Gelatin extraction
Gelatin was extracted from chicken skin according to the
method of Badii and Howell (2006) with slight modification. To
extract gelatin, 14 g defatted dried chicken skin was mixed with
200 ml sodium hydroxide (0.15% w/v). The mixturewas shakenwell
and slowly stirred at room temperature (22 C) for 40 min before
centrifuging at 3500 g for 10 min. This step was repeated three
times. The alkaline solution was changed every 40 min to remove
non-collagenous proteins and pigments. The alkaline treated
pellets were rinsed with distilled water and then mixed with
200 ml 0.15% (v/v) sulphuric acid. Again, the resulting pellets were
mixed with 200 ml of 0.7% (w/v) citric acid solution. The mixture
was shaken well and stirred gently at room temperature for 40 min
before centrifuging at 3500 g for 10 min. The acid solution was
changed every 40 min to denature the collagen in the chicken skin
matrix. Each treatment was repeated three times and each treatment
took about 2 h to complete. The pellets were washed with
distilled water to remove any residual salts followed by centrifuging
at 3500 g for 15 min. The final extractionwas carried out in
distilled water at a controlled temperature (45 C) overnight
without stirring. The resultant mixture was filtered in a Büchner
funnel with a Whatman filter paper (no.4) and deionised, using an
Amberlite mixed bed resin (MB-6113) according to the GME
Monograph Version 2000 (GME, 2000). The solution ionic strength
was checked with a conductivity meter to obtain 50 m Siemens/cm.
The pH was adjusted to 6.0 with 0.1 M sulphuric acid. The volume
was reduced to 1/10 by evaporation under vacuum (using a rotary
evaporator) at 45 C and then kept in the freezer overnight before
freeze-drying. The dry matter was referred to as ‘gelatin powder’.
ผมไม่เข้าใจ ว่าใส่สารเคมีไม่ว่าจะเป็น H2SO4 (0.15% v/v) Citric acid (0.7% v/v) NaOH (0.15%w/v) ไปเพื่ออะไร แล้วช่วงไหนที่เปิดขั้นตอนสกัดเจลาติน ขอรบกวนผู้รู้มาชี้ทางให้หน่อยน่ะครับ ขอบคุณมากครับ
การสกัดเจลาติน
Gelatin was extracted from chicken skin according to the
method of Badii and Howell (2006) with slight modification. To
extract gelatin, 14 g defatted dried chicken skin was mixed with
200 ml sodium hydroxide (0.15% w/v). The mixturewas shakenwell
and slowly stirred at room temperature (22 C) for 40 min before
centrifuging at 3500 g for 10 min. This step was repeated three
times. The alkaline solution was changed every 40 min to remove
non-collagenous proteins and pigments. The alkaline treated
pellets were rinsed with distilled water and then mixed with
200 ml 0.15% (v/v) sulphuric acid. Again, the resulting pellets were
mixed with 200 ml of 0.7% (w/v) citric acid solution. The mixture
was shaken well and stirred gently at room temperature for 40 min
before centrifuging at 3500 g for 10 min. The acid solution was
changed every 40 min to denature the collagen in the chicken skin
matrix. Each treatment was repeated three times and each treatment
took about 2 h to complete. The pellets were washed with
distilled water to remove any residual salts followed by centrifuging
at 3500 g for 15 min. The final extractionwas carried out in
distilled water at a controlled temperature (45 C) overnight
without stirring. The resultant mixture was filtered in a Büchner
funnel with a Whatman filter paper (no.4) and deionised, using an
Amberlite mixed bed resin (MB-6113) according to the GME
Monograph Version 2000 (GME, 2000). The solution ionic strength
was checked with a conductivity meter to obtain 50 m Siemens/cm.
The pH was adjusted to 6.0 with 0.1 M sulphuric acid. The volume
was reduced to 1/10 by evaporation under vacuum (using a rotary
evaporator) at 45 C and then kept in the freezer overnight before
freeze-drying. The dry matter was referred to as ‘gelatin powder’.
ผมไม่เข้าใจ ว่าใส่สารเคมีไม่ว่าจะเป็น H2SO4 (0.15% v/v) Citric acid (0.7% v/v) NaOH (0.15%w/v) ไปเพื่ออะไร แล้วช่วงไหนที่เปิดขั้นตอนสกัดเจลาติน ขอรบกวนผู้รู้มาชี้ทางให้หน่อยน่ะครับ ขอบคุณมากครับ