In recent decades, species within the genus Amaranthus L. (amaranth) have garnered growing global interest due to their exceptional nutritional value, functional properties, and agricultural versatility. Traditionally consumed as leafy vegetables or pseudo-cereals, several Amaranthus species are now receiving renewed attention in the context of the development of modern functional foods. This review evaluates the data on nutritional composition, health-promoting properties, and potential applications of Amaranthus spp. in sustainable food systems in peer-reviewed publications from the last 25 years. Amaranth is rich in high-quality proteins, essential amino acids, dietary fibre, vitamins, and minerals, positioning it as a significant factor in addressing malnutrition and enhancing food security. Furthermore, its bioactive compounds, such as flavonoids, phenolic acids, and peptides, exhibit antioxidant, anti-inflammatory, and hypocholesterolemic activities, suggesting its potential as a part of healthy diets, alleviating the risk of non-communicable diseases. The presence of anti-nutritional factors, including saponins, phytates, and oxalates, has also been explored, with implications for nutrient bioavailability and overall health effects. In addition to its nutritional advantages, Amaranthus spp. demonstrate strong adaptability to diverse climatic conditions, thus performing as a crop resilient under climate stress. Their olfactory and sensory attributes are also considered important for consumers’ acceptance and market integration. By synthesising traditional knowledge and contemporary scientific research, this review underscores the potential of Amaranthus spp. as a multifunctional food source that could support health promotion, climate resilience, and agricultural sustainability.

In this article a possibility of application of the ultrasonic non-contact method for assessing the quality of yogurt was researched. A prediction assessment was made by an ultrasound based on four parameters – pH, conductivity, fat content, and viscosity. An ultrasonic device was developed to determine the parameters of yoghurt by modified ultrasound sensor available commercially. In order to obtain data for post-processing, a software application was designed for recognizing the ultrasonic signal through the image processing and analysis techniques.The developed algorithms and procedures were applied to determine the distance between the object and the sensor, whereby basic physico-chemical parameters of yogurt could be predicted with the lowest relative error. The working distance was 35 cm for the considered system. The survey results show that the parameters fat content, pH, conductivity, and viscosity of yogurt could be predicted by the proposed system for contactless measurement with accuracy of 94-97%.

The chemical composition of ethanol extracts from wild and cultivated Bulgarian white oregano (Origanum heracleoticum L.) was determined. It was found that the aromatic compounds are the dominant group in the extracts of wild and cultivated white oregano – 89.75% in both extracts. The main components are carvacrol (70.97%) in the extract of wild oregano and carvacrol (60.47%) and thymol (8.55%) in the extract of cultivated oregano. The antimicrobial activity of aromatic products of Bulgarian white oregano was studied. The antimicrobial activity of the essential oils and ethanol extracts of oregano was determined against bacteria, which are found to be human pathogenic or food spoilage microorganisms – Staphylococcus aureus, Listeria monocytogenes and Escherichia coli ATCC 25922. Both the essential oils and the extracts showed antimicrobial activity against the tested microorganisms, more significant in the wild species, probably due to the high content of carvacrol. Gram-negative bacteria Escherichia coli showed resistance to the extracts, but were affected by the essential oils, the diameters of the zones of inhibition being comparable to those of the antibiotics Gentamicin and Tobradex. The results obtained suggest a potential application of these oils in preventing human pathogenesis and food spoilage due to microorganism growth.

The possibilities for application of essential oils and ethanol extracts of Bulgarian white oregano in the production of cooked-smoked sausages have been studied. In the composition of the sausage product were included essential oils (20 mg/kg) and ethanol extracts (75 mg/kg) from wild and cultivated white oregano. It has been found that adding essential oils and extracts improve the taste of the sausage without changing the appearance and texture of the meat product. The color characteristics on the surface and the inside of the sausage during storage for 24, 48 and 72 hours were determined. No significant changes in color parameters (L*, a* and b*) were established during storage for 72 h. The total microbial count in meat products remains within the permissible limits up to 12 days of their production. The essential oil and the ethanol extract of Bulgarian white oregano are suitable additives for cooked-smoked sausages improving their organoleptic characteristics and duration.

In this study, one of the main problems related to the development of new foods and the improvement of existing staple foods is examined. The effect of stalk pigweed flour in relation to the main raw material, wheat flour, at levels of 0%, 5%, 10%, and 15% was evaluated with respect to key characteristics of flour mixtures, dough, and biscuits with this additive. A selection of informative features was made, revealing that out of the 39 studied parameters, covering sensory, physicochemical, geometric, colorimetric, and spectral characteristics, only 19 proved to be informative. Principal component analysis showed that the relationship between amaranth green powder (AGP) concentration and the first two principal components explained up to 99% of the variance. The optimal addition level of 7.17% AGP was identified based on the convergence of biscuit characteristics. pH decreased from 6.55 to 6.28, electrical conductivity increased from 1075 to 3759 µS/cm, and sensory scores for aroma and taste peaked near 7% before declining at higher concentrations. It was demonstrated that the relationship between the amount of amaranth in biscuits and the first two principal components can be described with up to 99% accuracy. It was determined that the optimal amount of amaranth flour in biscuits is +7.17%. The results obtained provide a basis for further research into the rapid automated analysis of biscuits with added pigweed flour, which will contribute to the development of new foods with improved characteristics. It is suggested to carry out more research to study the effect of flours from other amaranth types, enhancing different varieties and cultivated in diverse ecological regions. This work also explores the viability of pigweed as a nutritious and sustainable flour alternative while providing a multivariate approach in view of newly developed bakery formulations.

This study presents a sensor-integrated framework for evaluating purslane (Portulaca oleracea L.) stalk flour as a functional ingredient in butter biscuits. A Design of Experiments (DoEs) approach was applied using multisensor probes (electrical conductivity, pH, TDS, ORP) and digital imaging sensors (visible reflectance spectra) for real-time, non-destructive quality assessment. Multivariate analysis with Repeated Relief Feature Selection (RReliefF) and Principal Component Analysis (PCA) reduced 54 initial measurements to 19 informative features, with the first two principal components explaining over 96% of the variance related to flour concentration. Regression modeling combined with linear programming identified an optimal substitution level of 9.62%. Biscuits at this level showed improved texture, enhanced elemental composition (Ca, Mg, Fe, Zn), stable color, and maintained sensory acceptability. The methodology demonstrates a reliable, low-cost sensing and chemometric approach for data-driven, non-destructive quality monitoring and product optimization in food manufacturing.