Stability of bioactive polyphenols from honey during different extraction methods

Physicochemical parameters, microbiological quality, and antibacterial activity of honey from the Bucovina region of Romania

In this study, the physicochemical properties (electrical conductivity (EC), pH, free acidity, moisture content, DPPH radical scavenging activity, total polyphenols content (TPC), flavonoids content (FC), individual polyphenols, carbohydrates, and organic acids), microbiological quality, and antibacterial activity of honey (raspberry, rosehip, alfalfa, hawthorn, and honeydew honey) from Bucovina were evaluated. Along with melissopalynological analysis, the physicochemical parameters were determined for the honey samples to characterize the samples and to assess their applicability in classifying honey based on its botanical origin. Another objective of the study was the evaluation of the microbiological quality and antibacterial activity of honey samples. The antibacterial activity was examined against the growth of four pathogenic bacterial strains (Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Salmonella enterica serovar Typhimurium ATCC 14028) by the diffusion test in the agar well and by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The analyzed honey samples were within the safe limits, except for three samples in which Bacillus cereus was detected and two other samples that had values above the acceptable limit for yeasts. Thus, 40.46% of all honey samples had bactericidal activity that was superior or at least comparable to manuka honey MGO550 against Staphylococcus aureus, 57.69% against Salmonella enterica serovar Typhimurium, 74.15% against Pseudomonas aeruginosa, and 75% against Escherichia coli. Of all types of honey analyzed in this study, honeydew honey had the highest bactericidal activity, followed by polyfloral honey.

Mead production and quality: A review of chemical and sensory mead quality evaluation with a focus on analytical methods

Mead, an alcoholic beverage made from the fermentation of honey in water by yeast, has an expanding global market and popularity, and a concurrently broadening library of related scientific literature. Quality of mead can be evaluated using both sensory and physicochemical characteristics, with volatile aroma and phenolic profiles being of particular importance. Different mead-making techniques can have significant impact on these parameters and thus the overall mead quality. With the increasing prevalence of mead-quality related research, optimised analytical methodologies are of great relevance to research in this field. This review provides an overview and discussion of the relevant published literature regarding mead quality analysis, with a focus on the analytical methodologies used to evaluate the volatile and phenolic profiles of mead. In addition, the mead production process is outlined, and studies related to the sensory evaluation of mead are summarised. The state of the literature regarding mead quality has seen significant growth in recent years, including the development of improved and increasingly tailored analytical methodology, particularly GC and HPLC methods, although these have great scope to be further optimised for the mead matrix, particularly GC methods. Additionally, there is great scope for studies which integrate multiple aspects of mead quality such as sensory characteristics, volatile aroma components, and potentially bioactive compounds. This review will aid researchers looking to design and develop their own mead-related experimental and analytical methodologies, furthering high-quality research in the field, and contribute towards the advancement of the mead industry.

Changes in the Content of Dietary Fiber, Flavonoids, and Phenolic Acids in the Morphological Parts of Fagopyrum tataricum (L.) Gaertn Under Drought Stress

BACKGROUND

Tartary buckwheat is a plant recognized for its resistance to various environmental stresses. Due to its valuable source of phenolic compounds, Fagopyrum tataricum is also characterized as a medicinal plant; therefore, the aim of this study was to investigate the drought stress for the levels of phenolic compounds in the morphological parts of the plant.

METHODS

This experiment was conducted in 7 L pots under laboratory conditions. Phenolic compounds were identified using a UHPLC-MS chromatography system. Antioxidant activity was assessed using well-known methods, including the DPPH scavenging activity and ferrous ion chelating activity.

RESULTS

In Tartary buckwheat leaves, stems, seeds, and husks, 57 phenolic compounds were identified, with a predominance of quercetin 3-rutinoside, quercetin, kaempferol-3-rutinoside, kaempferol, and derivatives of coumaric acid. It was observed that the Tartary buckwheat samples subjected to drought stress exhibited a slight decrease in the majority of individual phenolic compounds.

CONCLUSIONS

The measurement of biological parameters indicated that plant regeneration after drought stress demonstrated a rapid recovery, which can be a positive response to the progression of climate changes.

Optimized extraction methodology for phenolic compounds in soil and plant tissues: Their implications in plant growth and gall formation

Phenolic compounds, abundant secondary metabolites in plants, profoundly influence soil ecosystems, plant growth, and interactions with herbivores. Phenolic in soil microorganisms have the potential to impact a wide range of activities in plant-soil interactions. However, the existing methods for measuring microbial activity are typically time-consuming, intricate, and expensive. In this study, we propose modifications to the method used for the extraction and quantification of various types of phenolics in soil and plant tissues. There have been substantial advancements in research aimed at extracting, identifying, and quantifying phenolic compounds in the plant and soil samples. This study discusses the use of different methodologies in the analysis of phenolic compounds. In addition, we investigated the effect of phenolics on plant growth and cues in gall-forming under environmental disturbances.•This method is the optimum way to extract phenolic from soil and microbial activity in bulk and rhizosphere soil.•It can be used on any soil type and plant tissue, metabolites extracted from living organisms.

Effects of Larch Woolly Adelgid Infestation on Morphological, Histological and Allelochemical Traits of European Larch Needles

The study was carried out to assess the effect of the larch wooly adelgid Adelges laricis Vallot (Hemiptera: Adelgidae) infestation on its secondary host, the European larch Larix decidua Mill. Morphology and anatomy of adelgid-infested needles, and content of defense phenolic compounds including individual flavonoids isorhamnetin, kaempferol, quercetin, rutin, catechin, epicatechin, apigenin, ampelopsin and taxifolin, were analyzed. The amount of total phenols in needles from adelgid-infested twigs of L. decidua increased following the development of the A. laricis population, from the end of April until the end of June. The most abundant among flavonoids were the flavanols, mainly catechin and epicatechin, which predominated in the larch needles during the whole period of adelgid infestation. The content of catechin and epicatechin increased following the increase in the adelgid population number. An increase in content occurred also in flavanonols ampelopsin and taxifolin, while the content of the flavonol kaempferol decreased as the population number of A. laricis increased. The analysis of the anatomical structure of needles showed changes in the shape of the needles, the presence of a thicker layer of epicuticular waxes, and a higher number of mesophyll layers as a result of adelgid feeding.

