This review is dedicated to exploring recent advancements in the study of amaranth grain and presents research primarily on Amaranthus species such as Amaranthus cruentus, Amaranthus hypochondriacus, and Amaranthus caudatus, and to a lesser extent Amaranthus hybridus, Amaranthus mantegazzianus, Amaranthus muricatus, Amaranthus tuberculatus, Amaranthus viridis, Amaranthus spinosus, and Amaranthus tenuifoliu. Amaranth (Amaranthus spp.) is a promising, high-yield pseudocereal crop with significant commercial potential for developing functional food products. It contains a wide range of bioactive compounds, including squalene, tocopherols, phenolic compounds, phytates, and vitamins, which possess important physiological properties. Amaranth grain is characterized by high levels of starch, proteins, minerals, and dietary fiber. Moreover, amaranth proteins are distinguished by a balanced amino acid composition and exhibit greater resistance to external factors compared to animal-derived proteins. Grains of amaranth are free of gliadin, making it a valuable nutritional source for individuals with celiac disease, an immune-mediated disorder. Unlike traditional cereals, where prolamins and glutelins dominate the protein composition, the proteins of pseudocereals like amaranth primarily consist of albumins and globulins. The processing methods of amaranth grain influence their quantitative and qualitative composition, often significantly improving their physicochemical, antioxidant, functional, and rheological properties. This work provides a detailed analysis of amaranth’s chemical composition and bioactive components, along with its evaluation of therapeutic and preventive properties. Amaranth protein fractions (albumin, globulin, and glutelin) and squalene exhibit increased antioxidant activity, contributing to notable resistance to radiation and X-ray exposure. Bioactive compounds such as phytol, α-tocopherol, and a lunasin-like peptide (AhLun) with potential anticancer properties have also been identified in amaranth. Furthermore, six bioactive peptides were isolated and identified from amaranth, which, according to predictive models, demonstrate a high capacity to inhibit angiotensin-converting enzyme (ACE) activity, suggesting potential hypotensive effects. Certain amaranth peptides are considered promising functional food ingredients for the prevention and comprehensive treatment of conditions such as diabetes, inflammatory bowel diseases, hypercholesterolemia, cardiovascular diseases, and obesity. Amaranthus spp. and its processed products hold significant interest for the development of innovative food products, contributing to the expansion of their range and enhancement of nutritional value.

Fresh berries contain numerous components that can undergo complex changes during the drying process. This study aims to investigate the effect of freeze-drying on the sensory and chemical properties of black currant and sea buckthorn berries. Freeze-drying was performed at a shelf temperature of 35–55 °C with a step of 5 °C and durations of 18, 20, 22, and 24 h. Comparing the final freeze-dried berries with their fresh counterparts, it was observed that at a shelf temperature of 50 °C and a drying time of 18 to 20 h, there was a minimal loss in the content of vitamins, organic acids, and carbohydrates. However, based on organoleptic evaluations, the best results were achieved after drying for 20 h. Furthermore, the preservation of citric and malic acids in black currant berries, along with citric, tartaric acids, and sucrose in sea buckthorn berries, was only at 45.6% when the freeze-drying time was extended to 22 h. Considering the physical and chemical properties of listed freeze-dried berries, the optimal parameters were identified as a shelf temperature of 50 °C and a drying time of 20 h. The findings from this study serve as a foundation for selecting appropriate freeze-drying parameters for various types of berries.

The demand for citric acid (CA) as a component of food products, pharmaceuticals, and cosmetics is increasing yearly. The use of adapted micro-organisms that convert naturally occurring carbohydrates into organic acids makes it possible to increase annual CA production significantly. The research aim was to study CA production by the Aspergillus niger strain in the medium based on carbohydrate-containing raw materials as a carbon source. We used a fermentation by A. niger. Starch hydrolysates were chosen as a nutrient medium. To improve the CA production of A. niger, multi-step mutagenesis was performed. This resulted in mutant strain A. niger R5/4, which had the highest acidogenic activity among the samples. The study evaluated the effect of temperature on the productivity of the mutant strains. The quantitative content of citric acid was analyzed at different incubation times (144, 168, and 192 h). The effect of the initial medium pH (4.5, 5.0, and 5.5) on acid formation was also investigated. The strain's optimum temperature, pH, and cultivation time parameters were determined. A three-factor, three-level Box-Benken design (BBD) was used to optimize CA production by A. niger strain R5/4 on a starch-containing medium. When assessing the impact of temperature on CA production, the ideal range was between 29 and 31 °C.

Porridge is one of the most important processed cereal products. Useful properties are lost from processing, the biochemical composition changes and organoleptic properties deteriorate. In this connection, enrichment with natural additives is an alternative solution. The criteria for choosing vegetable supplements were their functional properties and harmonious combination with cereals. Therefore, vegetables in the form of additives, widely used, easily accessible, and not too expensive, such as carrots, and pumpkins were chosen. Studies have shown that the vitamin, mineral and amino acid composition of vegetables varies significantly depending on the type and variety of crops. The vitamin and mineral composition of carrots, regardless of variety, is superior in value to pumpkin. However, the amino acid composition of pumpkins significantly exceeds that of carrots. Thus, carrot varieties "Alau" and "Derbes", as well as pumpkin varieties "Karina", considering the chemical composition, can be used to enrich instant cereals with vitamins, minerals and amino acids.

Berries play an important role in antioxidant protection, prevention and treatment of diseases of the human body, therefore they are widely used in the food industry. The purpose of this work is to study the composition of vitamins and organic acids in berries of various types. Generally accepted chemical and analytical methods were used in the research. As a result of the conducted research, it was found that all berries differ in biochemical composition depending on the species. The content of vitamins and organic acids in the composition of berries varies greatly depending on the type of berries. Some species have a valuable vitamin composition, while others have an equally valuable composition of organic acids. Blueberry berries have the widest complex of vitamins, and sea buckthorn berries have a full complex of organic acids. The results of the experiments performed will be used in the development of requirements for raw materials for processing.

Duck eggs are rich in essential nutrients, such as amino acids, vitamins, and polyunsaturated fatty acids. However, their application in the food industry is hindered by glucose, which contributes to undesirable darkening during the Maillard reaction in processing. The present study examined the effect of the desugarization of duck eggs using baker’s yeast on their chemical composition. The results showed that the desugarization process reduces the content of glucose and minerals (Cu, Fe, and Zn) and alters the vitamin composition depending on the treatment conditions. Changes were also observed in the fatty acid profile, including increased levels of oleic acid (C18:1), palmitoleic acid (C16:1), and linoleic acid (C18:2, ω − 6). A high intragroup correlation among saturated fatty acids indicates the stability of their distribution. An increase in the content of essential amino acids—glycine, leucine, valine, and phenylalanine—was also recorded. Correlation analysis of the amino acid composition revealed significant relationships among both essential and non-essential amino acids. Overall, the desugarization process using baker’s yeast not only improves the nutritional profile of duck egg powder but also enhances its functional properties, positioning it as a promising ingredient for the food processing industry.