Development of a LC-QTOF-MS based dilute-and-shoot approach for the botanical discrimination of honeys.

Honeys of particular botanical origins can be associated with premium market prices, a trait which also makes them susceptible to fraud. Currently available authenticity testing methods for botanical classification of honeys are either time-consuming or only target a few "known" types of markers. Simple and effective methods are therefore needed to monitor and guarantee the authenticity of honey. In this study, a 'dilute-and-shoot' approach using liquid chromatography (LC) coupled to quadrupole time-of-flight-mass spectrometry (QTOF-MS) was applied to the non-targeted fingerprinting of honeys of different floral origin (buckwheat, clover and blueberry). This work investigated for the first time the impact of different instrumental conditions such as the column type, the mobile phase composition, the chromatographic gradient, and the MS fragmentor voltage (in-source collision-induced dissociation) on the botanical classification of honeys as well as the data quality. Results indicated that the data sets obtained for the various LC-QTOF-MS conditions tested were all suitable to discriminate the three honeys of different floral origin regardless of the mathematical model applied (random forest, partial least squares-discriminant analysis, soft independent modelling by class analogy and linear discriminant analysis). The present study investigated different LC-QTOF-MS conditions in a "dilute and shoot" method for honey analysis, in order to establish a relatively fast, simple and reliable analytical method to record the chemical fingerprints of honey. This approach is suitable for marker discovery and will be used for the future development of advanced predictive models for honey botanical origin.

Physicochemical and antioxidant properties of Apis cerana honey from Lombok and Bali Islands.

Limited honey production worldwide leads to higher market prices, thus making it prone to adulteration. Therefore, regular physicochemical analysis is imperative for ensuring authenticity and safety. This study describes the physicochemical and antioxidant properties of Apis cerana honey sourced from the islands of Lombok and Bali, showing their unique regional traits. A comparative analysis was conducted on honey samples from Lombok and Bali as well as honey variety from Malaysia. Moisture content was found slightly above 20% in raw honey samples from Lombok and Bali, adhering to the national standard (SNI 8664:2018) of not exceeding 22%. Both honey types displayed pH values within the acceptable range (3.40-6.10), ensuring favorable conditions for long-term storage. However, Lombok honey exhibited higher free acidity (78.5±2.14 meq/kg) than Bali honey (76.0±1.14 meq/kg), surpassing Codex Alimentarius recommendations (≤50 meq/kg). The ash content, reflective of inorganic mineral composition, was notably lower in Lombok (0.21±0.02 g/100) and Bali honey (0.14±0.01 g/100) compared to Tualang honey (1.3±0.02 g/100). Electric conductivity, indicative of mineral content, revealed Lombok and Bali honey with lower but comparable values than Tualang honey. Hydroxymethylfurfural (HMF) concentrations in Lombok (14.4±0.11 mg/kg) and Bali (17.6±0.25 mg/kg) were slightly elevated compared to Tualang honey (6.4±0.11 mg/kg), suggesting potential processing-related changes. Sugar analysis revealed Lombok honey with the highest sucrose content (2.39±0.01g/100g) and Bali honey with the highest total sugar content (75.21±0.11 g/100g). Both honeys exhibited lower glucose than fructose content, aligning with Codex Alimentarius guidelines. The phenolic content, flavonoids, and antioxidant activity were significantly higher in Lombok and Bali honey compared to Tualang honey, suggesting potential health benefits. Further analysis by LC-MS/MS-QTOF targeted analysis identified various flavonoids/flavanols and polyphenolic/phenolic acid compounds in Lombok and Bali honey. The study marks the importance of characterizing the unique composition of honey from different regions, ensuring quality and authenticity in the honey industry.

Sacrificial template synthesis of hollow sulfonate group functionalized microporous organic network for efficient solid phase extraction of sulfonamide antibiotics from milk and honey samples.

