摘要: 本試驗的目的在探討套袋對‘珍珠拔’番石榴果實品質與生化特性的影響。冬果生長期長,套袋後至果實成熟需87天,春果生長期較短,只需71天,果實生長曲線皆呈雙S型。以聚乙烯塑膠袋內襯白色舒果套套袋的果實較套網袋者生長快速、果形較大且全可溶性糖含量較高;澱粉、總酚類化合物含量、過氧化酵素與苯丙胺酸脫氨裂解酶活性在二處理間無顯著差異。網袋處理較聚乙烯塑膠袋內襯白色舒果套處理的乙烯釋放率及呼吸率高。兩個季節的果實全可溶性糖隨生長發育逐漸增加,澱粉含量維持平穩,總酚類化合物含量與苯丙胺酸脫氨裂解酶活性變化趨勢相似。過氧化酵素可能與番石榴果實肥大有關。在八種不同套袋材質中顯示,以聚乙烯塑膠袋內襯白色舒果套的處理果實生長較快且果皮顏色翠綠,與套網袋者有顯著差異,銀粉聚乙烯塑膠袋內襯白色舒果套之果實N、P、K、Ca和Mg元素的含量最低,套網袋果實各種大量元素含量相對較高。除了Zn元素外,聚乙烯塑膠袋內襯白色舒果套處理的果實所含各微量元素都較其他處理低。不同套袋材質處理全可溶性糖含量除套網袋果實的含量較低外,其他各處理間沒有差異。澱粉含量也沒有差異。總酚類化合物含量與過氧化酵素活性,皆以套網袋與聚乙烯塑膠袋內襯網袋的處理最高,而銀粉聚乙烯塑膠袋內襯白色舒果套與聚乙烯塑膠袋內襯白色舒果套處理的果實最低。‘珍珠拔’番石榴雖然屬於非更年型的果實,但成熟後有容易軟化的問題。在比較品種間果實軟化相關物質的試驗中發現,‘梨子拔’果實後熟時乙烯釋放率及呼吸率均逐漸上升,並出現明顯之更年性高峰,ACC含量大量增加且ACC oxidase活性也之上升,而‘珍珠拔’和‘世紀拔’後熟時呼吸速率變化不大亦無高峰出現,乙烯釋放率與ACC含量極低,ACC oxidase活性後熟期才上升。三品種全可溶性糖含量隨果實發育而增加,除‘梨子拔’外,澱粉含量在各發育階段均無顯著差異。‘世紀拔’和‘梨子拔’果實水溶性果膠含量呈平穩增加,‘珍珠拔’在stageⅢ時水溶性果膠含量最高,之後減少,而各品種不同發育階段的不溶性果膠含量呈現不規則的變化。三品種番石榴的果膠甲酯酶(PE)活性以未熟果實最高,隨著果實發育PE活性逐漸下降,後熟期的活性最低。聚半乳糖醛酸酶(PG)活性方面,‘珍珠拔’與‘世紀拔’番石榴活性變化趨勢相似,以stageⅡ和stageⅢ時PG活性最高,而‘梨子拔’果實以綠熟期(stageⅣ) PG活性最高,三品種果實後熟期PG活性都明顯下降。The purpose of this study was to investigate the effect of bagging on fruit quality and biochemical characteristics of ‘Jen-Ju Bar’ guava. Fruit growth showed a double sigmoidal pattern, with winter fruit needing 87 days while spring fruit needing 71 days to reach the mature. Fruit bagging with expanded polystyrene net sleeve (EPNS) within polyethylene (PE) bag were rapid growth, increased fruit size, and increased total soluble sugar content. However starch and total phenolic compound, peroxidase and phenylalanine ammonia-lyase activity were no significantly between the two treatments. Fruit bagging with net bag had higher respiration rate and ethylene production during growth and development. Total soluble sugar content was increased, starch content remaining steadily, and similar currents of changes were total phenolic compound content and phenylalanine ammonia-lyase activity with growth and development both winter and spring fruit. Bagging on promoting fruit growth seems to be related to the peroxidase activity. Effect of different bagging material on fruit growth results showed, fruit bagging with EPNS within PE bag rapid and peel color was dark green, were significantly as compared with net bag. Fruit bagging with EPNS within bag were made with PE and silver powder (Silver-PE) that N, P, K, Ca, Mg concentrations was very low, and fruit bagging with net bag had higher N, P, K, Ca, Mg concentrations. Fruit bagging with EPNS within PE bag had lower mirco element concentrations compared with other treatments. Effect of different bagging material on fruit Zn concentrations, total soluble sugar and starch contents were no different. The results showed that total phenolic compound content and peroxidase activity to be similar on different bagging material, fruit bagging with EPNS within PE bag and net bag had higher total phenolic compound content and peroxidase activity than EPNS within Silver-PE bag and EPNS within PE bag. ‘Jen-Ju Bar’ guava tends to turn soft after ripe. Biochemical and physical changes in fruits of three guava cultivars at different fruit development stage were studied. Results showed ‘Li-Tzy Bar’ guava had higher respiration rate and ethylene production at ripening, exhibited a typical climacteric pattern of respiration, ACC content and ACC oxidase activity suddenly increased at ripening. While ‘Jen-Ju Bar’ and ‘Shyh-Jii Bar’ respiration rate, ethylene production and ACC content very low at different fruit development stage , and ACC oxidase activity suddenly increased at ripening, as well as ‘Li-Tzy Bar’ guava. Changes in contents of the total soluble sugar increased progressively during the different fruit development stage. Except ‘Li-Tzy Bar’ guava, starch content had no significant different. Water soluble pectin content of ‘Shyh-Jii Bar’ and ‘Li-Tzy Bar’ guava increased systematically up to the ripe stage, while ‘Jen-Ju Bar’ guava increase at stageⅢ and then decreased. Change in hydrochloric acid soluble pectin content were checkered of ‘Jen-Ju Bar’, ‘Shyh-Jii Bar’ and ‘Li-Tzy Bar’ guava at different fruit development stage. Pectinesterase (PE) activity increased at stageⅠ to stageⅢ and subsequently decreased, minimum activity at ripe stage. A similar pattern of changes in polygalacturonase (PG) activity of ‘Jen-Ju Bar’ and ‘Shyh-Jii Bar’, the PG activity highest at stageⅡ and stageⅢ. While ‘Li-Tzy Bar’ guava at mature green stage (stageⅣ) had highest PG activity and three guava cultivars ripe stage PG activity decreased. |