A diagnosis of the microbiological quality of dehydrated bee-pollen produced in Brazil

Bee wisdom: exploring bee control strategies for food microflora by comparing the physicochemical characteristics and microbial composition of beebread

IMPORTANCE

Bees are a valuable model for investigating the relationship between environmental factors, gut microbiota, and organismal health. Beebread, produced from collected pollen, is a natural food source and a primary reservoir of gut microorganisms. Although pollen typically has diverse bacterial species, beebread has low species richness and bacterial abundance. Consequently, considerable attention has been paid to the adaptive strategies employed by honey bees to cope with the microorganisms within their food environment during co-evolution with plants. This study identified the distribution patterns of beebread's physicochemical characteristics, showing how bees use fermentation to enrich specific microbes. These findings help understand the relationship between environmental and food-associated microbes and bee intestinal microbiota. They also bridge gaps in the literature and provide a valuable reference for studying the complex interplay between these factors.

Quality of bee pollen submitted to drying, pasteurization, and high-pressure processing - A comparative approach

Bee Pollen is a valuable and useful natural food product that can be used for different purposes, among which medical ones. This matrix is deemed a superfood because of its chemical composition, which is rich in nutrients and possesses significant bioactivities, including antioxidant and microbiological properties. Nevertheless, the storage conditions and processing methods must be optimized to maintain their properties and maximise their application. This work investigates the best bee pollen conservation process and its impact on individual constituents. Monofloral bee pollen was analysed for 30 and 60 days after three different storage processes (drying, pasteurization, and high-pressure pasteurization). The results showed a decrease mainly in fatty acid and amino acid content for the dried samples. The best results were obtained with high-pressure pasteurization, maintaining the proteins, amino acids and lipids characteristics of pollen and the lowest microbial contamination.

Evaluation of Environmental and Nutritional Aspects of Bee Pollen Samples Collected from East Black Sea Region, Turkey, via Elemental Analysis by ICP-MS

Honeybee pollens are good food sources in terms of their mineral contents and are specific to the regions they are collected. In addition, they may be used as bioindicators in the assessment of environmental pollution based on their potentially toxic element contents. In the present study, mineral element composition and potentially toxic element levels of honeybee pollen samples collected from various cities in East Black Sea Region of Turkey (18 samples) were determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave assisted acid digestion. The method validation was performed by using CRM (Certified Reference Material-BCR®279-Sea Lettuce-Ulva lactuca) to evaluate the accuracy and precision. Elemental composition of honeybee pollens were detected within the following ranges (minimum-maximum, mg kg^-1 dry pollen); Mn (manganese): 11.579-117.349, Fe (Iron): 34.865-811.043, Zn (zinc): 17.707-56.223, Se (selenium): 0.422-0.722, Cr (chromium): 0.848-6.949, Cu (copper): 7.510-26.344, Mg (magnesium): 549.921-2149.716, Ca (calcium): 726.575-2201.837, Na (sodium): 36.518-120.283, Pb (lead): < 0.005-0.622, Cd (cadmium): 0.039-1.390, Ni (nickel): 2.317-21.710, and As (arsenic): 1.331-2.248. Recommended daily allowance, target hazard quotients, hazard index, and carcinogenic risk values of the pollens were calculated with the help of these results. In considering THQ values, pollens were determined to be safe for the consumption of both genders. Based on the carcinogenic risk calculation, most of the pollens examined in this study were categorized as moderately risky. Monitoring studies can be used to identify new sources of contamination or the origin and spread of a particular element. Hence, bee pollens can also be considered as potential bioindicators of toxic metal pollution. HIGHLIGHTS: • Mineral content and potentially toxic metal levels of 18 honeybee pollens were determined. • Recommended daily allowance (RDA) values were calculated. • The nutritional aspects of honeybee pollen samples were evaluated. • Hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR) estimation of honeybee pollens were assessed. • The potentiality of honeybee pollens as a bioindicator for pollution was discussed.

