Konzervirana morska riba na srpskome tržištu: razine cinka, bakra i željeza i njihov doprinos dnevnom unosu ovih esencijalnih metala

The aim of this study was to determine the levels of Zn, Cu, and Fe in three canned fish species marketed Serbia to see if they meet recommended daily intake requirements or exceed safety limits. We collected a total of 207 samples of canned tuna, sardine, and mackerel, in oil or tomato sauce and analysed them with inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. The highest levels were obtained for Zn (15.1 mg kg-1) and Cu (1.37 mg kg-1) in sardine in oil and tomato sauce, respectively, and for Fe (18.98 mg kg-1) in mackerel in tomato sauce. Our results keep within the ranges reported by several national food databases and available literature data, with a few exceptions. Our findings also single out canned sardines as the richest source of the three essential elements combined. The estimated daily intake (EDI) of the three essential elements, however, was subpar, and ranged between 0.14 % and 0.72 % of the recommended dietary allowance (RDA) for Zn, Cu, and Fe.Cilj ovoga rada bio je utvrditi razinu cinka, bakra i željeza u trima vrstama ribljih konzervi sa srpskoga tržišta kako bi se ustanovilo zadovoljavaju li zahtjeve za preporučenim dnevnim unosom, ili pak prekoračuju sigurnosne granice. Sadržaj esencijalnih elemenata utvrđen je u ukupno 207 uzoraka konzerve tune, sardine i skuše primjenom masene spektrometrije s induktivno spregnutom plazmom (ICP-MS) nakon kisele digestije uzoraka. Najveći sadržaj cinka (15,1 mg kg-1) utvrđen je u sardini u ulju, bakra (1,37 mg kg-1) u sardini u umaku od rajčice, a željeza (18,98 mg kg-1) u skuši u umaku od rajčice. Dobiveni rezultati su u opsegu vrijednosti za analizirane elemente koje je objavilo nekoliko nacionalnih baza podataka o hrani, kao i u opsegu dostupnih literaturnih podataka, s nekoliko iznimaka. Rezultati istraživanja izdvajaju sardinu u konzervi kao najbogatiji izvor proučavanih esencijalnih elementa. Procijenjeni dnevni unos (EDI) bio je između 0,14 % i 0,72 % preporučenih dnevnih unosa cinka, bakra i željeza. Iako sardina u konzervi, u odnosu na tunu i skušu, doprinosi oko 1,5 puta više preporučenom dnevnom unosu (RDI) esencijalnih elemenata, konzervirana morska riba ne može se smatrati značajnim izvorom cinka, bakra i željeza u prehrani srpskoga stanovništva

Hemometrijski pristup razvoju kolorimetrijske metode za procenu količine prehrambenih boja u proizvodima od mesa

The aim of this research was to develop a novel colorimetric method based on mathematical models, by multiple linear regression (MLR), from the CIE L*a*b* measurements and data of the HPLC determination of food colorants. Calibration set of 10 production batches of finely grinded cooked sausage with food colorants added was manufactured in industrial conditions as follows: one control batch and 9 products with various quantities of added food colorants: E120 (3.4, 7.5 and 12.5 mg/kg), E 124 (5.0, 15.0, 25.0 mg/kg) and E 129 (5.0, 15.0, 25.0 mg/kg). The estimation of the added food colorants was assessed by measuring L*, a*, b* parameters of cross-section. The quantification of food colorants was achieved by HPLC-PDA. Food colorants were extracted from meat products using Accelerated Solvent Extraction (ASE). Quantification of food colorants was achieved in the range from 1 to 100 mg / kg, and recovery values were from 76.15% to 107.04%, for E 120, from 97.61% to 101.03%, for E 124 and from 99.91% to 101.67%, for E 129. Correlation of the results obtained using HPLC and colorimetric measuring data was assessed by Multiple Linear Regression (MLR). The results from colorimetric and chromatographic determinations in four experimental batches (three batches with different quantities of food colorants and one control batch) were used for calibration. Coefficients of determination (R2) for linear models in experimental batches were 0.954, for E 124, 0.987, for E 120 and 0.993, for E 129. Correlation functions of food colorant quantities and corresponding L*a*b* values were established. The obtained mathematical models were tested for the estimation of the content of dyes in 21 samples of finely grinded cooked sausages purchased in retail stores. Food colorants were confirmed in 20 samples (95.24 %), and one sample (4.76 %) did not contain any of these compounds. Out of the positive samples, sixteen samples (80.00 %) contained E 120, while four samples (20.00 %) contained E 129. Food colorant E124 was not established in any of the analyzed samples. Colorimetric CIE L*a*b* method might be used during sensory evaluation of meat products for the assessment of the added food colorants.Cilj ovog rada je bio da se, merenjem vrednosti parametara boje preseka proizvoda od mesa u CIE (Commission Internationale de l'Eclairage, Međunarodna komisija za osvetljenje) L*a*b* prostoru (L* – svetloća, a* – udeo crvene boje i b* – udeo žute boje) ispita mogućnost procene sadržaja dodate prehrambene boje u proizvodima od mesa. Količina prehrambene boje u uzorcima od mesa određena je metodom visokoefikasne tečne hromatografije sa detekcijom na fotodiodnom sloju (HPLC-PDA), a međusobna zavisnost dobijenih vrednosti i kolorimetrijskih parametara ispitana je višestrukom linearnom regresijom (MLR). Kalibracioni set od 10 proizvodnih partija fino usitnjene barene kobasice, sa tri dodate boje, izrađen je u industrijskim uslovima, i to: kontrolni proizvod bez boje i 9 proizvoda sa različitim količinama dodatih boja E 120 (3,4; 7,5 i 12,5 mg/kg), E 124 (5, 15 i 25 mg/kg) i E 129 (5, 15 i 25 mg/kg). Postavljene su jednačine funkcije zavisnosti količine boje od L*, a* i b* vrednosti. Dobijeni matematički modeli su provereni i primenjeni za procenjivanje sadržaja boje u 21 uzorku fino usitnjenih barenih kobasica sa tržišta. Utvrđeno je da se kolorimetrijskom CIE L*a*b* metodom mogu, u toku senzorskog ocenjivanja boje proizvoda, proceniti količine dodatih boja u proizvodima od mesa i da se ova metoda može primeniti kao komplementarna HPLC-PDA

