壓縮膨發處理對蘆薈及五葉松萃取抗氧化物之影響

Abstract

壓縮膨發處理已被證明為一新穎的萃取前處理方法，被用來提升萃取植物抗氧化物的含量，在本研究中，利用壓縮膨發來對蘆薈(42.47 g/g)及五葉松(1.61 g/g)做試驗，探討不同含水量及不同乾燥方法造成的影響，利用掃描式電子顯微鏡(SEM)可以發現樣品表面在前處理過後出現許多微孔，藉由水銀測孔儀(MIP)，發現熱乾燥的蘆薈經壓縮膨發後，總孔隙面積從2.16上升到13.59 m2/g，冷凍乾燥的蘆薈則是從2.39上升到9.64 m2/g。當熱乾燥後蘆薈含水量在1 g/g，經前處理後所得到的抗氧化物含量為未處理的2.6倍，反觀冷凍乾燥後的蘆薈(1 g/g)，抗氧化物含量僅上升1.6倍。且當壓縮膨發溫度為180、200、220ºC時，臨界含水量個別為0.33、1、1.5 g/g。另外對熱乾燥後的五葉松進行壓縮膨發處理，在同樣的前處理條件下，可以發現一樣在1 g/g含水量時會有最大的提升效果，多酚含量從未處理的19.2上升到51.4 GAE mg/g DW，抗氧化能力由137.9上升到392.8 TE umol/g DW。藉由乾燥的過程再加上壓縮膨發的前處理，可以使得在特定含水量下，有最大的萃取含量，得到比未乾燥的原樣品有更好的壓縮膨發效果。

Compressional-puffing pretreatment recently has been reported to become a novel method used to increase the extraction yields from plants. In this study, two plants, aloe vera (42.47 g/g) and pinus morrisonicola (1.61 g/g), were dried to different moisture content and conducted under the same pretreatment and extraction process. SEM pictures showed that a large amount of small pores appeared after pretreatment. MIP results indicated that the total pore area increased from 2.16 to 13.59 m2/g for thermal-dried aloe pieces and from 2.39 to 9.64 m2/g for freeze-dried aloe pieces. When the thermal-dried aloe was 1 g/g, the results showed a 2.5 fold increase in the extraction yields of antioxidant compounds after 200 ºC and 20 seconds pretreatment. But when the freeze-dried aloe was 1 g/g, the treated one was only 1.6 times the untreated. For different puffing temperature 180, 200 and 220 ºC, the critical moisture content were 0.33, 1 and 1.5 g/g respectively when the highest extraction yields occurred. On the other hand, for thermal-dried pine needles, the largest enhancement of antioxidants occurred also at 1 g/g under the same condition, which increased from 19.2 to 51.4 GAE mg/g DW of phenolic compounds and from 137.9 to 392.8 TE umol/g DW of antioxidant activity. By using a simple step of drying, higher enhancement of extraction yields could be obtained than the original sample.