Removal of Nitrate and Nitrite from Tomato Derived Products by Lemon Juice

Parisa Ziarati^1* and Fatemehsadat Mir Mohammad-Makki²

¹Department of Medicinal Chemistry, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran - Iran (IAUPS). ²Department of Food Sciences & Technology, Faculty of Advanced Sciences & Technology, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran - Iran (IAUPS) .

DOI : http://dx.doi.org/10.13005/bbra/2258

ABSTRACT: In recent years, many different parts of the world have been facing the problem of nitrate and nitrite contamination in food products, essentially due to the potential reduction of nitrate to nitrite, which is known to cause adverse effects on human and animal health. Therefore a simple, practical and economic process to reduce nitrate and nitrite concentrations in tomato processed products was the major objective of this research. In this study measuring nitrite and nitrate contents of tomato derived products samples commercially available in Iran market was conducted and then by adding different amount of fresh lemon juice the remained nitrate was determined. 280 samples tomato products during 5 consecutive months of 2014 - 2015 were taken and analyzed. In order to conduct a comparison between the content of nitrate and nitrite in the samples studied, dry matter content was determined according to the association of office analytical chemists (AOAC, 2000). A fifty gram sample of the prepared tomato was blended with 50ml deionized water in a home blender. The mixture was filtered and was passed through a glass 39 column fitted with a tape and filled with activated alumina, in order to separate the color of Chlorophyll and get a transparent solution. The eluted solution by water filtered using 0.45um filter paper in order to eliminate the turbidity and get a clear solution. Nitrite concentration in tomato samples were determined by spectrophotometric methods at a wavelength of 538 nm, and nitrate concentration was determined after reducing nitrate to nitrite by using cadmium column. The fresh lemon juice in this research show a significant removal effect on the nitrate and nitrite contents in tomato samples tested (pd”0.001). The highest level of nitrate was found in ketchup by range of: 15.01-167.54 and mean content of 65.73±0.007 (mg/kg FW ±SE) which was treated by 0.02%w/w of lemon juice and removing 93% nitrate content in this product. Natural and fresh Lemon juice in other tomato processed treated also removed nitrite contents significantly (pd”0.003).

KEYWORDS: Removing nitrate; Tomato processed products; Lemon juice

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