Tomato quality: the effect of cold on logistics circuits

The effect of temperature and logistics circuits on tomato quality

During a presentation at SIVAL 2024, CTIFL presented the results of the FreshQualiTom project to analyze the impact of cold on tomato quality during logistical circuits. The experiments measured the effects of temperature, harvest stage and storage times on various tomato quality criteria. The researchers studied two harvest stages: red with some green coloration (C5) and ripe red (C8). The tomatoes were stored at temperatures of 3°C, 8°C and 15°C.

Tomatoes stored at 15°C showed increased concentrations of lycopene, a key antioxidant pigment, and took on a beautiful red color. In contrast, tomatoes stored at 3°C and 8°C showed a decrease in lycopene concentration, resulting in an orange color. The analysis also revealed that acidity decreased more rapidly for tomatoes stored at 15°C, although early fruits remained more acidic than those harvested when ripe. With regard to firmness, no significant difference was found according to storage temperature, which decreased over time in a similar way for all batches.

Analysis of logistics channels and tomato varieties

Surveys carried out among sector professionals identified three typical logistical circuits. The circuits differed in temperature and duration, ranging from an extreme cold mode with temperatures as low as 3°C, to a very long circuit with extended storage times. In the early stages of the logistical chain, professionals maintain tomatoes at minimum temperatures of 12°C, while lower temperatures are observed at the end of the circuit, due to constraints linked to the conservation of other fresh produce.

The simulations covered four tomato varieties with very contrasting profiles: cluster, heart, ribbed and cherry tomatoes. The results showed that the small cherry tomato had higher levels of acidity, sugars and vitamin C than the other varieties. However, quality criteria such as acidity and aromatic compounds varied little according to the conditions of the different circuits, indicating a limited impact of temperature in these variations. In terms of firmness, only the grape variety showed significant losses in the extreme long circuit, with a notable deterioration after 32 days of storage.

Good practices and the role of post-harvest temperatures

All these results underline the importance of good practices for maximizing the quality potential of tomatoes. Variety and stage of ripeness at harvest play a fundamental role. Harvesting tomatoes early and storing them at low temperatures maintains their firmness and acidity, but compromises their color and lycopene content. A storage temperature of 12-15°C during the first week post-harvest promotes optimal development of qualitative compounds such as color and aroma.

In terms of logistics circuits, time plays a more critical role than temperature in the variability of parameters such as firmness. At consumer level, storage in the refrigerator (8°C) or at room temperature (20°C) for a few days has shown no significant effects on aroma criteria, when the fruit is returned to room temperature before tasting. It is essential to take account of specific storage conditions to guarantee optimum tomato quality, both throughout the logistics chain and in the consumer's home.