| 摘要: | 菊糖是由果糖組成的果聚醣，儲存在眾多植物中。依來源、物理化學性質及生理特性，得知菊糖是不被人體消化道酵素消化、吸收的，為水溶性膳食纖維。工業生產上，菊糖之果糖數介於2 - 60之間；其中，果糖數介於2 - 10之間的菊糖，又稱寡果糖；介於11 - 60則稱HP-菊糖。本研究分為兩大部分：(1)測定常見食材中菊糖之含量，以供後續瞭解國人攝食菊糖情況。(2)以市售果寡糖、菊糖與HP-菊糖為原料，測定其一般組成分與分子量/聚合度分佈之差異性；探討其添加量的多寡對豆漿與豆花成品之物性與感官的影響。
結果顯示，研究定量分析21種國人常食用植物中之菊糖含量，屬菊科植物的蒜頭(16.24 %)與牛蒡(8.52 %)為高，其餘則低於1.0 % (鮮重)。由市售果寡糖、菊糖與HP-菊糖粉末測得之一般組成分，水分含量的多寡由高至低依序為HP-菊糖(4.68 %)、菊糖(3.63 %)與果寡糖(2.11 %)，粗蛋白、粗脂肪與灰分含量均低；分子量分佈指數(PDI)分別為果寡糖(1.66)、菊糖(1.89)與HP-菊糖(1.32)。添加不同濃度(5 %, 7 %, 9 %)果寡糖、菊糖與HP-菊糖至豆漿與豆花中發現，其流變性質於10℃下，以5 %果寡糖-豆漿k值較高，n值較低；於加熱-降溫過程，其黏彈性質皆G’大於G”，隨著溫度降至20 ℃，以添加9 % HP-菊糖tan δ值較高。隨著果寡糖、菊糖與HP-菊糖濃度的增加，所得豆漿與豆花顏色均L*值較低，a*值較高。在硬度、彈性、膠著性與咀嚼度等質地，以及感官品評中硬度、彈性、甜味、顏色與整體喜好性方面，皆以添加5 %果寡糖-GDL-豆花為高，卻皆未能改善離水現象。經本研究結果得知，果寡糖與菊糖的添加雖不影響豆花成品的品質，但其添加可增進國人(銀髮族)對膳食纖維攝取的不足。
關鍵字：菊糖、果寡糖、膳食纖維、黃豆加工品、流變性、質地、
感官品評
Inulin is the fructan that is composed by fructose, and it is stored in numerous plants. In industrial production, the number of fructose molecules of inulin is between 2 to 60, in which the inulin with 2 to 10 fructose molecules is called oligofructose and with 11 to 60 fructose molecules is called HP-inulin. There are two purposes in this study: (1) Determination of inulin contents of the common edible plants in Taiwan, for follow-up to understand the people by ingestion to inulin conditions. (2) Commercial products of oligofructose, inulin and HP-inulin as ingredients, determination of proximate composition, then, the distribution of the molecular weight and polymerization of oligofructose, inulin and HP-inulin are discussed thoroughly. Sensory analysis and texture profile analysis were performed to evaluate the effect of the different concentrations of oligofructose, inulin and HP-inulin addition of soymilk and tofu pudding.
The results showed that inulin contents of some remarkable differences were present among the common edible plants in Taiwan. Garlic and burdock contain significant high levels of inulins, which were, respectively, 16.24 % and 8.52 % (as-is). Inulin contents of the other plants were less than 1.0 %. Measured by proximate composition of commercial products of oligofructose, inulin and HP-inulin powder, the moisture content of the layer increased in the order, HP-inulin (4.68 %)、inulin (3.63 %) and oligofructose (2.11 %). The crude protein, crude fat and ash content were low. Oligofructose, inulin and HP-inulin contain of Polydispersity index (PDI), which were, respectively, 1.66, 1.89 and 1.32. They were found the addition different concentrations (5 %, 7 %, 9 %) (w/v) of oligofructose, inulin and HP-inulin in soymilk and tofu budding with different coagulants. The rheological properties of soymilk contained 5 % oligofructose at 10℃, the consistency index (k) value was higher and flow behavior index (n) value was lower than the others. Dynamic viscoelastic parameters were storage modulus (G’) larger than loss modulus (G”) of different concentrations of oligofructose, inulin and HP-inulin of soymilk with 0.3 % (w/v) GDL during heating and cooling process. As the temperature dropped to 20 ℃, the tan delta (tan δ) value was higher in soymilk with 0.3 % GDL and added to 9 % HP-inulin than the others. As oligofructose, inulin, and HP-inulin concentration increased. The L* of the soymilk and tofu pudding were reversely related to the addition of inulin, oligofructose or HP-inulin. The a* was significantly affected by the type and amount of fructans. Oligofructose was added to soymilk at 5 % along with 0.3 % GDL to prepare tofu budding had the highest hardness, springiness, gumminess, chewiness, and sensory evaluation of hardness, springiness, sweetness, color, overall acceptability which were compared with the other groups. After 4-day storage at 4°C, the syneresis were higher in tofu pudding with inulin, oligofructose and HP-inulin than in control group.
Though the tofu budding added to oligofructose or inulin did’t change the quality, it could enhanced people (seniors) lack of dietary fiber intake. The results of this study could provide useful information for general consumers and future purification studies.
Keywords: Inulin; Oligofructose; Dietary fibre; Soybean processed foods;
Rheology; Texture; Sensory evaluation |
