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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Radish anthocyanin extract as a natural red colorant for maraschino cherries

Hundskopf, Maria Monica Giusti 07 April 1995 (has links)
Red radish anthocyanin extract (RAE) was investigated for coloring brined cherries as an alternative to FD&C Red No. 40. Red radish (Raphanus sativus L.) anthocyanins were extracted from liquid nitrogen powdered epidermal tissue using acetone, partitioned with chloroform, and isolated using C-18 resin. The monomeric anthocyanin content was determined by pH differential to be 154 ± 13 mg/100 g of epidermal tissue (on pelargonidin-glucoside basis). The major pigments were identified as pelargonidin-3-sophoroside-5-glucoside monoacylated with p-coumaric or ferulic acids by HPLC and spectral analyses. Primary and secondary bleached cherries were sweetened to 40° Brix (pH of 3.50), and colored using two concentrations of RAE (600 and 1200 mg/L syrup, designated Cl and C2) and FD&C Red No. 40 (200 ppm). Color was measured for both cherries and syrup. Reflectance measurements (CIE L*, a*, b*), chroma and hue angle, showed that RAE imparted red color to the cherries and syrup extremely close to that of FD&C Red No. 40. RAE C2 gave the primary bleached cherries the closest color characteristics (L*= 18.20, a*= 20.00, b*= 8.47) to FD&C Red No. 40 (L*= 18.00, a*= 24.35, b*= 12.13). RAE Cl gave the secondary bleached cherries the closest color characteristics (L*= 15.27, a*= 16.21, b*= 5.21) to FD&C Red No. 40 (L*= 16.38, a*= 19.91, b*= 8.99). Color and pigment stability of secondary bleached cherries were evaluated during a year of storage in the dark at 25°C. Monomeric anthocyanin degradation followed first-order kinetics and the half-lives were 29 and 33 weeks for syrups colored with RAE Cl and RAE C2, respectively. However, cherry color showed no significant changes in hue, color intensity nor lightness during storage. Color changes of syrup samples over time were dependant on anthocyanin concentration, higher anthocyanin concentration exerted a protective effect on color stability. Haze formation was observed in syrup samples colored with RAE, possibly due to pigment polymerization. Syrup samples colored with RAE and FD&C Red No. 40 were also exposed to light for a year at 25°C. Light had a small but significant effect on L*, a*, and monomeric anthocyanin content. From color and pigment stability data and visual observations we concluded that RAE was effective in coloring secondary bleached cherries with results very similar to those of FD&C Red No. 40 for 6 months of storage. / Graduation date: 1995
2

Diffusion rate of dye in preparation of maraschino cherries

Henney, Edward Nathan 01 May 1951 (has links)
Graduation date: 1951

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