梅子 ( Prunus mume ) 英文名為mei，微甜、酸度高的水果，通常將其加工後食用，被當成天然的健康食品。梅精 ( Mei-Gin )為梅汁有效成分加熱濃縮後的加工品。本試驗利用梅子為材料，經真空濃縮和取梅汁加熱濃縮汁產物後，以安氏試驗 ( Ames test ) 進行抗致突變性和抗氧化能力試驗。結果顯示在所選取之劑量範圍內梅子真空濃縮物、熱濃縮物及梅精 ( 0.04~5 mg/plate ) 無論是否添加S9混和物對Salmonella typhimurium TA98及TA100菌株均不具毒性及致突變性。在抗致突變試驗中，梅子真空濃縮物對直接型致突變劑4-nitroquinoline 1-oxide之抗致突變率分別為4.4~34.2% ( TA98 ) 及 29.4~90.8% ( TA100 ) 之間；梅子真空濃縮物對間接型致突變劑2-aminoanthracene之抗致突變率分別為16.5~53.6% ( TA98 ) 及 27.3~43.5% ( TA100 ) 之間。梅子熱濃縮物對直接型致突變劑4-nitroquinoline 1-oxide之抗致突變率分別為 2.8~19.3% ( TA98 ) 及 43.3~103.7% ( TA100 ) ；梅子熱濃縮物對間接型致突變劑2-aminoanthracene之抗致突變率分別為6.1~24.5% ( TA98 ) 及 22.1~71.6% ( TA100 ) 之間。，梅精對直接型致突變劑4-nitroquinoline 1-oxide之抗致突變率分別為6.5~27.3% ( TA98 ) 及0.4~90.1% ( TA100 ) 之間；梅精對間接型致突變劑2-aminoanthracene之抗致突變率介於3.4~32.8% ( TA98 ) 及8.5~52.4% ( TA100 )之間。在抗氧化方面，總酚類化合物含量分別為梅精 (612.1±8.9 mg of GAE/g )、真空濃縮物 ( 540.4±2.0 mg of GAE/g )及熱濃縮物 ( 784.3±8.1 mg of GAE/g )；總類黃酮含量分別為梅精 ( 248.5±1.1 mg of rutin/g )、真空濃縮物 ( 177.2±5.3 mg of rutin/g )及熱濃縮物 ( 155.6±3.8 mg of rutin/g )。在抗氧化能力中，總抗氧化能力以熱濃縮物 ( 1.4±0.0 mM of trolox )最高；熱濃縮物其EC50（ Effective concentration 50 ） 值分別為，清除DPPH自由基 ( 1.6±0.1 mg/ml ) 、還原力 ( 10.1±0.1 mg/ml ) 及螯合亞鐵離子 ( 0.4±0.0mg/ml )效果為最佳。綜合以上結果，梅子濃縮物及梅精對TA98及TA100不具致突變性，熱濃縮物對直接型抗致突變率可達到103.7%為最高，抗氧化能力皆以熱濃縮物能力最佳。 Mei fruit is slightly sweet and high acidity, usually its processing for edible, is as natural health food. Mei-gin is the processed concentrated by heating of mei juice, having efficacy about 30 times greater than the marinated prunes. The study was investigated the antioxidant and antimutagenic activity of mei concentrate, hot concentrate and mei-gin by several antioxidant activity determinated methods and Ames test. Results indicate that microbial toxicity and mutagenicity assay ( Ames test ) showed that all the concentrate ( 0.04~5 mg/plate ) , with or without rat liver enzyme mixture ( S9 ), had no toxicity and mutagenicity effect toward both tester strains ( Salmonella typhimurium TA98 and TA100 ). Antimutagenic test of mei concentrate showed inhibition effect toward TA98 against 4-NQO ( the inhibition was 2.8~34.2% ) and toward TA100 ( the inhibition was 29.4~103.7% ) against 4-NQO, and in mei-gin showed inhibition effect toward TA98 against 4-NQO ( the inhibition was 6.5~27.3% ) and toward TA100 ( the inhibition was 0.4~90.1% ) against 4-NQO；mei concentrate effect toward TA98 ( the inhibition was 6.1~53.6% ) and toward TA100 ( the inhibition was 22.1~71.6% ) , and mei-gin effect toward TA98 ( the inhibition was 3.4~32.8% ) against 2-aminoanthracene and toward TA100 ( the inhibition was 8.5~52.4%) against 2-aminoanthracene. Total antioxidant capacity, results indicated that the total content of phenolic compounds were 612.1±8.9 mg of GAE/g of mi-gin, 540.4±2.0 mg of GAE/g of concentrate and 784.3±8.1 mg of GAE/g of hot concentrate；the total content of flavonoid compounds were 248.5±1.1 mg of rutin/g of mi-gin, 177.2±5.3 mg of rutin/g of concentrate and 155.6±3.8 mg of rutin/g of hot concentrate. The TEAC of hot concentrate of mei highest,and values were 1.4±0.0 mM of trolox；Hot concentrate of the EC50 values of the best results were 1.6±0.1 mg/ml of DPPH scavenging capability, 10.1±0.1 mg/ml of Reducing power and 0.4±0.0 mg/ml of chelating abilities on ferrous ions. In conclusion, mutagenic test showed the mei concentrate and mei-gin had no mutagenicity effect toward both tester strains(Salmonella typhimurium TA98 and TA100). Hot concentrate of directly mutagenic rate of 103.7 % for the highest, antioxidant capacity are the highest ability of hot concentrate.
