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  3. Investigating the effects of heating and cold storage of some vegetables on the amount of nitrate, nitrite and ascorbate salts

Investigating the effects of heating and cold storage of some vegetables on the amount of nitrate, nitrite and ascorbate salts

Number of pages: 61 File Format: word File Code: 32472
Year: 2014 University Degree: Master's degree Category: Food and Packaging Industries
Tags/Keywords: Ascorbic acid - Cold storage - freezing - Heating methods - Nitrate - Nitrite - Vegetables
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  • Summary of Investigating the effects of heating and cold storage of some vegetables on the amount of nitrate, nitrite and ascorbate salts

    Food Science Engineering

    Dissertation for M. Sc degree

    Abstract

    Nitrate, nitrite and ascorbic acid are present in a wide range of foods. Vegetables are an important source of nitrate, nitrite and ascorbic acid absorption in the diet. The purpose of this research is to investigate the effect of frying and boiling process on the amount of nitrate, nitrite and ascorbic acid of commonly consumed vegetables. In this research, 6 vegetable samples from Sanandaj city were randomly selected. After being boiled or fried, these samples were analyzed under the conditions of storage in the refrigerator. The amount of nitrate and nitrite was measured using the diazo method, and the amount of ascorbic acid of the samples was measured using the D.pinot method. The results were analyzed using three-way analysis of variance and Duncan's test using SPSS software. Over time, the results showed that the amount of ascorbic acid decreased significantly (p<0.05) and nitrate and nitrite increased to some extent. The average amount of ascorbic acid in fried samples was lower than that of boiled samples, while the average amount of nitrate and nitrite in boiled samples was higher than fried. During the storage time, the amount of nitrate and nitrite increased and the amount of ascorbic acid decreased. In general, between the two methods of steaming and frying, it is better to use the boiling method to preserve ascorbic acid, but if the initial content of nitrate and nitrite of vegetables is high, it is better to reduce their concentration by frying.