Mass Spectrometry-Based Identification of Bioactive Bee Pollen Proteins: Evaluation of Allergy Risk after Bee Pollen Supplementation

Bee pollen, because of its high content of nutrients, is a very valuable medicinal and nutritional product. However, since its composition is not completely studied, the consumption of this product may cause adverse effects, including allergic reactions. Therefore, this study aimed to discover and characterize the bioactive proteins of bee pollen collected in Poland, focusing mainly on the allergens. For this purpose, the purified and concentrated pollen aqueous solutions were analyzed using the nanoLC-MALDI-TOF/TOF MS analytical platform. As a result of the experiments, 197 unique proteins derived from green plants (Viridiplantae) and 10 unique proteins derived from bees (Apis spp.) were identified. Among them, potential plant allergens were discovered. Moreover, proteins belonging to the group of hypothetical proteins, whose expression had not been confirmed experimentally before, were detected. Because of the content of bioactive compounds-both beneficial and harmful-there is a critical need to develop guidelines for standardizing bee pollen, especially intended for consumption or therapeutic purposes. This is of particular importance because awareness of the allergen content of bee pollen and other bee products can prevent health- or life-threatening incidents following the ingestion of these increasingly popular "superfoods".

Distribution and statistical analysis of major and trace elements in the bee pollen from the territory of Republic of Kosovo

The objective of this study was the determination of major and trace elements in the bee pollen samples from the whole territory of Republic of Kosovo. Pollen, as a natural plant product, is exposed to different contaminations absorbed by plants from the soil through the root system or with water intake, as well as to pollutants of different origins, including anthropogenic ones, deposited directly on pollen. In total 67 pollen samples were collected in 2019. The samples were analyzed for 27 macro and microelements by using ICP-AES and ICP-MS. The mean content of major elements in bee pollen was 4065, 3455, 1375 and 549 mg/kg for K, P, Ca and Mg, respectively. The range of the contents for some potentially toxic elements was 11.9-139.1, 1.9-16, 0.11-6.25, 0.01-0.329 and 0.001-0.38 mg/kg for Zn, Cu, Pb, Cd and As, respectively. Three groups of elements of mixed origin were identified through factor analysis: the first and the third Factors, are mostly of geogenic origin (Ag, Li, Al, Fe, Ca, Sr, K, Mg and P and Co, Ni, Cr, Cu and Mn) and the second Factor association is related to anthropogenic processes (Sb, As, Pb, Tl, Sn and Cd).

Biotechnological Processes Simulating the Natural Fermentation Process of Bee Bread and Therapeutic Properties-An Overview

Recent signs of progress in functional foods and nutraceuticals highlighted the favorable impact of bioactive molecules on human health and longevity. As an outcome of the fermentation process, an increasing interest is developed in bee products. Bee bread (BB) is a different product intended for humans and bees, resulting from bee pollen's lactic fermentation in the honeycombs, abundant in polyphenols, nutrients (vitamins and proteins), fatty acids, and minerals. BB conservation is correlated to bacteria metabolites, mainly created by Pseudomonas spp., Lactobacillus spp., and Saccharomyces spp., which give lactic acid bacteria the ability to outperform other microbial groups. Because of enzymatic transformations, the fermentation process increases the content of new compounds. After the fermentation process is finalized, the meaningful content of lactic acid and several metabolites prevent the damage caused by various pathogens that could influence the quality of BB. Over the last few years, there has been an increase in bee pollen fermentation processes to unconventional dietary and functional supplements. The use of the chosen starters improves the bioavailability and digestibility of bioactive substances naturally found in bee pollen. As a consequence of enzymatic changes, the fermentation process enhances BB components and preserves them against loss of characteristics. In this aspect, the present review describes the current biotechnological advancements in the development of BB rich in beneficial components derived from bee pollen fermentation and its use as a food supplement and probiotic product with increased shelf life and multiple health benefits.

