Optimisation of Bee Pollen Extraction to Maximise Extractable Antioxidant Constituents

Abstract

This paper presents the findings of a comprehensive review on common bee pollen processing methods which can impact extraction efficiency and lead to differences in measured total phenolic content (TPC) and radical scavenging activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) data. This hampers the comparative analysis of bee pollen from different floral sources and geographical locations. Based on the review, an in-depth investigation was carried out to identify the most efficient process to maximise the extraction of components for measurement of TPC, DPPH and FRAP antioxidant activity for two bee pollen samples from western Australia (Jarrah and Marri pollen). Optimisation by Design of Experiment with Multilevel Factorial Analysis (Categorical) modelling was performed. The independent variables included pollen pulverisation, the extraction solvent (70% aqueous ethanol, ethanol, methanol and water) and the extraction process (agitation, maceration, reflux and sonication). The data demonstrate that non-pulverised bee pollen extracted with 70% aqueous ethanol using the agitation extraction method constitute the optimal conditions to maximise the extraction of phenolics and antioxidant principles in these bee pollen samples.

Investigating the Antioxidant and Color Properties of Bee Pollens of Various Plant Sources

“…In general, it can be concluded that organic solvents at 60–80 % concentration levels provide adequate extraction efficiency for bee pollen samples. This observation is in accordance with the findings of previous studies [17,48,49,50] . With regard to these results, aqueous solution of ethanol at 60 % concentration level was used as the extraction solvent for further determinations considering the environmental, economic and occupational safety reasons.…”

“…Based on previous research works, bee pollens originating from phacelia can be characterized as a moderately good source of phenolics, flavonoids and/or antioxidants [54,58,61] . It should also be noted that the results of TPC, TFC and antioxidant capacity determinations depend not only on the botanical composition of pollen pellets, but also influenced by extraction conditions [17] . For example, Kostić and co‐workers found that methanol is more effective in comparison to ethanol for extracting the phenolic compounds of sunflower bee pollen [22] …”

“…Based on more than a hundred studies, Thakur & Nanda found that the total phenolic content (TPC) vary widely (0.69–213.20 mg GAE/g) in bee pollens [16] . This great variance can be attributed to the differences between plant sources, [4,8,12] but results are also influenced significantly by the extraction conditions [17] . In addition, sample processing and storage may also have a significant impact on this parameter [18,19] .…”

Investigation of Botanical Origin, Phenolic Compounds, Carotenoids, and Antioxidant Properties of Monofloral and Multifloral Bee Bread

“…Flavonoids and other phenolic compounds work as powerful natural antioxidants that are efficient in minimizing the negative effects of reactive oxygen species. [39] Depending on the various impacts of the compounds, different extraction procedures can be used to obtain the highest recovery of phenolic compounds. [40] In this investigation, ethanol was 6.5 � 0.3 [d] 7.4 � 0.5 [c] 5.6À 5.…”

The Development and Application of a HPTLC-Derived Database for the Identification of Phenolics in Honey

“…An artificial honey solution was prepared by diluting 2 g of a sugar stock solution (21.625 g of fructose, 18.125 g of glucose, 1.000 g of maltose, 0.750 g of sucrose and 8.500 g of water) to 5 mL (40%) with deionised water. The solution was stored at 0 °C and used within a week [ 65 ].…”