酶解结合高剪切破壁技术对蜂花粉酚类物质及抗氧化活性的影响.

Bee pollen is collected by honeybees from the pollen of flowers, with the addition of the nectar and their own secretions to form grains. Approximately 70% of the substances in bee pollen have biological activities, such as antioxidant, liver protection, anti-inflammatory, antibacterial and anti-cancer. However, the outer wall of pollen spores has the characteristics of acid resistance, alkali resistance, and anti-microbial decomposition. Without breaking the wall of spores, phenolic compounds can only be released from the germination pores, and thus the digestibility of bee pollen is only 52%-59% in vivo, meaning that most of them cannot be digested by human. Therefore, the wall breaking of spores has become necessary to improve the bioavailability of bee pollen. In this study, taking six kinds of bee pollen as research objects, including lotus, jujube, camellia, rape, rose, and schisandra, a wall breaking method of enzymatic hydrolysis combined with high-shear technology was used to reveal the effect of wall breaking on the phenolic compounds and antioxidant activities of bee pollen. An attempt was made to explore the protective effect of bee pollen, with or without wall breaking, on the OH-mediated oxidative damage of plasmid DNA for bee-pollen functional foods. An investigation was also made to find the effects of cellulase enzymatic hydrolysis on the wall breaking rates of different kinds of bee pollen. Different kinds of bee pollen exhibited different degrees of tolerance to the cellulase. The wall breaking rate of bee pollen increased with the increase of cellulase concentration. After six kinds of bee pollen enzymatically hydrolyzed, the wall breaking rate was significantly improved with high shear at 10 000-15 000 r/min for 30 s. More than 90% of wall breaking rate was achieved with less cellulase in the combined methods. The release of phenolic compounds from rape bee pollen was the most significant after the wall was broken (P<0.05). The total flavonoid content increased by 6.4 times, and the total phenol content increased from 8.6 mg/g to 21.6 mg/g, as well as the total phenol content of camellia bee pollen was 15.7 mg/g, an increase of 11.3% after the wall was broken. The phenolic compounds in six kinds of bee pollen were analyzed using high-performance liquid chromatography method with diode array detection (HPLC-DAD). The results showed that the types and content of phenolic compounds in bee pollen increased after the wall was broken. The concentration of jujube bee pollen to scavenge 50% DPPH free radicals is reduced by about 95%, and rape bee pollen is reduced by about 92%, the Fe2+ complex ability of jujube bee pollen increased from 0.36 mg/g to 1.16 mg/g, increased by about 2.2 times. The Fe3+ reducing power in the six types of bee pollen increased after the walls were broken. The Fe3+ reducing power of rape bee pollen increased from 6.2 mg/g to 55.8 mg/g, increased 8 times. After walls breaking, the protective abilities against DNA oxidative damage increased by 60.5%, 12.4%, 287.7%, 82.5%, 442.7% and4.8% in the six kinds of bee pollen( lotus, jujube, camellia, rape, rose and schisandra), respectively, indicating that the wall breaking made phenolic compounds of bee pollen fully be released, which can effectively improve the protective ability of OH-induced pBR322 plasmid DNA oxidative damage. This findings can provide a theoretical basis and strategy for the development of bee-pollen functional foods. [ABSTRACT FROM AUTHOR]