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

High-resolution mass spectrometry-based assessment of chemical composition's effect on the honey color

Honey is a nutrient-rich natural functional food, with its color being considered as a key indicator of quality and consumer acceptance. Although various secondary metabolites are closely related to the color of honey, the specific substances and their exact effects on honey color remain unclear. In this study, the chemical composition, such as organic acids, polyphenols and vitamins, in different colored honey (Acacia, buckwheat, linden, vitex, lychee and jujube honey) were quantitatively analyzed using liquid chromatography-high resolution mass spectrometry (LCHRMS). The correlations between the chemical composition and the honey color were established by the mantel test. The results showed that quinic acid, ascorbic acid, and other composition were identified as significantly related with honey color. The validation experiments indicated that adding these significantly related substances to honey samples could multiplicatively deepen the honey color, and the value of the deepening color was positively correlated with that of the initial color. The study developed a practical and systematic LCHRMS method for analyzing chemical composition in honey. The results provided valuable scientific insights into the relationship between chemical composition and honey color. Additionally, it introduced a novel and feasible approach for investigating the effects of substances on the color of complex mixture systems.

Mannitol: A novel chemical marker in stingless bee honey

Stingless bee honey (SBH) has garnered attention as a natural sweetener and functional food, recognized for its exceptional biological activity and distinctive flavour. Compared to honey bee honey, SBH has lower annual production but commands a higher market value, making it more susceptible to adulteration. During an analysis of trehalulose in SBH, we unexpectedly identified the naturally occurring sugar alcohol, mannitol. The presence of mannitol in SBH was confirmed using UHPLC/Q-TOF-MS, 1H and 13C NMR analyses. A systemic analysis of 104 SBH samples from various stingless bee species revealed mannitol in all samples, with concentrations ranging from 0.06 g to 13.49 g/100 g. The detection of previously neglected mannitol levels in SBH offers additional evidence supporting its health benefits. This study not only highlights the potential application of SBH in the food industry but also introduces mannitol as a distinctive marker for detecting SBH adulteration.

Rainy and Dry Seasons Are Relevant Factors Affecting Chemical and Antioxidant Properties of Meliponini Honey

Brazilian stingless bee species produce honey with distinct physicochemical and bioactive properties shaped by environmental factors. This study investigated the effects of the rainy and dry seasons on the physicochemical characteristics, chemical fingerprinting, mineral content, and antioxidant capacity of honey from Melipona mondury and Melipona bicolor. The honey samples were analyzed for their phytochemical properties (official methods), total phenolics (Folin-Ciocalteu method), flavonoid content (aluminum complex formation method), antioxidant capacity (FRAP and ABTS assays), and antioxidant activity (erythrocyte model). The mineral content was assessed via TXRF spectroscopy, and chemical fingerprinting was conducted using mass spectrometry. Chemometric tools were used for the samples' discriminating analyses, including Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA). Seasonal variations significantly affected the moisture, total soluble solids, and acidity. In turn, the antioxidant capacity was influenced mainly by the bee species. The mineral composition, particularly potassium, phosphorus, and calcium, remained stable. Multivariate analysis identified m/z ions (VIP scores > 2.5), rather than physicochemical or antioxidant capacity parameters, as critical for seasonal discrimination. The antioxidant activity, assessed by oxidative hemolysis prevention, was robust across the seasons, with M. mondury honey (2 mg·mL-1) from the rainy season outperforming ascorbic acid. These findings underscore the impact of the rainy and dry seasons and the potential of secondary metabolite fingerprinting to identify collection periods.