The highly conjugated and hydrophobic characteristics of microporous organic networks (MONs) have largely impeded their broad applications in sample pretreatment especially for the polar or ionic analytes. In this work, a novel uniform hollow shaped sulfonate group functionalized MON (H-MON-SO3H-2) was synthesized via the sacrificial template method for the efficient solid phase extraction (SPE) of sulfonamides (SAs) from environmental water, milk, and honey samples prior to HPLC analysis. H-MON-SO3H-2 exhibited large specific surface area, penetrable space, good stability, and numerous hydrogen bonding, electrostatic, hydrophobic and π-π interaction sites, allowing sensitive SPE of SAs with wide linear range (0.150-1000 µg L-1), low limit of detection (0.045-0.188 µg L-1), good precisions (intra-day and inter-day RSD < 7.3%, n = 5), large enrichment factors (95.7-98.5), high adsorption capacities (250.4-545.0 mg g-1), and satisfactory reusability (more than 80 times). Moreover, the established method was successfully applied to extract SAs from spiked samples with the recoveries of 86.1-104.3%. This work demonstrated the great potential of H-MON-SO3H-2 in the efficient SPE of trace SAs in complex environmental water and food samples and revealed the prospect of hollow MONs in sample pretreatment.

Identification of toxic Gelsemium elegans in processed food and honey based on real-time PCR analysis.

Gelsemium elegans (GE) is a widely distributed hypertoxic plant that has caused many food poisoning incidents. Its pollen can also be collected by bees to produce toxic honey, posing a great threat to the health and safety of consumers. However, for the complex matrices such as cooked food and honey, it is challenging to perform composition analysis. It is necessary to establish more effective strategies for investigating GE contamination. In this study, the real-time PCR (qPCR) analysis combined with DNA barcode matK was proposed for the identification and detection of GE. Fifteen honey samples along with twenty-eight individuals of GE and the common confusable objects Lonicera japonica, Ficus hirta, Stellera chamaejasme and Chelidonium majus were gathered. Additionally, the food mixtures treated with 20-min boiling and 30-min digestion were prepared. Specific primers were designed, and the detection capability and sensitivity of qPCR in honey and boiled and digested food matrices were tested. The results demonstrated that the matK sequence with sufficient mutation sites was an effective molecular marker for species differentiation. GE and the confusable species could be clearly classified by the fluorescence signal of qPCR assay with a high sensitivity of 0.001 ng/µl. In addition, this method was successfully employed for the detection of deeply processed food materials and honey containing GE plants which even accounted for only 0.1 %. The sequencing-free qPCR approach undoubtedly can serve as a robust support for the quality supervision of honey industry and the prevention and diagnosis of food poisoning.

Insights into Q-markers of honey-fried licorice in treating spleen deficiency based on substance and energy metabolism regulation.

BACKGROUND: Honey-fried Licorice (HFL) is a dosage form of Glycyrrhizae Radix et Rhizome processed with honey, which has been recorded to exhibit better efficacy in tonifying the spleen compared to the raw product. In contrast, different processing methods of Glycyrrhizae Radix et Rhizome exhibit different efficacies and applications, but their current quality control index components remain consistent. PURPOSE: Based on the discovery and research strategy of traditional Chinese medicine decoction piece quality marker (Q-marker), this study aimed to conduct a multidimensional integration of constituents absorbed into the body and metabolomics based on the tonifying spleen and stomach effects of HFL to effectively identify the Q-marker of HFL. METHODS: In this study, a spleen deficiency rat model was established using the "exhausted swimming + poor diet" method to investigate the pharmacodynamics of tonifying the spleen and stomach by HFL. The constituents absorbed into blood was conducted using UPLC-Q-TOF/MS, correlation analysis between metabolomics and constituents absorbed into blood recognized the Q-Marker of HFL. RESULTS: The pharmacodynamic data demonstrated that HFL exhibited a significant regulatory effect on the disordered levels of PP, trypsin, chymase, PL, α-Glu, MTL, GAS, VIP, IL-2, IFN-γ, and IgA in the spleen deficiency model. Furthermore, HFL was found to improve the pathological changes in the spleen and intestine in the spleen deficiency model, highlighting its significant "tonifying spleen and stomach" effect. In the serum containing HFL, a total of 17 constituents were identified as being absorbed into the blood. Among these, 11 were prototypical components, while 6 were metabolites. Metabolomics data revealed that 9 differentially expressed metabolic markers were observed. Furthermore, the analysis of endogenous metabolic markers indicated that 10 components exhibited significant correlations with these biomarkers. CONCLUSION: The effect of "tonifying spleen and stomach" of HFL is closely related to the regulation of the material and energy metabolism pathway. The Q-Marker of HFL is glycyrrhizic acid and 18ß-glycyrrhetinic acid as the main control standards and liquiritin, isoliquiritin, liquiritin, isoliquiritin, isolicorice flavonol, licorice chalcone C and Formononetin were used as auxiliary standards.

