Setup of a UHPLC-QqQ-MS method for the analysis of phenolic compounds in cherry tomatoes, tomato sauce, and tomato juice

Color Variation and Secondary Metabolites' Footprint in a Taxonomic Complex of Phyteuma sp. (Campanulaceae)

In the genus Phyteuma, the taxonomic delimitation of some species is difficult since a high variability of morphological traits, such as flower color, is present, probably due to high levels of hybridization. Historic descriptions and the morphological traits used in the taxonomic keys are sometimes unclear and lead to misinterpretations. Here, a detailed analysis of flower color variability in different populations of sympatric P. spicatum, P. ovatum, and P. persicifolium constitutes a new approach to clarifying the taxonomic statuses. The numeric analysis of color, providing colorimetric variables, together with the detailed description of the metabolic profiles of populations with different flower colors, constitute a unique chemical fingerprint that identifies species and subspecies with clear markers. This study is the most complete metabolic research on genus Phyteuma, since we identified and quantified 44 phenolic compounds using HPLC-MS, comprising 14 phenolic acids, 23 flavonols and flavones, and, for the first time in the genus, 7 anthocyanins involved in flower color variability. This approach contributes to clarifying the differences between species, which is particularly relevant in taxonomic complexes such as the present, where morphology fails to clearly differentiate taxa at specific and intraspecific levels.

Bioaccessibility and Antioxidant Capacity of Bioactive Compounds From Various Typologies of Canned Tomatoes

Tomato (Solanum lycopersicum L.) is one of the most consumed vegetables in the world; it contains high amounts of antioxidant phytochemicals and essential nutrients. Although it is commonly consumed fresh, more than 80% of its consumption derives from processed products. Since limited information on changes in the bioaccessibility of bioactive compounds during gastrointestinal digestion was reported, this current study aimed to monitor the antioxidant activity, total polyphenolic and carotenoid content, and bioaccessibility during in vitro gastrointestinal digestion of different typologies (n = 7) of canned tomatoes. A comprehensive evaluation of the polyphenolic profile of digested and not digested samples was ascertained by ultra-high-performance liquid chromatography combined with high-resolution Orbitrap mass spectrometry. The results highlighted a considerable content of rutin (1.191-9.516 mg/100 g), naringenin (0.359-1.452 mg/100 g), chlorogenic acid (1.857-11.236 mg/100 g), and lycopene (50.894-222.061 mg/kg) in the analyzed matrices. After in vitro gastrointestinal digestion, large variability, losses and low recovery were recorded. An appreciable percentage of rutin (30.7%), naringenin (29.6%), chlorogenic acid (25.8%), and lycopene (varied between 9.3 and 20%) remained bioaccessible after the in vitro gastrointestinal digestion. Our study could be a valid support to evaluate which content of bioactive compounds could be really bioaccessible to exercise beneficial effects on human health.

Production system influences tomato phenolics and indoleamines in a cultivar-specific manner

Tomato (Solanum lycopersicum) fruit is a rich source of health-promoting compounds, and epidemiological studies show that tomato consumption may reduce the risk of chronic diseases. This study compared the effect of genotype, production system, and their interaction on eight tomato varieties grown in the open-field (OF) or net-house (NH), a structure completely covered with a 50-mesh screen to reduce pest and wind damage, in South Texas. The NH structure reduced solar radiation up to ~30% and decreased wind speed by 6.44 km/h compared with conditions measured in the OF. We simultaneously analyzed 16 phenolics and indoleamines using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry (UHPLC/ESI-HR-QTOFMS). The chemometric analysis showed a distinct difference between NH- and OF-grown tomatoes irrespective of the variety. The melatonin and serotonin contents showed a cultivar-specific effect of the production system. Likewise, the effect of cultivation systems on levels of phenolic acids and flavonoids varied based on tomato cultivar. Among the studied phenolic acids, significantly enhanced levels of sinapic acid were observed in OF-grown tomatoes. Similarly, we detected a considerable genotypic effect on gallic acid, p-coumaric acid, ferulic acid, sinapic acid, and naringin. The interaction of cultivar and production system substantially affected gallic acid, protocatechuic acid, sinapic acid, and apigenin. However, further studies need to be performed to explore the environment-specific effects on the total composition. In summary, our results indicate that the production system plays an important role in tomato composition beyond the natural genetic variation among cultivars.