End-to-end dataflow engineering framework of honey manufacturing from intermediates to process by TAS1R2@AuNPs/SPCE biosensor coupled with quality transfer principle

This study reported an original end-to-end dataflow engineering framework for the quality transfer principle to overcome the quality challenges in real-world honey manufacturing. Firstly, 650 pivotal data points of physical and chemical quality attributes from 65 batches of honey intermediates were characterized through multiple sensors, which included rheological properties, acidity, moisture, and sugars. Furthermore, a hypersensitized TAS1R2@AuNPs/SPCE biosensor was developed to identify biological quality attributes of honey, the powerful affinities between honey intermediates and the TAS1R2 receptor were discovered (KD < 1 × 10-8 M), and the abnormal batches of B2, B23 and C23 were diagnosed by TAS1R2@AuNPs/SPCE biosensor and multivariable algorithm. Finally, the end-to-end dataflow containing physical, chemical and biological critical quality attributes was successfully established to interpret the quality transfer principle of honey manufacturing, which revealed that the front-end refining process was relatively unstable and the back-end refining process was a negligible influence on the quality of honey manufacturing. This framework embraces quality management, quality transfer, and biosensor information, which will contribute to discovering the quality transfer principle in industrial innovation for intelligent manufacturing.

The Physicochemical Parameters, Phenolic Content, and Antioxidant Activity of Honey from Stingless Bees and Apis mellifera: A Systematic Review and Meta-Analysis

The most common bee species used for honey production is Apis mellifera (A. mellifera), followed by stingless bees. This study included scientific articles using the PRISMA approach. A random effect model was implemented and the effect size (ES) was calculated and reported as the standardized mean difference (SMD) and raw mean difference (RMD). The mean phenolic content in A. mellifera honey was 61.21 ± 28.3 mg GAE/100 g and stingless bee honey +33.69 mg GAE/100 g; p = 0.01. The antioxidant activity, discovered by the Ferric Reducing Antioxidant Power (FRAP) method, showed a mean of 97.34 ± 7.84 μmol Fe(II)/100 g in A. mellifera and stingless bee honey +63.39 μmol Fe(II)/100 g; p = 0.009. The physicochemical properties showed significant differences in moisture (A. mellifera honey 19.54 ± 3.65%; stingless bee honey +8.02%; p = 0.0001), hydroxymethylfurfural (HMF) (A. mellifera honey 20.14 ± 16.27 mg/kg; stingless bee honey -11.25 mg/kg; p = 0.001), and free acidity (A. mellifera honey 31.32 ± 16.67 meq/kg; stingless bee honey +34.76 meq/kg; p = 0.01). The variability in the trials was explained by the heterogeneity, and a meta-regression analysis incorporated four covariates: (1) stingless bee species; (2) floral source; (3) country, and (4) latitude. This study highlights the importance of conducting further studies on stingless bee honey.

Brazilian stingless bee honey: A pioneer study on the in vitro bioaccessibility of phenolic compounds

In this study, the effect of in vitro gastrointestinal digestion of phenolic compounds, the total phenolic content, and the antioxidant potential of stingless bee honey were investigated. Among the 33 phenolic compounds investigated, 25 were quantified, and only eight were not bioaccessible (p-aminobenzoic acid, sinapic acid, pinobanksin, isorhamnetin, quercetin-3-glucoside, syringaldehyde, coumarin, and coniferaldehyde). Benzoic acid was predominant in most undigested samples (21.3 to 2414 μg 100 g-1), but its bioaccessibility varied widely (2.5 to 534%). Rutin, a glycosylated flavonoid, was quantified in all samples and might have been deglycosylated during digestion, increasing the bioaccessibility of quercetin in a few samples. Overall, the concentration of phenolic compounds prior digestion and their bioaccessibility varied greatly among samples. Nevertheless, higher concentrations before digestion were not correlated to greater bioaccessibility. This study is the first to assess the in vitro bioaccessibility of phenolic compounds in SBH, providing novel insights into SBH research.

