Studies On The Extraction And Related Properties Of Chestnut Pigment

Brown pigment of chestnut shells is natural pigment extracted from wasted chestnut shells. The content of brown pigment is high. It can be widely used in food,soft goods coloration and so on. The majority of research indicate that the active ingredient of the brown pigment is flavonoids. The flavonoids generally have antioxidant activity. So it is valuable that extraction of pigment and research the relative nature.1. Optimization of smashing tissue extraction of brown pigment from chestnut shells via response surface methodology. The results showed that the optimum extraction conditions were an smashing tissue extraction 3 min, extraction concentration of 1.5%, smashing tissue power 600W and ratio of liquid to material 24 mL*g-1. Under the optimum extraction conditions, the absorbance of the extraction concentration diluted reach 1.186 and the extraction rate of the brown pigment from chestnut shells can reach 33.65%.2. This experiment extracts brown pigment from chestnut shells with 1%sodium hydroxide and 40% ethyl alcohol and compares the antioxidant activity of the two kinds of pigment with universal antioxidant. The total antioxidant activity, DPPH radical scavenging ability, hydroxyl radical scavenging capability and superoxide radical scavenging capability are standards. The results show that Vitamin C is the highest.The second is brown pigment extracted with ethyl alcohol. The brown pigment extracted with sodium hydroxide is close to the BHT; The order is in turn Vitamin C,brown pigment extracted with ethyl alcohol,brown pigment extracted with sodium hydroxide and BHT when DPPH radical scavenging ability is a standard. The IC50 of the brown pigment extracted with ethyl alcohol is about 0.02mg/mL. The IC50 of the brown pigment extracted with sodium hydroxide is about 0.09mg/mL. When hydroxyl radical scavenging capability is a standard, The four samples are all close. When superoxide radical scavenging capability is a standard, the IC50 of the brown pigment extracted with sodium hydroxide is about 0.71mg/mL. The IC50 of the brown pigment extracted with ethyl alcohol is about 0.83mg/mL.The brown pigment is weaker than Vitamin C and BHT.3. The vis spectra of the brown pigment from chestnut shells extracted by alcohol and NaOH is similar, but the IR spectra of the both brow pigment shows the difference.The carbonyl makes pigment have antioxidant activity. 4. Effects of NaHSO3 on the stability of the brown pigments is not clear. The brown pigments from chestnut shells is less affected when it is shined by lamplight,UV-light and sunlight. When the pH from 3 to 7 and 10 to 13, the colour of the brown pigment is changed greatly. But While the pH from 7 to 10, the colour of the brown pigment is changed weakly.5. According to the result of acute toxicity LD50 test in mice, the LD50 of brown pigment is more than 21.5g/kg, which fall into the brown pigment of non-toxicity.