Kinetic Study of Water and Total Soluble Solid Changes of Black Cherry Tomato (Solanum Lycopersicum cv. OG) Sauce using Rotary Vacuum Evaporation

Kinetics of water removal and total soluble solid (TSS) content change of black cherry tomato (cv. OG) sauce by rotary vacuum evaporation (RVE) were investigated. The effect of different vacuum conditions (vacuum levels and boiling temperatures of 500 mmHg - 80oC, 550 mmHg - 75oC, 600 mmHg - 70oC and 650 mmHg - 65oC) during evaporation /concentration was examined. Tomatoes puree with an initial TSS of 13.47±0.18oBrix was concentrated to 39.83±0.30oBrix. There was a linear relationship between water removal and time during the concentration of black cherry tomato sauce by RVE. The TSS change of tomato sauce during the concentration was applied to three exponential mathematical models (two-parameter, three-parameter, and four-parameter). In studying the consistency of all models, some statistical indicators, namely the coefficient of determination (R2), the chi-square (χ2) as well as the root mean square error (RMSE) were considered. Among the models, the three-parameter exponential model was proven to best describe the concentration behavior of the tomato sauce using rotary vacuum evaporation with the highest R2, the lowest χ2, and the lowest RMSE. The validation with the experimental data at other vacuum levels had also confirmed the consistency of the selected model. This knowledge is very important for process optimization and product quality improvement.

Variation in secondary metabolites in a unique set of tomato accessions collected in Turkey

In this study, 50 tomato landraces grown in Turkey were investigated in terms of their secondary metabolite profiles. Each accession was planted in 2016 and 2017 in 3 replicates in an open field. In this study, color, pH and brix of the fruit samples were measured and an unbiased LCMS-based metabolomics approach was applied. Based on Principal Components Analysis (PCA) and Hierarchical Cluster Analysis (HCA) of the relative abundance levels of >250 metabolites, it could be concluded that fruit size was the most influential to the biochemical composition, rather than the geographical origin of accessions. Results indicated substantial biodiversity in various metabolites generally regarded as key to fruit quality aspects, including sugars; phenolic compounds like phenylpropanoids and flavonoids; alkaloids and glycosides of flavour-related volatile compounds. The phytochemical data provides insight into which Turkish accessions might be most promising as starting materials for the tomato processing and breeding industries.

Mediterranean sofrito home-cooking technique enhances polyphenol content in tomato sauce

BACKGROUND

Sofrito, a basic culinary technique widely used in the Mediterranean, may preserve dietary polyphenols and enhance their intake in the Mediterranean population. The aim of this study was to investigate if the sofrito technique improves the polyphenol extractability in a tomato-based sofrito sauce.

RESULTS

A full factorial design was applied using mathematical models. The content of chlorogenic acid, ferulic acid hexoside and naringenin was higher in the sofrito sauce than in raw tomato. The bioaccessibility of some tomato polyphenols was enhanced by the presence of olive oil and they were protected from oxidation during the cooking process by the use of onion.

CONCLUSION

The use of olive oil and onion in Mediterranean cooking as a base for sauces and dishes, with an appropriate cooking time, preserve the polyphenol content of food. Thus, Mediterranean cuisine may contribute to the health effects of the Mediterranean diet. © 2019 Society of Chemical Industry.

Using Extra Virgin Olive Oil to Cook Vegetables Enhances Polyphenol and Carotenoid Extractability: A Study Applying the sofrito Technique

Olive oil is the main source of fat in the Mediterranean diet and the most frequently used ingredient in Mediterranean cuisine. Cooking with olive oil has been attracting attention because it can act as a food excipient, thereby increasing the bioaccessibility and bioavailability of ingested bioactive compounds. The aim of this study was to understand the effect of cooking with olive oil on the bioactive components in other ingredients (tomato, onion, and garlic) of sofrito sauce, a representative model of Mediterranean cuisine. After the cooking process, polyphenols from tomato, onion, and garlic were detected in the olive oil, especially naringenin, ferulic acid, and quercetin, as well as a high content of carotenoid Z-isomers, which are more bioavailable than the E-isomers. Therefore, traditional Mediterranean cuisine could play an important role in the health-improving effects of the Mediterranean diet.

