Investigation of application possibilities of novel analytical methods for controlling the addition of natural and artificial dyes in meat products

Kontrola upotrebe boja koje se kao aditivi danas široko koriste u proizvodnji hrane ima veliki značaj za bezbednost i kvalitet proizvoda od mesa. Pored zakonskih regulativa važnu ulogu imaju i analitičke metode za utvrđivanje prisustva i određivanje količine boja. Cilj ove doktorske disertacije je bio da se razviju metode za istovremeno, rutinsko određivanje više boja kod različitih proizvoda od mesa. Analiza podataka iz literature pokazala je da ima malo analitičkih metoda za određivanje boja u proizvodima od mesa, da referentna metoda obuhvata samo veštačke boje, priprema uzoraka je, često, komplikovana i nepodesna za rutinski rad i da su savremene analitičke metode tečne hromatografije primenjene za određivanje boja u bezalkoholnim i alkoholnim pićima, konditirskim proizvodima, želeu, džemovima itd., ali ne i kod proizvoda od mesa. Za ispitivanja su izrađivani eksperimentalni proizvodi od mesa (finousitnjena barena kobasica - „pariska kobasica“ i konzerva od mesa u komadima - „kuvana šunka“), i proizvodi od mesa sa tržišta iz navedenih grupa. Eksperimentalni proizvodi su izrađivani u industrijskoj klanici i radionici Instituta za higijenu i tehnologiju mesa, Beograd. Izrađeni su kontrolni proizvodi bez dodatih boja i proizvodi u koje su u toku postupka izrade posebno dodavane boje Košenila, Ponso 4R i Alura crvena AC. U toku ispitivanja proizvoda od mesa korišćene su hemijske i fizičko-hemijske metode: (određivanje sadržaja azota (proteina): SRPS ISO 937:192, određivanje sadržaja slobodne masti: SRPS ISO 1444:1998, određivanje sadržaja vlage: SRPS ISO 1442:1998, određivanje sadržaja ukupnog pepela: SRPS ISO 936:1999 i određivanje pH vrednosti: SRPS ISO 2917:2004), senzorna ispitivanja boje preseka proizvoda, ujednačenosti boje preseka i postojanost boje 10 minuta nakon narezivanja (kvantitativna deskriptivna analiza, zasnovana na metodi SRPS ISO 6564:2001 i SRPS ISO 6658:2001), originalna metoda visokoefikasne tečne hromatografije sa fotodiodnom detekcijom (HPLC – PDA) sa prethodnim izolovanjem boja iz uzorka ubrzanom ekstrakcijom na visokom pritisku i temperaturi i merenje boje preseka proizvoda CIE L*a*b kolorimetrijom...Proper control of dyes that are widely used as food additives in production of foodstuffs is of considerable significance for safety and quality of meat products. Besides the adoption of legislative regulating this area, analytical methods for qualitative and quantitative determination of dyes also play an important role. The aim of this Doctoral dissertation was to develop routine analytical methods for simultaneous determination of multiple dyes in various meat products. Review of available literature showed that the number of analytical methods for determination of dyes in meat products is scarce, while the current reference method is intended for artificial dyes only. Furthermore, sample preparation techniques are often tedious and time-consuming, while available modern liquid chromatographic methods are mainly focused on dyes determination in alcoholic and non-alcoholic beverages, confectionary products, jellies, marmalades, etc., as opposed to availability of such methods applicable to meat products. For the purposes of investigations, experimental meat products were manufactured (finely grinded cooked sausage – “Parisian sausage” and chopped meat products – “cooked ham”), and a number of products of the same type were obtained from the retail as well. Manufacturing took place in industrial slaughterhouse and within the facilities of the Institute of meat hygiene and technology, Belgrade. Two types of products were made – control batches without addition of dyes and experimental batches – products with addition of the following dyes: Cochineal, Ponceau 4R and Allura red AC. The following chemical and physico-chemical methods were used during the experiments: (determination of nitrogen (protein) content SRPS ISO 937:192, determination of free fats content: SRPS ISO 1444:1998, determination of moisture content: SRPS ISO 1442:1998, determination of total ash content: SRPS ISO 936:1999 and determination of pH: SRPS ISO 2917:2004), sensory investigations of cut-surface color, consistency of cut-surface color and color stability ten minutes after slicing (quantitative descriptive test based on the methods SRPS ISO 6564:2001 and SRPS ISO 6658:2001), original liquid chromatographic method with photodiode array detection (HPLC – PDA) with dyes isolation from the sample using accelerated solvent extraction under high pressure and high temperature and color measuring of products’ cut-surface using CIE L*a*b colorimetry..

