濃縮苦瓜汁噴霧乾燥產品之研究

Studies on the Spray-drying Product of Bitter Gourd Concentrate

李穎宏(Ying-Hung Lee) ； 陳正敏(Cheng-Min Chen) ； 龔賢鳳(Hsien-Feng Kung)

《高雄區農業改良場研究彙報》 18卷1期 (2007/06) Pp. 53-64

https://doi.org/10.6958/RBKDAIS.200706.0053

摘要

本研究借重苦瓜其本身具有之保健功能，探討苦瓜汁濃縮與乾燥脫水加工，藉以開發成為調味隨身包產品，或以養生飲用或以烹煮調味用，期盼透過擴大苦瓜之加工利用，達到應用現代科技創造我國農產加工品更高附加價值之目的。為開發苦瓜保健產品，本研究進行苦瓜抗氧化能力分析，再利用RO配合真空濃縮將苦瓜汁濃縮成15，20，25，30%固形物後，分別比較添加不同糊精種類、比例對其噴霧乾燥產物之品質影響，其結果如下：苦瓜之還原力以乙醇萃出物＞水萃物，其亞鐵螯合力則以水萃物＞乙醇萃物，DPPH清除能力以乙醇萃物＞水萃物。當以不同濃縮苦瓜榨出液進行噴霧乾燥時，其產品之回收率及白色度隨糊精添加比例增加而增加，但隨苦瓜濃縮程度增加而下降，而產品之流動性則與回收率、白色度呈相反趨勢。苦瓜濃縮液固形物含量為25，30 %時，添加玉米糊精較添加馬鈴薯糊精者明顯具有較高之回收率、白色度。當苦瓜濃縮液添加抗濕劑進行噴霧乾燥時，會使產品之流動性上升假密度下降，但對白色度及回收率之影響不明顯。

關鍵字

苦瓜 ； 薄膜濃縮 ； 噴霧乾燥 ； 抗氧化

並列摘要

The aims of this study were to utilize the bioactive components of bitter gourd for developing their relative healthy food products, such as the product of concentrate and dehydrate-powder. Through developing their new healthy food products, the utilization and the appended value of this crop will also be exploited and increased, respectively. In recent year, our study was focused on the optimal spray drying conditions of bitter gourd and the anti-oxidative abilities in its raw materials included of the DPPH scavenging abilities, reducing power and Fe^(2+) chelating abilities. For investigating the influence of drying operation and material medium factors on the qualities of spray drying powder, the bitter gourd juice by pectin-hydrolyzed was first concentrated to soluble solid content of 15% by membrane filtration, and then further concentrated to 20%, 25%, 30% by vacuum at 50℃. And the effects of soluble solid content in bitter gourd, kinds and ratio of maltodextrin-adding, outlet and inlet drying temperature, and anti-caking agent added during drying courses on the recovery, color, flow-ability, bulk density, particle distribution of spray powder were discussed in detail. The results were showed as follows: Comparisons of the anti-oxidative activities between ethanol-extract and water extract from bitter gourd showed that: the DPPH scavenging abilities and reducing power in ethanol-extract was higher than in water-extract, whereas there are higher Fe^(2+) chelating abilities in water-extract than in ethanol-extract. As for optimal spray drying condition for bitter gourd powder, systematic approaches were performed, included of influence of soluble solid content of juice, carrier, outlet and inlet temperature and anti-caking agent. Results of influence of soluble solid content on recoveries, white index, flow-ability and bulk density for bitter gourd spray-drying power showed that: The higher soluble solid content in juice, the low recoveries, white index, and the higher flow-ability were in spray-drying power. Contras to the effect of soluble solid content in juice, the more malto-dextrin ratio added the higher recoveries, white index, and the lower flow-ability of drying powder were observed. In addition, our study also showed that: While the soluble solid content of bitter gourd juice reached to 25-30 %, the recoveries and white index of bitter gourd spraying powder with corn maltodextrin-adding were higher than that with potato maltodextrin-adding. Besides, adding tricalicum phosphate in bitter gourd juice as anti-caking agent, increased the flow-ability of powder along with decreasing its bulk density, however, that was no significantly different for the recoveries and white index.

並列關鍵字

Bitter gourd ； Membrane concentration ； Spray-drying ； Antioxiditive ability