Determining pyroxasulfone herbicide in honey samples using liquid-liquid extraction with low temperature purification (LLE-LTP).

Pyroxasulfone is a selective, systemic, pre-emergence herbicide which acts to inhibit weeds in potato, coffee, sugar cane, eucalyptus, and soybean plantations, among others. This active ingredient was classified by Brazilian legislation as a very dangerous product for the environment, and to date there are no studies involving the development of extraction methods for monitoring this compound in environmental matrices. Therefore, the objective of this study was to optimize and validate liquid-liquid extraction with low temperature purification followed by a gas chromatography coupled to mass spectrometry analysis to determine this herbicide in honey samples. The results showed that the best extractor phase was acetonitrile and ethyl acetate (6.5 mL:1.5 mL), with recovery rates close to 100% and relative standard deviations below 11%. The validation proved that the extraction method was selective, precise, accurate and linear in the range of 3-225 µg kg-1, reaching a limit of quantification of 3 µg kg-1, with a -25.95% matrix effect. Monitoring on real samples did not reveal episodes of environmental contamination with pyroxasulfone residue.

Traceability of chemicals from Tripterygium Wilfordii Hook. f. in raw honey and the potential synergistic effects of honey on acute toxicity induced by celastrol and triptolide.

The object of this study was to trace TwHf-derived toxins in raw honey and clarify their acute toxic effect related to the addition of honey or sugars. TwHf flowers, raw honey from TwHf planting base and from beekeepers in high-risk area were detected using LC-MS/MS. The results revealed five target toxins were detected in TwHf flowers; only celastrol was detected in one raw honey sample, as a food safety risk factor, celastrol had been traced back to TwHf flowers from raw honey. In a series of acute toxic tests on zebrafish, toxification effects were observed when honey, mimic honey or sugar was mixed with toxins. The degree of toxicity varied among various sugar-based solutions. At the same mass concentration, they follow this order: raw honey/mimic honey > glucose > fructose. The main toxic target organs of triptolide and celastrol with honey were the heart and liver.

Impact of Different Adulterants on Honey Quality Properties and Evaluating Different Analytical Approaches for Adulteration Detection.

The study was carried out keeping in view the recently emerging concern of adulteration of natural honey on the honey markets. This study intended to investigate honey adulteration detection using physical and chemical composition to achieve a foreign component (a marker) that is present in the honey that confirms either the adulteration or authenticity of the honey. The technique was evaluated on honey samples that were 5-50% adulterated with various common adulterants in Ethiopia. Preliminary quick tests and characterization of physicochemical and antioxidant properties were tested as alternative analytical approaches for honey adulteration detection. Preliminary quick test methods were used to detect adulterated honey, but these methods were found specific to adulterant materials. The proline and pH levels decreased as molasses, sugar, and banana adulterants increased, while increased as melted candy and shebeb adulterants increased. Moisture content decreased as sugar, melted candy, and shebeb adulterants were increased, while decreased as molasses and banana adulterants increased. HMF content increased as molasses, melted candy, and shebeb adulterants were increased. The sugar compositions are key differential criteria to detect the adulteration of honey with sugar. Based on their physical characteristics, PCA demonstrated a considerable difference between samples of pure and contaminated honey. In conclusion, it was observed that honey adulteration was detected based on significant deviations of physicochemical and biochemical components from expected values in the concentration of naturally occurring components. This study successfully demonstrated a method to rapidly and accurately classify and authenticate honey. Accordingly, it is recommended that frequent training for stakeholders on adulteration detection methods should be carried out to avoid adulteration of honey from the markets.