Changes of microorganism composition in fresh and stored bee pollen from Southern Germany

Analysis of plant pollen can provide valuable insights into the existing spectrum of microorganisms in the environment. When harvesting bee-collected pollen as a dietary supplement for human consumption, timely preservation of the freshly collected pollen is fundamental for product quality. Environmental microorganisms contained in freshly collected pollen can lead to spoilage by degradation of pollen components. In this study, freshly collected bee pollen was sampled at different locations and stored under various storage conditions to examine the hypothesis that storage conditions may have an effect on the composition of microorganisms in pollen samples. The samples were analyzed using 16S and 18S amplicon sequencing and characterized by palynological analysis. Interestingly, the bacterial communities between pollen samples from different locations varied only slightly, whereas for fungal community compositions, this effect was substantially increased. Further, we noticed that fungal communities in pollen are particularly sensitive to storage conditions. The fungal genera proportion Cladosporium and Mycosphaerella decreased, while Zygosaccharomyces and Aspergillus increased during storage. Aspergillus and Zygosaccharomyces fractions increased during storage at 30 °C, which could negatively impact the pollen quality if it is used as a dietary supplement.

Traceability of potential enterotoxigenic Bacillus cereus in bee-pollen samples from Argentina throughout the production process

Bee-pollen is a functional food sold for human and animal consumption but also is a favorable microhabitat for many spore-forming bacteria. Among them, Bacillus cereus can produce several toxins and other virulence factors, causing an emetic or diarrheal syndrome after ingestion. The study involved 36 bee-pollen samples obtained from different sampling points throughout the production process (collecting, freezing, drying, and cleaning) in Argentina. Fifty isolates of B. cereus yielded 24 different fingerprint patterns with BOX and ERIC primers. Only three fingerprint patterns were maintained throughout the production process. In contrast, others were lost or incorporated during the different steps, suggesting that cross-contamination occurred as shown by differences in fingerprint patterns after freezing, drying, and cleaning steps compared to the initial collection step. Genes encoding for cereulide (ces), cytotoxin K (cytK), sphingomyelinase (sph), the components of hemolysin BL (hblA, hblB, hblC, hblD) and non-hemolytic complex (nheAB) were studied. All the isolates displayed one or more enterotoxin genes. The most frequent virulence genes detected belong to the HBL complex, being the most abundant hblA (98%), followed by hblD (64%), hblB (54%), and hblC (32%), respectively. Ten strains (20%), present at all sampling points, carried all the subunits of the HBL complex. The non-hemolytic enterotoxic complex (nheAB) was found in 48 strains (96%), while seven strains (14%) present at all sampling points showed the amplification product for sphingomyelinase (sph). One cereulide-producer was isolated at the cleaning step; this strain contained all the components for the hemolytic enterotoxin complex HBL, the NHE complex, and cytotoxin K related to the foodborne diarrhoeal syndrome. In total, 11 different virulence patterns were observed, and also a correlation between rep-fingerprint and virulence patterns. The results suggest that bee-pollen can be contaminated at any point in the production process with potential enterotoxic B. cereus strains, emphasizing the importance of hygienic processing.

Phytochemicals, mineral contents, antioxidants, and antimicrobial activities of propolis produced by Brunei stingless bees Geniotrigona thoracica, Heterotrigona itama, and Tetrigona binghami

The present study focused on the evaluation of phytochemical properties, essential mineral elements, and heavy metals contained in raw propolis produced by stingless bees Geniotrigona thoracica, Heterotrigona itama, and Tetrigona binghami found in the same ecological conditions and environment in Brunei Darussalam. The results indicated that propolis of the three stingless bee species mainly consisted of lipids (45.60–47.86%) and very low carbohydrate (0.17–0.48%) and protein contents (0.18–1.18%). The propolis was rich in mineral elements, thus good sources of minerals, while they contained low concentrations of all heavy metals. Propolis of the different bee species could be distinguished based on their mineral compositions. The vibrational and absorption spectra suggested that propolis contains π-conjugated aliphatic and aromatic compounds as well as aromatic acids having amine, ester, carbonyl, alkyl, and hydroxyl functional groups which might be attributed to the presence of phenolic and flavonoid compounds. The antioxidant capacity of the propolis, based on radical scavenging activity of their ethanol extract, was in line with their total phenolic content. The ethanol extract of the propolis also showed antimicrobial activities against four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa). The propolis showed slightly higher antibacterial activity against Gram-positive (B. subtilis and S. aureus) bacteria, indicating that the antimicrobial active compounds could be associated with flavonoids, which were quantified to be approximately comparable in all the propolis.

