Analytical Methods for Carotenes of Lycopersicon Species and Strains

Nutritional Characterization of a Traditional Cultivar of Tomato Grown Under Organic Conditions-cv. "Malacara"

The loss of genetic diversity due to the replacement of local tomato (Solanum lycopersicum L.) varieties by improved cultivars has been mitigated in many cases by the good work of organic farmers in maintaining local agricultural biodiversity. In parallel to these initiatives, in recent years, consumers have developed an increasing awareness of both food-related health, environmental issues, and food demand to recover the flavors of the past. In the case of tomatoes, these attributes (nutritional, organoleptic, social, and environmental) are closely related to organic production using local varieties. “Malacara” tomato is an example of a local variety. Coming from Sierra de Cádiz, it is a varietal type called “Cuelga” (“for hanging,” because the tomato trusses are hung from beams in the farmhouses). Cultivated and harvested in the open air during the summer months, these tomatoes are commercialized and consumed in the winter. Historically, this variety has enabled the fresh consumption of tomatoes during the winter, without the need to force cultivation. It is highly appreciated in the local cuisine and is the basis for sauces figuring in typical dishes. Its characteristic traits are small, pallid fruits, and long shelf life. The main objective of this work has been to typify two Malacara tomato cultivars (red and yellow color) grown under organic farming conditions, through the characterization of morphological, nutritional, and volatile parameters. The main differences are due to morphological parameters (fruit weight and color of the exocarp and endocarp). Other characteristics such as the content of ash, fiber, moisture, the concentration of iron, magnesium, and calcium, and content of lycopene are different between both cultivars. This study provides information on the nutritional and aromatic composition of two Malacara tomato cultivars, differentiated by their color and grown under organic farming conditions. The results add value to the native horticultural heritage and can aid in the selection of tomato varieties suitable for a sustainable production system and to produce tomatoes with high nutritional value and rich in aroma.

Fruit composition profile of pepper, tomato and eggplant varieties grown under uniform conditions

The study of the diversity within and between major Solanaceae crops (pepper, tomato, eggplant) is of interest for the selection and development of balanced diets. We have measured thirty-six major fruit composition traits, encompassing sugars, organic acids, antioxidants and minerals, in a set of 10 accessions per crop for pepper, tomato and eggplant, grown under the same cultivation conditions. The aim was to evaluate the diversity within species and to provide an accurate comparison of fruit composition among species by reducing to a minimum the environmental effect. Pepper, tomato and eggplant had a clearly distinct composition profile. Pepper showed the highest average content in total sugars and organic acids. Fructose and glucose were the major sugar compounds in the three species, although in pepper and tomato sucrose was present only in trace amounts. Citric acid was the major organic acid in pepper and tomato, while in eggplant it was malic acid. Pepper and eggplant had the highest total antioxidant activity. Vitamin C content was much higher in pepper than in tomato and eggplant, while eggplant accumulated high concentrations of chlorogenic acid. Furthermore, eggplant was the species with higher content in most minerals, particularly for K, Mg and Cu, while pepper was the richest in Fe. Due to their complementary nutritional profiles, a combined regular consumption of the three vegetables would supply more than 20% of the Dietary Reference Intake of several of the analysed phytochemicals. The large diversity within each species is of interest for selecting varieties with better nutritional and organoleptic profiles, as well as for breeding new cultivars.

