本研究以紫膠蟲色素添加媒染劑進行染白頭髮實驗做為中華民國中小科學展覽。實驗結 果顯示，100g 紫膠蟲以乙醇/超音波震盪萃取後得到4.02 g 天然色素。紫膠蟲色素染髮後偏向 紅色，泡過荔枝木灰水的白頭髮偏向橙紅色，浸泡木醋酸鐵液的白頭髮則偏向紫紅色，因此， 紫膠蟲色素在不同的酸鹼值下會有明顯的差異。木醋酸鐵液做為媒染劑時，其染髮後色素滲 透率達27.15%，比荔枝木灰水的16.88 %高，此結果證明紫膠蟲色素在酸性下有很好的染髮 色牢度。此外，如添加指甲花粉以複染方式進行，其CIE L＊值為51.22 比單以指甲花粉染髮 的57.40 低，而此數據代表複染方式優於單次染髮，如紫膠蟲色素添加指甲花粉能增加染髮的 色彩。綜合前述結論，此研究結果可將危害果樹生長之紫膠蟲，開發成具有經濟價值的化妝 品。而參與此計畫之學生，亦可將理論與實務結合，成功達到科學教育往下扎根之目的。

This study conducted an experiment on dyeing grey hair with the mixture of lac insect pigment and mordant and the experiment was presented at the National Primary and High School Science Fair. The results of the experiment indicate that 4.02g of natural pigment were obtained from 100g of lac insects through ethanol/ultrasonic extraction. Depending on pH condition, lac insect pigment has different effects in grey hair: common red, red-orange in hair soaked with lychee wood ash water, and red-violet in hair soaked with iron acetate solution. 27.15% of pigment penetrates hair when using iron acetate solution as a mordant, while only 16.88% does when using lychee wood ash water. This demonstrates that the effect of lac insect pigment lasts longer in acidic condition. Besides, double dyeing along with Henna achieves lower CIE L* index (51.22) than single dyeing with Henna alone (57.40), which suggests that double dyeing is better than single dyeing. Applying double dyeing along with Henna to hair dyeing can enhance hair color. In summary, this study finds a potential cosmetic value in lac insect, known as an agricultural pest. Participants have learned to integrate theory and practice, with which the goal of solidifying science education in youths has been successfully achieved.