Rapid Authentication of Intact Stingless Bee Honey (SBH) by Portable LED-Based Fluorescence Spectroscopy and Chemometrics

Indonesian stingless bee honey (SBH) of Geniotrigona thoracica is popular and traded at an expensive price. Brown rice syrup (RS) is frequently used as a cheap adulterant for an economically motivated adulteration (EMA) in SBH. In this study, authentic Indonesian Geniotrigona thoracica SBH of Acacia mangium (n = 100), adulterated SBH (n = 120), fake SBH (n = 100), and RS (n = 200) were prepared. In short, 2 mL of each sample was dropped directly into an innovative sample holder without any sample preparation including no dilution. Fluorescence intensity was acquired using a fluorescence spectrometer. This portable instrument is equipped with a 365 nm LED lamp as the fixed excitation source. Principal component analysis (PCA) was calculated for the smoothed spectral data. The results showed that the authentic SBH and non-SBH (adulterated SBH, fake SBH, and RS) samples could be well separated using the smoothed spectral data. The cumulative percentage variance of the first two PCs, 98.4749% and 98.4425%, was obtained for calibration and validation, respectively. The highest prediction accuracy was 99.5% and was obtained using principal component analysis-linear discriminant analysis (PCA-LDA). The best partial least square (PLS) calibration was obtained using the combined interval with R2cal = 0.898 and R2val = 0.874 for calibration and validation, respectively. In the prediction, the developed model could predict the adulteration level in the adulterated honey samples with an acceptable ratio of prediction to deviation (RPD) = 2.282, and range error ratio (RER) = 6.612.

Unveiling Stingless Bee Honey Anti-inflammatory Potential Through the Polarization of LPS-induced J774 Macrophages

Macrophages play an important role during the inflammatory process. These cells can adopt either the pro- or anti-inflammatory phenotypes. While stingless bee honeys have demonstrated evidence of anti-inflammatory potential, their capacity to induce a shift from a pro-inflammatory state to an inflammation-resolution state has not been thoroughly investigated. In this study, the anti-inflammatory activity of two stingless bees (Scaptotrigona bicunctata-honey A and Melipona quadriasciata-honey G) honeys in J774 macrophages induced by LPS was evaluated. Both honeys exhibited non-cytotoxic effects and reduced nitrite and IL-4 levels. However, only honey G increased the levels of the anti-inflammatory cytokine IL-13, by 163.1 ± 14.8% (p < 0.05) and was further investigated for its immunomodulatory effect. This honey reduced the expression of TLR4 by 59.3 ± 3.5% (p < 0.001) and increased the mannose receptor levels by 67.3 ± 2.4% (p < 0.001). Moreover, it increased the phagocytic activity by 25.0 ± 7.7% (p < 0.01) and decreased the death of the macrophages by 32.1 ± 1.7% (p < 0.001). Collectively, these findings highlight stingless bee honey from Melipona quadriasciata bee has an important immunomodulatory effect, as it reduces the markers of the pro-inflammatory state of J774 cells and increases the markers of resolution or anti-inflammatory responses.

Chemical Profile and Biological Potential of Scaptotrigona Bee Products (Hymenoptera, Apidae, Meliponini): An Review

Stingless bees belong to the Meliponini tribe and are widely distributed in the tropics and subtropics, where they perform important ecological services. Among the best distributed groups of stingless bees is the genus Scaptotrigona, which includes 22 species distributed throughout the neotropical region, including the area from Mexico to Argentina. Bees of this genus are responsible for the production of products such as honey, propolis, geopropolis and fermented pollen ("saburá"). This review aimed to provide an overview of the chemical composition and biological activities associated with derived products from stingless bees of the genus Scaptotrigona. The bibliographic review was carried out through searches in the Scopus, Web of Science, ScienceDirect and PubMed databases, including publications from 2003 to January 2023. The study of the chemodiversity of products derived from Scaptotrigona demonstrated the mainly presence of flavonoids, phenolic acids, terpenoids and alkaloids. It was also demonstrated that products derived from bees of the genus Scaptotrigona exhibit a wide range of biological effects, such as antibacterial, antioxidant, anti-inflammatory and antifungal activities, among other bioactivities. This review provides an overview of phytochemical and pharmacological investigations of the genus Scaptotrigona. However, it is essential to clarify the toxicity and food safety of these products.

