Correlation between Antimicrobial Activity Values and Total Phenolic Content/Antioxidant Activity in Rubus idaeus L.

Plant by-products, which are discarded into the environment, are rich in valuable compounds. The aim of this research was to determine the antibacterial activity of Rubus idaeus L. morphological parts and its correlation with total phenolic content and antioxidant activity. The authors also aimed to evaluate the plant's potential as added-value products. New aspects were revealed for further use and for making novel and natural products. The study's results indicated that raspberry leaves, inflorescences, and fruits could effectively combat three Gram-positive bacteria. According to the findings, among the various plant parts, root and seed extracts had the lowest antibacterial activity. Data revealed moderate, weak, or very weak correlation between the antimicrobial activity and phenolic content parameters. These findings underscore the viability of substituting synthetic antimicrobials with natural alternatives. The present study is significant for preparing novel products as antibacterials by appropriate and optimized processing using all raspberry morphological parts, and the research results show promising prospects for future purposeful utilisation of nature-based products. Raspberry plant parts can find applications in emerging fields that generate economic and environmental value.

Exploring the Antimicrobial Potential and Stability of Black Soldier Fly (Hermentia illucens) Larvae Fat for Enhanced Food Shelf-Life.

The larvae of the Black Soldier Fly (BSF, Hermetia illucens) have been introduced as one of the tools to create a circular economy model, which will be used in areas such as waste management and the treatment of industrial by-products to produce high-added-value food grade ingredients. The main aim of this research was to investigate the fat composition and antimicrobial activity against food pathogens and spoilers of Black Soldier Fly larvae. The research revealed that the Black Soldier Fly larvae fats are predominantly lauric fatty (40.93%), which are followed by palmitic, oleic, myristic, linolenic and palmitoleic fatty acids, accounting for 19.11, 17.34, 6.49, 8.79 and 3.89% of the fatty acid content, respectively. The investigation of the fats showed stability through a one-year monitoring period with no indication of chemical or microbiological spoilage. Different fat fractions were tested for antimicrobial activity, which showed efficiency against Candida albicans (the inhibition zone varied from 10.5 to 12.5 mm), Bacillus subtilis (from 12.5 to 16.5 mm), Staphylococcus aureus (12.5 mm) and Escherichia coli (10.0 mm). The inhibitory effect on Candida albicans was confirmed by shelf-life studies using larvae fat-based oleogel in a model food matrix. GraphPad Prism (ver. 8.0.1) was used for the statistical data processing. This research revealed the potential of Black Soldier Fly larvae fat as a very stable ingredient with promising antibacterial properties that can extend the product shelf-life in food matrixes even when used in relatively small amounts.

Antibacterial Activity of Copper Particles Embedded in Knitted Fabrics.

The composition and antibacterial properties of copper particles synthesized by a very simple reduction method were studied. For the preparation of particles in knitted fabrics, copper(II) sulfate was used as a precursor and ascorbic acid as a reducing natural agent. X-ray diffraction analysis showed the crystalline nature of the obtained particles. The round or oval particles and their agglomerates in knitted fabrics consisted of copper with traces of copper(I) oxide-cuprite. The element maps and energy dispersive X-ray spectra showed a high content of copper in the samples. The samples of wool and cotton knitted fabrics with copper particles had excellent antibacterial activity against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) bacterial strains. The maximum zones of inhibition were 19.3 mm for S. aureus and 18.3 mm for E. coli using wool knitted fabric and 14.7 mm and 15.3 mm using cotton knitted fabric, respectively. The obtained results showed that the modified wool and cotton fabrics are suitable for use as inserts in reusable masks due to their noticeable and long-term activity against pathogenic bacteria.

Bioactive Compounds, Antioxidant, and Antibacterial Properties of Lonicera caerulea Berries: Evaluation of 11 Cultivars.

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in 'Vostorg' to 784.5 ± 0.3 mg/100 g in 'Obilnaja', and TAC ranged from 277.8 ± 1.1 mg/100 g in 'Celnocnaja' to 394.1 ± 8.4 mg/100 g in 'Nimfa'. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.

Chemical composition, antioxidant, antimicrobial and antiproliferative activities of the extracts isolated from the pomace of rowanberry (Sorbus aucuparia L.).

In the present work, acetone, ethanol and water extracts of rowanberry (Sorbus aucuparia L.) pomace were evaluated for their antiproliferative, antimicrobial and antioxidative effects. Chemical composition of the extracts was determined by UPLC-ESI-MS/MS and spectrophotometric methods. Neochlorogenic and chlorogenic acids were the major phenolic compounds. The water extract contained the highest total proanthocyanidins content (301 ± 18.9 mg/g) and demonstrated the highest antioxidant activity in the all assays (DPPH, FRAP and ORAC). Extracts isolated from rowanberry pomace effectively inhibited the growth of undesirable microorganisms, especially Gram-positive bacteria. Acetone extract was the strongest antimicrobial agent followed by water and ethanol extracts. Acetone and water extracts demonstrated also higher cytotoxic potential in cell viability assays (SRB and MTT) using Caco-2 cells. In general, the results suggest that rowanberry pomace is a promising source of natural compounds with antioxidant and biological activities.

Japanese Quince (Chaenomeles japonica) as a Potential Source of Phenols: Optimization of the Extraction Parameters and Assessment of Antiradical and Antimicrobial Activities.