Nematicidal activity of paucimannose-type glycoconjugates from acacia honey.

Natural honey contains glycoconjugates as minor components. We characterized acacia honey glycoconjugates with molecular masses in the range of 2-5 kDa. The glycoconjugates were separated by RP-HPLC into three peaks (termed RP-2-5 k-I, RP-2-5 k-II, and RP-2-5 k-III) which demonstrated paralyzing effects on the model nematode C. elegans (ED50 of 50 ng glycoconjugates/µL). To examine molecular mechanisms underlying the nematicidal effects of honey glycoconjugates, expressional analyses of genes that are essential for the growth, development, reproduction, and movement of C. elegans were carried out. Quantitative PCR-based assays showed that these molecules moderately regulate the expression of genes involved in the citric acid cycle (mdh-1 and idhg-1) and cytoskeleton (act-1 and act-2). MALDI-ToF-MS/MS analysis of RP-HPLC peaks revealed the presence of paucimannose-like N-glycans which are known to play important roles in invertebrates e.g., worms and flies. These findings provided novel information regarding the structure and nematicidal function of honey glycoconjugates.

Impact of harvesting seasons on physicochemical properties and volatile compound profiles of Malaysian stingless bee honey analysed using chemometrics and support vector machine.

Stingless bee honey's nutritional value is gaining attention, but the impact of harvesting seasons, specifically the rainy (September 2018) and dry (February 2019) seasons in Malaysia on the honey's physicochemical properties and volatile compounds remains insufficiently explored. This research revealed marginal differences in the physicochemical properties between seasons. However, through individual bee species and cumulative data analysis, honey samples were effectively differentiated based on harvesting seasons. A set of seventeen volatile compounds were identified as potential chemical markers for distinguishing H. bakeri, G. thoracica, and T. binghami honey between rainy and dry seasons. For cumulative data, four significant markers were proposed. These discrimination methods and chemical markers can serve as valuable references in distinguishing stingless bee honey, whether its entomological origin is specified or not between rainy and dry seasons.

Flake-like structure of SrTiO3 nanoparticles dispersed on graphene oxide: A selective and sensitive electrochemical sensor for determination of chloramphenicol in milk and honey samples.

The use of Chloramphenicol (CAP), a potent antibiotic with broad-spectrum capabilities in food-producing animals has been restricted by the European Union and several other countries due to its severe side effects. Thus, CAP must be detected quickly and sensitively. In this investigation, the preparation of SrTiO3 nanoparticles was carried out utilizing a hydrothermal technique. The as-synthesized strontium titanate was decorated on the graphene oxide (SrTiO3/GO) using an ultrasonication method. An electrochemical sensor was developed by employing a modified electrode consisting of SrTiO3/GO, which can accurately detect CAP in food samples. The synergistic effect of SrTiO3 and GO could improve the peak current response. Remarkably, the SrTiO3/GO-modified glassy carbon electrode has a LOD and sensitivity of 6.08 µM nM and 2.771 µA·µM-1·cm-2, respectively. This modified electrode was evaluated in food samples and had an outstanding reaction with a high percentage of recovery, which makes it a potential electrocatalyst for CAP detection.

Biochemical Profiling and Physicochemical and Biological Valorization of Iraqi Honey: A Comprehensive Analysis.

