A comparative study on chemical composition of organic versus conventional fresh and frozen tomatoes

Abstract

In this paper, comparative study on fresh and frozen tomatoes of organic and conventionally cultivated crops was performed. Fruits of tomato cv. Rio Grande((c)) were used and stored at 18 degrees C for 12months. Quality parameters of ascorbic acid, lycopene, beta-carotene, glucose, fructose and proteins, pH, color, acidity, water-soluble solids, and elements and azoxystrobine were measured. The results showed that amount of ascorbic acid and beta-carotene were similar in organic and conventional fresh tomatoes, but lycopene was found higher in conventional ones. Na and Mg were higher in conventional samples, but P, K, Ca, and Cu were higher in organic tomatoes. Organic samples were pesticide free, however, conventional fresh and 3month stored tomatoes contained pesticides. Nitrite was not detected in any sample. These results show that organic products are healthier. Organic fresh tomatoes got the highest scores in sensory analyses. Practical applicationsTomato is one of the most consumed fruits in the world. A comparative study was performed between organic and conventionally cultivated tomato fruits, in terms of some physicochemical and secondary metabolites for measure their quality properties and also investigated of effects on storage period both of the types of tomatoes. The results showed that serious reductions were observed after 12month of storage at -18oC in fruit quality criteria and antioxidant compounds, as well as nutritional parameters. Therefore, it can be recommended that conventional and organic tomatoes should not be stored longer than 9months. Nutritive products with high yield and quality can be obtained through the optimization of controllable conditions. Further researches are needed about the effect of cultural practices such as irrigation and fertilization on the quality and nutritional value of fruit, both in organic and conventional growing systems.