Bee Bread: A Promising Source of Bioactive Compounds with Antioxidant Properties-First Report on Some Antimicrobial Features

Bee bread has received attention due to its high nutritional value, especially its phenolic composition, which enhances life quality. The present study aimed to evaluate the chemical and antimicrobial properties of bee bread (BB) samples from Romania. Initially, the bee bread alcoholic extracts (BBEs) were obtained from BB collected and prepared by Apis mellifera carpatica bees. The chemical composition of the BBE was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and the total phenols and flavonoid contents were determined. Also, a UHPLC-DAD-ESI/MS analysis of phenolic compounds (PCs) and antioxidant activity were evaluated. Furthermore, the antimicrobial activity of BBEs was evaluated by qualitative and quantitative assessments. The BBs studied in this paper are provided from 31 families of plant species, with the total phenols content and total flavonoid content varying between 7.10 and 18.30 mg gallic acid equivalents/g BB and between 0.45 and 1.86 mg quercetin equivalents/g BB, respectively. Chromatographic analysis revealed these samples had a significant content of phenolic compounds, with flavonoids in much higher quantities than phenolic acids. All the BBEs presented antimicrobial activity against all clinical and standard pathogenic strains tested. Salmonella typhi, Candida glabrata, Candida albicans, and Candida kefyr strains were the most sensitive, while BBEs' antifungal activity on C. krusei and C. kefyr was not investigated in any prior research. In addition, this study reports the BBEs' inhibitory activity on microbial (bacterial and fungi) adhesion capacity to the inert substratum for the first time.

Effects of Fermentation on Bioactivity and the Composition of Polyphenols Contained in Polyphenol-Rich Foods: A Review

Polyphenols, as common components with various functional activities in plants, have become a research hotspot. However, researchers have found that the bioavailability and bioactivity of plant polyphenols is generally low because they are usually in the form of tannins, anthocyanins and glycosides. Polyphenol-rich fermented foods (PFFs) are reported to have better bioavailability and bioactivity than polyphenol-rich foods, because polyphenols are used as substrates during food fermentation and are hydrolyzed into smaller phenolic compounds (such as quercetin, kaempferol, gallic acid, ellagic acid, etc.) with higher bioactivity and bioavailability by polyphenol-associated enzymes (PAEs, e.g., tannases, esterases, phenolic acid decarboxylases and glycosidases). Biotransformation pathways of different polyphenols by PAEs secreted by different microorganisms are different. Meanwhile, polyphenols could also promote the growth of beneficial bacteria during the fermentation process while inhibiting the growth of pathogenic bacteria. Therefore, during the fermentation of PFFs, there must be an interactive relationship between polyphenols and microorganisms. The present study is an integration and analysis of the interaction mechanism between PFFs and microorganisms and is systematically elaborated. The present study will provide some new insights to explore the bioavailability and bioactivity of polyphenol-rich foods and greater exploitation of the availability of functional components (such as polyphenols) in plant-derived foods.

Phytotherapy in Diabetic Foot Ulcers: A Promising Strategy for Effective Wound Healing

Despite the advancement in wound care, the effective therapy of chronic diabetic ulcers continues to be a challenge. Wound healing is a highly controlled process, which involves a sequence of complex overlapping steps. This healing pathway comprises of hemostasis, inflammation, proliferative, and remodeling phases. Recent evidence suggests that phytomedicines can prevent or repair different kinds of destructive cellular damage, including chronic wounds. Several phytochemicals such as polyphenols, alkaloids, flavonoids, terpenoids, and glycosides have pleiotropic effects, including stimulation of fibroblast proliferation, the main step in wound healing. Besides, the mechanism involves induction of collagen synthesis, migration, and reepithelization and their antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory actions. Similarly, the use of phytochemicals alone or as an adjuvant with standard therapy has demonstrated promising results in managing complications in the diabetic foot. For instance, the extract of Carica papaya has been shown antioxidant, antimicrobial, and anti-inflammatory, and immunomodulatory effects, which, together with proteolytic enzymatic activity, contributes to its wound healing property. It is generally believed that phytotherapy has no or minimal toxicity than synthetic therapeutic agents, favoring its use in diabetic foot ulcer management. The current review highlights the selected phytochemicals and their sources; and potential application in diabetic foot ulcer management.Key teaching points and nutritional relevanceCurrently, phytochemicals have been shown wide potential in disease. management including alleviating clinical manifestations, preventing degenerative disease, and curing illness.Increased evidence of phytochemical as anti-infective and anti-inflammatory suggests its role in the management of diabetic foot ulcer(DFU).Potential benefit along with minimal adverse effect favors its application as adjuvant therapy.Further research is needed to standardize its dose and formulation to enhance its clinical application in DFU management.