Comparative Study of Phenolic Content and Antioxidant and Hepatoprotective Activities of Unifloral Quillay Tree (Quillaja saponaria Molina) and Multifloral Honeys from Chile

Honey is a natural sweet element that bees make with flower nectar, revered for its distinct flavor, nutritional value, and potential health benefits. Chilean beekeeping has a diverse range of honey varieties, many of which are unique. The quillay (Quillaja saponaria Molina, soapbark tree) is a Chilean endemic tree whose honey has not been studied in depth. We characterized various Chilean honeys with different botanical origins, with a particular focus on quillay tree honey, analyzing its total phenolic and flavonoid content and its antioxidant activities. Cytotoxicity and hepatoprotective activity were also evaluated using HuH-7 cells. The Spearman correlation between the percentage of quillay pollen in the honey samples and the total phenolic content (R = 0.72; p < 0.05), plus the oxygen radical absorbance capacity, suggests that compounds from quillay contribute to the overall antioxidant capacity of honey. Unifloral quillay honey extracts also protect hepatic cells from oxidative damage induced by peroxyl radicals generated by AAPH. This analysis sheds light on the potential of quillay tree honey, underscoring its significance as a natural source of bioactive phenolic compounds with possible hepatoprotective effects.

Silicon-Mediated Improvement in Drought and Salinity Stress Tolerance of Black Gram (Vigna mungo L.) by Modulating Growth, Physiological, Biochemical, and Root Attributes

Water is a precious commodity for plant growth and metabolism; however, its scarcity and saline sand conditions have a drastic effect on plant growth and development. The main objective of the current study was to understand how silicon (Si) application might help Black gram (Vigna mungo L.) against the negative impacts of salt stress and drought. The treatments of this study were: no silicon = 0 mg/kg; silicon = 40 mg/kg; control = no stress; drought stress = 50% field capacity (FC); salinity = 10 dSm-1; drought + salinity = 10 dSm-1 + 50% field capacity (FC). The findings showed that the application of silicon in the sand significantly affected growth indices such as leaf area (LA), shoot fresh weight (SFW), shoot dry weight (SDW), and shoot length (SL). Root length (RL) increased significantly up to 55.9% in response to drought stress. Applying Si to the sand increased the root length (RL) by 53.9%. In comparison to the control, the turgor potential of leaves decreased by 10.3% under salinity, while it increased by 44.7% under drought stress. However, the application of silicon to the sand significantly improved the turgor potential of leaves by 98.7%. Under both drought and salt stress, gas exchange characteristics and photosynthetic pigments dramatically decreased. Applying 40 mg/kg silicon to sand improved the gas exchange characteristics, protein contents, and photosynthetic pigments of plants under drought and salt stress, such as levels of chlorophyll (a, and b) increased by 18% and 26%, respectively. Under control conditions, the hydrogen peroxide (H2O2) concentration was lower but increased during periods of drought and salinity stress. The concentrations of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) were decreased by salt and drought stress and increased by sand application of silicon at a rate of 40 mg/kg. Application of silicon at 40 mg/kg sand rate improved the growth and development under control and stress conditions. Overall, this study provides an extensive understanding of the physiological mechanisms underlying the black gram's ability to withstand under salt stress and drought stress by application of Si which will serve as a roadmap for future cellular research.

Changes in health-promoting metabolites associated with high-altitude adaptation in honey

The levels of metabolites in honey are influenced by floral origin, production region, and bee species. However, how environmental factors affect honey quality remains unclear. Based on untargeted metabolomics and using UPLC Q-Orbitrap MS, we analyzed 3596 metabolites in 51 honey samples from Yunnan and Shennongjia. Comparative analysis revealed that geniposidic acid, kynurenic acid and caffieine accumulated at significantly different levels between Shennongjia and Yunnan honey. Based on cluster structure analysis, 36 Yunnan honey samples were divided into two distinct groups by altitude. Notably, quercetin, hyperoside, taxifolin, rutin, tryptophan, astragalin and phenylalanine were higher levels in high-altitude honey (>1700 m), whereas abscisic acid was higher levels in low-altitude honey (≤1700 m). Among these, significantly elevated levels of hyperoside, taxfolin, astragalin, and tryptophan were observed in honey collected from high-altitude areas in Shennongjia. Our findings highlight the effect of altitude on honey health-promoting components, providing valuable insights into honey quality.

Method development with high-throughput enhanced matrix removal followed by UHPLC-QqQ-MS/MS for analysis of grape polyphenol metabolites in human urine

Grape and grape derived products contain many bioactive phenolics which have a variety of impacts on health. Following oral ingestion, the phenolic compounds and their metabolites may be detectable in human urine. However, developing a reliable method for the analysis of phenolic compounds in urine is challenging. In this work, we developed and validated a new high-throughput, sensitive and reproducible analytical method for the simultaneous analysis of 31 grape phenolic compounds and metabolites using Oasis PRiME HLB cleanup for sample preparation combined with ultra-performance liquid chromatography with triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). Using this new method, the accuracy achieved was 69.3 % ∼ 134.9 % (except for six compounds), and the recovery achieved was 52.4 % ∼ 134.7 % (except for two very polar compounds). For each of the 31 target analytes, the value of intra-day precision was less than 14.3 %. The value of inter-day precision was slightly higher than intra-day precision, with a range of 0.7 % ∼ 19.1 %. We report for the first time on the effect of gender and BMI on the accuracy and recovery of human urine samples, and results from analysis of variance (ANOVA), and principal component analysis (PCA) indicated there was no difference in the value of accuracy and recovery between different gender or BMI (>30) using our purposed cleanup and UHPLC-QqQ-MS/MS method. Overall, this newly developed method could serve as a powerful tool for analyzing grape phenolic compounds and metabolites in human urine samples.

