DEVELOPMENT OF TECHNOLOGY FOR OBTAINING MULTIPLE EMULSION OF OVARIAN LIQUID (CAVIAR SOL), ENSURING THE DURATION OF ITS STORAGE

Дефицит пищевого белка обусловливает актуальность развития отечественного производства пищевых белковых продуктов из биоресурсов вторичного происхождения. Овариальная жидкость (икорный золь) – вторичный продукт икорного производства – может быть использована как физиологически функциональный ингредиент для пищевых продуктов сбалансированного питания. Применяемые способы сохранности овариальной жидкости (ОЖ) приводят к изменению нативных свойств ее компонентов за счет температурного или химического воздействия. Высказано предположение, что капсулирование во множественную эмульсию ОЖ позволит сохранить ее нативные свойства и увеличить срок хранения. Цель настоящего исследования – разработка технологии получения множественной эмульсии ОЖ и установление эффективности новой формы продукта при хранении. Объектом исследования была ОЖ, полученная при заборе икры осетровых рыб с применением метода прижизненного получения. Множественную эмульсию готовили двухступенчатым способом. На первом этапе получали стандартную эмульсию вода–масло, которую затем использовали в качестве одной из фаз для множественной эмульсии вода–масло–ОЖ. Полученный продукт и контрольный образец (ОЖ, прошедшая только фильтрацию) размещали в чашках Петри и хранили в термостатируемой холодильной камере при температуре не ниже 4°С в течение 40 сут. Через каждые 5 сут в отобранных пробах определяли по методу Кьельдаля содержание белковых веществ, небелкового азота и азота летучих оснований. Установлено, что при хранении в ОЖ, прошедшей только фильтрацию, белок разрушался быстрее и его содержание через 40 сут снизилось на 34%, тогда как в ОЖ, заключенной во множественную эмульсию, этот показатель снизился только на 5,9%, что коррелирует со скоростью накопления продуктов распада белков в ОЖ после 40 сут хранения. Предложенный способ получения множественной эмульсии ОЖ позволяет обеспечить сохранность ее белкового комплекса в процессе хранения и разработать новый ассортимент физиологически функциональных продуктов с использованием отечественного биологически ценного пищевого ингредиента. The shortage of dietary protein determines the relevance of the development of domestic production of food protein products from bioresources of secondary origin. Ovarian liquid (caviar ash), or caviar sol, – a secondary product of caviar production – can be used as a physiologically functional ingredient for balanced nutrition foods. The applied methods of preservation of ovarian fluid (OF) lead to a change in the native properties of its components due to temperature or chemical exposure. It is suggested that encapsulation in a multiple emulsion of OF will preserve its native properties and increase the shelf life. The purpose of this study is to develop a technology for obtaining multiple OF emulsion and to establish the effectiveness of a new product form during storage. The object of the study was the OF obtained by sampling the caviar of sturgeon fish using the method of lifetime production. The multiple emulsion was prepared in a two-stage way. At the first stage a standard water–oil emulsion was obtained, which was then used as one of the phases for a multiple water–oil–OF emulsion. The resulting product and the control sample (OF that passed only filtration) were placed in Petri dishes and stored in a thermostatically controlled refrigerator at a temperature of at least 4°C for 40 days. Every 5 days the content of protein substances, non-protein nitrogen and nitrogen of volatile bases was determined in the selected samples by the Kjeldahl method. It was found that when stored in the OF that passed only filtration, the protein was destroyed faster and its content decreased by 34% after 40 days, whereas in the OF enclosed in a multiple emulsion, this indicator decreased by only 5.9%, which correlates with the rate of accumulation of protein breakdown products in the OF after 40 days of storage. The proposed method for obtaining a multiple emulsion of COOLANT makes it possible to ensure the safety of its protein complex during storage and to develop a new range of physiologically functional products using a domestic biologically valuable food ingredient.

ASSESSMENT OF BIOINDICATORS OF HOMEOSTASIS CONSTANTS REPAIRING STURGEON FISH STUFF

More recently, sturgeon fish were classified as a national treasure of our country, since among the world's reserves, Russia accounted for up to 90%. Nevertheless, over the past 10-15 years there has been a catastrophic decline in sturgeon stocks in almost all water bodies of the country. The main reason for the widespread landslide decline in stocks of sturgeon fish is the excess of the withdrawal over the recruitment of generations. In conditions of anthropogenic pollution of water bodies, the creation of sturgeon broodstock using industrial methods of rearing is a way to preserve the gene pool of these most valuable representatives of the world ichthyofauna and obtain seedlings for commercial fish farming. In connection with the use of industrial methods of fish rearing, the need for their physiological control increases. One of the sensitive methods that allows you to quickly and accurately establish the physiological state of fish, as well as assess the conditions for their cultivation, is the physiological-biochemical, hematological method, the leukocyte formula, since blood is a polyfunctional system of the body that dynamically responds to all changes, both internal and external. Wednesday. The aim of the study is to determine the boundaries of the reference values in terms of physiological, biochemical, hematological indicators, as well as the leukocyte formula in aquatic organisms of different-age replacement broodstock of sterlet and the quality of conditions for its cultivation in the conditions of the cage complex.

