Saturation of the consumer market with food with regulated nutritional value is one of the leading trends in the development of the food industry both in our country and abroad. Food products of a gerodietic orientation should be balanced in terms of chemical composition, energy value, easily digestible and well-absorbed by the body of an elderly person. Often, for targeted regulation of the nutritional and biological value of food products, a well-established technology for enriching the food dispersed systems with special ingredients: minerals, vitamins, phospholipids, caro-
tenoids, and other biologically active components is used. It is proposed to use hydrolysates and enzymes from echinoderms, Holothuroidea, the Far East trepang and cucumaria japonica that contain a set of biologically active substances in their composition as food fortifiers and biocorrectors [1, 2].
Far Eastern State Technical Fisheries University developed in recent years the cryotechnologies for dry concentrates of seafood (cryoconcentrates) exhibiting the properties of food biocorrectors due to the content of carotenoids, nucleoproteins, amino acids, collagen, hexosamines, glycosides, mineral and ballast substances, and polyunsaturated fatty acids, including ω3 and ω6. Getting into the human body with food, they have a positive effect on many physiological processes, which generally improves the physical and mental state of a person, his (or her) mental abilities and cognitive functions. This is especially important for the elderly, as in general the quality of their life improves and its duration increases.
Recipes have been developed and technological parameters have been substantiated for the production of fish sausages enriched with dry concentrates
of seafood intended for the nutrition of the elderly. The goal of the research was to study the physico-chemical, organoleptic characteristics and safety indicators of new types of enriched molded fish products.
Objects and methods of study
To achieve the goal, we studied the fish molded products (sausages) made on technology in accordance with STO 00471515-087-2021 “Fish sausages enriched with dry concentrates from seafood. Quality and safety requirements. Requirements for production, storage, sale”.
Enrichers of fish sausages for gerodietetic nutrition were mixtures of dry concentrates from seafood: cucumaria, squid, Pacific herring milt, octopus skin, scallop mantle, and seaweed. The mixtures according to their characteristics met the requirements of STO 00471515-071-2019 “Dry seafood concentrates”.
The raw material was thawed, cut, washed, crushed, mixed with enrichers and auxiliary components, stuffed into a casing, subjected to heat treatment and cooled.
The study of the general chemical composition
of the developed fish products was carried out according to GOST 7636 - 85. Besides, there was used the express method to find the amount of water in dispersed systems by using an ML - 50 moisture meter; drying was carried out at a temperature of 200 °C.
Determination of the content of hexosamines, carotenoids, triterpene glycosides, and deoxyribonucleic acid (DNA) was carried out by spectrophotometric method on a UV-2100 spectrophotometer (Shimadzu, Japan) using standard methods for preparing the materials for research.
The fatty acid composition of the lipid fraction was determined by a gas-liquid chromatograph GC – 2010 (Shimadzu).
The organoleptic evaluation of gerodietic fish sausages was carried out by the tasting commission of experts, who used the scoring scales developed by us .
The water-holding capacity was determined by pressing method.
The study of the sanitary-indicative characteristics of the developed fish sausages, the content of toxic elements, nitrosamines, pesticides, polychlorinated biphenyls, and radionuclides in them was determined in accordance with the current standards and guidelines.
Results of study
We position the developed new range of enriched fish sausages, first of all, as products containing biologically complete proteins, carotenoids, hexosami-
nes, triterpene glycosides, nucleic acids, and minerals. Seafood сryoconcentrates include organically bound iodine in the mineral composition, which normalizes the functioning of the thyroid gland, the production
of thyroxine and triiodothyronine hormones that are important for the body . One of the defining characteristics of the quality of a developed functional product is the content of key functional food ingredients. These food ingredients should be present in the product in an amount of at least 15% of the daily norm per one daily serving of the product . Estimated data on the content of physiologically functional ingredients in one consumer package of a molded product weighing 100 g are given in Table 1, the results of determining the chemical parameters of new types of molded fish products (sausages) are shown in Table 2.
Content of nutritional components in enriched fish sausages
Indicators Daily rate* In 100 g of product, not less than
Protein, g 68 10.2
Iodine, mg 0.150 0.0225
Glycosides, mg 2 0.3
DNA, mg 325 48.8
Carotenoids, mg 2 0.3
Hexosamines, mg 700 105
Chemical characteristics of enriched fish sausages
Indicators Sausage recipe name
“General-strengthening” “Mineral-correcting” “Restorative” “Immunomodulatory”
Protein, % 15.6 15.4 17.7 17.3
Water, % 72.9 73.3 68.5 67.9
Lipids, % 8.9 9.7 10.1 10.6
Minerals, % 2.57 3.61 2.80 2.77
Iodine, mg/100g 0.016 0.126 0.065 0.061
Glycosides, mg/100g 0.75 0.80 0.60 2.40
DNA, mg/100g 165 0.00 255 680
Carotenoids, mg/100g 0.45 0.60 0.567 0.917
Hexosamines, mg/100g 110 108 280 245
Calorie content, kcal/100g 142.5 148.9 161.7 164.6
Protein content in 100 g of fish sausages ranges from 15.4 to 17.7 g, depending on the recipe. This means that using one portion of sausages weighing 100 g will provide an elderly person’s daily need in valuable protein (68 g) by more than 22.6%. It should be borne in mind that the proteins in sausages are mainly represented by proteins of pollock, pink salmon, and seafood, which exhibit a high biological value.