The value of fruits is determined by the quantity and variety of biologically active compounds they contain, and their benefits on human health. This work presents the first study of the biochemical composition and antibacterial activity of the new Japanese quince (JQ) cultivars 'Darius', 'Rondo', and 'Rasa' fruits. The total phenolic content (TPC) was determined using the Folin-Ciocalteu method and each compound was identified by HPLC High Performance Liquid Chromatography. The antimicrobial activity against three Gram-positive and three Gram-negative bacteria, and one yeast strain, was evaluated by the agar well diffusion method using three different concentrations. The free radical scavenging activity was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) methods and ranged from 99.1 to 115.9 µmolTE/100 g, and from 372 to 682 µmolTE/100 g, respectively. TPC ranged from 3906 to 4550 mgGAE/100 g, and five compounds, isoquercitrin, rutin, (+)-catechin, (-)-epicatechin, and chlorogenic acid were identified. All JQ extracts possessed antimicrobial activity against Gram-positive and Gram-negative bacteria, and Enterococcus faecalis (ATCC 29212) was the most sensitive strain. These results indicate that JQ fruits are a significant source of bio-compounds, which can enrich the diet with strong antioxidants, and they are very promising as a substitute for chemical preservatives in the food and cosmetic industry.

Inactivation of some pathogenic bacteria and phytoviruses by ultrasonic treatment.

High intensity ultrasound is becoming important and more widely used in the food industry for microorganisms decontamination. This sterilization technique has been evaluated to improve food safety and to replace common processing with chemical additive compounds. The efficiency of a horn-type power ultrasound treatment (300 W and 600 W, 28 kHz, 10-30 min) on Listeria monocytogenes, Bacillus cereus, Escherichia coli, Salmonella typhimurium bacteria suspensions and phytoviruses was examined in this study. The results of this study showed that ultrasonic treatment can be used to eliminate vegetative cells of gram-positive and gram-negative bacteria from 1.59 to 3.4 log in bacterial suspensions and some phytoviruses in fruits.

Determination of the total phenolic and anthocyanin contents and antimicrobial activity of Viburnum opulus fruit juice.

Viburnum opulus is a plant with fruits that are rich in biologically active substances, making it valuable to the food and pharmaceutical industries. Here, we present our study of the total phenolic and anthocyanin contents and antimicrobial activity in the fruit juice of six V. opulus L. accessions. The cultivar 'Krasnaya Grozd' was notable for its exceptionally large amount of total phenolics, 1168 mg/100 g, with anthocyanins comprising 3-5 % of the total phenolic content. The evaluation of the antimicrobial properties confirmed that the juice of V. opulus fruits strongly inhibited the growth of a wide range of human pathogenic bacteria, both Gram-negative (Salmonella typhimurium and S. agona) and Gram-positive (Staphylococcus aureus, Lysteria monocytogenes, and Enterococcus faecalis) organisms. Conversely, the yeasts Debaryomyces hansenii and Torulaspora delbrueckii showed complete resistance to the fruit juice, whereas a low sensitivity was demonstrated by Trichosporon cutaneum, Kluyveromyces marxianus var. lactis, Saccharomyces cerevisiae, S. cerevisiae 12R, and Candida parapsilosis.

Comparative study of anthocyanin composition, antimicrobial and antioxidant activity in bilberry (Vaccinium myrtillus L.) and blueberry (Vaccinium corymbosum L.) fruits.

Simultaneous comparison of bilberry (Vaccinium myrtillus L.) and blueberry (Vaccinium corymbosum L) fruits for their anthocyanin composition, antimicrobial and antioxidant activity is reported. The aim of this study was to investigate and to compare anthocyanin composition, antimicrobial and antioxidant activity in bilberry and blueberry fruits and their skins. The investigations revealed that the highest amount of total anthocyanins was observed in fruits skins of blueberry cultivars. The results, obtained by chromatographic analysis, indicated that cyanidin is a dominant anthocyanidin in bilberry and malvidin in blueberry samples. Extracts of "Herbert", "Coville", "Toro" blueberry cultivars and bilberry fruits revealed antimicrobial properties. Citrobacter freundii (ATCC 8090) and Enterococcus faecalis (ATCC29212) were the most sensitive among eight tested Gram-negative and Gram-positive bacteria. Significant differences between berry and skin extracts were not established. Studies with fruits showed that the strongest antioxidant activity possesses blueberry cultivar "Berkeley" (82.13 +/- 0.51%). Meanwhile, the amount of quenched free radicals in bilberry samples was 63.72 +/- 1.11%, respectively. The lowest antioxidant activity was estimated in blueberry cultivar "Coville". Accordingly, the strongest antiradical properties were estimated in blueberry cultivar "Ama" fruit skins. Bilberry fruit skin samples possess strong antiradical activity as well (82.69 +/- 0.37%).

Phenolics and anthocyanins in berries of European cranberry and their antimicrobial activity.

UNLABELLED: European cranberry is a berry plant rich in biologically active substances, making it valued by both the phyto-pharmaceutical and food industries. The aim of this study was to examine the accumulation of phenolic compounds and anthocyanins in berries of European cranberry and to assess their antibacterial activity. MATERIAL AND METHODS: Different wild clones of European cranberry were investigated according to berry weight and the amounts of total phenolics and anthocyanins. Anthocyanin profiles of extracts were evaluated by HPLC, whereas the antimicrobial properties were determined by the agar well diffusion method. A strong negative correlation between berry weight and the amount of anthocyanins was found. The amount of total phenolics among different cranberry clones in the field collection ranged from 224.0 mg/100 g to 498.0 mg/100 g, and the amount of total anthocyanins ranged from 40.7 mg/100 g to 207.3 mg/100 g. Quantitative HPLC-UV analysis revealed six anthocyanins in the berries of European cranberry, among which the anthocyanin peonidin-3-galactoside was most prevalent. CONCLUSIONS: Investigation of the antimicrobial properties showed that European cranberry extracts inhibited the growth of wide range of human pathogenic bacteria, both gram-negative (Escherichia coli and Salmonella typhimurium) and gram-positive (Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, and Bacillus subtilis).