Some aspects of fishery development of sturgeon hybrids in Russia. Part 2

With the development of commercial sturgeon breeding, creating hybrid forms of sturgeon fish in order to obtain a larger volume of gourmet marketable products is of increasing interest to fish farmers. The choice of objects for creating hybrid forms for commercial cultivation depends on the conditions and biotechnologies of intensive fish culture. One of the widely used technologies that can several times reduce the time for growing objects and receive viable juveniles and marketable products year-round is the technology using recirculating aquaculture system (RAS). With this cultivation technique, the advantage is given to species with high adaptive capabilities and growth intensity. The most popular objects for hybridization and creation of hybrid forms are beluga, sterlet, Siberian and Russian sturgeon, etc. Beluga is the largest representative of the sturgeon family. It reaches commodity weight (3–5 kg) against the background of natural temperatures within 2–3 years. The Sterlet is a pure freshwater form. It is an excellent object for cross-breeding with other sturgeon species, in particular with beluga to obtain a bester hybrid. The Siberian sturgeon grows most intensively at a temperature of 15–25°C, however, the growth persists at lower temperatures (1–10°C). The Russian sturgeon in artificial conditions reaches a marketable weight of 1.5–3.0 kg in the second-third years of cultivation. In order to facilitate the orientation of fish farms, fish farmers engaged in the production of commercial products, the article discusses the creation of hybrid forms of sturgeon fish in domestic and foreign aquaculture, provides their brief fish-breeding and biological characteristics when grown in fish farms of various types. Knowledge of the fish-breeding and biological characteristics of sturgeon fish species hybrids when grown in specific conditions will make it possible to successfully introduce them into the practice of commercial cultivation. English version of the article is available at URL: https://panor.ru/articles/some-aspects-of-fishery-development-of-sturgeon-hybrids-in-russia-part-2/74467.html

IMPLEMENTATION OF AQUAPONICS IN ARTIFICIAL POOLS FOR GROWING CARP AND STURGEON FISH

Показана актуальность проблемы, связанной с особенностями ведения рыболовного хозяйства и растениеводства в условиях неблагоприятного климата, ограниченных территорий. Приведено описание опыта по внедрению аквапоники в схему выращивания осетровых и карповых рыб в искусственных бассейнах с использованием оборотной воды, включающую узлы очистки. В ходе исследования была разработана установка, принцип работы которой может быть использован, как решение проблематики выращивания рыб и растений в искусственно созданных условиях. Определены и описаны узлы фильтрации и очистки воды. Приведены показатели воды, показывающие работоспособность и эффективность установки. Проведено сравнение показателей оборотной воды при проведении опытов по выращиванию карповых и осетровых рыб. Приведены результаты экспериментального исследования скорости роста растений в аквапонной установке с использованием различных субстратов и воды. Выявлены преимущества проращивания семян растений при использовании оборотной воды из рыбоводного бассейна в сравнении с использованием водопроводной воды. We demonstrated the relevance of the problem associated with the difficulty of fishing and plant growing in an unfavorable climate, limited territories. We described the experience of introducing aquaponics into the scheme of growing sturgeon and carp fish in artificial pools using circulating water, including purification units. In the course of the study we developed an installation, the principle of operation of which can be used as a solution to the problem of growing fish and plants in artificially created conditions. As well we identified and described the nodes of water filtration and its purification. We demonstrated indicators of water that show the operability and efficiency of the installation. We also carried out comparison of indicators of circulating water during experiments with growing carp and sturgeon fish. As well we made a comparison of the efficiency and growth rate of plants in an aquaponic installation using various substrates and water. The advantages of germination of plant seeds with the use of circulating water from the fish-breeding basin in comparison with the use of tap water have been revealed.

