Grapefruit Pigment Determination, Spectrophotometric Methods for Determining Pigmentation-Beta-Carotene and Lycopene-in Ruby Red Grapefruit

Abstract

Two methods for the measurement of pigments occurring in colored grapefruit are outlined and the results compared. Method A involves extraction of the sample, separation of the major pigments-lycopene and carotene-on a magnesia-Super Cel column, elution, and spectrophotometric measurements of the separated pigments. By method B, a more rapid but less precise procedure, the pigment is extracted and the absorptivity of the extract determined a t 451 mp for carotene and 503 mp for lycopene. Results of total concentration of the pigments, as determined by simultaneous equations, show

Changes in the contents of carotenoids, phenolic compounds and vitamin C during technical processing and lyophilisation of red and yellow tomatoes

“…We compared the carotenoid content of red and yellow tomatoes using the spectrophotometric technique given in the quantification method by Lime, Griffiths, O'Connor, Heinzelman, and McCall (1957) and the HPLC technique. The carotenoids contents of both extracts were very similar using both methods (data not shown).…”

“…The concentrations of lycopene and b-carotene were determined spectrophotometrically (Perkin Elmer -Lambda 25) using the following equations (Lime, Griffiths, O'Connor, Heinzelman, & McCall, 1957):…”

Postharvest quality of tomato fruits sacked with nonwoven fabric (TNT)

“…The lycopene, the ß-carotene and total carotenoids were determined by the Lime et al (1957) method with the Moretti et al (1998) proposed modifications. In a 125 mL Erlenmeyer were placed 4 g of pulp and 2 0mL of acetone, followed by 1-min agitation in ULTA-TURRAX.…”

Characterization of quality indices on storage of puree of mutant (dgandogc) and normal tomatoes

“…The carotenoids (lycopene and β-carotene) were extracted and determined following the acetone/petroleum ether method according to Buret (1991). The concentrations of lycopene and β-carotene were determined spectrophotometrically using the following equations (Lime et al, 1957): C β-carotene = 4.624×A 450 -3.091×A 503 C lycopene = 3.956×A 450 -0.806×A 503 where C is the concentration of carotenoid expressed in µg ml -1 and A 450 and A 503 represent the absorbance at 450 nm and 503, respectively. Finally, the concentration is expressed in mg/100 g wet weight of tomato or puree.…”