Stability of Propolis Phenolics during Ultrasound-Assisted Extraction Procedures

Propolis has gained popularity in recent years as a potential preventive and therapeutic agent due to its numerous health benefits, which include immune system boosting, blood pressure lowering, allergy treatment, and skin disease treatment. The pharmacological activity of propolis is primarily attributed to phenolics and their interactions with other compounds. Given that phenols account for most of propolis's biological activity, various extraction methods are being developed. The resin-wax composition of the propolis matrix necessitates the development of an extraction procedure capable of breaking matrix-phenol bonds while maintaining phenol stability. Therefore, the aim of this study was to assess the stability of two major groups of phenolic compounds, flavonoids and phenolic acids, in propolis methanol/water 50/50 (v/v) extracts obtained after ultrasound-assisted extraction (USE) under different extraction parameters (extraction time and pH) and heat reflux extraction (HRE). The methodology involved varying the USE parameters, including extraction time (5, 10, and 15 min) and pH (2 and 7), followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify phenolic recoveries. Results revealed that benzoic acid and chlorogenic acid derivatives demonstrated excellent stability across all ultrasound extraction procedures. The recoveries of flavonoids were highly diverse, with luteolin, quercitrin, and hesperetin being the most stable. Overall, neutral pH improved flavonoid recovery, whereas phenolic acids remained more stable at pH = 2. The most important optimization parameter was USE time, and it was discovered that 15 min of ultrasound resulted in the best recoveries for most of the phenols tested, implying that phenols bind strongly to the propolis matrix and require ultrasound to break the bond. However, the high variability in phenol extraction and recovery after spiking the propolis sample shows that no single extraction method can produce the highest yield of all phenols tested. As a result, when working with a complex matrix like propolis, the extraction techniques and procedures for each phenol need to be optimized.

The Evolution of Sonochemistry: From the Beginnings to Novel Applications

Sonochemistry is the use of ultrasonic waves in an aqueous medium, to generate acoustic cavitation. In this context, sonochemistry emerged as a focal point over the past few decades, starting as a manageable process such as a cleaning technique. Now, it is found in a wide range of applications across various chemical, physical, and biological processes, creating opportunities for analysis between these processes. Sonochemistry is a powerful and eco-friendly technique often called "green chemistry" for less energy use, toxic reagents, and residues generation. It is increasing the number of applications achieved through the ultrasonic irradiation (USI) method. Sonochemistry has been established as a sustainable and cost-effective alternative compared to traditional industrial methods. It promotes scientific and social well-being, offering non-destructive advantages, including rapid processes, improved process efficiency, enhanced product quality, and, in some cases, the retention of key product characteristics. This versatile technology has significantly contributed to the food industry, materials technology, environmental remediation, and biological research. This review is created with enthusiasm and focus on shedding light on the manifold applications of sonochemistry. It delves into this technique's evolution and current applications in cleaning, environmental remediation, microfluidic, biological, and medical fields. The purpose is to show the physicochemical effects and characteristics of acoustic cavitation in different processes across various fields and to demonstrate the extending application reach of sonochemistry. Also to provide insights into the prospects of this versatile technique and demonstrating that sonochemistry is an adapting system able to generate more efficient products or processes.

Profiling of the Polyphenol Content of Honey from Different Geographical Origins in the United States

The presence of phenolic compounds in honey can serve as potential authenticity markers for honey's botanical or geographical origins. The composition and properties of honey can vary greatly depending on the floral and geographical origins. This study focuses on identifying the specific markers that can distinguish honey based on their geographical areas in the United States. The main approach presented in this study to identify the geographic origins of honey involves chemometric methods combined with phenolic compound fingerprinting. Sample clean-up and phenolic compound extraction was carried out using solid phase extraction (SPE). Reversed phase liquid chromatography in combination with tandem mass spectrometry were utilized for the separation of the compounds. The honey physicochemical qualities were predominantly determined via spectrophotometric methods. Multivariate statistical tools such as principal component analysis (PCA), analysis of variance (ANOVA), and partial-least squares discriminant analysis (PLS-DA) were employed as both classification and feature selection tools. Overall, the present study was able to identify the presence of 12 potential markers to differentiate the honey's geographical origins. The total phenolic content ranged from 81.6 to 105.7 mg GAE/100 g corresponding to honey from Colorado and Washington, respectively (GAE: gallic acid equivalents). The regression analysis shows a tendency for the total phenolic content of honey to increase as the color of honey increases. The most important result obtained in this study is the demonstration that the geographical origin of honey plays a critical role in predicting the physical properties and phenolic composition of honey.

Sonoprocessing improves phenolics profile, antioxidant capacity, structure, and product qualities of purple corn pericarp extract

For the first time, purple corn pericarp (PCP) was converted to polyphenol-rich extract using two-pot ultrasound extraction technique. According to Plackett-Burman design (PBD), the significant extraction factors were ethanol concentration, extraction time, temperature, and ultrasonic amplitude that affected total anthocyanins (TAC), total phenolic content (TPC), and condensed tannins (CT). These parameters were further optimized using the Box-Behnken design (BBD) method for response surface methodology (RSM). The RSM showed a linear curvature for TAC and a quadratic curvature for TPC and CT with a lack of fit > 0.05. Under the optimum conditions (ethanol (50%, v/v), time (21 min), temperature (28 °C), and ultrasonic amplitude (50%)), a maximum TAC, TPC, and CT of 34.99 g cyanidin/kg, 121.26 g GAE/kg, and 260.59 of EE/kg, respectively were obtained with a desirability value 0.952. Comparing UAE to microwave extraction (MAE), it was found that although UAE had a lower extraction yield, TAC, TPC, and CT, the UAE gave a higher individual anthocyanin, flavonoid, phenolic acid profile, and antioxidant activity. The UAE took 21 min, whereas MAE took 30 min for maximum extraction. Regarding product qualities, UAE extract was superior, with a lower total color change (ΔE) and a higher chromaticity. Structural characterization using SEM showed that MAE extract had severe creases and ruptures, whereas UAE extract had less noticeable alterations and was attested by an optical profilometer. This shows that ultrasound, might be used to extract phenolics from PCP as it requires lesser time and improves phenolics, structure, and product qualities.