Some aspects of fishery development of sturgeon hybrids in Russia. Part 1

With the development of commercial sturgeon breeding, creating hybrid forms of sturgeon fish in order to obtain a larger volume of gourmet marketable products is of increasing interest to fish farmers. The choice of objects for creating hybrid forms for commercial cultivation depends on the conditions and biotechnologies of intensive fish culture. One of the widely used technologies that can several times reduce the time for growing objects and receive viable juveniles and marketable products year-round is the technology using recirculating aquaculture system (RAS). With this cultivation technique, the advantage is given to species with high adaptive capabilities and growth intensity. The most popular objects for hybridization and creation of hybrid forms are beluga, sterlet, Siberian and Russian sturgeon, etc. Beluga is the largest representative of the sturgeon family. It reaches commodity weight (3–5 kg) against the background of natural temperatures within 2–3 years. The Sterlet is a pure freshwater form. It is an excellent object for cross-breeding with other sturgeon species, in particular with beluga to obtain a bester hybrid. The Siberian sturgeon grows most intensively at a temperature of 15–25 °C, however, the growth persists at lower temperatures (1–10 °C). The Russian sturgeon in artificial conditions reaches a marketable weight of 1.5–3.0 kg in the second-third years of cultivation. In order to facilitate the orientation of fish farms, fish farmers engaged in the production of commercial products, the article discusses the creation of hybrid forms of sturgeon fish in domestic and foreign aquaculture, provides their brief fish-breeding and biological characteristics when grown in fish farms of various types. Knowledge of the fish-breeding and biological characteristics of sturgeon fish species hybrids when grown in specific conditions will make it possible to successfully introduce them into the practice of commercial cultivation.

Assessment of food intensity and growth rate young sevryuga (Acipenser stellatus Pallas, 1771) depending on from the terms of fishing of growing ponds

Artificial reproduction of sturgeon fish in the Volga-Caspian basin in modern conditions is the only real opportunity to replenish natural populations with juveniles, therefore, increasing its efficiency is the key to restoring the stocks of these relict fish species. Improving the technological processes of growing juvenile sturgeon fish, including the Caspian stellate sturgeon, the number of which has been rapidly decreasing in recent years, is one of the main tasks at present. We studied the conditions for growing stellate sturgeon larvae in the nursery ponds for artificial reproduction at different periods of their watering. It is known that the stocking of ponds with larvae that have switched to exogenous feeding occurs at the end of June or the beginning of July, this coincides with the time of maximum water heating in nursery ponds to extreme (26–28 °C) values and with a depletion of the food supply in them. Hydrobiological studies were carried out to assess the food supply in water bodies that were watered in the traditional (June 12–14) terms (control option) and earlier (May 28) 2 weeks earlier than usual (experimental option). In addition, the intensity of feeding and the growth rate of juvenile starred sturgeon in the indicated ponds was studied for 20–24 days. The results of the studies performed showed that the food supply in the experimental pond was higher, so the zooplankton was represented by four orders, the biomass on average ranged from 2,8 to 4,6 g/m³, and in the control variant, planktonic organisms were represented by three orders, total biomass from 0,3 to 2,5 g/m³. The same tendency can be traced for zoobenthos. The feeding intensity of stellate sturgeon fry reared in ponds of early watering had indicators in terms of the gastrointestinal tract filling index, fatness coefficient and growth rates higher than the juveniles kept in water bodies of traditional watering periods.

Cages’ farming foundation as a limiting factor in cultivation of sturgeon fish hybrids

The work experimentally confirmed the negative influence of fouling of cage structures on the growth and survival rates of reared young sturgeon hybrid — bester (Huso (Linnaeus, 1758) × Acipenser ruthenus (Linnaeus, 1758)). A significant decrease in growth and an increase in fish mortality in modules with a maximum biofouling area was noted. The possibility of using alternative cleaning methods in comparison with traditional mechanical and chemical ones has been investigated. The positive results of the experimental approbation of the author’s development — the practical application of a specially designed structure made of tarpaulin for the cage are given. The use of an easy-to-manufacture and operate device prevented active contamination of the cells, increased the efficiency of keeping fish, which is economically beneficial for commercial sturgeon growing in cages. In general, in fish farms located in a natural reservoir in the spring-summer period, the overgrowth of fodder bottoms and cage walls with filamentous algae has a strong negative effect on the cultivation of sturgeon fish. To optimize the fish-breeding process and reduce the number of algae during the period of their active growth on cages (the timing must be determined according to the conditions of a particular reservoir), special canvas covers should be used. This device will reduce the amount of sunlight entering the cage bottoms and slow down the growth of filamentous algae. To install this device on the cage, two workers are required, the approximate installation time (and, if necessary, dismantling) will be 20 minutes. To reduce the negative effect of algae fouling of the cage bed, measures should be taken to mechanically clean the stern bottoms and walls of the cage with high-pressure cleaning (washer) devices, after transplanting the cultivated objects into another fish hatchery