    Key words: ascorbic acid; freezing; to cook nitrate; Nitrite

    1-1- Background

    Due to the growing population in Iran, the demand for food is increasing day by day. For this reason, excessive use of chemical and organic fertilizers is very common in many places for more production per unit area. Nitrogen is the most consumed element required by plants, which is used in large quantities in agriculture. Indiscriminate use of nitrogen fertilizers may cause groundwater pollution and high absorption of nitrate by plants (Ardakani et al., 2014). Consumption of these waters and plants causes large amounts of nitrates to enter the body and causes many diseases in humans. 1-2 Statement of the problem Nitrates and nitrites are present in a wide range of food. These compounds are found naturally in plants and green plants. But their amount can increase to a great extent in plants due to the addition of chemical fertilizers and even in organic materials that are added to planted plants. Some plants, such as spinach, have the greatest response to nitrogen fertilizers and can accumulate large amounts of nitrate due to factors such as the cultivation method and harvesting time (Morosi [1], 2010). The amount of nitrates and nitrites in the diet varies greatly from one region to another, and this issue depends on factors such as the frequency of cultivation, weather conditions, soil quality, food production processes, the type and amount of chemical fertilizers used, and the state of laws in that region (Su[2] et al., 2009). Nitrite and nitrate are routinely added to meat and meat products to preserve them against microorganisms such as Clostridium botulinum that can cause food poisoning (Swan [3], 1977). Today, the problem of nitrate pollution is one of the most important issues of water and food quality in many parts of the world. The presence of nitrites and nitrates in food and their adverse effects on health is a subject that is still debated today (Kamak [4] et al., 1999). Gastrointestinal cancers are one of the most common cancers in the world and are responsible for many deaths each year. Among them, esophageal cancer with a high mortality rate and stomach cancer are of particular importance due to their high prevalence in the world. Several underlying factors such as nutrition, genetics, environmental factors, etc. are involved in the etiology of these diseases. Several risk factors play a role in causing esophageal and stomach cancers.Tobacco consumption, drinking alcoholic beverages, lack of vitamins and trace elements, drinking hot drinks, and especially food contamination with carcinogenic substances such as nitrosamines and fungal toxins have been highly regarded in causing esophageal cancer. Factors such as diet, exogenous chemicals, carcinogens produced in the digestive system, and genetic and infectious factors are also known to be involved in stomach cancer (Sun and Rustagi[5], 2003; Semnani et al., 2006). One of the environmental factors involved in the development of cancers of the upper digestive tract is the amount of nitrites and nitrates in drinking water and food. Human interference in nature's nitrogen cycle has caused a gradual increase in the accumulation of this material in the environment (Ward[6] et al., 2006). Based on clinical and epidemiological studies, high levels of nitrite and nitrate in the diet are known to cause stomach cancer (Jusen[7] et al., 1996). Nitrate can be reduced to nitrite in the oral cavity and stomach. This compound in the stomach can react with amines and amides to give nitrogen-containing organic substances and create carcinogenic groups called N-nitrosamine compounds (Walter [8], 1980; Dennis [9] et al., 1990).  Exposure to N-nitrosamine compounds formed in the stomach has been associated with an increased risk of stomach, esophagus, and gallbladder cancer (Bartsch et al., 1990). A high amount of nitrates in the diet is associated with stomach cancer in England, Colombia, Chile, Japan, Denmark, Hungary and Italy. Nitrite may react in the stomach with nitrosable compounds (such as secondary or tertiary amines or amides in food) in the form of N-nitroso compounds. N-nitroso dialkylamines have been tested in laboratory animals and it has been determined that 85% of 209 nitrosamines and 92% of 86 nitrosamides have carcinogenic effects (Forman and Shaker [11], 1997). Most nitrosamines cause liver cancer, but some of them cause cancer in certain organs (bladder, lung, esophagus, nasal cavities, etc.) (Sadeghi, 2019). Human exposure to nitrosamine compounds has been associated with an increased risk of esophageal, stomach, and bladder cancer (Mathew [12], 1998). A case-control study conducted in Canada regarding human contact with nitrites and nitrates used to preserve meat products showed a significantly increased risk of stomach cancer (Spigers [13], 1998).

  • Contents & References of Investigating the effects of heating and cold storage of some vegetables on the amount of nitrate, nitrite and ascorbate salts

    List:

    Table of contents. C

    List of tables. and

    list of figures

    abstract. H

    The first chapter: generalities. 1

    1-1- Background. 2

    1-2- statement of the problem. 2

    1-3- Importance of the subject. 5

    1-4- research objectives. 7

    1-5- research limitations. 8

    The second chapter: research literature. 9

    2-1- Nitrite and nitrates 10

    2-1-1- Nitrate and nitrite toxicity. 12

    2-1-2- The permissible amount of nitrite and nitrate. 14

    2-2-ascorbic acid. 16

    2-3- Vegetables investigated in the current research. 19

    2-3-1- Zucchini 19

    2-3-2- Carrot. 19

    2-3-3- Spinach. 20

    2-3-4- tomatoes. 21

    2-3-5- Celery. 22

    2-3-6- Eggplant. 23

    2-4- An overview of previous researches. 23

    Chapter Three: Materials and Methods 29

    3-1- Materials. 30

    3-1-1- sample of vegetables. 30

    3-1-2- Determination of dry matter. 30

    3-1-3- Chemicals. 31

    3-1-3- Equipment used 32

    3-2- Measurement methods. 32

    3-2-1- Nitrate measurement by diazo method 32

    3-2-2- Nitrite measurement by diazo method 34

    3-2-3- Ascorbic acid measurement by spectrophotometry method. 36

    3-3- Experiment and statistical analysis. 37

    Chapter four: results and discussion. 38

    4-1- Investigating the effect of vegetable type, process and storage time on the amount of ascorbic acid. 39

