Tomato Products Testing

Marcondes, Melissa Moliterno, et al. Journal of Food Composition and Analysis 100 (2021): 103927.

5-Hydroxymethylfurfural (5-HMF) is a compound that forms in carbohydrate-containing foods during thermal processing, particularly under acidic conditions, and high levels of it can be harmful to consumer health.

In this context, the study aims to determine 5-HMF using a green and validated capillary electrophoresis method, as well as to analyze the sugars (fructose, glucose, and sucrose), pH, and titratable acidity in tomato ketchup, tomato sauce, and tomato paste. The separation of 5-HMF was achieved using short-end injection (-50 mbar/3 s), a separation voltage of +30 kV, and a background electrolyte consisting of 5 mmol L^-1 tetraborate and 120 mmol L^-1 sodium dodecyl sulfate (pH 9.3), with direct detection at 284 nm.

The results indicate that the evaluated validation parameters (linearity, matrix effect, precision, and recovery) are satisfactory, and according to green chemistry principles, the method is rated as excellent. The 5-HMF content in the 23 analyzed tomato products ranged from 1.30 to 312 mg kg^-1, showing a positive correlation with the levels of sugars (fructose and glucose) and acidity. This study highlights the significance of monitoring 5-HMF levels in tomato products and the need to establish maximum legal limits to safeguard consumer safety.

Salomon, María Victoria, Patricia Piccoli, and Ariel Fontana. Microchemical Journal 159 (2020): 105390.

Tomatoes are a source of nutrients and antioxidants, including carotenoids, vitamins, phenolic compounds, and sugars, which are important not only for current consumer preferences but also for human health.

A rapid and cost-effective chromatographic method based on core-shell columns and high-performance liquid chromatography with diode array detection (HPLC-DAD) has been proposed for quantifying carotenoids in fresh tomatoes and their derived products. Using an Accucore C30 chromatography column (3.0 mm × 150 mm, 2.6 µm), a gradient of methanol, methyl tert-butyl ether (MTBE), and ultrapure water at a temperature of 10 °C and a flow rate of 0.4 mL/min allowed the separation of different polarity analytes, such as lutein, β-carotene, and lycopene, in under 16.5 minutes (with a total run time of 20 minutes). The maximum back pressure achieved was 270 bar, making the developed method suitable for standard HPLC instruments commonly found in laboratories.

After a comprehensive evaluation of the solvents used for resuspending the extracts, it was found that a methanol:MTBE (1:1) mixture was the most suitable for accurate quantification, avoiding the underestimation of analytes. The limits of detection (LOD) ranged from 0.03 to 0.46 mg/kg of dry sample weight, with overall recovery rates (accuracy) for the target compounds between 86% and 116%. The developed method was applied to determine carotenoids in seven fresh and processed tomato samples, demonstrating its effectiveness in quantifying analytes across various matrices.

Da Motta, S. I. L. V. A. N. A., and LM Valente Soares. Food Chemistry 71.1 (2000): 111-116.

Tenuazonic acid (TEA) has been shown to be toxic to chick embryos and can cause hemorrhage and death in mice. Cyclopiazonic acid (CPA) can lead to weight loss, diarrhea, muscle and visceral degeneration and necrosis, as well as convulsions and death in rodents, birds, dogs, and pigs.

The simultaneous occurrence of mycotoxins produced by fungi from different genera in the same commodity is not uncommon and may not have been thoroughly investigated in food products. Tomatoes are particularly susceptible to microbial invasion after bruising or tearing. Even when stored at lower temperatures (10-12°C), species of Cladosporium and Penicillium remain dominant, raising concerns.

For the first time, a method has been proposed for the simultaneous determination of the mycotoxins tenuazonic acid (TEA) and cyclopiazonic acid (CPA). This method has been applied to tomato products and involves simple extraction, defatting, and partitioning steps, followed by metal complex chromatography on a reverse-phase C18 column. The limits of quantification for TEA and CPA in tomato products are 11.0 ng/g and 8.0 ng/g, respectively, with average recoveries of 88% for TEA and 78% for CPA.