Honey's Antioxidant and Antimicrobial Properties: A Bibliometric Study

Research attention has been drawn to honey's nutritional status and beneficial properties for human health. This study aimed to provide a bibliometric analysis of honey's antioxidant and antimicrobial properties. The research advancements within this field from 2001 to 2022 were addressed using the Scopus database, R, and VOSviewer. Of the 383 results, articles (273) and reviews (81) were the most common document types, while the annual growth rate of published manuscripts reached 17.5%. The most relevant topics about honey's antimicrobial and antioxidant properties were related to the agricultural and biological sciences, biochemistry, and pharmacology. According to a keyword analysis, the most frequent terms in titles, abstracts, and keywords were honey, antimicrobial, antioxidant, bee, propolis, phenolic compounds, wound, antibacterial, anti-inflammatory, and polyphenols. A trend topic analysis showed that the research agenda mainly encompassed antioxidants, pathogens, and anti-infection and chemical agents. In a co-occurrence analysis, antioxidants, anti-infection agents, and chemistry were connected to honey research. The initial research focus of this domain was primarily on honey's anti-inflammatory and antineoplastic activity, wound healing, and antibacterial agents. The research agenda was enriched in the subsequent years by pathogens, propolis, oxidative stress, and flavonoids. It was possible to pinpoint past trends and ongoing developments and provide a valuable insight into the field of honey research.

Malicia honey (Mimosa quadrivalvis L.) produced by the jandaíra bee (Melipona subnitida D.) improves depressive-like behaviour, somatic, biochemical and inflammatory parameters of obese rats

Malícia honey produced by the jandaíra bee has hypoglycaemic and hypolipidemic effects and antioxidant activity in vitro and in vivo, which makes it potential adjuvant treatment for obesity. This study aimed to evaluate the effects of malícia honey on somatic and biochemical parameters, depressive-like behaviour and anti-inflammatory activity in obese rats. A total of 40 adult male Wistar rats were initially randomized into a healthy group (HG, n = 20) that consumed a control diet, and an obese group (OG, n = 20) which consumed a cafeteria diet for eight weeks. Then, they were subdivided into four groups: healthy (HG, n = 10); healthy treated with malícia honey (HGH, n = 10); obese (OG, n = 10); and obese treated with malícia honey (OGH, n = 10), maintaining their diets for another eight weeks. The HGH and OGH groups received malícia honey (1000 mg/kg body weight) via gavage. Food intake was monitored daily and body weight was monitored weekly. Biochemical tests related to obesity and glucose and insulin tolerance test, somatic parameters, histological parameters and quantification of NF-κB in the brain were performed. Treatment with malícia honey improved depressive-like behaviour, reduced weight (14 %), body mass index (6 %), and improved lipid profile, leptin, insulin, HOMA-β, and glucose and insulin tolerance in obese rats. It also decreased NF-κB (58.08 %) in the brain. Malícia honey demonstrated anti-obesity and anti-inflammatory effects, and reversed changes in obesity-induced depressive-like behaviour.