Characterisation of bioactive compounds and assessment of antioxidant activity of different traditional Lycopersicum esculentum L. varieties: chemometric analysis

Eight different Serbian genotypes were analysed for their polyphenol, carotenoid, vitamin C content and evaluated for their antioxidant properties. The highest content of biologically important carotenoids such as lutein (4.58 mg/10 g), lycopene (160.64 mg/10 g) and β-carotene (189.64 mg/10 g) were detected in the genotype S606. Rutin was the most abundant phenolic compound in all tastes samples, but its content is highest in the genotype S615 (1424.30 µg/100 g dw). All tomato samples were the great source of vitamin C, where the sample S615 stood out (68.54 mg AA g^-1 of dw). Their content of antioxidant compounds suggested that genotypes S606 and S615 showed the best antioxidant potential. Principal component analysis (PCA) and Partial least squares (PLS) were applied to analyse results. The results obtained in the present study could be of considerable interest for breeding programmes wishing to select tomato genotypes with high biological and nutritional properties.

Flavor characteristics of the juices from fresh market tomatoes differentiated from those from processing tomatoes by combined analysis of volatile profiles with sensory evaluation

Various commercial tomato juices with different flavors are available at markets worldwide. To clarify the marker compounds related to the flavor characteristics of tomato juice, we analyzed 15 pure commercial tomato juices by a combination of volatile profiling and sensory evaluation. The correlations among volatiles and the relationship between volatiles and sensory descriptors were elucidated by multivariate analyses. Consequently, the tomato juices made from fresh market tomatoes (including the popular Japanese tomato variety “Momotaro”) were clearly separated from other juices made from processing tomatoes, by both the volatile composition and sensory profiles. cis-3-Hexenol, hexanal, and apocarotenoids negatively contributed to the juices from fresh market tomatoes, whereas Strecker aldehydes and furfural showed positive contributions to the juices. Accordingly, the sensory characteristics of juices from fresh market tomatoes were related to cooked and fruity flavors but not to green or fresh notes.

Bioavailability of tomato polyphenols is enhanced by processing and fat addition: Evidence from a randomized feeding trial

SCOPE

Tomato contains a variety of phenolics associated with health-promoting properties. However, the effects of processing and the addition of oil during tomato sauce preparation on microbial metabolism of phenolics in the small intestine are still unclear.

METHODS AND RESULTS

An open, controlled, randomized, and crossover feeding trial with 40 healthy volunteers was carried out to analyze the metabolites in plasma and urine after the consumption of tomato and tomato sauces, with tomato sauce enriched with refined olive oil (ROOE) and without refined olive oil (oil-free: OF). Ten phenolics in plasma and 93 metabolites in urine were quantified. Processing tomatoes into sauce enhanced the bioavailability of flavanones, flavanols, and some hydroxycinnamic acids, as reflected by the increase in the area under the plasma concentration versus time curve. An increase in their plasma half-life was also observed, particularly after ingestion of ROOE, possibly favored by enterohepatic circulation. A wide variety of gut microbial metabolites was also detected, namely flavanones, hydroxycinnamic acids, flavonols, hydroxyphenylpropanoic acids, hydroxyphenylacetic acids, and hydroxybenzoic acids.

CONCLUSIONS

Flavanones and flavonols in ROOE presented higher bioavailability, suggesting that the processing undergone by the raw tomato improved their absorption.

Sensitive and Rapid UHPLC-MS/MS for the Analysis of Tomato Phenolics in Human Biological Samples

An UHPLC-MS/MS method for the quantification of tomato phenolic metabolites in human fluids was optimized and validated, and then applied in a pilot dietary intervention study with healthy volunteers. A 5-fold gain in speed (3.5 min of total run); 7-fold increase in MS sensitivity and 2-fold greater efficiency (50% peak width reduction) were observed when comparing the proposed method with the reference-quality HPLC-MS/MS system, whose assay performance has been previously documented. The UHPLC-MS/MS method led to an overall improvement in the limits of detection (LOD) and quantification (LOQ) for all the phenolic compounds studied. The recoveries ranged between 68% and 100% in urine and 61% and 100% in plasma. The accuracy; intra- and interday precision; and stability met with the acceptance criteria of the AOAC International norms. Due to the improvements in the analytical method; the total phenolic metabolites detected in plasma and urine in the pilot intervention study were 3 times higher than those detected by HPLC-MS/MS. Comparing with traditional methods; which require longer time of analysis; the methodology described is suitable for the analysis of phenolic compounds in a large number of plasma and urine samples in a reduced time frame.