Calidad sensorial, capacidad antioxidante y compuestos funcionales en genotipos de jitomate (Solanum lycopersicum) con distinta coloración
The tomato (Solanum lycopersicum L.) is the most consumed vegetable crop throughout the world and belongs to family Solanaceae. This species has been widely used for the study of fleshy fruits and is also an interesting model to understand the cross-linking and regulation of the biosynthesis pathway...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:f1881k92v |
| Acceso en línea: | https://doi.org/10.24275/uami.f1881k92v |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Biotecnología vegetal info:eu-repo/classification/LEM/Jitomates -- Composición info:eu-repo/classification/LEM/Jitomates -- Análisis info:eu-repo/classification/LEM/Plant biotecholology info:eu-repo/classification/LEM/Tomatoes -- Composition info:eu-repo/classification/LEM/Tomatoes -- Analysis info:eu-repo/classification/cti/6 |
| Sumario: | The tomato (Solanum lycopersicum L.) is the most consumed vegetable crop throughout the world and belongs to family Solanaceae. This species has been widely used for the study of fleshy fruits and is also an interesting model to understand the cross-linking and regulation of the biosynthesis pathways of tocopherols, chlorophylls and carotenoids. Mexico is considered a center of diversification and domestication of tomato and is a source of genotypes of different shapes, colors and sizes that have been little characterized to date. These genotypes could be consumed either directly or included in breeding programs aiming to rescue functional compounds such as carotenoids and polyphenols, as well as to improve flavor. Although tomato flavor has not been a major goal for breeders, nowadays it becomes important as it is a subject of consumer complaint. The present study aimed at evaluating quality parameters [(TA (titratable acidity), TSS (total soluble solids), firmness, pH, weight, weight loss and color), characterizing the cuticle and epidermis, as well as the expression of PGA (polygalacturonase), sugar (sucrose, glucose and fructose) and organic acid content (malic and citric)], sensory quality [carotenoid-derived volatiles (β-cyclocitral, geranylacetone, damascenone, β-ionone and 6-methyl-5-hepten-2-one) and consumer preference (flavor and aroma)], antioxidant capacity (ABTS, DPPH and CUPRAC), antioxidant content (vitamin C, vitamin E (tocopherols α, β, δ and γ), total polyphenols, total flavonoids and anthocyanins), chlorophylls a and b and the expression of genes associated with fruit pigmentation (PSY-1, PSY-2, LYC-B, CYC B, HPPD, DXS, GGDR, VTE-2, VTE-5) as well as related transcription factors (NAC1, NAC-4, NAC-5, NAC-7 and NAC-9) in four native genotypes (red, orange, yellow and purple) and four experimental lines (light red, light orange, chartreuse yellow and black) of tomato (Solanum lycopersicum) with different color. The red genotypes showed higher contents of lycopene and β-carotene and of the volatiles damascenone, β-cyclocitral and β-ionone, as well as greater lipophilic antioxidant capacity, higher expression of PSY-1 and CYC-B and high consumer preference. The yellow genotype showed higher total polyphenol contents, higher hydrophilic antioxidant capacity, and higher expression of PSY-2, LCY-B, VTE-5 and GGDR. The content of vitamin C was higher in the native red and orange genotypes. On the other hand, the orange genotypes (native orange and light orange hybrid) had higher sugar and organic acid contents, as well as higher content of tocopherols, higher expression of VTE-2 DXS and HPPD and high consumer preference. The chartreuse yellow experimental line was characterized by its greater firmness and associated with lower PGA expression. The black and purple genotypes showed the highest levels of chlorophylls and anthocyanins. It is therefore suggested that the coloration of these genotypes is a result of the combination of such pigments. The black genotype had the slowest weight loss among the cherry type genotypes. This parameter was associated with a smaller peduncle scar. This genotype was also perceived as the most fresh by consumers and was located close to the ideal tomato despite its unusual coloration. In addition, important differences were observed in the histological analysis between native genotypes and experimental lines, since native genotypes showed irregular epidermal cells and a rougher surface, as well as a thicker epidermis and longer anticlinal pegs when compared with experimental lines. Finally, the expression of NAC transcription factors was higher in the native genotypes, confirming their participation in stress responses. A reason could be due to the constant exposition of these genotypes to environmental changes. Due to the high consumer ratings and high levels of carotenoids and tocopherols, the direct consumption of the red, light red, orange, light orange and black genotypes is recommended, as well as their inclusion in breeding programs aimed at improving the taste and antioxidant levels of commercial varieties. Additionally, the inclusion of the yellow and chartreuse yellow genotypes in genetic improvement programs aimed at increasing polyphenol levels and firmness, respectively, is highly recommended. |
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