枫香叶正丁醇提取物抗氧化活性及其对金橘的保鲜效果

为追踪枫香叶正丁醇提取物的体外抗氧化活性及其对果品的采后贮藏保鲜效果，以枫香叶正丁醇提取物（枫香叶依次经醇提、正丁醇萃取、大孔树脂层析、50%乙醇溶液洗脱后所得产物）为材料，分别研究其对1,1-二苯基-2-苦基肼（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基、羟自由基（·OH）、超氧阴离子自由基（O2 － ·）的体外清除能力和还原力；并用不同质量浓度（10、30、50 mg/100 mL）的枫香叶正丁醇提取物对金橘果实进行浸泡处理，室温（14～16 ℃）贮藏，每3 d测定金橘果实的质量损失率、腐烂率、硬度、可溶性固形物（total solublesolids，TSS）含量、可滴定酸（titratable acid，TA）含量、丙二醛（malondialdehyde，MDA）含量、超氧化物歧化酶（superoxide dismutase，SOD）活性、VC含量等果实的品质和生理指标。结果表明，枫香叶正丁醇提取物的体外清除DPPH自由基、·OH、O2－·能力和还原力较强；可以减少金橘果实腐烂、质量损失和MDA含量，减缓果实硬度下降和TSS、TA、VC含量的降低，增强SOD的活性，在金橘果实的贮藏应用上有较好的前景。

Antioxidant Activities of n-Butanol Extract from Liquidambar formosana Leaves in vitro and Their Effects on the Quality of Kumquats (Fortunella margarita) during Storage

The antioxidant activities in vitro of n-butanol extract from Liquidambar formosana leaves prepared by sequential
extraction with ethanol and n-butanol, and macroporous resin chromatography as the 50% ethanol eluate were examined by
1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydroxyl (·OH), superoxide anion (O2 - ·) and reducing power assays. The effects of
different concentrations of the extract（0, 10, 30, and 50 mg/100 mL）on storage characteristics of post-harvest kumquats
were investigated. After pre-impregnation with the extract at 10, 30, or 50 mg/100 mL, kumquats were stored at room
temperature (14–16 ℃). During storage, mass loss rate, decay rate, hardness, total soluble solids (TSS), titratable acid (TA),
malondialdehyde (MDA), superoxide dismutase (SOD), and vitamin C (VC) were measured at 3-day intervals. The results
showed that the extract from L. formosana leaves possessed strong reducing power and scavenging activities against DPPH,
hydroxyl, and superoxide anion free radicals, and could reduce decay rate, mass loss and MDA content, retard the decrease
in hardness and TSS, TA, VC content and enhance the activity of SOD. These results indicated that the n-butanol extract
from L. formosana leaves has promising applications in postharvest preservation of kumquat fruits.