摘要
【目的】探究套袋处理对‘马家柚’果实挥发性物质积累的影响。【方法】以套袋和未套袋的‘马家柚’果实为试材,利用气相-质谱联用仪(GC-MS)比较分析了5个发育时期‘马家柚’果皮和果肉中的挥发性物质组成,并采用半定量计算方法对结果进行定量分析。【结果】‘马家柚’果实中挥发性物质以醇类、酯类、烯类等化合物为主,在果皮和果肉组织中分别鉴定到69种和40种挥发性物质,其中诺卡酮及部分单烯类物质如β-月桂烯(β-Myrcene)、β-水芹烯(β-Phellandrene)等挥发性成分在果皮中特异积累。套袋和未套袋处理的‘马家柚’果实在果实发育过程中的挥发性物质变化趋势总体相同。套袋处理未改变‘马家柚’果实积累的挥发性物质种类,但对其含量产生了显著影响:套袋处理的成熟‘马家柚’果实果皮的挥发性物质总量(1294.20±14.67)μg·g^-1显著低于未套袋处理(4869.44±30.78)μg·g^-1,其中倍半萜酮和单萜的含量降幅最大;成熟‘马家柚’果肉挥发性物质总量在套袋处理(257.06±29.90)μg·g^-1与未套袋处理(355.30±36.54)μg·g^-1间无显著差异,表明套袋处理对‘马家柚’主要食用部位—果肉的香气成分影响较小。【结论】研究结果为改进‘马家柚’果实品质以及深入研究光信号对香气品质的形成调控机制提供了基础。
【Objective】Bagging,as a common cultivation technique in fruit industry,is widely used in many types of fruit trees except citrus,such as apple,peach,grape,etc.Volatile compounds can directly affect fruit flavor s and are an important indicator of fruit quality.Till now,little research has conducted on the physiological and molecular changes of volatile compounds accumulation in response to environmental stimuli in citrus.The present study was mainly to explore the effect of bagging on the accumulation of volatile compounds in the peel and pulp of unbagged and bagged‘Majiayou’pumelo fruits at five developmental stages,for purpose of providing some guidance in the application of bagging and new clues for understanding the molecular mechanism to volatile compound regulation in citrus.【Methods】The determination of volatile compounds can be divided into three steps:The first step was the extraction of volatile compounds.0.5 g peel or 1.0 g pulp was weighed,put into a 2 mL centrifuge tube,0.5 mL ultrapure water was added,and mixed evenly in vortex.Then 0.5 mL MTBE was added containing methyl nonanoate(Vmethyl nonanoate∶VVMTBE=1∶80),and vortex was performed with the mixture again.The mixture was then subjected to ultrasonic extraction at 4℃for 40 min.Next,the extract was centrifuged at 12000 g for 10 min below 4℃,and then filtered through a 0.22μm membrane prior to GC MS analysis.The second step was determination.GC-MS was performed by tr-5ms gas chromatography column(30 m×0.25 mm×0.25μm,Thermo Scientific,Bellefonte,PA,USA),the specific temperature of sample inlet and ion source were 280℃and 260℃,respectively.The programmed temperature rise conditions were as follows:treating at 40℃for 3 min,then raising the temperature to 160℃at 2℃·min^-1 and holding for 1 minute,and then raising the temperature to 200℃at 5℃·min^-1,next raising the temperature to 240℃at 8℃·min^-1 and holding for 3 min.The last step was data analysis.The analysis of volatile components was carried out by Xcalibur and AMDIS.In this study,the quantitative calculation of volatile components was performed by semi quantitative analysis.First,the area normalization method was used to get the area percentage of each component.Then,the concentration of each component was calculated by the concentration of internal standard compounds in the sample.【Results】Esters and terpenes were the main volatile compounds in‘Majiayou’pumelo fruit.A total of 69 and 40 kinds of volatile compounds were identified in peel and pulp,respectively.The alcohol,ester,aldehyde,terpene and other compounds in the pulp were less than those in the pericarp,and nootkatone and some monoene compounds such asβ-myrcene andβ-phellandrene were found to be specifically accumulated in the peel.Bagging affected the content of volatile compounds but not the composition.During maturation stage,the total content of volatile compounds in peel with bagged