Changes in total viable count and TVB-N content in marinated chicken breast fillets during storage

Marination is a popular technique for enhancing meat properties. Depending on the marinade type and ingredients added, marination can improve sensory, chemical and microbiological quality of meat products. In this study, the total viable count and total volatile basic nitrogen (TVB-N) content in marinated chicken breast fillets were investigated. The possible correlation between bacterial growth and formation of TVB-N was also tested. Chicken breast fillets were immersed in a solution of table salt (as a control) orthree different marinades, which consisted of table salt, sodium tripolyphosphate and/or sodium citrate, and stored in air for nine days at 4 +/- 1 degrees C. Analyses of the total viable count and TVB-N were performed on days0, 3, 6 and 9 day of storage. The total viable count gradually increased in all examined groups, and statistically significant differences (p<0.01; p<0.05) between treatments on days0, 3 and 6 day of storage were established. TVB-N values in marinated chicken were significantly higher (p<0.01; p<0.05) compared to the control. Using the multiple linear regression, a positive correlation between total viable count and formation of TVB-N in chicken marinated with sodium citrate was established (p<0.05), while the intensity of TVB-N formation was lowest in chicken marinated with sodium tripolyphosphate

Evaluation of the diet supplementation strategy on the flesh quality and fatty acid profiles in common carp (Cyprinus carpio L)

The objective of this study was to evaluate the influence of three supplementary diets on the nutritional quality of marketable common carp. Supplementary diets (Carp1-maize, Carp2-extruded and Carp3-pelleted feed) exhibited significantly different (p≤0.05) influences on the protein, lipids, moisture and ash content in market-sized carp. The most abundant saturated FA (SFA) was palmitic acid (C16:0), the most predominant monounsaturated FA (MUFA) was oleic acid (C18:1n-9), and the most abundant polyunsaturated FA (PUFA) was linoleic acid (C18:2n-6). The highest content of SFAs was established in Carp1 (24.57% and 1888.72 mg/100 g wet fillet). MUFAs were presented in the highest quantities (61.77%, I.e. 4854.91 mg/100 g wet fillet) in Carp1, and PUFA accounted the highest quantities (33.48%, I.e. 1763.01 mg/100 g wet fillet) in Carp3. The most nutritionally beneficial n-6/n-3 ratio was obtained in Carp2 (5.83). The results obtained in this study indicate that introducing supplementary diets containing extruded or pelleted feed instead of maize improved carp nutritional quality. PCA (principal component analysis) and LDA (linear discriminant analysis) of the FAs demonstrated that carp could be reliably classified based on their supplementary feed

Element concentration and fatty acid composition of Serbian bee bread

The element concentration (Cu, Fe, Zn, Mn, Cr, Co, Ni, Se, K, Na, Ca and Mg), heavy metal concentration (Cd, Hg, Pb and As) and fatty acid composition of 12 Serbian bee bread samples from different geographical origins were examined. The element concentration was examined using ICP-MS, and total lipids for fatty acid determination were extracted from homogenized bee bread samples with hexane/isopropanol mixture by accelerated solvent extraction. Potassium was the major element, ranging between 5515 +/- 361.20 mg/kg and 7487 +/- 381.50 mg/kg. The highest As and Pb concentrations were found in bee breads from Lazarevac. This bee bread also contained the highest level of PUFA and SFA. Also, the n-6/n-3 ratio ranged between 0.86 +/- 0.28 and 1.40 +/- 0.05, indicating bee bread can be a good source of unsaturated fatty acids. Bee bread could be useful in monitoring environmental contamination by heavy metals (Cd, Hg, Pb and As), although complex studies of all bee products give sufficient information on this topic