Off-Line SPE LC-LRMS Polyphenolic Fingerprinting and Chemometrics to Classify and Authenticate Spanish Honey

The feasibility of non-targeted off-line SPE LC-LRMS polyphenolic fingerprints to address the classification and authentication of Spanish honey samples based on both botanical origin (blossom and honeydew honeys) and geographical production region was evaluated. With this aim, 136 honey samples belonging to different botanical varieties (multifloral and monofloral) obtained from different Spanish geographical regions with specific climatic conditions were analyzed. Polyphenolic compounds were extracted by off-line solid-phase extraction (SPE) using HLB (3 mL, 60 mg) cartridges. The obtained extracts were then analyzed by C18 reversed-phase LC coupled to low-resolution mass spectrometry in a hybrid quadrupole-linear ion trap mass analyzer and using electrospray in negative ionization mode. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were employed to assess the pattern recognition capabilities of the obtained fingerprints to address honey classification and authentication. In general, a good sample discrimination was accomplished by PLS-DA, being able to differentiate both blossom-honey and honeydew-honey samples according to botanical varieties. Multiclass predictions by cross-validation for the set of blossom-honey samples showed sensitivity, specificity, and classification ratios higher than 60%, 85%, and 87%, respectively. Better results were obtained for the set of honeydew-honey samples, exhibiting 100% sensitivity, specificity, and classification ratio values. The proposed fingerprints also demonstrated that they were good honey chemical descriptors to deal with climatic and geographical issues. Characteristic polyphenols of each botanical variety were tentatively identified by LC-MS/MS in multiple-reaction monitoring mode to propose possible honey markers for future experiments (i.e., naringin for orange/lemon blossom honeys, syringic acid in thyme honeys, or galangin in rosemary honeys).

Chemical Composition and the Anticancer, Antimicrobial, and Antioxidant Properties of Acacia Honey from the Hail Region: The in vitro and in silico Investigation

In consideration of the emergence of novel drug-resistant microbial strains and the increase in the incidences of various cancers throughout the world, honey could be utilized as a great alternative source of potent bioactive compounds. In this context, this study pioneers in reporting the phytochemical profiling and the antimicrobial, antioxidant, and anticancer properties of Acacia honey (AH) from the Hail region of Saudi Arabia, assessed using in vitro and molecular docking approaches. The phytochemical profiling based on high-resolution liquid chromatography-mass spectrometry (HR-LCMS) revealed eight compounds and three small peptide-like proteins as the constituents. The honey samples exhibited promising antioxidant activities (DPPH-IC₅₀ = 0.670 mg/mL; ABTS-IC₅₀ = 1.056 mg/mL; β-carotene-IC₅₀ > 5 mg/mL). In the well-diffusion assay, a high mean growth inhibition zone (mGIZ) was observed against Staphylococcus aureus (48.33 ± 1.53 mm), Escherichia coli ATCC 10536 (38.33 ± 1.53 mm), and Staphylococcus epidermidis ATCC 12228 (39.33 ± 1.15 mm). The microdilution assay revealed that low concentrations of AH could inhibit the growth of almost all the evaluated bacterial and fungal strains, with the minimal bactericidal concentration values (MBCs) ranging from 75 mg/mL to 300 mg/mL. On the contrary, high AH concentrations were required to kill the tested microorganisms, with the minimal bactericidal concentration values (MBCs) ranging from approximately 300 mg/mL to over 600 mg/mL and the minimal fungicidal concentration values (MFCs) of approximately 600 mg/mL. The AH exhibited effective anticancer activity in a dose-dependent manner against breast (MCF-7), colon (HCT-116), and lung (A549) cancer cell lines, with the corresponding IC₅₀ values of 5.053 μg/mL, 5.382 μg/mL, and 6.728 μg/mL, respectively. The in silico investigation revealed that the observed antimicrobial, antioxidant, and anticancer activities of the constituent compounds of AH are thermodynamically feasible, particularly those of the tripeptides (Asp-Trp-His and Trp-Arg-Ala) and aminocyclitol glycoside. The overall results highlighted the potential of AH as a source of bioactive compounds with significant antimicrobial, antioxidant, and anticancer activities, which could imply further pharmacological applications of AH.

Hesperidin: A Review on Extraction Methods, Stability and Biological Activities

Hesperidin is a bioflavonoid occurring in high concentrations in citrus fruits. Its use has been associated with a great number of health benefits, including antioxidant, antibacterial, antimicrobial, anti-inflammatory and anticarcinogenic properties. The food industry uses large quantities of citrus fruit, especially for the production of juice. It results in the accumulation of huge amounts of by-products such as peels, seeds, cell and membrane residues, which are also a good source of hesperidin. Thus, its extraction from these by-products has attracted considerable scientific interest with aim to use as natural antioxidants. In this review, the extraction and determination methods for quantification of hesperidin in fruits and by-products are presented and discussed as well as its stability and biological activities.

Potential Therapeutic Benefits of Honey in Neurological Disorders: The Role of Polyphenols

Honey is the principal premier product of beekeeping familiar to Homo for centuries. In every geological era and culture, evidence can be traced to the potential usefulness of honey in several ailments. With the advent of recent scientific approaches, honey has been proclaimed as a potent complementary and alternative medicine for the management and treatment of several maladies including various neurological disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis, etc. In the literature archive, oxidative stress and the deprivation of antioxidants are believed to be the paramount cause of many of these neuropathies. Since different types of honey are abundant with certain antioxidants, primarily in the form of diverse polyphenols, honey is undoubtedly a strong pharmaceutic candidate against multiple neurological diseases. In this review, we have indexed and comprehended the involved mechanisms of various constituent polyphenols including different phenolic acids, flavonoids, and other phytochemicals that manifest multiple antioxidant effects in various neurological disorders. All these mechanistic interpretations of the nutritious components of honey explain and justify the potential recommendation of sweet nectar in ameliorating the burden of neurological disorders that have significantly increased across the world in the last few decades.