Our study aimed to analyze five monovarietal honeys from the Salah Eddine region in Iraq, focusing on physicochemical, antioxidant, and antimicrobial properties and polyphenolic compounds. Our objective was to evaluate the strengths and qualities of Iraqi honeys, ensuring compliance with the Codex Alimentarius standard for honey. The spectrophotometric analysis included assessments of reduced sugar (75.8-77.7%), fructose-to-glucose ratio (0.7-0.9%), sucrose (2.2-2.9%), HMF (17.23-18.87 mg/kg), and melanoidin content (0.25-0.44), which were all determined. The electrical conductivity (0.39-0.46 mS/cm) using a conductivity meter, pH (4.02-4.31), and mineral composition were determined in all samples using atomic absorption spectrometry. Antioxidant activities were spectrophotometrically determined, through DPPH free radical scavenging (7.87-95.62 mg/mL), as was the total antioxidant activity (14.26-22.15 mg AAE/g), with correlations established with biochemical constituents such as the total phenol content, highlighting the significant presence of Coumaric acid (0.38-2.34 µg/mL), Catechin (1.80-2.68 µg/mL), and Quercetin (0.30 µg/mL) using HPLC. The study also observed notable antimicrobial activities using Escherichia coli, Staphylococcus aureus, and Candida albicans on Mueller-Hinton agar as well as through diffusion technique. In conclusion, our findings, including the antioxidant and antimicrobial strengths, underscore the substantial potential of Iraqi honeys in mitigating damage and preventing the onset of various diseases, affirming their good quality and adherence to international honey standards.

Quantitative analysis of biochemical characteristics and anti-cancer properties in MCF-7 breast cancer cell line: a comparative study between Ziziphus jujube honey and commercial honey.

BACKGROUND: There is increasing evidence that honey has anti-inflammatory, antioxidant, and anti-cancer effects. This study aims to assess and contrast the cytotoxic, anti-metastatic, and apoptotic effects of Ziziphus jujube honey and commercial honey on MCF7 cells. METHODS AND RESULTS: Two honey samples, Ziziphus jujube (JH) and commercial honey (CH), were categorized into high and low groups based on their phenolic content, antioxidant capacity, and diastase activity (PAD score). The viability and migration ability of MCF-7 cells treated with JH and CH were evaluated. Also, quantitative polymerase chain reaction (Q-PCR) was performed to assess the effect of the two honey samples on the expression of Bax, p53, p21 and Bcl-2 genes. JH had a total phenolic content of 606.4 ± 0.1 µg gallic acid equivalent/mg, while CH had a value of 112.1 ± 0.09 µg gallic acid equivalent/mg. The total antioxidant capacity of the two samples was compared. It was 203.5 ± 10.5µM/l in JH and 4.6 ± 10.5 µM/l in CH. In addition, JH had a diastatic activity of 524.1 ± 0.25 U/l, while CH had a value of 209.7 ± 0.56 U/l. According to the results, JH had a high PAD value, while CH had a low PAD value. Cell viability was measured using the results of the MTT assay. The results showed that JH inhibited the growth of MCF-7 cells more strongly (IC50 of 170 ± 4.2 µg/ml) than CH (IC50 of 385.3 ± 4.5 µg/l). The scratch assay showed that treatment with JH decreased the migration rate of MCF-7 cells in a dose-dependent manner compared to the CH and control groups. In addition, the results of q-PCR analysis showed significant upregulation of Bax, p53 and p21 genes and downregulation of Bcl-2 gene in the JH-treated group compared to the CH and control groups. CONCLUSION: These results showed that honey with an increased content of phenolic compounds, antioxidant capacity, and diastatic activity has anticancer properties by effectively suppressing tumor development. This suppression occurs via several mechanisms, including suppression of proliferation and metastasis, and promotion of apoptosis.

Green application of surfactant modified silica as effective sorbent for extraction and preconcentration of sulfonamide residues in environmental water and honey samples.

Micro-solid phase extraction (µ-SPE) using surfactant coated silica for extraction and preconcentration of sulfonamide residues at trace levels in environmental water and honey samples prior their analysis by high performance liquid chronatography coupled with photodiode array detector (HPLC-PDA). The sample solution were dispersed in a small amounts of solid sorbent by vacuum manifold for sample preparation, and extraction occurred by adsorption in a short time. Finally, the analytes were subsequently desorbed using an appropriate solvent. The pure and coated silica were physicochemically and morphologically characterized by nittrogen (N2) sorptions analyses, and transmission electron microscopy (TEM). Parameters influencing extraction efficiency, such as amount of sorbent, kind, concentration and volume of surfactant, and kind and volume of desorption solvent, were investigated. The optimum conditions of the proposed method, were mixed standard/sample solution (10 mL), 0.4 g silica, 0.03 M CTAB (150 µL), and 500 µL methanol (as elution solvent). The proposed method, under optimal conditions, showed excellent linearity in different ranges (9-300 µg L-1, the a coefficient of determination (R2) of greater than 0.99), good repeatability (RSD < 6.72 %), good sensitivity (LODs in the range of 1 to 3 µg L-1), high enrichment factor (5.63-13.33), and acceptable relative recoveries (61.0-121.4 %). The developed µ-SPE method was applied to analyze sulfonamide residues in water and honey samples with relative recoveries of 60.9-119.4 % were obtained. This alternative method is simple and is also environmentally friendly which assessed using Analytical Eco-scale and Analytical GREEnness metric (AGREE).

