Evaluation of chemical parameters for authenticity of commercial lime juice

مجله پژوهشهای علوم و صنایع غذایی ایران

Article 10, Volume 15, Issue 4 - Serial Number 58, September and October 2019, Pages 497-506   

Document Type: Research Article

DOI: 10.22067/ifstrj.v15i4.64465

Author

Zahra Alaei Roozbahani^*

Food Engineering and Technology, Standard Research Institute, Iranian National Standards Organization.

Abstract

Introduction: Citrus fruits are rich sources of dietary fibre and bioactive compounds, including vitamin C, phenolics and flavonoids, with potential health-promoting properties. Nowadays citrus production is the main activity of the producers of fruit trees in the world (104 million tons, 7.1 _ 106 ha) and the countries with higher production are Brazil, China, India, USA, Mexico and Spain, as well as many other tropical and subtropical regions in the world. The authenticity and safety of food is of great importance to both producers and consumers. Foods must be produced in accordance with legal requirements. Adulterated foods affect the consumer negatively in terms of nutrition, health and economics; they cause an imbalance in the domestic market and furthermore, they cause harm to regional economics. The expensive production and consumption of adulterated foods is widespread. Profit is gained with the adulterate, the consumer is deceived as well. The adulteration of citrus juice is a significant worldwide problem. Fruit juices may have undergone dilution with water (Boland, 1988), addition of sugar (Brause et al., 1987), acidification and aroma intensification (Benk, 1976; Richard, 1978). Addition of foreign substances to the juices or addition of juices from other fruits are the other fraudulent practices (Iranzo, 1977). The AIJN, Association of the Industry of Juices and Nectars of the European Union (EU), has established reference guidelines for several fruit juices, including lime. The referred values in these guidelines are based on pure, authentic fruit juices obtained from the edible part of mature and sound fruits of different varieties and geographical origins obtained by mechanical processes.  The characterisation of Iranian lime juices by measuring their physicochemical quality parameters is of special interest to contrast them with the actual international standards: Codex Alimentarius and AIJN Code of practices. It is also very useful to detect adulteration or dilution of juices and to distinguish these high-quality juices. The aim of this study was to contribute to the knowledge of commercial lime juice and pure lime juice characteristics, the obtained parameters will be compared with the international standards.
 
Material and methods: Ten samples of lime juice were obtained from different fruit juice factories in 2016. Three samples were prepared in laboratory by pressing fresh fruits. All samples were analyzed in duplicate .A panel of different analytical techniques established by IFU (International Federation of Fruit Juice Producers, Paris, France), codex and ISIRI were used for determination of physicochemical parameters, organic and mineral contents in lime juices.
 
Results and discussion :Parameters that characterize the absolute quality requirements:According to these results, relative density of the all lime juice samples varied between 1.030 and 1.040.in all lime juice samples tested, relative density was higher  than 1.0298, the maximum prescribed value by AIJN (2016). Titratable acidity of juices typically varied between 50 and 90 g/L calculated as anhydrous citric acid. In all lime juice samples tested, titratable acidity was found to be acceptable. Ethanol and volatile acids are not present in sound fruits; they are indicators of spoilage by epiphytic microorganisms such as yeasts, acetic acid bacteria (AAB) and lactic acid bacteria (LAB). The small amounts detected can be taken as an indication of the processing of good quality and absence of fermentation processes in juice. The amounts detected in juices from all samples was lower than the maximum (universal) limit of 0.4 g/L. Heavy metal elements contained in fertilizer and contaminated soils are transmitted into fruits and other farm produces. Heavy metal contents detected in all samples by atomic absorption spectrometry (AAS) were acceptable. 5-Hydroxymetylfurfural (5-HMF) is practically not present in fresh fruit juice, but it is naturally generated during heating or storage processes in the Maillard reaction as well as sugar caramelization and degradation. Therefore, 5-HMF can be used as an indicator for excess heat treatment and deterioration. In all lime juice samples tested, concentration of 5-HMF was much lower than 20 mg/L, the maximum prescribed value by AIJN. Synthetic color and preservative material such as sorbic and benzoic acids were also carry out. Values were not obtained for these parameters. Criteria relevant to the evaluation of identity and authenticity: Analysis of  proteins, formol index, calcium, magnesium, sodium, potassium, phosphorus and sucrose have indicated ash, mineral elements and protein and formol index to be useful parameters for detection of adulteration. Ash and phosphorus content are fairly independent of regional variation and soil and are a fair criterion of added water in berry and fruit juices. The ash that represents the total mineral content of lime juice was between 2.84 and 3.85 g/L. The concentration of various elements in the tested samples were, in decreasing order, potassium (10-1350 mg/L) > sodium (63-907mg/L) > calcium (34–172 mg/L) >phosphorous (0-123 mg/L)>magnesium (10-75 mg/L).Potassium typically is the main mineral in lime. The finding of 1350 mg/L is consistent with this knowledge. Also 9 commercial samples did not reach the limits proposed by AIJN for more than one of these elements. The formol number, or formol titration, is merely an index which reflects the amount of free amino acid. It varied between 18 and 30 mL NaOH 0.1 N/100 mL. A chemical matrix method which allows identification of several compounds such as L-malic acid, chlorogenic acid and the fructose/glucose ratio, sucrose, fructose ,glucose can detect adulteration in apple and orange juices such as dilution with water, and addition of sugar, high fructose corn syrup, beet sugar and spent process water. Glucose, fructose and sucrose were detected and quantified in all juices tested. The presence of sucrose, glucose and fructose in lime juices varied between 0.0 - 4.6 g/L,1.48-12.7 and 0-9.8 respectively. 4 commercial samples did not reach the limits proposed by AIJN for these sugars.