Isolation of Laurus nobilis Leaf Polyphenols: A Review on Current Techniques and Future Perspectives

In recent years, the market demand for products enhanced with ingredients derived from natural products, such as polyphenols, is rapidly increasing. Laurus nobilis L., known as bay, sweet bay, bay laurel, Roman laurel or daphne is an evergreen Mediterranean shrub whose leaves have traditionally been used in cuisines and folk medicine due to their beneficial health effects, which can nowadays be scientifically explained by various biological activities of the leaf extracts. Many of these activities can be attributed to phenolic compounds present in L. nobilis leaves which include flavonoids, phenolic acids, tannins (proanthocyanidins) and lignans. In order to enable efficient industrial utilization of these valuable compounds, it is crucial to establish optimal extraction procedures resulting in the highest yields and quality of the extracts. This paper offers the first systematic review of current literature on the influence of conventional and advanced extraction techniques, including microwave-assisted, ultrasound-assisted, enzyme-assisted, supercritical-CO2 and mechanochemical-assisted extraction on the phenolic content of L. nobilis leaf extracts, allowing more efficient planning of further research and simplifying the steps towards industrial utilization of this plant.

The effect of cranberry juice and a cranberry functional beverage on the growth and metabolic activity of selected oral bacteria

BACKGROUND

The oral microbiota is a significant risk indicator for oral diseases, such as dental caries and periodontal inflammation. Much attention is presently paid to the development of functional foods (e.g. beverages containing cranberry constituents, or foods containing probiotics) that may serve as adjuncts for oral disease treatments (e.g. periodontitis and caries). Cranberry fruit, due to its unique chemical composition and antimicrobial potential, is a possible ingredient of such foods. The study aimed to investigate the effects of cranberry juice (CJ) and a cranberry functional beverage (mixture of 80% v/v apple juice, 20% v/v cranberry juice, and 0.25 g/100 mL ground cinnamon; CFB) on the growth and metabolic activity of selected oral bacteria.

METHODS

Serial dilution pour plate method (SDPP) was used to examine the effect of CJ and CFB on the growth of Actinomyces naeslundii, Streptococcus mutans, and Lactobacillus paracasei subsp. paracasei. 48-h electrical impedance measurements (EIM) during the cultivation of A. naeslundii were applied to evaluate the utility of the method as a rapid alternative for the assessment of the antimicrobial potential of cranberry beverages.

RESULTS

The tested bacteria differed in their susceptibility to the antimicrobial action of CJ and CFB, with L. paracasei subsp. paracasei being least vulnerable to CFB (according to SDPP). Although CJ at a concentration of 0.5 mL/mL, showed a bactericidal effect on the growth of S. mutans, A. naeslundii was more sensitive to CJ (SDPP). Its inhibitory effect on A. naeslundii was seen even at concentrations as small as 0.03125-0.125 mL/mL (SDPP and EIM). On the other hand, S. mutans seemed to be more vulnerable to CFB than A. naeslundii (SDPP).

CONCLUSIONS

CFB may be considered an adjunct in the treatment of oral diseases due to its action against selected oral pathogens, and not against the presumably beneficial L. paracasei subsp. paracasei. Bioelectrical impedance measurements appear to be a quick alternative to evaluating the antimicrobial activity of fruit beverages, but their utility should be confirmed with tests on other bacteria.

Enzymatic glucosylation of polyphenols using glucansucrases and branching sucrases of glycoside hydrolase family 70

Polyphenols exhibit various beneficial biological activities and represent very promising candidates as active compounds for food industry. However, the low solubility, poor stability and low bioavailability of polyphenols have severely limited their industrial applications. Enzymatic glycosylation is an effective way to improve the physicochemical properties of polyphenols. As efficient transglucosidases, glycoside hydrolase family 70 (GH70) glucansucrases naturally catalyze the synthesis of polysaccharides and oligosaccharides from sucrose. Notably, GH70 glucansucrases show broad acceptor substrate promiscuity and catalyze the glucosylation of a wide range of non-carbohydrate hydroxyl group-containing molecules, including benzenediol, phenolic acids, flavonoids and steviol glycosides. Branching sucrase enzymes, a newly established subfamily of GH70, are shown to possess a broader acceptor substrate binding pocket that acts efficiently for glucosylation of larger size polyphenols such as flavonoids. Here we present a comprehensive review of glucosylation of polyphenols using GH70 glucansucrase and branching sucrases. Their catalytic efficiency, the regioselectivity of glucosylation and the structure of generated products are described for these reactions. Moreover, enzyme engineering is effective for improving their catalytic efficiency and product specificity. The combined information provides novel insights on the glucosylation of polyphenols by GH70 glucansucrases and branching sucrases, and may promote their applications.

Evaluating the Presence and Contents of Phytochemicals in Honey Samples: Phenolic Compounds as Indicators to Identify Their Botanical Origin

Honey is a natural product well known for its beneficial properties. It contains phytochemicals, a wide class of nutraceuticals found in plants, including compounds with highly demonstrated antimicrobial and antioxidant capacities as phenolic compounds and flavonoids. The main goal of this work is the development of a miniaturized and environmentally friendly methodology to obtain the phenolic profile of Galician honeys (Northwest Spain) from different varieties such as honeydew, chestnut, eucalyptus, heather, blackberry and multi-floral. The total phenolic content (TPC) and antioxidant activity (AA) were also evaluated. As regards sample preparation, miniaturized vortex (VE) and ultrasound assisted extraction (UAE) employing aqueous-based solvents were performed. Individual quantification of 41 target phenolic compounds was carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results revealed the presence of 25 phenolic compounds in the 91 analyzed samples, reaching concentrations up to 252 µg g⁻¹. Statistical tools such as analysis of variance (ANOVA) and principal component analysis (PCA) were employed to obtain models that allowed classifying the different honeys according to their botanical origin. Obtained results, based on TPC, AA and ∑phenolic compounds showed that significant differences appeared depending on the honey variety, being several of the identified phenol compounds being responsible of the main differentiation.