    4-2- Examining the effect of time, type of process and type of vegetable on the amount of nitrate. 45

    4-3- Investigating the effect of the type of process on the nitrite concentration of different vegetables during storage time in the refrigerator. 50

    4-4- Investigating the correlation of nitrite, nitrate and ascorbic acid concentration. 55

    Chapter five: conclusions and suggestions. 56

    5-1- Conclusion. 57

    5-2- Suggestions. 58

    Resources and references. 59

    Source:

    Ardkanis S, Shaisheta K, Efioni M, Sofiani N. 1384. Nitrate concentration in some herbal products of Isfahan, Environmental Journal, No. 37, 76-69.

    Pourmoqim M, Khosh Taynet K, Sadeghi Makia, Kamili Fanud R, Golestan B, Pir Ali M. 1388. Determining the amount of nitrates in lettuce, tomato and potato sold in Tehran's Tare Bar Square by HPLC method, Iranian Journal of Nutritional Sciences and Food Industry 63 - Year 5, Number 1, Spring 2019, Pages 63-70

    Dezfouli A, Abdulahi H. 2019. Nitrate Monitoring Plan, Fars Province Agricultural Jihad Journal, No. 280/89, 11-4

    Shahbazzadgani S, Hashemi Majed K, Shahbazi B. 1389. Measurement of Nitrate Concentration in Vegetables and Fruits Marketed in Ardabil City, Scientific Research Journal of Ardabil University of Medical Sciences, Volume 10, Number 1-39-38.

    Sadeghi S.M., Organic Chemistry. Third volume, second edition, Isfahan University, 1379.

    Al Masi A, Sadeghi A, Hashemian A, Mohammadi M, Bahloulis S, Maskini H, Mohammadi R. Investigating the effect of cooking and freezing process on the amount of nitrate and nitrite of widely consumed vegetables. Journal of Science and Nutrition and Food Industries of Iran. eighth year No. 3. Pages: 209-215.

    Noshad H, Ronghi A, Karimian N. 1380 Improving the efficiency of nitrogen fertilizer in corn cultivation, by measuring soil nitrate nitrogen and leaf chlorophyll, volume 5, number 3, 65-78. Changes in nitrate and nitrite contents of the same vegetables during processing. Annals of Agricultural Science 45(2):531 – 539.

    Aworh, O.C., J.R. Hicks, P.L. Minotti and C.Y. Lee, 1980. Effects of plant age and nitrogen fertilization on nitrate accumulation and postharvest nitrite accumulation in fresh Spanish. Journal of American. Society for Horticultural Science. 105:18-20.

    Bartsch, H., Ohshima, H., Shuker, D., Pignatelli, B., & Calmels, S. 1990, Exposure of humans to endogenous N-nitroso compounds: Implications in cancer etiology. Mutation Research, 238, 255–267.

    Brownand, J.R and Smith G.E, 1967. Nitrate accumulation in vegetable crops as influenced by soil fertility practices". Missouri agricultural experiment station research bulletin.920:1-43.

    Cammack, R., Joannou, C. L., Cui, X.-Y., Martinez, C. T., Maraj, S. R., & Hughes, M., 1999. N. Nitrite and nitrosyl compounds in food preservation. Biochimica et Biophysica Acta, 141, 475–488.

    Chung, J.C. Chou, S.S. & Hwang, D.F. 2004. ChangesChanges in nitrate and nitrite content of four vegetables during storage at refrigerated and ambient temperatures Food Additives and Contaminants, Vol. 21, No. 4 (April 2004), pp. 317-322.

    Dejon CW, Stekbaut W. Nitrate in food commodities of vegetable origin and the total diet in Belgium, University of Ghent, FLTBW; 1995.

