ISHS Acta Horticulturae 1233: XV International Symposium on Processing Tomato
Development of a fermented green tomato base for dressings and sauces with high nutritional value |
| Authors: | R. Santos, I. Sousa, A. Raymundo, J. Santos Silva, C. Prista, M. Mota |
| Keywords: | green tomato, tomato paste, tomato industry, lactic acid bacteria, functional foods |
| DOI: | 10.17660/ActaHortic.2019.1233.33 |
| Abstract:
Tomato industry is focused on a single high value product - tomato paste, produced only from completely red tomato. The non-use of high quantities of unripe fruits - ca 112 kt year-1 in Portugal - is a huge loss of energy, water and food. Lactic acid fermentation is considered a simple and valuable process to keep and/or enhance the safety, nutritional, sensory and shelf life properties of green tomato. This work integrates a project dedicated to promote the rational use of unripe industrial crops of tomatoes as a source of new functional food based on lactic acid fermentation. Tomatoes from the industrial cultivar 'H1423' were classified in three groups based on their external colour - completely green, yellow-orange and completely red, and physico-chemically characterized. Green tomato presented 4.7 °Brix, and 8.01 g L-1 titratable acidity expressed in citric acid equivalent. °Brix and soluble proteins content increased slightly from green to red tomatoes (to about 5.3 °Brix), whereas acidity decreased from 8.0 to 4.7 g L-1. Differences in soluble contents were not particularly high, supporting that all tomatoes had a similar nutritional value, worth to explore. Different characteristics (e.g., acidity), may be very useful for blends and specific fermentation conditions. Twelve lactic acid bacteria (LAB) strains were screened for their ability to grow on MRS media at 25, 30 and 36°C, pH between 2 and 5 and NaCl concentrations up to 2.5%. Growth/ fermentative performance on pasteurized tomato paste of each ripening class was also tested. Based on these results, five LAB strains (Lactobacillus plantarum, Pediococcus pentosaceus, Leuconostoc mesenteroides and Lactobacillus brevis) were selected as potential starters for tomato fermentation. Selected LAB strains will be tested on pastes based on different proportions of red, yellow and green tomatoes to make the best use of the different rejected tomato groups and fermented products will be subjected to rheological, chemical and nutritional characterization. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
