低壓脈衝電場處理對青花芽菜生長之影響

Effect of low-voltage pulsed electric field treatment on the sprouting of broccoli seeds

蕭宗汶(Hsiao Tsung-Wen)

指導教授 ： 吳明昌 ； 黃至君

國立屏東科技大學/農學院/食品科學系所/碩士(2019年)

https://doi.org/10.6346/NPUST201900319

摘要

十字花科中的青花菜相較於其他十字花科蔬菜有更多的營養素，且青花芽菜所含有的抗氧化物質比青花菜還多。脈衝電場(PEF)處理為利用可調節電壓之新興技術，為非熱處理且對植物組織具電穿孔之特性，可應用於食品加工領域。近年來許多研究發現通過電流刺激導致種皮的細胞產生電位差，能使水分更快進入細胞內。植物長時間生長在惡劣環境之下，會產生次級代謝物或加快生長速度以抵抗環境逆境。因為目前以脈衝電場刺激青花芽菜相關文獻較少，所以本研究選擇用低壓脈衝電場(1KV/cm)處理0.5、1、2…30分鐘以製造惡劣環境，對青花種子與芽菜進行測試，研究對芽菜生長狀況(包括萌芽率、水分含量、增重率、生長倍數)及抗氧化活性(DPPH、ABTS自由基清除能力)與抗氧化物質(包括總酚、類黃酮、硫配醣體、葉綠素與類胡蘿蔔素)含量的影響，並觀察掃描式電子顯微鏡(SEM)的結果來評估PEF處理效率。結果顯示，PEF處理的種子達萌芽率90%所需時間為48-60小時，相較於未處理種子所需72小時，表示PEF處理能提高萌芽率及縮短萌芽時間；在影響芽菜的生長狀況中，以在第3天處理0.5分鐘的組別有顯著上升；在抗化能力及抗氧化物含量的整體影響則是在第0天及第3天處理0.5分鐘的組別有顯著上升。與控制組相比，在種子或是萌芽時以PEF處理後會使青花芽菜生長狀況及抗氧化特性上升，但若在發芽後每天處理(播種後第4、5及6天)，則無顯著差異。此外，SEM之觀察顯示，若以PEF處理30分鐘，子葉表皮細胞則有電穿孔的跡象。期許未來能將PEF方法應用於縮短種子萌芽時間、刺激作物生長及提高其抗氧化物質含量。

關鍵字

次級代謝物 ； 電脈衝 ； 非熱處理 ； 萌芽

並列摘要

Broccoli, a member of the Brassicaceae family, contains more nutrients than the others of the same family, while its sprouts contain more antioxidants than the broccoli itself. The pulsed electric field (PEF) treatment is a new and non-thermal technique that utilizes adaptable voltage and has a characteristic causing electroporation in plant tissues, which can be used in food processing fields. Recent studies have shown that it is possible to create potential differences between the cells of the seed coats through current stimulation, which allows for quicker submersion of moisture into the cells. When a plant is exposed to a harsh environment, it would secrete secondary metabolites or increase its growth pace to tackle it. Since there are few cases of broccoli seeds treated by PEF, the objectives of this study were to apply a lower voltage of the PEF (1KV/cm) on the broccoli seeds and sprouts for 0.5 ,1 , 2 to 30 minutes in order to cause a stress and to study the effects on their growth status (the germination rate, the moisture content, the weight gain rate and the multiple growth), as well as antioxidant activities (DPPH and ABTS radical scavenging abilities) and the contents of antioxidants (total phenols, flavonoids, glucosinolates, chlorophylls and carotenoids). The results obtained from the scanning electron microscope (SEM) were also studied to evaluate the efficiency of PEF treatment. The result shows that the PEF-treated seeds take 48 to 60 hours to reach a germination rate of 90%, while the untreated seeds would take 72 hours. This shows that the PEF can increase the germination rate hence reducing the germination time. Regarding the effects on sprouting status, the group that was processed by the PEF on day three for 0.5 minutes shows significantly higher values than the others. As for the overall effects on the antioxidant activities and the contents of antioxidants, the PEF-treated for 0.5 minutes on day zero and day three shows a significant increase, compared to the others. When compared to the control group, processing with the PEF on the seeds or the germination stage can boost the sprout growth and the antioxidant capabilities; however, treating daily after germination (on day fourth, fifth and sixth after seeding) shows insignificant differences. Moreover, the SEM examination shows signs of electroporation in the cotyledon epidermal cells when treated by the PEF for 30 minutes. The PEF treatment in hopes can be used in the future to reduce the germination time of seeds as well as to stimulate the crop growth while increasing the contents of antioxidant substances.

並列關鍵字

secondary metabolites ； pulsed electric field ； non-heat treatment ； germination

參考文獻

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