- 背景資料
穀類(例如:小麥)在製作麵粉的過程中，部分的澱粉顆粒會因為碾磨時物理性的破壞，以及機器產生的熱能與壓力而造成損傷，故此類澱粉被稱為損傷澱粉(damaged starch)。損傷澱粉相比於未受傷澱粉(健全澱粉)，其吸水量較高且因為澱粉結構受到破壞，在製作麵團的過程中，損傷澱粉較容易被α-和 β-澱粉酶(α- and β-amylases)水解成麥芽糖，此麥芽糖會被酵母菌作為養分來源，並且會將麥芽糖分解成葡萄糖。此外，酵母菌會進一步將葡萄糖發酵成酒精及二氧化碳，進而使麵包蓬鬆。
損傷澱粉的功能:
1️⃣麵團中酵母菌的養分來源
2️⃣促使麵團蓬鬆(因酵母菌發酵葡萄糖並產生二氧化碳)
- 操作流程(ASSAY PROCEDURE)
1. Accurately weigh 100 ± 10 mg of wheat flour or milled gelatinised starch sample into a thick-walled glass centrifuge tube (16 x 120 mm; 12 mL capacity).
2. Pre-equilibrate the tubes plus contents at 40°C for approx. 5 min.
3. Pre-equilibrate solution 1 (α-Amylase, 50 U/mL) at 40°C for approx. 5 min in a small glass beaker.
4. Add 1.0 mL of pre-equilibrated solution 1 (α-Amylase, 50 U/mL) to each tube, stir the tube on a vortex mixer for approx. 5 sec and incubate at 40°C for exactly 10 min (from time of addition of the enzyme).
5. Add 8.0 mL of dilute sulphuric acid solution (0.2% v/v) to each tube after exactly 10 min from the time of addition of solution 1 and stir the tube vigorously for approx. 5 sec. This inactivates the enzyme and thus terminates the reaction.
6. Centrifuge the tubes at 3,000 rpm (1,000 g) for 5 min or filter the slurry through Whatman No. 1 (9 cm) filter paper.
7. Carefully and accurately transfer 0.1 mL aliquots of the supernatant solution (or filtrate) to the bottom of two test tubes.
8. Add 0.1 mL of solution 2 (Amyloglucosidase 20 U/mL) to each tube, stir the tubes on a vortex mixer and incubate them at 40°C for 10 min.
9. Add 4.0 mL of GOPOD reagent solution to each tube (including glucose standards and reagent blank tubes) and incubate the tubes at 40°C for 20 min.
10. Measure the absorbance of all solutions at 510 nm against a reagent blank.
商品特色
商品規格
- 商品規格(200個檢測反應)
Bottle 1:
Fungal α-Amylase (10 mL, 1,000 U/mL on Ceralpha reagent* at pH 5.4 and 40°C). Ammonium sulphate suspension.
Store at 4°C. See individual label for expiry date.
*Full assay procedure is available at “www.megazyme.com” - Product Code: K-CERA.
Bottle 2:
Amyloglucosidase (4 mL, 200 U/mL on soluble starch at pH 4.5 and 40°C). Ammonium sulphate suspension.
Store at 4°C. See individual label for expiry date.
Bottle 3:
GOPOD Reagent Buffer (50 mL, pH 7.4), p-hydroxybenzoic acid and sodium azide (0.09% w/v).
Store at 4°C. See individual label for expiry date.
Bottle 4:
GOPOD Reagent Enzymes. Glucose oxidase plus peroxidase and 4-aminoantipyrine. Freeze- dried powder.
Store below -10°C. See individual label for expiry date.
Bottle 5:
D-Glucose standard solution (5 mL, 1.5 mg/mL) in 0.2% (w/v) benzoic acid.
Store sealed at room temperature. See individual label for expiry date.
Bottle 6:
Wheat flour standard. Level of starch damage shown on vial label.
Store sealed at room temperature. See individual label for expiry date.
