樹脂及活性碳處理對Noni發酵果汁所含酚類化合物及風味之影響

Abstract

檄樹 (Morinda citrifolia.L.) 又名諾麗 (Noni)，主要的加工產品為發酵諾麗果汁，具有臭氣與苦味而造成風味不佳的問題，又其苦臭味來源之呈味因子目前仍尚未知悉，故本實驗嘗試以Amberlite XAD-4、XAD-7HP、XAD-16、XAD-761等吸附性樹脂及活性碳粒以攪拌浸泡與管柱流洗方式進行發酵諾麗果汁不良風味之脫除，並同時評估吸附劑處理對發酵諾麗果汁一般成分與機能性成分之影響。 發酵諾麗果汁經攪拌吸附後，可溶性固形物、可滴定酸度、pH值等一般成分變化不大，但在色澤上，XAD-7HP、XAD-16、XAD-761樹脂處理後之果汁有肉眼可見的明顯差異。機能性成分的差異則較大，以活性碳處理為例，三次的攪拌吸附分別造成52%、37%、35%的總酚類損失，40%、27%、15%的縮合單寧損失及66%、51%、41%的類黃酮損失，由此可知吸附劑經再生重複使用後，其吸附能力有明顯衰退的趨勢。此外，攪拌吸附處理由於有吸附劑易碎裂、與果汁接觸不全的問題，因此並不是理想的處理方式。 發酵諾麗果汁以連續式管柱再生流洗處理後，顯示出與攪拌吸附類似之趨勢，除色澤外之一般成分變化不大，但機能性成分變化顯著，以XAD-4處理為例，三次的管柱流洗分別造成35%、34%、28%的總酚類損失，50%、38%、37%的縮合單寧損失及62%、53%、45%的類黃酮損失。 發酵諾麗果汁以連續式管柱單次流洗處理後，較先流出的果汁及最末段果汁其被吸附的成分較多，中間的部分則較少。 發酵諾麗果汁以連續式管柱再生流洗處理所得之吸附劑酒精再生液中，以XAD-4、XAD-7HP及XAD-16樹脂清洗液有較高的酚類含量及DPPH自由基清除率，應有再利用的潛力。 官能品評中，以XAD-16的處理對臭氣減弱的效果最顯著， XAD-16、活性碳可使果汁異味減弱為原來的1/3，XAD-4可減弱為原來的1/2，XAD-7HP、XAD-761減弱為原來的2/3。整體評估上，以XAD-4連續式管柱流洗為較適合的諾麗果汁脫除苦臭味方式。

Morinda citrifolia. L. also called Noni, Its main product, fermented Noni juice, has the odor and the bitter taste causes undesirable flavor problem, and the poor flavor sources factor were still not known, so this experiment attempted using adsorbent resin Amberlite XAD-4, XAD-7HP, XAD-16, XAD-761 and active carbon tablets by stir batch or column flow to treat fermented Noni juice for undesirable flavor removing. Meanwhile, evaluate the influence of general and functional ingredient in fermented Noni juice after adsorbents treating. After adsorption by stir batch, the soluble solids, titratable acidity, and pH values of fermented Noni juice changed little. But in color and hue, after XAD-7HP, XAD-16, the XAD-761 resin treatment, the fermented Noni juice has shown obvious difference to the naked eye. The functional ingredient's difference is big, take active carbon treatment as the example, three times stir batch adsorption causes 52%, 37%, 35% total phenols to lose separately; 40%, 27%, 15% condensed tannin loss and 66%, 51%, 41% flavanoid loss. Thus it may be known the repeated use of absorbent, causes the adsorption capacity decreased significantly. Because of having easy to break, incomplete contact with the juice and less efficient problems in stir batch, therefore it‘s not an ideal processing mode. After adsorption by continuous column regeneration flow, it shows the similar trend, the change of general ingredient on fermented Noni juice is not significant, besides the color and hue, but the functional ingredient change obviously. Take the XAD-4 processing as the example, three time tube column class washes causes 35%, 34%, 28% total phenols lose separately, 50%, 38%, 37% condensed tannin loss and 62%, 53%, 45% flavonoid loss. After adsorption by continuous column single flow, the former part and the final part of fermented Noni juice flow out from column loss more ingredient than the middle parts. Absorbents' alcohol regeneration solution from Continuous column flow, XAD-4, XAD-7HP and XAD-16 resin cleaning liquid has higher total phenol content and DPPH free radical scavenging rate, may have the reusable potential. In the sensory evaluation, odor reducing by XAD-16 treatment shows the most remarkable effect, and in undesirable taste weakening, XAD-16 and active carbon may cause the taste to weaken for original 1/3, XAD-4 may weaken for original 1/2, XAD-7HP, XAD-761 weaken for original 2/3. In the overall assessment, XAD-4 column flow treatment is more suitable for the Noni juice undesirable flavor removal .