| Summary: | 碩士 === 實踐大學 === 食品營養與保健生技研究所 === 95 === Sprouts are a nutritious vegetable containing abundant amounts of vitamins, minerals and dietary fiber. In this study, a variety of sprouts, including alfalfa sprouts, broccoli sprouts, buckwheat sprouts, lentil sprouts, radish sprouts, sunflower sprouts and wheat grass, were examined for their functional components and in vitro antioxidant properties including scavenging effects on DPPH radicals and super oxide anions, reducing power, and chelating effects on ferrous ions. Buckwheat sprouts were then chosen to be added in bread production due to their highest antioxidant activities, and buckwheat sprout breads were compared with white bread for physicochemical properties, functional components, antioxidant properties, storage properties and sensory properties.
With regard to the functional components of different sprouts, buckwheat sprouts contained the greatest total amount of phenols (33.72±0.27 mg/g d.w.), and radish sprouts and broccoli sprouts the second greatest. Broccoli sprouts contained the greatest amount of ascorbic acid (1.09±0.01 mg/g d.w.), and radish sprouts (0.94±0.01 mg/g d.w.) the second greatest. Among the various solvents utilized to extract components from sprouts, the 50% methanol solvent was found to be the most effective extracting solvent based on scavenging activities on DPPH radicals exhibited by the extracts. In terms of antioxidant properties, the sprouts ranked in the following order according to reducing power: buckwheat sprouts (0.75) ＞ radish sprouts (0.49) ＞ broccoli sprouts (0.36) ＞ wheat grass (0.20) ＞ sunflower sprouts (0.11) ＞ alfalfa sprouts (0.07) ＞ lentil sprouts (0.05). The strong antioxidant activity of buckwheat sprouts might be accounted by their large total amount of phenol components. For broccoli sprouts and radish sprouts, the antioxidant properties might be contributed not only by the total amount of phenol components but also by the presence of other antioxidant vitamins. Compared with other sprouts, alfalfa sprouts and lentil sprouts had weaker antioxidant activities.
Two types of buckwheat sprout breads were produced in this study. Both were made by adding buckwheat sprout powder as 3% of dough, but one of them was called heated buckwheat sprout bread because the buckwheat sprout powder added was pre-heated to remove the grass taste. There was no significant difference in bread specific volume between buckwheat sprout breads and white bread (p＜0.05). In texture analysis, buckwheat sprout breads exhibited higher degree of hardness but lower degree of springiness and resilience than white bread.
After the three kinds of breads were extracted by methanol, regular (0.39) and heated buckwheat sprout breads (0.33) had significantly higher reducing power than white bread (0.12) at 20 mg/mL. Similar trends were observed for scavenging effects on DPPH radicals and superoxide anions, and chelating effects on ferrous ions. With regard to functional components, the amount of ascorbic acid in the three kinds of breads was extremely small after baking. However, buckwheat sprout breads still preserved some amount of phenol components (2.36~2.41 mg/g d.w.) and flavonoids (48.98~51.30 mg/100g d.w.).
When the three kinds of breads were stored at 25℃ for 4 days, the total bacterial counts reached inedible range for white bread (5.08 log CFU/g), but were lower in heated (3.39 log CFU/g) and regular buckwheat sprout breads (4.98 log CFU/g). In terms of sensory properties, all of the three kinds of breads were well accepted.
|
|---|
