Evaluation of carotenoids and anthocyanins in high pigment, processing, heirloom and anthocyanin fruit tomatoes

approved: (/r/ri-s*^-—y*——i j-vt ^James R. Myers The health benefits of carotenoids present in tomatoes provides impetus to assess their presence and quantity in tomato germplasm. The feasibility of assessing large numbers of accessions is limited by both the time and technical challenges involved in HPLC of carotenoids. We developed a protocol for extraction and HPLC analysis of tomato carotenoids that eliminates the use of roto-evaporation and partitioning into a twophase system. Tomatoes are extracted using tetrahydraftiran and the filtered extract is combined 1:1 v/v with the mobile phase of the HPLC system. This system allows separation and quantitation of the primary carotenoids present in tomato: lycopene, Pcarotene, phytofluene and phytoene, while limiting exposure of compounds to heat and oxygen and reducing extraction time and solvent use. This rapid HPLC method was used to evaluate lycopene, P-carotene, phytoene and phytofluene content in isogenic tomato genetic stocks containing individually or in common, the genes high pigment (hp-1), dark green (dg), Intense pigment (Ip), crimson (og) and Anthocyanin Fruit (Af). The hp-1 gene increased lycopene levels by 48%, while the hp-I/og increased lycopene levels 81%. The presence of dg increased lycopene content 37% in 'Walter' and 164% in 'Manapal'. LA3771, the hp-l/og double mutant. had the highest mean lycopene values of 9.43 mg/lOOg FW. Three processing cultivars had lycopene levels between those of normal genotypes and high pigment genotypes, but very low P-carotene levels, resulting in lycopene/p-carotene ratios similar to tomatoes containing the crimson gene. Intense pigment (Ip) tomatoes had greater lycopene content than normal genotypes but significantly less than hp-1 or dg. "Black" heirloom tomatoes appear to have the green flesh (gf) gene and had the lowest carotenoid and lycopene content. We investigated the inheritance of anthocyanin expression in a cross of LA 1996 (Af) and processing tomato 'UC82B'. Af tomato plants have dark green foliage, high anthocyanin expression in the hypocotyl of seedlings and anthocyanin in the skin and outer pericarp tissues of the fruit. Segregation ratios in F2 and BCi generations are consistent with a single dominant gene. Anthocyanin expression was lower in BCi populations compared to the F2 population and the data suggest that expression may be stronger in the homozygous plants. Anthocyanin concentration, as measured by the pH differential method, was estimated to be 5.6 mg/lOOg and 18.2 mg/lOOg in the pericarp and skin tissues, respectively. Carotenoid content in Af tomatoes was similar to normal tomatoes. The results of these experiments provide a framework for the analysis, understanding and utilization of pigment-rich tomato germplasm. ©Copyright by Carl M. Jones September 22, 2000 All Rights Reserved Evaluation of Carotenoids and Anthocyanins in High Pigment, Processing. Heirloom and Anthocyanin Fruit Tomatoes. by Carl M. Jones A Thesis submitted to Oregon State University in partial fulfillment of the requirements for the degree of "to Master of Science Presented on September 22, 2000 Commencement June 2001 Master of Science thesis of Carl M. Jones presented on September 22, 2000