    Dennis M.J, Key P.E, Papworth T, Pointer M, Massey R.C.1990. Food Additives & Contaminants: Part. A Chemistry Analysis, Control, Exposure & Risk Assessment. Vol. 7. 455-460.

    Fenell D. 2004. Determinants of Supplement Usage. Preventive Medicine, 5: 932-939. Food and Nutrition Board, Institute of Medicine, 2000. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academies Press, Washington, DC, USA.

    Food Chemistry 19 (1986) 265-275.

    Forman, D., & Shuker, D. 1997,. Helicobacter pylori and gastric cancer – A case study in molecular epidemiology. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 379, S159.

    Graun, G.F. and Greathouse, D.G. and Gundersan, D.H. 1981. Methemoglobin levels in young children consuming high nitrate well water in the U.S. International journal of Epidemiology No.4:309-

    Hsu J, Arcot J, N. Lee A, 2009. Nitrate and nitrite quantification from cured meat and vegetables and their estimated dietary intake in Australians. Food Chemistry 115, 334–339.

    Joossens, J. V., Hill, M. J., Elliott, P., Stamler, R., Stamler, J., Lesaffre, E. 1996,. Dietary salt, nitrate and stomach cancer mortality in 24 countries. International Journal of Epidemiology, 25,494–504.

    Kmiecik, W., Lisiewska, Z., S?upski, J. 2004. Effects of freezing and storing of frozen products on the contact of nitrate, nitrite, and oxalates in dill (Anethum graveolens L.) Food Chemistry 86:105-111

    Leszczy?ska T, Filipiak-Florkiewicz A, Cie?lik E, Sikora E, Pisulewski P.M.2009. Effects of some processing methods on nitrate and nitrite changes in cruciferous vegetables. J Food Comp Anal 22: 315–21.

    Leszczynska, T. Filipiak-Florkiewicz, A. Cies´lik , E. Sikora, E. Pisulewski, PM. 2009. Effects of some processing methods on nitrate and nitrite changes in cruciferous vegetables Journal of Food Composition and Analysis 22 (2009) 315-321.

    Lorenz, O.A., 1978. Potential nitrate levels in edible plant parts. In nitrogen in the environment, edited by Nielsen D.R. and J.G. MacDonald, Academic press, 201-219.

    Merusi C, 2009. Determination of nitrates, nitrites and oxalates in food products by capillary electrophoresis with pH-dependent electroosmotic flow reversal. Food Chemistry. 120(2), 615–620

    Moorcroft M.J, Davis J, Compton R.G. Detection and determination of nitrate and nitrite: a review. Talanta 2001; 54(5):785-803

    Muramoto, J. 1999. Comparison of nitrate content in leafy vegetables from organic and conventional farmers in California. Center for Agro ecology and sustainable food system. Univ. of. califor.  santacruz.

    Muramoto, J, 1999. Comparison of nitrate content in leafy vegetable from organic and conventional farmers in California, Center for Agro ecology and sustainable food system. University of California Santa cruze, 1-66.

    Mynard, D.N., Barker A.V,., Minotti P.L, 1976. Nitrate accumulation in vegetable Advances in Argonomy,28:71-118.

    Pavlou GC, Ehaliotis C. 2007. Effect of organic and inorganic fertilizers applied during successive crop seasons on growth and nitrite accumulation in lettuce. Scientia Horticulturae, 319: 111-25.

    Prasad S, Avinesh Chetty A.2008. Nitrate-N determination in leafy vegetables: Study of the effects of cooking and freezing. Food Chem, 106: 772–80.

    Semnani S, Sadjadi A, Fahimi S, Nouraie M, Naeimi M, Kabir J, 2006. Declining incidence of esophageal cancer in the Turkmen Plain, eastern part of the Caspian Littoral of Iran: A retrospective cancer surveillance. Cancer Detect Prev; 30(1): 9-14.

Investigating the effects of heating and cold storage of some vegetables on the amount of nitrate, nitrite and ascorbate salts
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