The changes of physiological and biochemical indices in jujube fruits during the late development were investigated from 6-year-old jujube trees (Zizyphus jujuba Mill. cv. Lingwuchangzao). The results showed that th...The changes of physiological and biochemical indices in jujube fruits during the late development were investigated from 6-year-old jujube trees (Zizyphus jujuba Mill. cv. Lingwuchangzao). The results showed that the flesh firmness decreased slowly from white-green stage to full-red stage, being significantly related with the developmental maturity of jujube fruits negatively, the correlation coefficient reached -0.980 3^**. The contents of ascorbic acid and titratable acid in jujube fruits were significantly related with the developmental process of jujube fruits negatively or positively, the correlation coef- ficients were -0. 973 1^**and + 0. 974 6^ * * , respectively. The contents of soluble solids, total sugar, and sucrose increased with jujube ripening, while the relative sweetness of jujube fruits showed the same variation pattern, the correlation coefficients were 0. 996 6 ^* * , 0. 988 0^** , and 0. 982 8 ^* * , respectively. Before white-green stage during fruit development, the accumulation of monosaccharide was predominant in jujube fruits, following a fast accumulation of sucrose, indicating that the main component of sugars is sucrose at the crisp-ripe stage. Furthermore, the starch content of the flesh reached the peak at about thirty percentage of jujube maturity, being 51,54 mg/100 g.FW. The respiratory rates varied between 10 mg/( kg.h) and CO2 26 mg/( kg.h) after fruit turning red and before softening, indicating a non-climacteric respiratory type.展开更多
The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species (TBARS) assay, total phenol...The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species (TBARS) assay, total phenol content, evaluation of reactive oxygen species (ROS) in liver mitochondria, Fe2+ chelating and 2,2-diphenyl-lpicrylhydrazyl (DPPH) scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE+ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested (15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous). Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2+ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.展开更多
基金Natural Science Foundation of Ningxia Hui Autonomous Region(B1007)~~
文摘The changes of physiological and biochemical indices in jujube fruits during the late development were investigated from 6-year-old jujube trees (Zizyphus jujuba Mill. cv. Lingwuchangzao). The results showed that the flesh firmness decreased slowly from white-green stage to full-red stage, being significantly related with the developmental maturity of jujube fruits negatively, the correlation coefficient reached -0.980 3^**. The contents of ascorbic acid and titratable acid in jujube fruits were significantly related with the developmental process of jujube fruits negatively or positively, the correlation coef- ficients were -0. 973 1^**and + 0. 974 6^ * * , respectively. The contents of soluble solids, total sugar, and sucrose increased with jujube ripening, while the relative sweetness of jujube fruits showed the same variation pattern, the correlation coefficients were 0. 996 6 ^* * , 0. 988 0^** , and 0. 982 8 ^* * , respectively. Before white-green stage during fruit development, the accumulation of monosaccharide was predominant in jujube fruits, following a fast accumulation of sucrose, indicating that the main component of sugars is sucrose at the crisp-ripe stage. Furthermore, the starch content of the flesh reached the peak at about thirty percentage of jujube maturity, being 51,54 mg/100 g.FW. The respiratory rates varied between 10 mg/( kg.h) and CO2 26 mg/( kg.h) after fruit turning red and before softening, indicating a non-climacteric respiratory type.
文摘The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species (TBARS) assay, total phenol content, evaluation of reactive oxygen species (ROS) in liver mitochondria, Fe2+ chelating and 2,2-diphenyl-lpicrylhydrazyl (DPPH) scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE+ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested (15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous). Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2+ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.