Background: In the agro-industrial sectors, including fisheries, there is a growing focus on rapidly determining the composition and quality of food products. Traditional chemical methods are too slow for quick quality assessments. Spectral methods have become preferred for rapid analysis, although the spectral range suitable for determining the storage days of fish samples has not been thoroughly explored.Purpose: To evaluate the shelf-life and freshness of refrigerated rainbow trout using mid-infrared spectroscopy.Materials and Methods: Refrigerated rainbow trout steaks stored at +4 °C were examined. The fish were raised in an open tank at Lake Motkozero in the Vologda region. A mid-infrared FT-801 FTIR spectrometer with an attenuated total internal reflection (ATR) attachment was employed to determine the fish's shelf-life, freshness, and quality. The spectrum range spanned from 4000 to 700 cm-1 with a resolution of 4 cm-1, conducting 16 scans. Spectral data were analyzed using ZaIR 3.5 software, with measurements taken daily over a 16-day storage period.Results: Mid-infrared spectroscopy effectively differentiated rainbow trout samples by storage day, with each day displaying a unique spectral signature. The spectral range of 1700–1500 cm-1 clearly distinguished between samples from the first and last days of storage (day 16), showing an increase in absorption intensity at wavelengths corresponding to amides and amino groups, indicative of biochemical changes due to spoilage.Conclusion: This study's findings contribute to developing a new, rapid, and non-destructive method for assessing fish freshness, which is crucial for food safety control authorities and consumers. The methods developed hold significant potential for optimizing quality control processes in the food industry.

According to the FAO, the world is gradually transitioning from industrial fishing to aquaculture, which accounted for 130.9 million tons of fish in 2022. Data on the state of aquaculture and the prospects for its development in the world, in the Russian Federation, in particular the Vologda oblast, are presented. The Russian Federation has a huge fish farming potential. In 2023, salmon fish occupy the first place in the territory of the Russian Federation in terms of commercial aquaculture production. One of the common species for commercial fish farming is rainbow trout (Oncorhynchus mykiss). The widespread development of industrial trout farming in Russia is possible due to the suitable geographical location and favorable climatic conditions for breeding rainbow trout. Since the first half of the 20th century, the breeding of commercial fish species has been the most important direction for the development of fisheries in the reservoirs of the Northwestern Federal District of Russia, and therefore at least 25 species of fish, including rainbow trout, have been introduced into the reservoirs of the Vologda Region. Currently, there are 15 operating enterprises in the Vologda Region and 13 more commercial fish farming enterprises are planned to operate. The ecology of rainbow trout is considered, and a comparative characteristic of the favorable habitat conditions of this species with the conditions of the reservoirs of the Vologda region is given. It is noted that the reservoirs of the Vologda region are suitable for breeding rainbow trout in aquaculture conditions according to various criteria.

For the first time, the component composition of the low-molecular-weight metabolome of perfoliate pondweed (Potamogeton perfoliatus L., family Potamogetonaceae), which grows in the Astrakhan region (lower zone of the Volga river delta), has been investigated. Low molecular weight organic compounds (LMWOCs) in the composition of essential oil were obtained from dried plants by steam hydrodistillation using the Clevenger apparatus. The qualitative and quantitative compositions of the LMWOCs were investigated using gas chromatography-mass spectrometry (GC/MS complex TRACE ISQ (Thermo Scientific) with a quadrupole mass analyzer). The low molecular weight metabolome of P. perfoliatus contained 164 components, of which 151 were identified. Major LMWOCs were carboxylic acids – tetradecanoic (69.7%) and hexadecanoic (10.1%), as well as phytol (3.4%) and phyton (1.4%), characterized by diverse biological activities. The antioxidant activity of an aqueous-alcoholic extract of P. perfoliatus was investigated by a photometric method based on the reaction of DPPH (2,2-diphenyl-1-picrylhydrazyl) dissolved in ethanol with an antioxidant sample. It has been shown that P. perfoliatus extract has more pronounced antioxidant properties than the tested drugs (ascorbic acid and emoxipine). P. perfoliatus from the lower zone of the Volga River delta can be considered as a naturally renewable resource for obtaining raw materials for creating effective composites of new generation algicides to combat cyanobacterial "bloom", as well as for obtaining valuable natural forms of LMWOCs of plant origin for various types of application in pharmacology, medicine, cosmetology, food industry, and other industries.

Потенциал рамановской спектроскопии как метода экспресс-оценки срока хранения и свежести филе охлажденной радужной форели

The interaction of estrogen receptor alpha (ERα) with various metabolites—both endogenous and exogenous, such as those present in food products, as well as gut microbiota-derived metabolites—plays a critical role in modulating the hormonal balance in the human body. In this study, we evaluated a suite of 27 machine learning models and, following systematic optimization and rigorous performance comparison, identified linear discriminant analysis (LDA) as the most effective predictive approach. A meticulously curated dataset comprising 75 molecular descriptors derived from compounds with known ERα activity was assembled, enabling the model to achieve an accuracy of 89.4% and an F1 score of 0.93, thereby demonstrating high predictive efficacy. Feature importance analysis revealed that both topological and physicochemical descriptors—most notably FractionCSP3 and AromaticProportion—play pivotal roles in the potential binding to ERα. Subsequently, the model was applied to chemicals commonly encountered in food products, such as indole and various phenolic compounds, indicating that approximately 70% of these substances exhibit activity toward ERα. Moreover, our findings suggest that food processing conditions, including fermentation, thermal treatment, and storage parameters, can significantly influence the formation of these active metabolites. These results underscore the promising potential of integrating predictive modeling into food technology and highlight the need for further experimental validation and model refinement to support innovative strategies for developing healthier and more sustainable food products.

Fish quality control demands efficient analytical solutions. While conventional (targeted) assessment methods are reliable, their labor-intensive and destructive nature drives the development of rapid, non-destructive (untargeted) technologies. This review features rainbow trout ( Oncorhynchus mykiss) as a key global aquaculture species. It compares, systematizes, and summarizes data on the capabilities, limitations, and prospects of applying targeted and untargeted assessment methods to fish raw materials in general and rainbow trout in particular. The review spans a decade of publications, comparing conventional quality assessment approaches (sensory, physicochemical, and microbiological methods) with advanced instrumental techniques (infrared spectroscopies, Raman spectroscopy, hyperspectral imaging, nuclear magnetic resonance spectroscopy). Untargeted methods, e.g., spectroscopy and imaging, enable rapid, non-invasive assessment of such key freshness parameters as chemical composition, lipid oxidation degree, spoilage, and storage time. In contrast, targeted methods remain crucial for validation and precise quantification of specific indicators, especially at later stages of spoilage. Untargeted methods show strong suitability for integration into real-time monitoring systems at fish processing facilities. However, their implementation requires robust calibration, specialized mathematical mode ls, and representative reference databases. Rainbow trout (Oncorhynchus mykiss) demonstrates the effectiveness of spectroscopic fish quality control methods, combining speed, non-invasiveness and the potential for online monitoring.