Antixenosis in Glycine max (L.) Merr against Acyrthosiphon pisum (Harris)

To reveal the antixenosis potential against the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) we analyzed the pea aphid survival and probing behavior, and the quantitative and qualitative variation of flavonoids in the leaves of selected soybean Glycine max (L.) Merr (Fabaceae) cultivars 'Aldana', 'Annushka', 'Augusta', 'Madlen', 'Mavka', 'Simona', 'Violetta', and 'Viorica'. Aphid survival was drastically impeded on all cultivars. The electronic monitoring of aphid probing using the Electrical Penetration Graph (EPG) technique revealed that on all soybean cultivars, A. pisum readily probed into leaf tissues but the probes were usually terminated before reaching vascular tissues, which demonstrates the activity of antixenosis mechanisms in peripheral tissues epidermis and/or mesophyll in soybean leaves. The potency of antixenosis factors differed among soybean cultivars, which was reflected in differences in aphid survival and frequency and duration of phloem sap ingestion. Seven flavonoids were found: apigenin, daidzein, genistein, glycitein, isorhamnetin, kaempferol, and rutin, which occurred in different amount and proportion in individual cultivars. The content of apigenin and genistein in all soybean cultivars studied probably made them relatively unacceptable to A. pisum. Kaempferol in 'Aldana' might be responsible for the observed strong antixenosis resistance of this cultivar to A. pisum. The results of our survey provide the first detailed data that can be used for future studies.

Phenolic composition and biological activities of stingless bee honey: An overview based on its aglycone and glycoside compounds

Stingless bees are native to tropical and subtropical countries, such as Brazil. The wide variety of species, the sources of food collection (nectar and pollen), and the climate conditions strongly affect the chemical composition of the honey, making this a unique product with peculiar characteristics. Stingless bee honey presents higher water content, higher acidity, and a lower sugar concentration when compared to Apis mellifera honey. Moreover, there is a wide variety of microorganisms in stingless bees' environment, which leads their honey to go through a natural fermentative process during its production in the hive. Besides, fermentation and hydrolysis are effective ways to convert glycosides into aglycones, thus increasing the bioavailability of compounds. In this sense, stingless bee honey may possess a greater concentration of phenolic compounds aglycones than glycosides, which would increase its potential benefits. Therefore, this review aims to compile the most recent studies of stingless bee honey phenolic profile and its biological potential (antioxidant, antimicrobial, and anti-inflammatory activities) and a possible connection to its natural fermentation process.

Multidimensional Comparative Analysis of Bioactive Phenolic Compounds of Honeys of Various Origin

Honey is a natural product which owes its health benefits to its numerous bioactive compounds. The composition of honey is highly diverse and depends on the type of honey and its origin. Antioxidant capacity arises mainly from the total content of polyphenols and their composition. The aim of this study was to perform a multidimensional comparative analysis of phenolic compounds of honeys of various origins. Honeydew, buckwheat, manuka, Malaysian and goldenrod honeys had the highest antioxidant capacity (above 400 mg Trolox equivalents kg⁻¹). These honeys were also characterized by the highest total polyphenol content (about 2500 mg gallic acid equivalents (GAE) kg⁻¹) and the highest total flavonoid content (1400–1800 mg catechin equivalents (CAE) kg⁻¹). Other honeys had much lower antioxidant properties. A multidimensional analysis of the profiles of phenolic compounds showed that honeys constitute a non-homogeneous data set and manuka honey was in contrast to other samples. Principal component analysis (PCA) (based on 18 phenolic compounds) distinguished honeys into five groups. Manuka, Malaysian and honeydew honeys created their own separate groups and the location of other honeys was variable. Ultra-high-performance liquid chromatography (UHPLC) analysis demonstrated that profiles of polyphenols in honeys were highly varied. Caffeic acid, datiscetin and rhamnetin were characteristic compounds for manuka honey. Quercetin, kaempferol and apigenin were present in all honeys except Malaysian honey. The antioxidant properties and the profiles of bioactive phenolic compounds of honeys were miscellaneous. The richest sources of polyphenols were local buckwheat and honeydew honeys, alongside exotic manuka and Malaysian honeys. These honeys could provide valuable ingredients to the human diet, helping to prevent diseases.

Possible Potential Effects of Honey and Its Main Components Against Covid-19 Infection

Coronavirus disease 2019 (COVID-19) is a viral pneumonia that is spreading rapidly worldwide. The main feature of this disease is a severe acute respiratory syndrome and caused by coronavirus 2 (SARS-CoV-2). There are several unknowns about the pathogenesis and therapeutically treatment of COVID-19 infection. In addition, available treatment protocols have not been effective in managing COVID-19 infection. It is proposed that natural anti-oxidants such as lemon, green tea, saffron, curcuma longa, etc. with high flavonoids like safranal, crocin, crocetin, catechins, resveratrol, calebin A, curcumin have therapeutic potential against viral infections. In this context, honey and its main components are being investigated as an option for patients with COVID-19. The present study may indicate that honey and its main components inhibit the entry of the virus into the host cell and its replication as well as modulate the inflammatory cascade. This review provides basic information for the possible potential effects of honey and its main components for fighting with SARS-CoV-2.