Effect of modified atmosphere and vacuum packaging on selected chemical parameters of rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio) cuts freshness

The purpose of food packing in modified atmosphere is to extend its sustainability by preventing both biochemical processes and growth of spoilage bacteria. Gases or their mixtures which are mostly used in the modified atmosphere food packing technology are carbon-dioxide (CO2), oxygen (O2) and nitrogen (N2). The aim of our research was to examine the influence of packaging in modified atmosphere and vacuum on the total volatile basic nitrogen (TVB-N) content and pH in muscle of rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio), as well as to determine the most suitable gas mixtures for packing of these freshwater species. Three sample groups of trout and carp cuts were investigated. The first two groups were packaged in modified atmosphere with different gas ratios: 60%CO2+40%N2 (I group) and 40%CO2+60%N2 (II group), whereas the samples from third, control group, (III group) were vacuum packaged. During trials samples were stored in refrigerator at +3°C. Determination of TVB-N and pH was performed on 1st, 7th and 14th day of storage. The obtained results indicate that the investigated mixtures of gases and vacuum as well had a significant influence on the values of TVB-N in trout and carp cuts samples. The lowest increase in TVB-N was established in trout and carp cuts samples from the group I, whereas the highest increase was established in samples from group III. Statistical significant difference (p < 0,001) between the average values of TVB-N for trout (I group: 18,17 ± 0,93; II group: 20,90 ± 0,81 and III group: 36,18 ± 2,65 mg N/100 g ) and carp cuts (I group: 26,74 ± 1,48; II group: 30,02 ± 0,31 and III group: 35,10 ± 1,75 mg N/100 g) was established on 14th day. The lowest pH value was established in samples packaged in modified atmosphere with 60% CO2 +40% N2 (I group). On 14th day of testing the obtained value was 6,15 ± 0,09 for trout and 5,94 ± 1,11 for carp samples. Increase in pH value in trout samples packed in vacuum was established during the whole period of investigation (p < 0,001), while in carp cuts samples packaged in vacuum the increase in pH value (p < 0,05) was established up to 7th day of testing. Based on the obtained results it can be concluded that gas mixture consisting of 60% CO2 and 40% N2 was the most suitable for packaging of fresh trout and carp cuts in terms of selected chemical parameters, such as TVB-N and pH. [Projekat Ministarstva nauke Republike Srbije, br. TR 31011 i br. TR 31075

Chemometric approach in the development of the colorimetric method for the estimation of food colorants in meat products

The aim of this research was to develop a novel colorimetric method based on mathematical models, by multiple linear regression (MLR), from the CIE L*a*b* measurements and data of the HPLC determination of food colorants. Calibration set of 10 production batches of finely grinded cooked sausage with food colorants added was manufactured in industrial conditions as follows: one control batch and 9 products with various quantities of added food colorants: E120 (3.4, 7.5 and 12.5 mg/kg), E 124 (5.0, 15.0, 25.0 mg/kg) and E 129 (5.0, 15.0, 25.0 mg/kg). The estimation of the added food colorants was assessed by measuring L*, a*, b* parameters of cross-section. The quantification of food colorants was achieved by HPLC-PDA. Food colorants were extracted from meat products using Accelerated Solvent Extraction (ASE). Quantification of food colorants was achieved in the range from 1 to 100 mg / kg, and recovery values were from 76.15% to 107.04%, for E 120, from 97.61% to 101.03%, for E 124 and from 99.91% to 101.67%, for E 129. Correlation of the results obtained using HPLC and colorimetric measuring data was assessed by Multiple Linear Regression (MLR). The results from colorimetric and chromatographic determinations in four experimental batches (three batches with different quantities of food colorants and one control batch) were used for calibration. Coefficients of determination (R2) for linear models in experimental batches were 0.954, for E 124, 0.987, for E 120 and 0.993, for E 129. Correlation functions of food colorant quantities and corresponding L*a*b* values were established. The obtained mathematical models were tested for the estimation of the content of dyes in 21 samples of finely grinded cooked sausages purchased in retail stores. Food colorants were confirmed in 20 samples (95.24 %), and one sample (4.76 %) did not contain any of these compounds. Out of the positive samples, sixteen samples (80.00 %) contained E 120, while four samples (20.00 %) contained E 129. Food colorant E124 was not established in any of the analyzed samples. Colorimetric CIE L*a*b* method might be used during sensory evaluation of meat products for the assessment of the added food colorants