**1. Introduction**

Plant pollination is accomplished by transferring pollen grains from the flower stamen of one plant to the stigma of another plant with agents such as wind, water, and insects [1–3]. Bees are actively involved in pollination by collecting and dispersing pollen from flower to flower. In addition to this essential function of ecosystem maintenance, the bees, during the collection of pollen, mix the grains with their own secretions, agglutinating it as small pellets on the hind legs of the insect, which are then transported to the hive. In beekeeping, these pellets generated by collecting pollen from flower stamens by the European honeybee *Apis mellifera* L. are known as bee pollen.

The pollen grains are recognized in apiculture as a source important of proteins, minerals and fats and are used mainly as food for the larvae and younger bees in the early stage of development inside the hive [1]. Moreover, since ancient times, pollen loads have been daily consumed throughout the world. Currently, due to both a trend towards natural diet supplementation and medical applications taking advantage of its numerous anticancer, anti-obesity, antimicrobial, anti-inflammatory and antioxidant properties, it is gaining more attention [4–7].

Bee pollen as a mixture of floral pollens collected by bees widely varies in shape, color, size, weight and in chemical composition. In the group of basic chemical substances, there are proteins, amino acids, lipids and fatty acids, carbohydrates, phenolic compounds and enzymes, as well as vitamins and bioelements [1,8,9]. Considering this excellent nutrient profile, bee pollen provides a significant daily intake of nutrients and complements the human diet. At the same time, this bee product comprises many compounds, especially

**Citation:** Rojo, S.; Escuredo, O.; Rodríguez-Flores, M.S.; Seijo, M.C. Botanical Origin of Galician Bee Pollen (Northwest Spain) for the Characterization of Phenolic Content and Antioxidant Activity. *Foods* **2023**, *12*, 294. https://doi.org/10.3390/ foods12020294

Academic Editors: Liming Wu and Qiangqiang Li

Received: 7 December 2022 Revised: 28 December 2022 Accepted: 5 January 2023 Published: 8 January 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

rich in biologically active substances that differ according to the origin of the plant species visited by the bees. Therefore, in addition to its importance as a functional food, bee pollen is gaining special attention due to its active natural metabolites, especially derivatives of essential amino acids, polyphenolic substances, vitamins and lipids [4,6,9]. Although several natural metabolites interfere in free radical scavenging activity, it appears that phenolic acids and flavonoids are responsible for most of the antioxidant properties [4,5,10,11]. However, the deviations in the antioxidant activity and polyphenolic content between pollens are remarkable, as a consequence of the particularities of the plant species source and different geographical areas [3,12].

On the other hand, consumers increasingly demand quality, safe and healthy food. This is the consequence of a proper monitoring of traceability and physicochemical characterization of food. Even though bee pollen is known as a potent natural food, its physicochemical characteristics and nutritional composition are ambiguous and vary greatly depending on bee species, and the botanical and geographical origins [3,4,6]. Palynology analysis is the most widely used method worldwide for identifying the botanical origins of bee products, as well bee pollen [4]. However, research studies that include a detailed pollen profile of this type of matrix and its relationship with the nutritional composition are infrequent [2,13–15].

In recent years, bee pollen as a commercial product has gained significant profitability in the beekeeping sector, taking advantage of its several functional properties as a health ingredient of multiples food [7]. Spain is the leading producer of bee pollen in the European Union. The unique qualities that contribute to beekeeping products are derived from the diversity in the flora, climate and soil of the Spanish territory. However, research on bee pollen from Spain is scarce from the point of view of its physicochemical and botanical characteristics, in comparison with other bee products such the honey. Polyphenolic and flavonoid compounds [16–18], in addition to profiling of amino acids, sugars, alkaloids and nucleic acids [18], and the amino acid content [19] of bee pollen collected in Spain were reported.

In order to guarantee well-characterized products, in recent years geographical indication has been included in the commercialization of bee products as an essential tool. Thus, the evaluation of the quality parameters and nutritional compounds of bee pollen from different geographical areas could provide differentiating information for producers in the sector and consumers [8]. Specifically, in the Northwest of Spain (Galicia) there are several unifloral honeys characterized and protected at European level by the quality scheme of Protected Geographical Indication (PGI) *Miel de Galicia* [20]. In this context, this study contributes to the knowledge of the bee pollen's characteristics, provides information for the inclusion as a quality product and consequently, favors the diversification of bee products.

Due to the variability in the chemical composition of bee products related to botanical origin, a set of bee pollen samples produced in different locations of Galicia was analyzed. The aim of this study was to evaluate the botanical diversity of bee pollen samples from Northwest Spain by means of palynological analysis and their influence on the total phenol content (TPC), total flavonoid content (TFC) and radical scavenging activity (DPPH and ABTS).