Recipes of fish sausages “Restorative” and “Immunomodulatory” provide the physiological daily needs of a human body by 22.3% or more for all studied biologically active substances: triterpene glycosides, carotenoids, nucleic acids, hexosamines, and iodine. Functionality of the molded product recipes (“General-strengthening”, “Mineral-correcting”) is also high and differs from the first two recipes in only one indicator:
a reduced iodine content of – 13.45% of the daily norm (“General-strengthening”) and the absence of DNA (“Mineral-correcting”).
The developed molded fish products contain an increased content of mineral substances (2.57-3.61%), which is a consequence of their enrichment with seafood cryoconcentrates. This is especially noticeable in “Mineral-correcting” sausages, which contain the maximum amount of minerals, including organically bound iodine due to Japanese kelp, which is part of the enriching additive.
The lipid content in enriched fish sausages is in the range of 8.9-10.6%. Depending on the recipe, they are represented by fatty components of fish muscle tissue
of pollock and pink salmon, as well as by lipids that make up butter and vegetable (sunflower) oil. The high nutritional value of pollock and pink salmon lipids is known due to their rather high content of polyunsa-
turated fatty acids (PUFA) [6, 7]. The group fatty acid (FA) composition of lipids in enriched fish sausages is shown in Table 3.
Lipid composition of enriched fish sausages
FA group Recipes
“General-strengthening” “Mineral-correcting” “Restorative” “Immunomodulatory”
% of FA sum g in 100 g
of product % of FA sum g in 100 g
of product % of FA sum g in 100 g
of product % of FA sum g in 100 g of product
UFA 33.12 2.45 41.65 3.09 30.46 2.62 38.15 2.89
MUFA 30.66 2.69 32.15 2.39 32.14 2.44 31.04 2.57
PUFA 36.12 2.71 26.20 2.17 37.40 2.85 30.81 2.11
ω3 2.11 0.049 2.07 0.042 3.32 0.048 2.27 0.031
ω6 19.32 0.51 18.15 0.46 25.38 0.75 17.92 0.55
From the data in Table 3 it follows that the qualitative composition of the lipids of enriched fish sausages depends on their prescription composition.
If vegetable oil (sunflower) is included in the recipes
of sausages of “General-strengthening” and “Restorative”, then the content of PUFA in these sausages is much higher compared to sausages
of “Mineral-correcting” and “Immunomodulatory”, where the added oil is butter. In general, it should be noted that enriched fish sausages in terms of the lipid component meet the requirements for gerodietetic products . The calculation of the content of essential lipid components in a 100 g portion of sausages shows that the developed molded fish products can be classified as functional products (more than 15% of the daily intake).
The water-retaining capacity of the developed fish sausages was studied (Fig.).
Water-retaining capacity of the developed fish sausages:
1 – “General-strengthening”; 2 – “Mineral-correcting”; 3 – “Restorative”; 4 – “Immunomodulatory”
The data of the figure show that fish sausages enriched with seafood cryoconcentrates have rather high water-holding capacity, which determines the yield
of finished products, their juiciness and consistency.
An equally important indicator, in addition
to functionality, is the organoleptic characteristic of the product, which shows that the developed enriched fish sausages exhibit high organoleptic properties. Sausages “Restorative” and “Immunomodulatory”, according to tasters, are more attractive in appearance, color, and consistency in comparison with sausages “General-strengthening” and “Mineral-correcting”. It is also noted that sausages made from minced pink salmon have higher WHC values than sausages made from minced pollock.
Thus, samples of enriched molded fish products obtained according to the developed recipes show high functionality, as they contain biologically active substances: proteins, triterpene glycosides, carotenoids, nucleic acids, hexosamines, and iodine. The content of these macro- and micronutrients corresponds to the recommended daily norms of the physiological needs
of the human body, established for functional foods.
Data on the safety assessment of the consumption of molded fish products enriched with seafood cryoconcentrates are presented in Table 4.
Physico-chemical safety indicators of developed fish sausages
Indicators Permissible level: less, mg/kg Content in products
Lead 1.0 0.3 0.1
Arsenic 5.0 1.0 0.8
Cadmium 0.2 0.05 0.06
Mercury 0.5 0.1 0.1
Histamine 100.0 21 31
Nitrosamines: sum of NDMA and NDEA 0.003 Not found Not found
Hexachlorocyclohexane (a, b, g-isomers) 0.2 0.03 0.02
DDT and its metabolites 2.0 1.0 1.0
2, 4 - D acid, its salts and esters Not allowed Not found Not found
Polychlorinated biphenyls 2.0 0.6 0.8
Cesium-137 130 60 55
Strontium-90 100 48 40
The data in Table 4 show that the developed enriched fish sausages correspond to the current regulatory documents in terms of the content of toxic elements, pesticides and radionuclides .
The results of microbiological studies of enriched fish sausages are shown in Table 5.
Microbiological safety indicators of developed fish sausages
QMAFAnM, CFU/g Bacteria of Escherichia
coli group (coli-forms) S. aureus Pathogenic bacteria, incl. Salmonella
and L. monocytogenes
Permissible levels Content
in products Standard product weight, g Result Standard product weight, g Result Standard product weight, g Result
1 • 104 0.025 • 104 0.1 Not found 0.1 Not found 25 Not found
1 • 104 0.042 • 104 0.1 Not found 0.1 Not found 25 Not found
The data in Table 5 indicate that by microbiological indicators new types of enriched molded fish products comply with the requirements of the current regulatory documents [8, 9].
Thus, based on the conducted research, it can be
concluded that the developed recipes of enriched fish sausages belong to the category of functional types
of products, have a high nutritional value, high consumer properties, and also meet the food safety requirements in terms of physico-chemical and microbiological indicators.