[Objective] The aim was to provide the theoretical basis for the separation and purification of peroxidase(POD) in carambola fruit.[Method] The POD in carambola was extracted using homogenate buffer and acetone extraction,and the extraction effects were compared.[Result] The optimal conditions for star fruit POD by homogenate buffer were PVPP concentration of 1.0%,extraction time of 4 h,pH of 7.0;and the optimal conditions for star fruit POD by acetone extraction were acetone concentration of 90%,acetone extraction time of 30 min,solid-liquid radio of 1∶4 g/ml.[Conclusion] The acetone extraction was better than homogenate buffer by comparing the two methods,which was about 15 times than the latter.Therefore,the extraction of peroxidase in carambola should select the acetone extraction method.

Statistical analysis of turbine engine controllers' long-term storage data reveals notable degradation on controller rotation speed.A mathematical model is derived from the data analysis to estimate the degradation rate with maximum likelihood estimation and interval estimation.The prediction of out-of-tolerance probability by numerical calculation demonstrates that the out-of-tolerance probability will obviously increase after ten years.The controllers in storage should be monitored and adjusted to their initial setting after certain years of storage to retain their reliability.

Five foliar calcium fertilizers were sprayed upon carambola(Averrhoa carambola) to evaluate the quality change of the carambola fruit.The results showed that the soluble solids content and firmness of carambola fruit could be increased by all of these calcium fertilizers.The best effect was achieved by spraying the complex of rare earth with amino acid calcium.The soluble solids content in treated fruits and the firmness increased by 13.0% and 19.6%,respectively.Both the differences were significant.However,there was no significant difference in the content of VC and titratable acidity.Total phenol content was significantly increased by spraying calcium fertilizers,especially in the period of young fruit.The best application method of the complex of rare earth with amino acid calcium was spraying once every 15 days during fruit growth and development period.

The dynamic changes of the Yangshuo kumquat fruits qualities were compared under rain shelter cultivation covered with plastic film and in open field cultivation as control from December 20,2010 to April 15,2011.In order to understand the effects of rain shelter cultivation on quality of Yangshuo kumquat(Fortunella crassifolia Swingle cv.Yangshuo) fruits on tree storage in Yangshuo county.The results showed that the storage period on tree of Yangshuo kumquat under rain shelter cultivation could extend to mid-April of the next year and the good fruit rate still could reach 98.9%.The rain shelter cultivation could not noly delay the decrease of the fruit firmness and maintain higher VC content of later period,but also increased its soluble solids content,TSS-TA ratio and TS-TA ratio.During the whole storage period on the tree,the fruit firmness under rain shelter cultivation was 10.08% to 14.26% higher than that in open field cultivation,its soluble solids content was 2.12% to 5.86% higher than the control;titratable acid content was 13.64% to 14.29% lower than the control;soluble sugar content,TSS-TA ratio and TS-TA ratio of fruit under rain shelter cultivation were all higher than that of control.The VC content of kumquat fruits on the tree storage increased during the first two months and reached maximum in the second month,then reduced rapidly,but the VC content of kumquat fruits under rain shelter cultivation was 8.69% to 14.73% higher than that of control.

The research status of the polyphenol oxidase and peroxidase in fruits is introduced,the activities and characteristics of the phenolases are summarized so as to provide reference for inhibiting the enzymatic browning in fruits.