Comparison of two analytical methods (ELISA and LC-MS/MS) for determination of aflatoxin B-1 in corn and aflatoxin M-1 in milk

The aim of this paper is to assess the closeness of agreement between results of ELISA and LC-MS/MS methods for determination of aflatoxin B-1 in corn and aflatoxin M-1 in milk. Samples of corn (n=100) and milk (n=250) were simultaneously analyzed using ELISA and LC-MS/MS methods, after the severe drought that affected Serbia in summer 2012 resulting in occurrence of aflatoxin B1 in corn and aflatoxin M-1 in milk. Regression analysis showed higher level of agreement between aflatoxin B-1 samples (R2=0.994), compared to aflatoxin M-1 samples (r(2)=0.920). However, both techniques were satisfactory in meeting the requirements for official control purposes

Use of inulin-collagen suspension for the total replacement of pork backfat in cooked-emulsified sausages

Total replacement of pork backfat with inulin-collagen suspension in the production of cooked-emulsified sausages was investigated. Four groups of sausages were produced: control sausages (backfat 25 %), Series A (backfat 15 %, inulin 4 %, and collagen 0.7 %), Series B (backfat 7.5 %, inulin 4 %, and collagen 1.2 %) and Series C (inulin 4 % and collagen 1.65 %). Physico-chemical properties, chemical composition, fatty acid profile, lipid oxidation parameters, colour, textural and sensory parameters were determined. The results showed that total replacement of pork backfat with inulin-collagen suspension is possible, considering that the low-fat Series C sausages had acceptable sensory properties, lower free fat content (8.5 ± 1.8 g∙kg-1), lower cholesterol content (462.3 ± 49.3 mg·kg-1) and higher content of carbohydrates-prebiotics (74.6 ± 8.4 g∙kg-1) than the control sausages. Series C sausages also had lower polyunsaturated, higher monounsaturated and a similar saturated fatty acids contents compared to the control product. Total fat replacement led to a decrease in values of lightness and redness but did not influence yellowness or the texture parameters. Regarding quality parameters, sausages with partially replaced pork backfat were not superior to those with total fat replacement

Quantitative deposition of nutrients in dorsal muscle, adipose tissue and liver in common carp (Cyprinus carpio L.) in a semi-intensive farming system

Carp is the dominant species grown in Serbia and makes up over 80% of the total fish production. The aims of the present study were to analyze changes of protein, lipid, ash and moisture in dorsal muscle, adipose tissue and liver in common carp additionally fed complete pellets during four months in natural carp ponds. Twenty fish from four ponds were sampled. Analysis of variance showed that protein content was the highest in dorsal muscle and adipose tissue and was the smallest in liver (P < 0.05). The percentage of protein was quite stable and reached a plateau value (18.42–19.49%) in dorsal muscle. Total lipid content in common carp was the highest in liver (14.79–17.24%) and smaller in dorsal muscle (1.92–5.42%) (P0.95), as were t-tests of significance (13.69, 18.04), and in the liver there was also an association since the coefficient of regression was 0.952 and the t-test was high (11.72)

Detection of milk fat in dairy products — an alternative approach

Milk fat is a highly valuable product, which is why accurate determination of its content in milk and milk products is very important. The use of the GC-FID method in our study proved to be very precise, as in the case of other authors, which signifies the importance of using this method to quantify milk fat. A total of 51 samples of dairy products were analyzed for fatty acid composition with particular attention to butyric acid. Butyric acid contents were in the range from 3.4 ± 0.73 in yogurt to 4.60 ± 0.08 in butter. Milk fat was in the range from 98.5 ± 4.77 in yogurt to 115.0 ± 1.73 in butter. Our results were in accordance with those of many other authors. Development of butyric acid and milk fat analyses in dairy products by GC-FID is essential for laboratories that must conduct analyses for food production, quality control during production, and inspection tasks for the import and export of these food products