fruit(1294.20±14.67)μg·g^-1 was significantly lower than that with unbagged fruit(4869.44±30.78)μg·g^-1.Especially,compared to unbagged fruits,the content of sesquiterpeneketone and monoterpene decreased dramatically in peel of bagged fruit.With regard to the pulp,there was no significant difference in the total content of volatile compounds between bagged fruits(257.06±29.90)μg·g^-1 and unbagged fruits(355.30±36.54)μg·g^-1,which indicated that bagging had little effect on the volatile compounds in the pulp.In addition,the contents of volatile compounds in‘Majiayou’pumelo fruit at different developmental stages(105,135,150,180 and 210 days after flower,DAF)were analyzed in this study.In the peel,we found that oxides,alcohols and ketones accumulated more in bagging than unbagging treatments at the middle stage of development,but alkenes,acids and aldehydes accumulated more and faster in unbagging than bagging treatments,and no significant difference were found in the content of esters between bagging and unbagging treatments.The content of volatile compounds in the peel of bagged and unbagged‘Majiayou’pumelo fruits showed a similar trend of increasing at first and then decreasing during developmental stages.In the pulp of both bagging and unbagging treatments,the content of oxides,alkenes and ketones decreased gradually with the development of fruit,and the accumulation of acids,aldehydes and alcohols increased at first and then decreased.However,no significant differences were detected in the content of each substance in the pulp between bagged and unbagged‘Majiayou’pumelo fruits,especially for the mature stage.【Conclusion】In this study,we found that bagging treatment had a great effect on the volatile compounds in the peel of‘Majiayou’pumelo fruits,among which the content of ketones and terpenes changed significantly.However,the composition and content of volatile compounds in the pulp of‘Majiayou’pumelo fruits were not affected by bagging treatment,suggesting bagging treatment had little effect on the aroma and the overall flavor of the pulp,the main edible part of‘Majiayou’pumelo fruits.Therefore,bagging can be widely used in‘Majiayou’pumelo cultivation in terms of our volatile compounds analysis.Previous studies have shown that the accumulation of volatile compounds is related to light quality and intensity.The peel is normally exposed to the sunlight,while the wrapped pulp is always under dark condition due to the thick peel either for bagging or unbagging treatment.This may explain the different behavior of peel and pulp with bagging treatment.These results can provide a basis for improving the fruit quality in the field practice with bagging treatment,and for studying the mechanism of light signal to regulate the formation of aroma quality in citrus.
作者
姜启航
朱凯杰
吴方方
徐娟
徐强
柴利军
邓秀新
叶俊丽
JIANG Qihang;ZHU Kaijie;WU Fangfang;XU Juan;XU Qiang;CHAI Lijun;DENG Xiuxin;YE Junli(Key Laboratory of Horticultural Plant Biology,Ministry of Education/Key Laboratory of Horticultural Crop Biology and Genetic Improvement(Fruit),Ministry of Agriculture and Rural Affairs/College of Horticulture&Forestry Sciences,Huazhong Agricultural University,Wuhan 430070,Hubei,China;Fruit Industry Management Office of Guangfeng District,Shangrao 334000,Jiangxi,China)
出处
《果树学报》
CAS
CSCD
北大核心
2020年第11期1701-1710,共10页
Journal of Fruit Science
基金
国家重点研发项目(2018YFD1000200)
现代农业柑橘产业技术体系(CARS-26)。
关键词
‘马家柚’
套袋
挥发性物质
果实品质
香气
‘Majiayou’pumelo
Bagging
Volatile compounds
Fruit quality
Aroma
