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Extractable Color in CapsicumsPurpose: To detennine the extractable color in capsicums and their oleoresins by measuring the absorbance of an acetone extract at 460 nm. A. Apparatus:1. Spectrophotometer:-capable of accurately measuring A. at 460 nm.2. Absorption cells-l cm. square matched ceIls with stoppers.3. Standard glass fllter-(Standard reference material 2030 from fue National Bureau of Standards).4. Volumetric flasks-1OO mI. with ground glass stoppers.5. Pipettes-transfer-type.B. Reagent:1. Acetone-reagent grade.C. Procedure for Caicums: l. Unground capsicums must be ground to pass 1 mm opening sieve.v2. Accurately weigh 70 to 100 rng. of sample and transfer to a 100 mI. Vol. flask.3. Fill to mark with acetone and stopper tightly.4. Shake fue flask and let stand 16 hr. at room temp. in fue dark.5. Shake the flask and allow 2 mino for fue particles to sett!.e.6. Transfer a portion of the ext. to the spectrophotometer cell and measure the A. at 460 nm with an acetone blank.7. Determine A. of glass fIlter at 465 nm.Calculatiom for Caicums: 1. Instrument correction factor = If 1 _NBS A. at 465 nmf- Lab A. at 465 nm VD.2. Extractable Color ASTA Color=A. of Acetone ext. X 16.4f Sample weight in gm. E.Procedure for Oleoresins:1. Mix sampJe welJ by2. Accurately weigh 70 Vol. flask.3. Fill to mark with acetone, stopper it tightly and shake well.ASfAANALYTlCAL Method 20.1and Their Oleoresimto 100 mg. o sample and transfer it to a 100 mI.Extractable Color in Capsicums Method 20.1 and Their Oleoresins4. Allow the solution to stand for 2 min.5. With a 10 mI. pipette, transfer 10.00 mi. of the solution into another 100 mi. Vol. tlask, and diJo to mark with acetone, stopper tightly and shake well.6. Transfer a portion of the solution to the spectrophotometer cell and measure the A. at 460 nm with an acetone blank.7. Detennine the A. of the standardF. Calculations for Oleoresins:l. Instrument correction2. Extractable Co)or ASTA Color=A. o Acetone soIutionx 164xIf Sample weight in gm.Notes:l.The A. of fue glass f1lter need only be detennined once per day.The recornmended range of A. values is A =0.30 and A =O. Extracts having A. greater than O.ro should be diluted with acetone to one-halfthe original concentration. Extracts having A. less than 0.30 should be discarded and fue extraction perfonned with a larger sample.2.ASf A ANALYflCAL METHODSfilter at 465 nm.glassfactor = If= NBSA. for glass filter at 465 nm A. of glass filter at 465 nm
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