Phytochemical study and antioxidant activity of Dalbergia ecastaphyllum

Abstract The chemical profile of Dalbergia ecastaphyllum has been indicated as the botanical origin of Brazilian red propolis, an apicultural product with proven therapeutic properties. However, few studies have investigated this plant species. This study evaluated and compared microbiological quality, chemical composition, and antioxidant activity of stem and leaf samples of D. ecastaphyllum. The samples were collected in February 2015, in the southern region of the state of Bahia, Brazil. We performed the microbiological analyses, determined the contents of fatty acid, total phenol and flavonoid, and identified the chemical profile and antioxidant activit. Escherichia coli, Salmonella spp. and sulfite reducing clostridial spores were not detected in the samples. Acids of the family ω3 were recorded in the stems and ω6 in the leaves. The leaves presented better nutritional quality of the fraction, better antioxidant capacity in the tests by the DPPH method and β-carotene bleaching. There were 49 chemical compounds, of which 38 belonged to the class of flavonoids. The results indicate that stems and leaves of D. ecastaphyllum have biological properties. Leaves particularly are better for functional food formulation and as natural antioxidant.

Novel solid-state fermentation of bee-collected pollen emulating the natural fermentation process of bee bread

Structure of lactic acid bacteria biota in ivy flowers, fresh bee-collected pollen (BCP), hive-stored bee bread, and honeybee gastrointestinal tract was investigated. Although a large microbial diversity characterized flowers and fresh BCP, most of lactic acid bacteria species disappeared throughout the bee bread maturation, giving way to Lactobacillus kunkeei and Fructobacillus fructosus to dominate long stored bee bread and honeybee crop. Adaptation of lactic acid bacteria was mainly related to species-specific, and, more in deep, to strain-specific features. Bee bread preservation seemed related to bacteria metabolites, produced especially by some L. kunkeei strains, which likely gave to lactic acid bacteria the capacity to outcompete other microbial groups. A protocol to ferment BCP was successfully set up, which included the mixed inoculum of selected L. kunkeei strains and Hanseniaspora uvarum AN8Y27B, almost emulating the spontaneous fermentation of bee bread. The strict relationship between lactic acid bacteria and yeasts during bee bread maturation was highlighted. The use of the selected starters increased the digestibility and bioavailability of nutrients and bioactive compounds naturally occurring in BCP. Our biotechnological protocol ensured a product microbiologically stable and safe. Conversely, raw BCP was more exposed to the uncontrolled growth of yeasts, moulds, and other bacterial groups.

Quality Control of Bee-Collected Pollen Using Bumblebee Microcolonies and Molecular Approaches Reveals No Correlation Between Pollen Quality and Pathogen Presence

Bee-collected pollen is an essential protein source for honey bee and bumblebee colonies. Its quality directly affects bee health. We estimated the quality of pollen samples using bumblebee microcolonies and high-throughput sequencing for the presence of microorganisms. The tested samples of bee-collected pollen were of different quality, as estimated from their effect on the development of bumblebee microcolonies. Based on the pollen quality, we selected a subset of high-quality and low-quality pollen samples to further analyze them for the presence of microorganisms and pathogens. High-throughput sequencing revealed that the most common microorganisms in the bee-collected pollen were Acinetobacter spp. and bacteria of the genera Lactobacillus and Lactococcus. No pathogenic bacteria infectious for honey bees (e.g., those causing American and European foulbrood) or bumblebees have been identified in the analyzed pollen samples. Among potentially harmful microorganisms, there were bacteria from the Enterobacteriaceae family. The fungal pathogens Nosema apis and Nosema ceranae were detected in four samples; Ascosphaera sp. was found in six samples. Several viruses were found in the pollen samples, such as chronic bee paralysis virus, Israeli acute paralysis virus, deformed wing virus, sacbrood virus, and Kashmir bee virus. No correlation between the presence of these microorganisms or viruses and the impact of low-quality pollen samples on the bumblebee development was found. It is possible that factors affecting pollen quality are the absence of certain biologically active compounds or the presence of pesticides.