Flavonoids and Phenylethylamides Are Pivotal Factors Affecting the Antimicrobial Properties of Stingless Bee Honey

Despite the recent approval of stingless bee honey to the Argentine Food Code, there are still many gaps in information. Likely, the main reason for this is that multiple ecological and chemical factors influence their production and antimicrobial properties. This work combined metabolomic, microbiological, and physicochemical analyses to characterize the honey ofTetragonisca fiebrigifrom Northeastern Argentina. The antimicrobial activity tests showed that honey samples (n = 24) inhibited some Gram-positive and Gram-negative bacteria at different sensitivity levels. Furthermore, samples selected for their high bioactivity revealed crystallizations, a positive correlation with fungal growth, and the presence of flavonoids. The major polyphenols annotated by liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis and supported by metabolomic tools were quercetin 3,4'-dimethyl ether, pachypodol, jaceoside, irigenin trimethyl ether, corymboside, chrysoeriol 7-neohesperidoside, and corymboside. In contrast, samples missing antimicrobial activity did not crystallize, lacked flavonoids, and were enriched in phenylethylamides. Based on these findings, we discuss the significance of flavonoids and phenylethylamides on honey's antimicrobial activity and food quality and how they may indeed reflect essential parameters of the hive, such as microbial balance and eubiosis.

Nature's Most Fruitful Threesome: The Relationship between Yeasts, Insects, and Angiosperms

The importance of insects for angiosperm pollination is widely recognized. In fact, approximately 90% of all plant species benefit from animal-mediated pollination. However, only recently, a third part player in this story has been properly acknowledged. Microorganisms inhabiting floral nectar, among which yeasts have a prominent role, can ferment glucose, fructose, sucrose, and/or other carbon sources in this habitat. As a result of their metabolism, nectar yeasts produce diverse volatile organic compounds (VOCs) and other valuable metabolites. Notably, some VOCs of yeast origin can influence insects' foraging behavior, e.g., by attracting them to flowers (although repelling effects have also been reported). Moreover, when insects feed on nectar, they also ingest yeast cells, which provide them with nutrients and protect them from pathogenic microorganisms. In return, insects serve yeasts as transportation and a safer habitat during winter when floral nectar is absent. From the plant's point of view, the result is flowers being pollinated. From humanity's perspective, this ecological relationship may also be highly profitable. Therefore, prospecting nectar-inhabiting yeasts for VOC production is of major biotechnological interest. Substances such as acetaldehyde, ethyl acetate, ethyl butyrate, and isobutanol have been reported in yeast volatomes, and they account for a global market of approximately USD 15 billion. In this scenario, the present review addresses the ecological, environmental, and biotechnological outlooks of this three-party mutualism, aiming to encourage researchers worldwide to dig into this field.

Protective Effects of Bee Pollen on Multiple Propionic Acid-Induced Biochemical Autistic Features in a Rat Model

Autism spectrum disorders (ASDs) are neurodevelopmental disorders that clinically presented as impaired social interaction, repetitive behaviors, and weakened communication. The use of bee pollen as a supplement rich in amino acids amino acids, vitamins, lipids, and countless bioactive substances may lead to the relief of oxidative stress, neuroinflammation, glutamate excitotoxicity, and impaired neurochemistry as etiological mechanisms autism. Thirty young male Western albino rats were randomly divided as: Group I-control; Group II, in which autism was induced by the oral administration of 250 mg propionic acid/kg body weight/day for three days followed by orally administered saline until the end of experiment and Group III, the bee pollen-treated group, in which the rats were treated with 250 mg/kg body weight of bee pollen for four weeks before autism was induced as described for Group II. Markers related to oxidative stress, apoptosis, inflammation, glutamate excitotoxicity, and neurochemistry were measured in the brain tissue. Our results indicated that while glutathione serotonin, dopamine, gamma-aminobutyric acid (GABA), GABA/Glutamate ratio, and vitamin C were significantly reduced in propionic acid-treated group (p < 0.05), glutamate, IFN-γ, IL-1A, IL-6, caspase-3, and lipid peroxide levels were significantly elevated (p < 0.05). Bee pollen supplementation demonstrates protective potency presented as amelioration of most of the measured variables with significance range between (p < 0.05)−(p < 0.001).