Validation of LC-MS/MS for food colors in foodstuffs and household products

The aim of this study was to develop a quadrupole liquid chromatography mass spectrometry (LC-MS/MS) method suitable for quantification of synthetic food colors, used as additives or occurring as adulterants in the food or cosmetics industries. Ten colors were validated in terms of limit of detection (LOD), limit of quantification (LOQ), precision, trueness and applicability. All tested parameters of the validation were within acceptable values, and the method was comparable to the existing high pressure liquid chromatography (HPLC UV-PDA) method

Mlađ i konzumna kalifornijska pastrmka (Oncorhynchus mykiss) - hemijski sastav, sadržaj holesterola i masnokiselinski sastav fileta

Rainbow trout (Onchorhynchys mykiss) is well known fish species in the nature. Changes in proximate composition of fish meat are associated with age and size of fish. Cholesterol content in animal tissues is associated with feeding method and quality of food, in spite of regulatory mechanism of cholesterol synthesis and absorption. Objective of this study was determination and comparison of proximate composition, cholesterol content and fatty acid profile of fingerlings and marketable size rainbow trout from aquaculture. Samples of fingerlings (average mass of 99 g and length of 18.6 cm) and marketable size rainbow trout (average mass of 229 g and length of 23.3 cm) were collected in August 2010, in the fishpond 'Ribnik', Mrkonjić city, Republic Srpska - Bosnia and Herzegovina. Fingerlings and marketable size rainbow trout were fed complete mixture of similar composition for both fish categories (fish products, oils and fats, cereal products and oil seeds). Obtained results showed that there was no statistically significant difference (p> 0.05) in the content of total lipids (3.81%, fingerlings and 4.17%, marketable size trout) and ash (1.27%, fingerlings and 1.29%, marketable size trout). Higher protein content was determined in marketable size trout fillets (18.69%), as well as lower water content (75.40%) compared to their content in fingerlings (17.72% proteins and 77.11% water). Cholesterol content was 82.59 mg/100g (fingerlings) and 70.12 mg/100g (marketable size trout). Statistically significant differences (p lt 0.05) in content of total saturated fatty acids was established between fingerlings and marketable size trout (31.81% and 29.14%, respectively), also in polyunsaturated fatty acids-PUFA (33.93% and 36.78%, respectively) and n-3 fatty acids (17.17% and 19.20%, respectively). Content of monounsaturated fatty acids was similar and ranged from 33.30%, in fingerlings, to 33.05% in marketable size trout. There was no statistically significant difference (p > 0.05) in content of total n-6 fatty acids in fingerlings (16.76%) and marketable size fish (17.58%). Higher quantities of n-3 PUFA in fingerlings (17.17%) and commercial trout (19.20%) and lower quantities of n-6 PUFA (16.76% in fingerlings and 17.58% in marketable size trout) resulted in favourable n-3/n-6 ratio (1.02 in fingerlings and 1.09 in commercial trout). Content of eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) was 2.78% and 8.21% in fingerlings and 3.36% and 9.29% in marketable size fish, respectively. Content of EPA+DHA in total fatty acids was 10.99% in fingerlings and 12.65% in marketable size rainbow trout. By consumption 200 g of this fish intake of desirable fatty acids, EPA and DHA, is 0.84 g in fingerlings, and 1.06 g in marketable size