Ultraviolet protecting agent for tobacco maturity period and application of ultraviolet protecting agent

The invention relates to an ultraviolet protecting agent for a tobacco maturity period and application of the ultraviolet protecting agent. The protecting agent is prepared from nanometer titania or a nanometer titania compound, sodium hexametaphosphate and water, wherein a weight ratio of the nanometer titania or the nanometer titania compound to the water is (0.01-1):(1000), and the usage amount of the sodium hexametaphosphate is 0.5-10% of the mass of the nanometer titania. The ultraviolet protecting agent disclosed by the invention can be used for performing ultraviolet protection on tobacco in the maturity period and further protecting the quality of the tobacco, particularly the quality of upper tobacco leaves. 本发明涉及种烟叶成熟期紫外线防护剂及其应用。所述防护剂由纳米二氧化钛或纳米二氧化钛复合物、六偏磷酸钠、水制成，其中纳米二氧化钛或纳米二氧化钛复合物与水的重量比为0.01-1∶1000，六偏磷酸钠的用量为纳米二氧化钛质量的0.5-10％。本发明可以用于成熟期烟叶的紫外线防护，进而保护烟叶的品质，尤其是上部烟叶的品质。