Related Experiment Video
Updated: Aug 13, 2026

Controlled-release of Chlorine Dioxide in a Perforated Packaging System to Extend the Storage Life and Improve the Safety of Grape Tomatoes
Published on: April 7, 2017
The influence of different electrical conductivity values in a simplified recirculating soilless system on inner and
Sandra Krauss1, Wilfried H Schnitzler, Johanna Grassmann
1Institute of Vegetable Science, Life Science Center Weihenstephan, TUM, Dürnast 2, 85350 Freising, Germany. krauss@wzw.tum.de
Abstract:
Irrigation with saline water affects tomato fruit quality. While total fruit yield decreases with salinity, inner quality characterized by taste and health-promoting compounds can be improved. For a detailed description of this relationship, the influence of three different salt levels [electrical conductivity (EC) 3, 6.5, and 10] in hydroponically grown tomatoes was investigated. Rising salinity levels in the nutrient solution significantly increased vitamin C, lycopene, and beta-carotene in fresh fruits up to 35%. The phenol concentration was tendentiously enhanced, and the antioxidative capacity of phenols and carotenoids increased on a fresh weight basis. Additionally, the higher EC values caused an increase of total soluble solids and organic acids, parameters determining the taste of tomatoes. Total fruit yield, single fruit weight, and firmness significantly decreased with rising EC levels. Regression analyses revealed significant correlations between the EC level and the dependent variables single fruit weight, total soluble solids, titrable acids, lycopene, and antioxidative capacities of carotenoids and phenols, whereas vitamin C and phenols correlated best with truss number, and beta-carotene correlated best with temperature. Only pressure firmness showed no correlation with any of the measured parameters. As all desirable characteristics in the freshly produced tomato increased when exposed to salinity, salinity itself constitutes an alternative method of quality improvement. Moreover, it can compensate for the loss of yield by the higher inner quality due to changing demands by the market and the consumer. This investigation is to our knowledge the first comprehensive overview regarding parameters of outer quality (yield and firmness), taste (total soluble solids and acids), nutritional value (vitamin C, carotenoids, and phenolics), as well as antioxidative capacity in tomatoes grown under saline conditions.
Related Concept Videos
Electrical Conductivity
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
Tonicity in Plants
Tonicity in Plants
Tonicity
Tonicity describes the capacity of a cell to lose or gain water depending on the solute...
Electrical Transport
Key Elements for Plant Nutrition
Water and Mineral Acquisition