Mycotoxins and Mycotoxin Producing Fungi in Pollen: Review

Due to its divergent chemical composition and good nutritional properties, pollen is not only important as a potential food supplement but also as a good substrate for the development of different microorganisms. Among such microorganisms, toxigenic fungi are extremely dangerous as they can synthesize mycotoxins as a part of their metabolic pathways. Furthermore, favorable conditions that enable the synthesis of mycotoxins (adequate temperature, relative humidity, pH, and aw values) are found frequently during pollen collection and/or production process. Internationally, several different mycotoxins have been identified in pollen samples, with a noted predominance of aflatoxins, ochratoxins, fumonisins, zearalenone, deoxynivalenol, and T-2 toxin. Mycotoxins are, generally speaking, extremely harmful for humans and other mammals. Current EU legislation contains guidelines on the permissible content of this group of compounds, but without information pertaining to the content of mycotoxins in pollen. Currently only aflatoxins have been researched and discussed in the literature in regard to proposed limits. Therefore, the aim of this review is to give information about the presence of different mycotoxins in pollen samples collected all around the world, to propose possible aflatoxin contamination pathways, and to emphasize the importance of a regular mycotoxicological analysis of pollen. Furthermore, a suggestion is made regarding the legal regulation of pollen as a food supplement and the proposed tolerable limits for other mycotoxins.

Caracterizações microbiológica e físico-química de pólens armazenados por abelhas sem ferrão

Resumo O estudo foi realizado com o objetivo de verificar tanto a condição microbiológica quanto as diferenças físico-químicas existentes em pólens armazenados por diferentes espécies de abelhas sem ferrão no Nordeste do Brasil. Os pólens armazenados foram coletados nas colônias mantidas em meliponários das seguintes espécies: Melipona subnitida, M.scutellaris, M. mandacaia, Scaptotrigona sp. e Frieseomellita varia. Com relação às análises de qualidade microbiológica, as mesmas foram realizadas em micro-organismos indicadores de qualidade comercial (mesófilos, bolores e leveduras), qualidade sanitária (Staphylococcus coagulase positiva, coliformes fecais e Escherichia coli), e de segurança (esporos de Clostridium sulfito redutores e Salmonella spp.). Para os parâmetros físico-químicos, os mesmos foram avaliados de acordo com a exigência do Regulamento Técnico (RT) de qualidade para pólen apícola, e também para compostos fenólicos. Todas as amostras apresentaram condição microbiológica de acordo com as recomendações aceitáveis para o consumo humano. Os resultados confirmaram as diferenças na composição físico-química do pólen armazenado das cinco espécies; no entanto, houve formação de três grupos de pólens armazenados com base nos parâmetros físico-químicos. As amostras da espécie M. scutellaris apresentaram conteúdo de compostos fenólicos cinco vezes mais elevado aos outros méis das espécies avaliadas. Logo, este estudo permitiu conhecer a composição dos pólens armazenados por abelhas sem ferrão, por conseguinte reforçando a necessidade de reformular o Regulamento Técnico (RT) existente no Brasil para pólen apícola, de forma a abranger os pólens armazenados das espécies nativas.

Microbial characterization of bee pollen from the Vesuvius area collected by using three different traps

Flower pollen is collected by honeybee foragers, adhered on their rear legs and transported into the hives in the form of pellets. Once in the hives, bee pollen is moisturised with nectar and bee mouth secretions and due to enzymatically modifications it becomes the so-called bee-bread, the protein reservoir of young bees. Bee pollen can be artificially removed from bee legs and collected by using specific systems, the bee pollen traps. Bee pollen is commercialized for human consumption as fresh product and after freezing or drying. Although bee pollen is nowadays largely consumed in developed countries, as food or food supplement according to local legislation, little is known on its safety related to microbiological hazards. In this work, we aimed to characterize for the first time the microbiological profile of Italian bee pollen in fresh, frozen and dried form collected along an entire harvesting season. Moreover, monthly microbiological analyses were performed on frozen (storage at -18°C) and dried (storage at room temperature) bee pollen over a 4 months period. Further aim of this work was the evaluation of the possible impact on production level of three different traps used for pollen collection. Our results on microbial contamination of fresh and frozen bee pollen show that a more comprehensive microbiological risk assessment of bee pollen is required. On the other side, dried pollen showed very low microbial contamination and no pathogen survived after the drying process and during storage.