Keywords

Lime juice; authenticity; sugar profile; chemical parameters

References

استاندارد ملی ایران شماره 2685؛ آب میوه‌ها- روش‌های آزمون.

استاندارد ملی ایران شماره 9265؛ مواد غذایی- اندازه‌گیری سرب، کادمیوم، مس، آهن، روی- روش طیف‌سنجی جذب اتمی.

استاندارد ملی ایران شماره 2685؛ آب میوه‌ها– روش‌های آزمون..

استاندارد ملی ایران شماره 11130؛ مواد غذایی- اندازه‌گیری آسه سولفام-کا، آسپارتام و ساخارین به روش کروماتوگرافی مایع با کارایی بالا.

استاندارد ملی ایران شماره 2634؛ افزودنی‌های خوراکی مجاز- رنگ‌های مصنوعی در مواد خوراکی- شناسایی به روش کروماتوگرافی لایه نازک-روش آزمون.

AFJA )Australian Fruit Juice Association).( 2009). Reference guideline for lemon.

Agusti, M., Mesejo, C., Reig, C., Martinez-Fuentes, A.(2014). Citrus production. Horticulture Plants for People and Places. vol. 1. Springer, Netherlands, pp. 159–195.

AIJN (Association of the Industry of Juices and Nectars of the European Union). (2016). Code of practice for evaluation of fruit and vegetable juices 6.26.Reference guideline for lime.

AIJN (Association of the Industry of Juices and Nectars of the European Union). (2013). Code of practice for evaluation of fruit and vegetable juices 6.6. Reference guideline for lemon.

Arena, E., Fallico, B., &Maccarone, E. (2001). Thermal damage in blood orange juice: Kinetics of 5-hydroxymethyl-2-furancarboxaldehyde formation. International Journal of Food Science and Technology, 36, 145–151.

Benk, E., (1976). Minerulbrunnen, 26(12):385-388.

Boland, EE. (1988). JAssoc. 0ff; c. Anal. Chem. 71(1):86-87

Brause, A., Doner, L. and Raterman, J.( 1987). Food Prod. Manag. 109(8):20-21.

Cordella, C., Moussa, I., Martel, A. C., Sbirrazzuoli, N., &Cuvelier, L. L. ( 2002). Recentdevelopments in food characterization and adulteration detection: Technique –oriented perspectives. Journal of Agricultural and Food Chemistry, 50, 1751–1764.

Directive 01/112 (2001).European commission and council directive related to fruit juices and certains similar product intended for human consumption.

 

Directive 95/2/EC (1995).European parliament and council directive on food additives other than coulours and sweeteners.

Esteve, M. J., Frigola, A., Rodrigo, C., & Rodrigo, D. (2005). Effect of storage periodunder variable conditions on the chemical and physical composition and colour of Spanish refrigerated orange juices. Food and Chemical Toxicology, 43, 1413–1422.

European committee for standardization (1994).Fruit and vegetable juices - Determination of sodium, potassium, calcium and magnesium content by atomic absorption spectrometry (AAS), EN 1134.

European committee for standardization (1994).Fruit and vegetable juices - Fruit and vegetable juices - Determination of phosphorus content - Spectrometric method, EN 1136.

European committee for standardization .(1999).Fruit and vegetable juices - Fruit and vegetable juices - Determination of glucose, fructose, sorbitol and sucrose contents - Method using high performance liquid chromatography, EN 12630.

Guyon, F., Auberger, P., Gaillard, L., Loublanches, C., Viateau, M., Sabathie, N., Salagoïty, M., Medina, B. (2014). 13C/12C isotope ratios organic acids, glucose and fructose determined by HPLC-co- IRMS for lemon juices authenticity, Food Chemistry 146, 36–40.

IFU (International Fruit and Vegetable Juice Association, (2005). IFU Methods of analysis, Determination of Formol Number, IFUMA30.