Identification of sugars and phenolic compounds in honey powders with the use of GC-MS, FTIR spectroscopy, and X-ray diffraction

This work aimed at the chemical and structural characterization of powders obtained from chestnut flower honey (HFCh) and honey with Inca berry (HBlu). Honey powders were obtained by spray drying technique at low temperature (80/50 °C) with dehumidified air. Maltodextrin (DE 15) was used as a covering agent. The isolation and evaluation of phenolic compounds and sugars were done by gas chromatography-mass spectrometry analysis. Scanning electron microscopy, Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction were performed to determine the morphology of the studied honey powders. The obtained results showed that the content of simple sugars amounted to 72.4 and 90.2 g × 100 g^-1 in HFCh and HBlu, respectively. Glucose was found to be the dominant sugar with a concentration of 41.3 and 51.6 g × 100 g^-1 in HFCh and HBlu, respectively. 3-Phenyllactic acid and ferulic acid were most frequently found in HFCh powder, whereas m-coumaric acid, benzoic acid, and cinnamic acid were the most common in HBlu powder. The largest changes in the FTIR spectra occurred in the following range of wavenumbers: 3335, 1640, and below 930 cm^-1. The X-ray diffraction profiles revealed wide peaks, suggesting that both honey powders are amorphous and are characterized by a short-range order only.

Identifying Plant-Based Natural Medicine against Oxidative Stress and Neurodegenerative Disorders

Free radicals and oxidative stress are among the most studied factors leading to the imbalance in mental health. With no exception, free radicals also damage neuronal cells, leading to various degenerative diseases. With existing modern medications, around 80% of the world population relies on herbal medicine for various ailments. Phytochemicals in plants have a wide range of pharmacological properties, the major being their ability to scavenge free radicals. Plant polyphenols are among the major class of antioxidants identified in plants. This antioxidative property of plant compounds and their ability to downgrade the process of oxidative stress can be used to treat neurodegenerative diseases. However, selecting plants and their active compounds is a crucial step in framing the mechanism of action underlying their therapeutic potential.

Kairomone-like activity of bile and bile components: A step towards revealing the chemical nature of fish kairomone

Despite the efforts of a number of research groups worldwide, we still have a poor understanding of the chemical nature of the fish kairomones which induce defensive morphology, life history and behavior in their planktonic prey. Bile excreted by foraging fish play a crucial role in their signaling systems. Using high-performance liquid chromatography (HPLC), we revealed the presence of primary and secondary bile acids and bile salts in fish-conditioned water, similar as in carp bile. Upon exposure to either fish bile or commercially acquired bile salts, Daphnia demonstrated similar changes in life history and behavior as when exposed to fish kairomones. The synergic effect of the injured Daphnia alarm substance with fish bile on Daphnia life history is similar to the adaptive effect of the same alarm substance combined with fish kairomones. This strongly supports the view that fish bile or selected bile acids/salts may be responsible for the biological activity of kairomones.

Antioxidant Activity, Total Phenolic Content, Individual Phenolics and Physicochemical Parameters Suitability for Romanian Honey Authentication

The present study aimed to evaluate the physicochemical characteristics of honey (raspberry, mint, rape, sunflower, thyme and polyfloral) produced in Romania. The honey samples were from the 2017 to 2018 harvest and were subjected to melissopalynological analysis, alongside the determination of the following physicochemical parameters: moisture content, pH, free acidity, electrical conductivity (EC), hydroxymethylfurfural (HMF) content, color, total polyphenols content (TPC), flavonoids content (FC), DPPH radical scavenging activity, phenolic acids, flavonols, sugars and organic acids in order to evaluate the usefulness of this parameters for the classification of honey according to botanical origin. The results of the melissopalynological analysis revealed that five types of honey samples had a percentage of pollen grains above the minimum of 45%, which was required in order to classify the samples as monofloral honey. The total polyphenols content reached the maximum value in the case of dark honey such as mint honey, followed by raspberry, thyme and polifloral honey. Fructose, glucose, maltose, sucrose, turanose, trehalose, melesitose, and raffinose were identified and quantified in all samples. Gluconic acid was the main organic acid in the composition of all honey samples. Principal component analysis (PCA) confirmed the possibility of the botanical authentication of honey based on these physicochemical parameters.

Viticultural wood waste as a source of polyphenols of interest: Opportunities and perspectives through conventional and emerging extraction methods

Viticultural waste has been widely demonstrated to contain high-added value compounds named the stilbenes. Among them, trans-resveratrol (Rsv) and trans-ε-viniferin (Vf) are the most abundant in particular in grape canes. Various emerging methods such as ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) or pressurized solvent extraction (PSE) have been studied to recover Rsv and Vf from grape canes in order to enhance their extraction. This paper gives a critical overview of the techniques used to this end, integrating conventional and non-conventional methods investigated in the literature as well as those used in industrial processes. It finally highlights that the unconventional technics are usually less time-consuming than conventional extraction ones but further investigations for the discussed compounds and biomass are needed to optimize and understand the influence of the individual parameters of each extraction process.

Recent Advances in Microwave Assisted Extraction of Bioactive Compounds from Complex Herbal Samples: A Review

Microwaves are utilized for extraction of Phytoconstituents from complex herbal sample as a result of incredible research. Conventional extraction strategies are tedious and need more solvents and are no more relevant for thermal sensitive plant components. This review emphasize on the working and significance of microwave extraction technology in herbal research and medical field. The extraction step must be more yielding; quick, particular, not more solvent consuming, ensuring stability of thermolabile components and these features are available with microwave extraction method. In this nonconventional technology heat is created utilizing microwave energy. The important parameters that influence extraction efficiency are solvent properties, volume, duration of exposure, microwave control, system attributes, temperature and application were discussed in this article. The microwave assisted extraction, as green technology is contrasted with other extraction technique. This review is intended to discuss this green extraction technique along with its critical parameters for extracting bioactive compounds from complex plant matrices.

