Of tomato peel phenolics

Fig. (12). HPLC chromatogram of tomato peel phenolics (1) chlorogenic acid, (2) quercetin 3-rutinoside, and (3) naringenin chalcone. HPLC conditions RP Cjg column (12 x 0.4 cm particle size S pm). Mobile phase acidified water (5% formic acid) and methanol. Gradient 0 min- 10% B, 30 min- 40% B, 40 min- 80% B. Flow rate 1 mL/min.

A number of handbooks and monographs are available with detailed descriptions of a variety of plant products and their use (Shahidi and Naczk, 1995). From a more practical point of view, an interlaboratory comparison between six university and industry laboratories of 17 extracts of spices, teas, coffees, and grape skin and of tomato peel slurry established within the framework of an EU sponsored programme, would be of interest (Schwarz et al, 2001). In this collaboration, detailed chemical analysis of the content of different phenolic compounds is compared with six antioxidant assays for the 17 extracts including different extraction procedures. 

Fig. 12 shows a characteristic chromatogram of the phenolic compounds of tomato peel. Especially interesting is the relatively large naringenin chalcone peak. Other peaks are observed in the chromatogram, corresponding to unidentified hydroxycinnamic and benzoic acid derivatives. 

Contreras-Calderon et al. (2011) To determine the antioxidant capacity and total phenolic compounds of the pulp, peel and seeds of 24 species of fruits. The results for passion fruit peel showed that the content of phenolic compounds were 288 8.41 mg of gallic acid / 100 g of sample the antioxidant capacity was 36.7 0.07 pmolTrolox / g of sample. The results observed for passion fruit pulp were highest in comparison with the peel, but compared with banana and tomato peel the values were higher. 

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