IFU (International Fruit and Vegetable Juice Association, (2005). IFU Methods of analysis, Determination of Relative Density (Pycnometer Method), IFUMA01.

IFU (International Fruit and Vegetable Juice Association, (2005). IFU Methods of analysis, Determination of Volatile Acids, IFUMA05.

IFU (International Fruit and Vegetable Juice Association), (2005). IFU Methods of analysis, Determination of Hydroxymethylfurfural (HPLC), IFUMA69.

IFU (International Fruit and Vegetable Juice Association), (2017). IFU Methods of analysis, Determination of Soluble Solids (Indirect Method by Refractometry), IFUMA08.

Iranzo, R.J. and Peres Toran, M.J. (1977). Relationship between the Brix of citrus juices and their soluble chemical components. Proceedzngs of the Internatzonal Society of Crtrzculture, pp 791-795 (Food Sa. Technol. Abs. 13:4H 737).

Iranzo, R.J., PerisToran, M.J. and Grima, R, (1977). Essenze Derzvatz Agrumarz, 47(4):485-490.

Kuljarachanan, T., Devahastin, S., Chiewchan, N. 2009. Evolution of antioxidant compounds in lime residues during drying, Food Chemistry 113, 944–949.

Lambert, G. F., Lasserre, A. A., Azzaro-Pantel, C., Miranda-Ackerman, M., Vazquez, R. P., Salazar, M. R. P. (2015). Behavior patterns related to the agricultural practices in the production of Persian lime (Citrus latifoliatanaka) in the seasonal orchard.Computers and Electronics in Agriculture, 116, 162–172.

Leclerq, C., Molinaro, M. G., Piccinelli, R., Baldini, M., Arcella, D., &Stacchini, P. (2000). Dietary intake exposure to sulphites in Italy – analytical determination of sulphite-containing foods and their combination into standard meals for adults and children. Food Additives and Contaminants, 17(12), 979–989.

Lorente, J.,Vegara, S., Martì, N., Ibarz, A., Coll, L., Hernandez, J. (2014). Chemical guide parameters for Spanish lemon (Citrus limon (L.) Burm.) Juices, Food Chemistry, 162, 186–191.

Lovacheva, G.N. and Eliarova, TS. (1974). VoprosyPitaniyaNo. 5:79-80.

Niedmann, P.D. (1976a). Chem. Mikrobiol. Technol. Lebensm. 4(5):132-135.

Paulo, R. M., Welliton, D. P., Leticia, A.F. N., Emy, T., Koiti, A.,Henrique E. T., Lúcio A., Marilene De V.C. P.(2011).Fast and reliable analyses of sulphite in fruit juices using a supramolecular amperometric detector encompassing in flow gas diffusion unit. Food Chemistry, 127:249–255.

Richard, J.P. (1978). Ann. Nutricion Aliment. 32(5): 1021-1033.

Sapers, G. M., (1993). Browning of foods – control by sulfites, antioxidants, and other means. Food Technology, 47(10), 75–84.

Scotter, M. (2015). Colour Additives for Foods and Beverages, Wood head Publishing Series in Food Science, Technology and Nutrition: Number 279.

Singhal, R. S., Kulkarni, P. R., Rege, D. V. (1997). Handbook of indices of food quality and authenticity, Cambridge, England.Chaptre3:77-119.

Tikka, J. and Johansson, L, (1947). ValtionTek. Tutkimuslaitos, TiedoitusNo.51, 5 pp.

Tosun, M., & Keles, F. (2012). Testing methods for mulberry pekmez adulterated with different sugar syrups. Academic Food Journal, 10(1), 17–23.

Vegara, S., Marti , N., Lorente, J., Coll, L., Streitenberger, S., Valero, M., Saura , D. (2014). Chemical guide parameters for Punicagranatum cv. ‘Mollar’ fruit juices processed at industrial scale, Food Chemistry 147, 203–208.

Vladimirov, G. (1972). Nauchni Trudove, Vissh Institut PO Khranitelnai Vkusova Promyshlennost .19 (1):59-72.

Directive 12/112/EC. (2012). Council directive relating to fruit juices and certain similar products intended for human consumption.

Sofos, J. N. (1995). Antimicro bialagents. In J. A. Maga, & A. T. Tu (Eds), Food additive toxicology. New York: Marcel Dekker. PP. 501-529.

WHO, (1987).Principles for the safety assessment of food additives and contamination in food. Environmental Health Criteria, 70.

Keng-Wen, L., Dennis P.H.H., Hui-Ying, H., Chiu-Hua, W., Shih-Pei, N., Min-Pei, L.(2016). Food safety risk assessment for estimating dietary intake of sulfites in the Taiwanese population.Toxicology Reports. 3, 544-551