representing a total of 5 - 10% with respect to the individual's body weight. d. Individuals with more than 2 g body weight (adults): 3 - 4 food rations, representing a total of 2 - 5% with respect to the individual's body weight.

16. Method according to any of claims 8 to 15, characterized in that the temperature is adjusted in the range of 15 to 28 ⁰ C, and the salinity in the range of 10 to 36 g / 1.

17. Method according to the preceding claim characterized in that the oxygen levels are in the range of 6 to 8 ppm.

18. Method according to the preceding claim characterized in that, depending on the culture phase, the physicochemical variables indicated below are adjusted in the following ranges of values: a. Players: 10 - 12 g / 1 of salt, 24 to 28 ⁰ C temperature; 7-8 ppm oxygen. b. Larval development (juvenile): 10 - 12 g / 1 of salt, 20 to 22 ⁰ C temperature, 8 ppm oxygen. C. Fattening: 36 g / 1 salinity, 15-28 ° C temperature, 6 ppm oxygen.

19. Method according to any of claims 3 to 18 characterized in that, depending on the culture phase, the renewal of the water in recirculation is: a. Players: 100% per day b. Pre-fat: 20-40% per day c. Fattening: 50 - 100% per day