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Hippophae rhamnoides L. leaves possess a remarkable amount of polyphenols that could serve as a natural remedy in various applications. In comparison, numerous techniques, such as conventional and high-pressure techniques, are available for extracting the bioactive fractions from sea buckthorn leaves (SBL). However, enzyme-assisted extraction (EAE) of SBL has not been comprehensively studied. The aim of this study was to optimize critical EAE parameters of SBL using the cellulolytic enzyme complex, Viscozyme L, to obtain a high-yield extract with a high concentration of bioactive compounds. In order to determine the optimal conditions for EAE, the study employed a central composite design and response surface methodology to analyze the effects of four independent factors (pH, temperature, extraction time, and enzyme concentration) on two different responses. Our findings indicated that under optimal conditions (3:15 h extraction, temperature 45 °C, pH 4.9, and 1% Viscozyme L v/w of leaves DW), EAE yielded 28.90 g/100 g DW of the water-soluble fraction. Furthermore, the EAE-optimized liquid extract was continuously fermented using an ancient fermentation starter, Tibetan kefir grains, which possess lactic acid bacteria (LAB) and have significant potential for use in biopreservation. Interestingly, the results indicated various potential prebiotic characteristics of LAB. Additionally, alterations in the cell wall morphology of the SBL residue after EAE were examined using scanning electron microscopy (SEM). This study significantly optimized EAE parameters for sea buckthorn leaves, providing a promising natural source of bioactive compounds for various applications, such as nutraceuticals, functional foods, and high-value products. [ABSTRACT FROM AUTHOR]

In recent years, much attention has been devoted to Vaccinium L. berries because of their substantial potential to be adapted for the development of innovative food and pharmaceutical applications. The accumulation of plant secondary metabolites is extremely dependent on climate and other environmental conditions. In order to increase the reliability of the findings, this study was conducted with samples collected in four regions in Northern Europe (Norway, Finland, Latvia, and Lithuania) and analyzed in a single laboratory using a standardized methodology. The study aims to provide a comprehensive understanding of the nutritional (biologically active compounds (phenolic (477–775 mg/100 g fw), anthocyanins (20–57 mg/100 g fw), pro-anthocyanidins (condensed tannins (141–269 mg/100 g fw)) and antioxidant activity in different systems (ABTS•+, FRAP). Physicochemical properties (acidity, soluble solids, color) of wild Vaccinium vitis-idaea L. were also evaluated. The results may contribute to the development of functional foods and nutraceuticals with potential health benefits in the future. To the best of our knowledge, this is the first comprehensive report on the evaluation of the biologically active compounds of wild lingonberries from different Northern European countries based on one laboratory's validated methods. The results indicated a geomorphological influence on the biochemical and physicochemical composition of wild Vaccinium vitis-idaea L. depending on their place of geographical origin. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) biosynthesized using aqueous medical plant extracts as reducing and capping agents show multiple applicability for bacterial problems. The aim of this study was to expand the boundaries on AgNPs using a novel, low-toxicity, and cost-effective alternative and green approach to the biosynthesis of metallic NPs using Calendula officinalis (Calendula) and Hyssopus officinalis (Hyssopus) aqueous extracts. The formation of AgNPs was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) techniques. The effectiveness of biosynthesized AgNPs in quenching free radicals and inhibiting the growth of Gram-positive and Gram-negative microorganisms was supported by in vitro antioxidant activity assay methods and using the Kirby–Bauer disk diffusion susceptibility test, respectively. The elucidated antimicrobial and antioxidative activities of medical plant extracts were compared with data from the engineered biosynthetic AgNPs. The antimicrobial effect of engineered AgNPs against selected test cultures was found to be substantially stronger than for plant extracts used for their synthesis. The analysis of AgNPs by TEM revealed the presence of spherical-shaped nano-objects. The size distribution of AgNPs was found to be plant-type-dependent. The smaller AgNPs were obtained with Hyssopus extract (with a size range of 16.8 ± 5.8 nm compared to 35.7 ± 4.8 nm from Calendula AgNPs). The AgNPs' presumably inherited biological functions of Hyssopus and Calendula medical plants can provide a platform to combat pathogenic bacteria in the era of multi-drug resistance. [ABSTRACT FROM AUTHOR]

Common buckwheat (Fagopyrum esculentum M.) is highly rich in starches and polysaccharides. Nowadays, the use of common buckwheat in brewing processes and functional product development is gaining popularity as it is gluten-free and therefore suitable for those suffering from coeliac disease. Moreover, enzyme-assisted extraction for common buckwheat releases these oligosaccharides as well as bioactive substances, which can be further used for developing new products. This research aims to compare different enzymatic hydrolysis methods and their effect on roasted common buckwheat flour. The degradation of buckwheat flour using these hydrolytic enzymes was captured using SEM. Oligosaccharide and sugar molecular mass distributions were identified using HPLC-SEC. The extract with the highest fermentable monomeric sugar content was further fermented with ancient lactic acid bacteria starters: Tibetan kefir grains and birch sap. Ferment extracts were analyzed for antimicrobial activity against ten different pathogenic bacteria. The results indicated that the incorporation of enzymes into the extraction process lead to the release of a wide variety of DP3-DP4. Furthermore, the successful fermentation of these extracts with ancient starters revealed promising antimicrobial activity against nine different pathogenic bacteria, including E. coli and L. monocytogenes. In general, common buckwheat is a suitable ingredient for developing beverages and products with high value and has high potential in pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Avena sativa (A. sativa) oats have recently made a comeback as suitable alternative raw materials for dairy substitutes due to their functional properties. Amylolytic and cellulolytic enzyme-assisted modifications of oats produce new products that are more appealing to consumers. However, the biochemical and functional alteration of products and extracts requires careful selection of raw materials, enzyme cocktails, and technological aspects. This study compares the biochemical composition of different A. sativa enzyme-assisted water extracts and evaluates their microbial growth using spontaneous fermentation and the antimicrobial properties of the ferment extracts. Fibre content, total phenolic content, and antioxidant activity were evaluated using traditional methodologies. The degradation of A. sativa flour was captured using scanning electron microscopy (SEM); moreover, sugar and oligosaccharide alteration were identified using HPLC and HPLC-SEC after INFOGEST in vitro digestion (IVD). Additionally, taste differentiation was performed using an electronic tongue with principal component analysis. The oat liquid extracts were continuously fermented using two ancient fermentation starters, birch sap and Tibetan kefir grains. Both starters contain lactic acid bacteria (LAB), which has major potential for use in bio-preservation. In fermented extracts, antimicrobial properties against Gram-positive Staphylococcus aureus and group A streptococci as well as Gram-negative opportunistic bacteria such as Escherichia coli and Pseudomonas aeruginosa were also determined. SEM images confirmed the successful incorporation of enzymes into the oat flour. The results indicate that using enzyme-assisted extraction significantly increased TPC and antioxidant activity in both the extract and residues. Additionally, carbohydrates with a molecular mass (MM) of over 70,000 kDa were reduced to 7000 kDa and lower after the incorporation of amylolytic and cellulolytic enzymes. The MM impacted the variation in microbial fermentation, which demonstrated favourable antimicrobial properties. The results demonstrated promising applications for developing functional products and components using bioprocessing as an innovative tool. [ABSTRACT FROM AUTHOR]