Exploring the role of NIR spectroscopy in quantifying and verifying honey authenticity: A review.

Honey, recognized for its diverse flavors and nutritional benefits, confronts challenges in maintaining authenticity and quality due to factors like adulteration and mislabelling. This review undertakes a comprehensive exploration of the utility of Near-Infrared (NIR) spectroscopy as a non-destructive analytical method for concurrently evaluating both honey quantity and authenticity. The primary purpose of this investigation is to delve into the various applications of NIR spectroscopy in honey analysis, with a specific focus on its capability to identify and quantify significant quality parameters such as sugar content, moisture levels, 5-HMF, and proline content. Results from the study underscore the effectiveness of NIR spectroscopy, especially when integrated with advanced chemometrics models. This combination not only facilitates quantification of diverse quality parameters but also enhances the classification of honey based on geographical and botanical origin. The technology emerges as a potent tool for detecting adulteration, addressing critical challenges in preserving the authenticity and quality of honey products. The impact of this critical analysis extends to shedding light on the current state, challenges, and future prospects of applying NIR spectroscopy in the honey industry. This analysis outlines the current challenges and future prospects of NIR spectroscopy in the honey industry. Emphasizing its potential to improve consumer confidence and food safety, the research has broader implications for authenticity and quality assurance in honey. Integrating NIR spectroscopy into industry practices could establish stronger quality control measures, benefiting both producers and consumers globally.

Extraction improvement of ionic liquid-functionalized silica by in situ anion-exchange for online solid-phase extraction of estrogens in honey.

The accurate detection of analytes in honey is affected by the complex substrates, making it crucial to employ an effective sample preparation technique. In this work, an imidazolium ionic liquid was functionalized to the silica surface by a click reaction for solid-phase extraction (SPE) column, and in situ anion-exchange process was performed with different organic anions (dodecyl sulfonate, dodecyl benzene sulfonate, and naphthalene sulfonate). These SPE columns were evaluated through extracting the estrogens. The naphthalene sulfonate-based SPE column displayed the best extraction ability among these, and it was combined with high-performance liquid chromatography-diode array detection to establish an online enrichment and analysis system. Under the optimal test conditions, an online analytical method was developed, with high enrichment factors (1872-4744), wide linear ranges (0.0033-1.50, 0.0165-1.50, and 0.0330-1.50 µg g-1), and low detection limits (0.001-0.010 µg g-1). The method successfully determined several estrogens in some honey samples, and achieved satisfactory recovery results.

The amount of antioxidants in honey has a strong relationship with the plants selected by honey bees.

As one of the main sources of natural antioxidants, flowering plants play a role in the prevention and treatment of many diseases directly and indirectly. Honey is considered as an important nutrient in the supply of natural antioxidants, the amount of which is directly dependent on the plant origin and geographical location of the bee feeding place. The existence of valuable communities of native and endemic plant species has turned Alborz, Zagros and Azerbaijan into the most important hubs of honey production in Iran. In this study, we collected samples of honey from more than 90 regions in Alborz, Zagros and Azerbaijan during the years 2020 to 2021. We evaluated the samples using melissopalynology method and measuring the amount of antioxidant activity. The rise of antioxidant activity in honey is dependent on the abundance of some plant families as well botanical origins. The abundance of plant families Rosaceae, Amaranthaceae, Fabaceae and Asteraceae showed a higher influence on the amount of antioxidants in honey than other plant families. Also, the abundance of plant families Rosaceae and Fabaceae increased with increasing altitude. In general, the amount of antioxidant activity of honey samples shows a different percentage under the influence of ecological and geographical changes.

