[Objective] This study aimed to investigate the enzymatic kinetics of polyphenol oxidase in peel of Nephelium lappaceum to explore the environmental factors affecting its catalytic activity. [ Method ] With N. lappace...[Objective] This study aimed to investigate the enzymatic kinetics of polyphenol oxidase in peel of Nephelium lappaceum to explore the environmental factors affecting its catalytic activity. [ Method ] With N. lappaceum peel as the experimental material and catechol as substrate, effects of temperature, pH, four inhibitors （EDTA, Vc, sodium bisulfite and citric acid） and substrate concentration on the activity of polyphenol oxidase were investigated. [ Result] The optimal temperature for polyphenol oxidase in N. lappaceum peel was 40 %, and the optimal pH was 6.8. EDTA, Vc, sodium bisulfite and citric acid all showed ideal in- hibitory effects on the activity of polyphenol oxidase; specifically, EDTA had the strongest inhibitory effect. [ Conclusion] At low temperature, EDTA, Vc, sodi- um bisulflte and citric acid with certain concentrations can inhibit the catalytic activity of polyphenol oxidase in peel of N. lappaceum, extend the storage and trans- portation time of N. lappaceum fruit, and inhibit the browning. This study provides theoretical basis for the development and utilization of polyphenol oxidase in peel of N. lappaceum.展开更多
Rambutan growing in the state of Chiapas has brought about a demand for new plantations;however, this species has several biotic and abiotic factors that limit its production. These factors include phytosanitary probl...Rambutan growing in the state of Chiapas has brought about a demand for new plantations;however, this species has several biotic and abiotic factors that limit its production. These factors include phytosanitary problems, deficient agronomical handling, and production alternancy. Because of this, the objective of the present study was to evaluate the effect of the application of agronomical practices such as pruning, ringing, water stress, and their interaction on the rambutan alternancy. The experiment was carried out in the “La Chinita” commercial orchard located on KM. 4.5 the Huehuetan Station, municipality of Huehuetan, Chiapas, Mexico. We used 48 rambutan trees in production with an age of 14 years. Two production cycles were evaluated. The experiment was established under a divided plot experimental design in random complete blocks with a factorial arrangement and six replicates;each tree being a replicate. The study factors were: water stress, pruning, girdling, irrigation (control), and their combinations, resulting in eight treatments. The evaluation was done during flowering, fruit set, and harvest. In flowering, the treatments with permanent irrigation in both evaluated cycles (2010-2011 and 2011-2012) manifested a production alternancy behavior, with an average 36.4% flowering in the first evaluation cycle and increased to 82.1% in the second cycle. The treatments with water stress kept a proportional flowering during the first and second cycles of 97.9% and 95.3%, respectively. The water stress influenced the bunch weight (PR) variable fruit set with bigger fruits and higher bunch weight than the irrigated treatments. In production, pruning and girdling together with water deficit had no alternancy in both production cycles.展开更多
基金Supported by Leading Academic Discipline Project of Botany in Guizhou Province ([2011] No.275)College-level Planning Project of Kaili University(Z0804)+1 种基金Leading Academic Discipline Project of Botany from Kaili University (KZD2008002)Construction Project for Basic Course Teaching Team of Biological Science from Kaili University (JXTD201003)
文摘[Objective] This study aimed to investigate the enzymatic kinetics of polyphenol oxidase in peel of Nephelium lappaceum to explore the environmental factors affecting its catalytic activity. [ Method ] With N. lappaceum peel as the experimental material and catechol as substrate, effects of temperature, pH, four inhibitors （EDTA, Vc, sodium bisulfite and citric acid） and substrate concentration on the activity of polyphenol oxidase were investigated. [ Result] The optimal temperature for polyphenol oxidase in N. lappaceum peel was 40 %, and the optimal pH was 6.8. EDTA, Vc, sodium bisulfite and citric acid all showed ideal in- hibitory effects on the activity of polyphenol oxidase; specifically, EDTA had the strongest inhibitory effect. [ Conclusion] At low temperature, EDTA, Vc, sodi- um bisulflte and citric acid with certain concentrations can inhibit the catalytic activity of polyphenol oxidase in peel of N. lappaceum, extend the storage and trans- portation time of N. lappaceum fruit, and inhibit the browning. This study provides theoretical basis for the development and utilization of polyphenol oxidase in peel of N. lappaceum.
文摘Rambutan growing in the state of Chiapas has brought about a demand for new plantations;however, this species has several biotic and abiotic factors that limit its production. These factors include phytosanitary problems, deficient agronomical handling, and production alternancy. Because of this, the objective of the present study was to evaluate the effect of the application of agronomical practices such as pruning, ringing, water stress, and their interaction on the rambutan alternancy. The experiment was carried out in the “La Chinita” commercial orchard located on KM. 4.5 the Huehuetan Station, municipality of Huehuetan, Chiapas, Mexico. We used 48 rambutan trees in production with an age of 14 years. Two production cycles were evaluated. The experiment was established under a divided plot experimental design in random complete blocks with a factorial arrangement and six replicates;each tree being a replicate. The study factors were: water stress, pruning, girdling, irrigation (control), and their combinations, resulting in eight treatments. The evaluation was done during flowering, fruit set, and harvest. In flowering, the treatments with permanent irrigation in both evaluated cycles (2010-2011 and 2011-2012) manifested a production alternancy behavior, with an average 36.4% flowering in the first evaluation cycle and increased to 82.1% in the second cycle. The treatments with water stress kept a proportional flowering during the first and second cycles of 97.9% and 95.3%, respectively. The water stress influenced the bunch weight (PR) variable fruit set with bigger fruits and higher bunch weight than the irrigated treatments. In production, pruning and girdling together with water deficit had no alternancy in both production cycles.