Variation for Composition and Quality in a Collection of the Resilient Mediterranean 'de penjar' Long Shelf-Life Tomato Under High and Low N Fertilization Levels

The 'de penjar' tomato (Solanum lycopersicum L.) is a group of local varieties from the Spanish Mediterranean region carrying the alc mutation, which provides long shelf-life. Their evolution under low-input management practices has led to the selection of resilient genotypes to adverse conditions. Here we present the first evaluation on nutritional fruit composition of a collection of 44 varieties of 'de penjar' tomato under two N fertilization levels, provided by doses of manure equivalent to 162 kg N ha-1 in the high N treatment and 49 kg N ha-1 in the low N treatment. Twenty-seven fruit composition and quality traits, as well as plant yield and SPAD value, were evaluated. A large variation was observed, with lycopene being the composition trait with the highest relative range of variation (over 4-fold) under both N treatments, and significant differences among varieties were detected for all traits. While yield and most quality traits were not affected by the reduction in N fertilization, fruits from the low N treatment had, on average, higher values for hue (5.9%) and lower for fructose (-11.5%), glucose (-15.8%), and total sweetness index (-12.9%). In addition, lycopene and β-carotene presented a strongly significant genotype × N input interaction. Local varieties had higher values than commercial varieties for traits related to the ratio of sweetness to acidity and for vitamin C, which reinforces the appreciation for their organoleptic and nutritional quality. Highest-yielding varieties under both conditions displayed wide variation in the composition and quality profiles, which may allow the selection of specific ideotypes with high quality under low N conditions. These results revealed the potential of 'de penjar' varieties as a genetic resource in breeding for low N inputs and improving the organoleptic and nutritional tomato fruit quality.

QTL analysis of fruit antioxidants in tomato using Lycopersicon pennellii introgression lines

Antioxidants present in fruits and vegetables may help prevent some chronic diseases such as cancer, arthritis, and heart disease. Tomatoes provide a major contribution to human dietary nutrition because of their widespread consumption in fresh and processed forms. A tomato introgression line population that combines single chromosomal segments introgressed from the wild, green fruited species Lycopersicon pennellii in the background of the domesticated tomato, Lycopersicon esculentum, was used to identify quantitative trait loci (QTL) for nutritional and antioxidant contents. The concentration of ascorbic acid, total phenolics, lycopene and beta-carotene, and the total antioxidant capacity of the water-soluble fraction (TACW) were measured in the ripe fruits. A total of 20 QTL were identified, including five for TACW (ao), six for ascorbic acid (aa), and nine for total phenolics (phe). Some of these QTL (ao6-2, ao6-3, ao7-2, ao10-1, aa12-4, phe6-2, and phe7-4) increased levels as compared to the parental line L. esculentum. For lycopene content, we detected four QTL, but none increased levels relative to L. esculentum. The two QTL (bc6-2 and bc6-3) detected for beta-carotene increased its levels. The traits studied displayed a strong environmental interaction as only 35% of the water-soluble antioxidant QTL (including TACW, ascorbic, and phenolic contents) were consistent over at least two seasons. Also, only two QTL for phenolics were observed when plants were grown in the greenhouse and none was detected for ascorbic or TACW. The analysis demonstrates that the introgression of wild germplasm may improve the nutritional quality of tomatoes; however regulation appears to be complex with strong environmental effects.

Inheritance of fruit color and pigment changes in a yellow tomato (Lycopersicon esculentum Mill.) mutant

A naturally occurring yellow tomato fruit mutant cv. Santa Clara was reciprocally crossed with the red wild type, after which F1 plants were self pollinated or backcrossed with both parents. Plants from F1 generations produced all fruits with a homogeneous deep red color when ripe. F2 plants showed a 3:1 red:yellow segregation of fruit color, and 100% red when backcrossed with red wild type or 1:1 red:yellow segregation in backcrosses with the yellow mutant; hence, yellow fruit color was determined by a recessive allele. Based on reciprocal crosses, fruit color is unlikely to be determined by maternal genes. Accumulation of lycopene dropped by 99.3% and<FONT FACE="Symbol"> b</font>-carotene by 77% in ripe yellow fruits, compared to the red wild type. Leaf and flower chlorophyll and total carotenoid concentrations were not affected by the yellow mutation. However, the mutant fruit had a higher rate of chlorophyll degradation during fruit ripening, whilst fruit from the F1 generation showed lower rates of degradation, similar to that observed in red wild type fruits.