High acidity of bracatinga honeydew honey: A new regulatory limit proposal.

The free acidity of bracatinga honeydew honey (BHH) was monthly monitored over short-term storage (four months) until all the samples exceeded 50 mEq kg-1 - the maximum value allowed by the international regulatory honey standards. In addition, BHH quality was also investigated through moisture content, water activity, electrical conductivity, pH, 5-hydroxymethylfurfural, and aliphatic organic acids (AOA) analyses. According to our results, most of the parameters investigated presented significant differences during the short storage period studied; however, the quality parameters (except acidity) did not exceed the limits established by the international regulatory honey standards. Therefore, the high free acidity observed in the BHH samples did not affect its quality. Moreover, the total AOA concentration decreased as the free acidity increased, indicating that the high acidity is not related to postharvest fermentation. Since all BHH samples exceeded the established limit of 50 mEq kg-1 after four months of storage (up to 62.7 mEq kg-1), this data corroborates that this type of honey does not comply with the regulatory honey standards, which represents an obstacle to its commercialization. Therefore, our data reinforce the need for a future reassessment of the international regulatory honey standards regarding the free acidity limit for BHH. In this sense, taking together all the studies developed by our research group since 2014, a new free acidity value of 65 mEq kg-1 is proposed, which may discourage fraud practices and negative impacts on the BHH beekeeping chain.

An updated review of functional ingredients of Manuka honey and their value-added innovations.

Manuka honey (MH) is a highly prized natural product from the nectar of Leptospermum scoparium flowers. Increased competition on the global market drives MH product innovations. This review updates comparative and non-comparative studies to highlight nutritional, therapeutic, bioengineering, and cosmetic values of MH. MH is a good source of phenolics and unique chemical compounds, such as methylglyoxal, dihydroxyacetone, leptosperin glyoxal, methylsyringate and leptosin. Based on the evidence from in vitro, in vivo and clinical studies, multifunctional bioactive compounds of MH have exhibited anti-oxidative, anti-inflammatory, immunomodulatory, anti-microbial, and anti-cancer activities. There are controversial topics related to MH, such as MH grading, safety/efficacy, implied benefits, and maximum levels of contaminants concerned. Artificial intelligence can optimize MH studies related to chemical analysis, toxicity prediction, multi-functional mechanism exploration and product innovation.

Bioactive compounds of honey from different regions of Brazil: the effect of simulated gastrointestinal digestion on antioxidant and antimicrobial properties.

Monofloral and multifloral honey produced in different regions may have different bioactive compounds and antioxidant capacities, resulting in changes in the antimicrobial activity of honey. However, many of these compounds degrade due to the extreme digestion conditions, which may inhibit the antimicrobial activity. Given this context, this study aimed to describe the bioactive compounds of honey produced in Brazil and verify if honey samples from different botanical and geographical origins differ in bioactive compounds, and if honey maintains its antimicrobial activity after digestion simulation. Multivariate analysis was used to identify characteristics that differentiated the honey samples according to the botanical and geographical origin criteria. The amount of the bioactive compounds varied significantly: the total phenolic compound content varied from 20.49 to 101.44 mg GAE per 100 g, flavonoids varied from 1.41 to 13.52 mg QE per 100 g, phenolic acids varied from 13.61 to 56.41 mg CAE per 100 g, and carotenoids varied from 0.66 to 4.27 mg ß-carotene per g. Multifloral honey (H22) produced in the dry season of northeastern Brazil presented the highest bioactive compound concentration except for the carotenoid content. HPLC-MS analysis showed the presence of six hydroxybenzoic acids, four hydroxycinnamic acids, eight flavonols, three flavanones, two flavones and two isoflavonoids; Pterodon pubescens monofloral honey (H14) from midwestern Brazil stood out in terms of the carotenoid content. All analyzed honey samples exhibited antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria before digestive process simulation, and bacteria were inhibited during in vitro digestion; this activity decreased during the simulation of the oral phase, remained in the gastric phase, and disappeared in the intestinal phase.