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Bee pollen and bee bread nutritional potential: chemical composition and macronutrient digestibility under in vitro gastrointestinal system

Publication . Aylanc, Volkan; Falcão, Soraia; Vilas-Boas, Miguel

Bee pollen (BP) and bee bread (BB) have been often investigated as potential functional foods. Both bee products are generally characterized by their high nutritional content, with BB being referred as more digestible than BP, however, there is a lack of scientific studies proving this claim. Here, we present a comparative evaluation of the macronutrient digestibility of BP and BB after applying a simulated in vitro gastrointestinal digestive system, together with the evaluation of its nutritional value and chemical composition. The digestibility scores for protein content were calculated on average as 69% and 76% for BP and BB, respectively, whereas digestibility scores for soluble sugars varied depending on bee product and sugar type. The results demonstrated that the nutritional values of both bee products changed depending on their botanical origin but BB is more accessible in the intestinal lumen, especially regarding protein.

2023Journal article

Open access

Nutritional composition, bioactivity and microbiological stability of bee bread during the preservation process

Publication . Aylanc, Volkan; Smati, Nehed; Martins, Vitor Manuel Ramalheira; Falcão, Soraia; Rodrigues, Paula; Vilas-Boas, Miguel

Bee bread (BB) is a precious beehive product, with growing commercial interest due to its nutritional value and richness in bioactive compounds responsible for its biological activity. In cases where the processing and storage practices of BB are not suitable, significant losses in its nutritional value can occur, becoming vulnerable to microbial growth and spoilage. Here, we aimed to evaluate the effects of different preservation methods (freezing (F), room temperature (RT), oven drying (OD), and freeze-drying (FD) on the physicochemical properties, antioxidant activity, and microbial stability of BB, during a 6-month period. The pH of fresh BB, 3.7, increased with F, OD, and FD preservation methods and reached a maximum of around pH 4.0. Besides, F resulted in the lowest total lipid content loss, 11%, among all the applied methods, followed by FD, OD, and RT with losses of 20%, 24%, and 31%, respectively. The initial protein content of BB, 28%, also decreased over time, for all preservation methods, with losses between 8 to 25%. Moreover, there was a decrease in the total phenolic content of BB with time, which was reflected in the antioxidant activity. Within the microbial parameters, the highest microbial loads were observed using the freezing method. Overall, each preservation technique acted differently on the nutritional, antioxidant activity and microbial stability of BB, nevertheless, considering the results, regular storage at RT seems adequate for this bee product.

2022Conference object

Open access

Structural Characterization of Microcapsules from Common Bee Pollen for the Development of Delivery Systems

Publication . Ertosun, Seymanur; Aylanc, Volkan; Peixoto, Andreia F.; Santamaria-Echart, Arantzazu; Russo-Almeida, Paulo; Freire, Cristina; Vilas-Boas, Miguel

Exine, in the form of a natural microcapsule, refers to the outermost layer of the pollen grains and is composed of a complex mixture of sporopollenin, a highly resistant polymer, which makes it durable and able to withstand harsh conditions. Distinctive features of sporopollenin have attracted interest in the encapsulation of bioactive substances. Herein, we describe the pathway to producing sporopollenin microcapsules (SMCs) by exploiting bees and trapping common bee pollen pellets, offering a simple approach to acquiring substantial amounts of pollen grains for industrial application. Palynological results showed that separating bee pollen pellets by colour could lead to almost pure products ranging from 90 to 96%, depending on the pollen species. Subsequently, a single extraction technique removed around 82– 86% of the proteinaceous content, which could cause potential allergic reactions in humans. Detailed morphological analysis by scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), and laser diffraction particle size (LDPS) analysis proved that the purified SMCs retained their 3D micro-structures, besides being hollow and uniform micron-scale size. Fourier-transform infrared spectroscopy (FTIR) findings point out that the sporopollenin biopolymer structure of the pollen grain comprises distinct aliphatic and aromatic domains, and the purification of the SMCs resulted in the loss of nitrogen-related peaks. The hydrophobic/hydrophilic properties of the SMCs, evaluated by contact angle measurements, showed variability between pollen, depending on the specificities of their chemical structure. Simultaneous thermal analysis (STA) confirmed SMCs thermal stability up to 451 °C. Altogether, we showed that green microcapsules with various morphological properties could be produced by simply processing Castanea spp., Cistus spp., Erica spp., Olea spp, and Rubus spp, all common bee pollen pellets available in large quantities in the northeast of Portugal, but also many other countries. These microcarriers promise applicability to various fields, from pharmaceuticals to the food industry.

2024Journal article

Open access