Phenolic acids: Natural versatile molecules with promising therapeutic applications

Plant phenolics are considered to be a vital human dietary component and exhibit a tremendous antioxidant activity as well as other health benefits. Epidemiology evidence indicates that a diet rich in antioxidant fruits and vegetables significantly reduces the risk of many oxidative stress related diseases viz. cancers, diabetes and cardiovascular. The number and position of hydroxyl group in a particular phenolic compound leads to the variation in their antioxidant potential. Polyphenols are the main source of dietary antioxidants, and are effortlessly absorbed in the intestine. Phenolic acids, a sub class of plant phenolics, possess phenol moiety and resonance stabilized structure which causes the H-atom donation results in antioxidant property through radical scavenging mechanism. Other mode such as radical quenching via electron donation and singlet oxygen quenching are also known for the antioxidant activity of phenolic acids. Furthermore, phenolic acids are found ubiquitously and well documented for other health protective effects like antimicrobial, anticancer, anti-inflammatory, anti-mutagenic etc. The contribution emphasize on the phenolic acids potential in drug discovery. In addition their occurrence, biosynthesis, metabolism and health effects are discussed in detail.

Comparison of Physicochemical, Microbiological Properties and Bioactive Compounds Content of Grassland Honey and other Floral Origin Honeys

The aim of this study was to compare the physicochemical, the microbiological, and the antioxidant characteristics of unifloral honey, polyfloral honey, honeydew, and hay meadows honey. Hay meadow is type of semi-natural grassland with a great floral diversity, an important resource for pollinators. Grasslands are the source of the spring nectar honey obtained in May and June. Water content, sugars (fructose, glucose, sucrose, trehalose, melezitose, maltose, erlose, turanose, and raffinose), electrical conductivity, phenolic content (gallic acid, protocatechuic acid, 4-hydrxybenzoic acid, vanilic acid, chlorogenic acid, caffeic acid, p-coumaric acid, rosmarinic acid, myricetin, quercitin, luteolin, kaempferol), color, viscosity, and microbiological characteristics were performed for all samples of honey. The total polyphenols content was significant for grassland honey (21.50 mg/100 g) and honeydew (30.49 mg/100 g) and less significant for acacia (0.08 mg/100 g) and rape honey (0.14 mg/100 g). All samples were microbiologically safe, and standard plate count (SPC) values were <10 cfu/g for all the samples, but the grassland honey had the highest microbiological quality: 33.3% of samples without microorganisms, 50.0% with the presence of yeast under limit, and 16.7% with yeast and mold under limit, a situation that does not meet other types of honey. The results of statistical analysis obtained with principal component analysis (PCA) showed a major difference between the grassland honey and the other types of honey.

Tuning Optical and Granulometric Properties of Gold Nanostructures Synthesized with the Aid of Different Types of Honeys for Microwave-Induced Hyperthermia

Size-controlled gold nanoparticles (AuNPs) were synthesised with solutions of three types of Polish honeys (lime, multiflower, honeydew) and used in microwave-induced hyperthermia cancer treatment. Optical and structural properties of nanostructures were optimized in reference to measurements made by using UV/Vis absorption spectrophotometry (UV/Vis), transmission electron microscopy (TEM) supported by energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and attenuated total reflectance Fourier transformation infrared spectroscopy (ATR FT-IR). In addition, concentrations of reducing sugars and polyphenols of honeys applied were determined to reveal the role of these chemical compounds in green synthesis of AuNPs. It was found that the smallest AuNPs (20.6 ± 23.3 nm) were produced using a 20% (w/v) multiflower aqueous honey solution and 25 mg·L-1 of Au(III) ions. These AuNPs were then employed in microwave-induced hyperthermia in a system simulating metastatic tissues. This research illustrated that AuNPs, as produced with the aid of a multiflower honey solution, could be suitably used for microwave-induced heating of cancer. A fluid containing resultant Au nanostructures, as compared to water, revealed facilitated heating and the ability to maintain a temperature of 45 °C required for hyperthermia treatment.

Recovery of chlorophylls from spent biomass of Arthrospira platensis obtained after extraction of phycobiliproteins

Extraction of chlorophylls has received scant attention or priority over phycobiliproteins from Arthrospira platensis. In fact extraction of chlorophylls from spent biomass (left after extraction of phycobiliproteins which goes as waste or underutilized) on drying, will improve the economics of the overall downstream processing. Ethanol (yield 5.75 mg/g, db), being a food grade solvent, was preferred over acetone and dimethyl sulfoxide in spite of their slightly better yields (5.85 mg/g, db). The best conditions were 100% concentration of ethanol, 1:8 S/L ratio, pH 6, 50 °C temperature and 1 h extraction time. An increase of 125% in yield besides reduction of 83.3% in extraction time (from 6 to 1 h) could be achieved at standardized conditions. Low-Humidity drying was observed to be a possible alternative to freeze drying for drying of spent biomass. Ultrasonication as pre-treatment and ethanol as solvent were found effective for extraction of chlorophylls from dry spent biomass.

Quality characterization and effect of sonication time on bioactive properties of honey from North East India

The North-Eastern region of India is known for its rich flora and has great potential for honey production. Honey samples collected from local markets of different regions of North-East India viz. Shillong, Sohra, Mawsynram, Jorhat and Tezpur were analyzed for physicochemical properties, bioactivity and mineral content. Effect of sonication time on the bioactive properties of honey was determined. All the honey samples had good bioactive properties and high content of potassium, sodium, calcium and iron. The Jorhat sample had the highest phenolic content (296.68 ± 2.16 mg GAE/100 g) and flavonoid content (155.26 ± 2.90 μg quercetin/100 g) whereas highest DPPH radical scavenging activity with an IC₅₀ value of 29.8 ± 0.20 g and a FRAP value of 7291.60 ± 584.6 μM Fe(II)/100 g were noted in Shillong sample. Sonication exhibited various effects on the bioactive properties of the selected honey samples based on their source and treatment time. Honey from Jorhat and Sohra exhibited good quality standards with HMF content less than 80 mg/kg.