rainbow trout, which is in accordance with recommendation of the American Heart Association for persons with cardiovascular disease (daily intake: in total 1g EPA and DHA). Trout growth was accompanied by increase of the protein content, decrease of the water content and increase in content of PUFA especially n-3 essential fatty acids. Due to significant content of proteins and unsaturated fatty acids and lower amounts of fat, rainbow trout can be considered as one of the most valuable food stuffs in human nutrition.Kalifornijska pastrmka (Oncorhynchus mykiss) je jedna od najpoznatijih vrsta ribe u prirodi. Promene u hemijskom sastavu mesa ribe su povezane sa starošću i veličinom ribe. Sadržaj holesterola u tkivima životinja je u vezi sa načinom i kvalitetom ishrane, uprkos regulatornom mehanizmu sinteze i apsorpcije holesterola. Cilj ovih ispitivanja je bio određivanje i poređenje hemijskog sastava, sadržaja holesterola i masnokiselinskog profi la mlađi i konzumne kalifornijske pastrmke iz akvakulture. Uzorci mlađi (prosečne mase 99 g i dužine 18,6 cm) i konzumne kalifornijske pastrmke (prosečne mase 229 g i dužine 23,3 cm) su sakupljeni u avgustu 2010. godine u ribnjaku 'Ribnik', Mrkonjić Grad, Republika Srpska - Bosna i Hercegovina. Mlađ i konzumna pastrmka su hranjene kompletnom hranom za pastrmku, sličnog sastava (riblji proizvodi, ulja i masnoće, proizvodi od žita i semena uljarica). Rezultati ispitivanja su pokazali da nema statistički značajne razlike (p > 0,05) u sadržaju ukupnih lipida (3,81%, mlađ i 4,17%, konzumna pastrmka) i pepela (1,27%, mlađ i 1,29%, konzumna pastrmka). U filetima konzumne pastrmke je utvrđen veći sadržaj proteina (18,69%) i manji sadržaj vode (75,40%) u poređenju sa njihovim sadržajem u filetima mlađi (17,72% proteina i 77,11% vode). Sadržaj holesterola je bio 82,59 mg/100 g (mlađ) i 70,12 mg/100 g (konzumna pastrmka). U filetima mlađi i konzumne pastrmke utvrđena je statistički značajna razlika (p lt 0,05) u sadržaju ukupnih zasićenih masnih kiselina (31,81% i 29,14%, respektivno), polinezasićenih masnih kiselina - PNMK (33,93% i 36,78%, respektivno) i n-3 masnih kiselina (17,17% i 19,20%, respektivno). Sadržaj mononezasićenih masnih kiselina je bio sličan i iznosio je u mlađi 33,30% i u konzumnoj pastrmci 33,05%. Nije postojala statistički značajna razlika (p > 0,05) u sadržaju ukupnih n-6 masnih kiselina u mlađi (16,76%) i konzumnoj ribi (17,58%). Veće količine n-3 PNMK u fi letima mlađi (17,17%) i konzumne pastrmke (19,20%) i manje količine n-6 PNMK (16,76% u mlađi i 17,58% u konzumnoj pastrmci) daju povoljan odnos n-3 i n-6 (1,02 u mlađi i 1,09 u konzumnoj pastrmci). Sadržaj eikozapentaenske (EPA, C20:5 n-3) i dokozaheksaenske kiseline (DHA, C22:6 n-3) bio je 2,78% i 8,21% u mlađi i 3,36% i 9,29% u konzumnoj ribi, respektivno. Sadržaj EPA+DHA u ukupnim masnim kiselinama je bio 10,99% u mlađi i 12,65% u konzumnoj kalifornijskoj pastrmci. Konzumiranjem 200 g ove ribe unos poželjnih masnih kiselina, EPA i DHA, iznosi 0,84 g za mlađ, odnosno 1,06 g za konzumnu kalifornijsku pastrmku, što je u skladu sa preporukom Američkog udruženja za srce za osobe sa kardiovaskularnim oboljenjima (dnevni unos: ukupno 1 g EPA i DHA). Rast pastrmke je bio praćen povećanjem sadržaja proteina, smanjenjem sadržaja vode i povećanjem PNMK, naročito n-3 esencijalnih masnih kiselina. Zbog značajnog sadržaja proteina i nezasićenih masnih kiselina i male količine masti, kalifornijska pastrmka se može svrstati u jednu od nutritivno najvrednijih namirnica u ishrani ljudi