Document Type : Full Paper
Authors
1 Department of Horticultural Sciences, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
2 Department of Horticulture Sciences, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
3 Department of Chemical Engineering, Faculty of Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
Abstract
Keywords
Main Subjects
Extended Abstract
Introduction
Tomato is the second most important vegetable in the world after potato, which is rich in minerals and vitamins and has a special place among vegetables, agricultural and commercial economy, although one of the postharvest problems of this product is its high wastes. The use of coatings for fresh fruits and vegetables is one of the oldest methods in order to maintain the quality and increase the storage life. Using this method leads to the reduction of some activities, such as the rate of water vapor loss from the product, respiration, the rate of degradation and spoilage of qualitative characteristics, and the rate of microbial growth in the product.
Materials and Methods
In 2021, an experiment was conducted to study the quality and storage life of ‘Sena’ cultivar of tomato by application of chitosan, vanillin and acetic acid treatments in the postharvest laboratory of department of horticultural sciences and engineering in Vali-e-Asr University of Rafsanjan. The statistical design of the experiment was a factorial in the form of a completely randomized design. The first factor included the control (distilled water), chitosan 1% (Chit), acetic acid 1% (AA), vanillin 1% (Van), and a combined treatment (AA1%+Van1%+ Chit1%), while the second factor comprised the storage time during 3 storage periods (7, 14 and 21 days) at a temperature of 4±1°C and relative humidity of 85±5%.
Results and Discussion
The results of the experiment showed that acetic acid prevented ionic leakage, microbial contamination, weight loss and maintained firmness. Vanillin treatment kept the fruit firmness during storage up to two times and prevented weight loss (3%) and ion leakage (14%), compared to the control. The lowest content of malondialdehyde, pectin methyl esterase activity, and microbial activity were observed in vanillin. In general, among the investigated treatments, vanillin, due to its antioxidant properties, performed more impressively in the preservation of tomato products than other treatments, and in the last period of storage samples treated with vanillin had the highest score. The vanillin treatment best preserved the evaluated characteristics of tomato fruit and is recommended for the tomato storage process. The treatment of acetic acid as a chitosan solvent was evaluated separately and this application led to the prevention of ionic leakage, microbial contamination, weight loss and maintaining firmness. With regard to results obtained from this research, chitosan and combined treatment had destructive effects on tomatoes, therefore the use of chitosan with low molecular weight is not recommended for the storage of tomato products.
Conclusion
In this study, vanillin and acetic acid were able to preserve the investigated traits. According to the obtained results, the use of 1% vanillin and 1% acetic acid is suggested as the best treatment for tomato storage during the storage period. The noteworthy point in this study was the unacceptable effects of chitosan and combined treatment, which showed the negative role of edible coating of low molecular weight chitosan on tomato product. Taking this into consideration, it seems that the use of chitosan with medium or high molecular weight should be considered in the next experiments. Also, the study of different concentrations of high molecular weight chitosan in tomatoes, during the storage process in the warehouse, and the study of different concentrations of vanillin alone, and combination with other food coatings on tomato storage are other subjects that can be considered in further research.
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