Istraživanje je provedeno na 119 nasumično odabranih svinjskih polovica podrijetlom od kastrata, zaklanih pri oko 100 kg žive mase u tri klaonice na području Istočne Hrvatske. Izmjerena su najvažnija svojstva kvalitete mesa: pH45, pH24, CIE-L* te otpuštanje mesnog soka mjereno metodom kompresije (WHC) i „metodom vrećice“ (otkapavanje). Pri ispitivanju statističke značajnosti perdiktora otpuštanja mesnog soka utvrđena je značajnost za WHC i pH24 vrijednosti (p0.05).The present research was conducted in 119 randomly chosen carcasses of barrows slaughtered at approximately 100 kg of live weight in three slaughterhouses in east Croatia. Main meat quality traits were measured: pH45, pH24, CIE-L* and drip loss by compression and bag method. Among the investigated drip loss indicators of drip loss the highest significance was found for WHC and pH 24 (p0.05).La ricerca è stata realizzata sulle 119 casualmente scelte metà suine, d`origine castrate, macellati con circa 100 kg di peso vivente nei tre luoghi di macello sul territorio orientale di Croazia. Sono state misurate le più importanti caratteristiche della qualità della carne: pH45, pH24, CIE-L* e il rilascio di succo della carne misurato con il metodo di compressione (WHC) e con „metodo borsino“ (gocciolare). Analizzando la significanza statistica dei perditori del rilascio di succo della carne è stata affermata la caratteristica per i valori di WHC e pH24 (p0.05)

Antun Petričević

Danica Hanžek

Goran Kušec

Gordana Kralik

Ivona Đurkin

V. Margeta

Zlata Maltar

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Vol. X (2008) siječanj - veljača br. 160SCIENTIFIC AND PROFESSIONAL PAPERS1 Ivona Đurkin, BScAgr, Assistant; Goran Kušec, DSc, Associate Professor; Gordana Kralik, DSc, Full Professor; Antun Petričević, DSc, Prof. Emeritus; V. Margeta, MSc, Junior Assistant; Danica Hanžek, BSc Agr, Expert Consultant; Zlata Maltar, MSc, Expert Consultant. Faculty of Agriculture, University J. J. Strossmayer in Osijek, Department of Special Zootechnics, Trg Sv. Trojstva 3, 31 000 OsijekCLASSIFICATION OF PORK SAMPLES ACCORDING TO DRIP LOSSSUMMARYThe present research was conducted in 119 randomly chosen carcasses of barrows slaughtered at approxi-mately 100 kg of live weight in three slaughterhouses in east Croatia. Main meat quality traits were measured: pH45, pH24, CIE-L* and drip loss by compression and bag method. Among the investigated drip loss indicators of drip loss the highest signifi cance was found for WHC and pH24 (p<0.05), while the values of pH45 and CIE-L* were not statistically signifi cant. Meat samples were classifi ed in „exudative” and „non-exudative“ groups by two discrimi-nant analyses. Overall accuracy of the fi rst analysis was not high (approximately 62%). When dependent variables were grouped according to cluster analysis of drip loss, overall accuracy was increased by approx. 77%. When the fi rst discrimination analysis was used, statistically signifi cant (p<0.05) differences between „exudative meat“ and „non-exudative meat“ groups were found only for two parameters of drip loss: pH24 and WHC. When the second discriminant analysis was used, statistically signifi cant differences (p<0.05) between the two groups were found only for pH45.Key words: pork, meat quality traits, indicator, discrimi-nant groupsINTRODUCTIONUnfavourable water-holding capacity or drip loss causes major problems in pig production and processing due to its negative impact on both the appearance of meat and yield in further processing. Another undesirable characteristic of such meat is unnaturally pale colour that consumers notice fi rst when judging the acceptability of meat. Since drip loss and colour are both affected by post-mortem glycolysis in the muscle, the initial and fi nal pH values are considered as meat quality indicators enabling fair predict-ing of these traits. Colour measurements are effective only after a period of time needed for meat to cool (24 hours) and to develop a fi nal hue on the cut surface (blooming time). Commonly used methods for measuring water loss in pork are the compression method after Grau and Hamm (1953) and the bag method developed by Honikel (1987). However, results of these methods are known relatively late. For this reason it is of special importance to differentiate the meat into different classes of drip loss on the basis of measurements of quality parameters as early as possible. Different criteria for sorting pork in meat qual-ity groups have been suggested. Kauffman et al. (1992) and Warner et al. (1997) suggested drip loss of >5% as threshold for differentiation of watery from “normal” meat; Joo et al. (1999) set the threshold for excessive drip loss to 6%. Regarding the pH values, the criteria are not clear either. Selier and Monin (1994) used the initial pH value less than 5.8 and fi nal pH less than 5.5 to predict pale, soft and exudative (PSE) pork. For the same purpose, For-est (1998) used the fi nal pH value of 5.5 or lower; while van Laack (2000) used the fi nal pH value lower than 5.7. Final pH value of 5.69 was interpolated as threshold value differentiating exudative from “normal” longissimus dorsi muscle.The aim of this paper was to investigate the signifi -cance of pork quality indicators predicting fi nal drip loss and determined by bag method and to set up a model for discrimination of meat samples according to excessive and “normal” drip loss. MATERIAL AND METHODSThe study was carried out in 119 randomly selected car-casses of barrows slaughtered at approximately 100 kg of live weight in three slaughterhouses in east Croatia. At the slaughter line, 45 minutes after sticking, the initial pH val-ues (pH45) and temperature were measured at m. longis-simus dorsi of primarily processed swine carcasses. After 24 hours of cooling, fi nal pH values (pH24), temperature and colour of m. longissimus dorsi were measured at the same place where the initial pH was measured. Water-holding capacity was measured after the method of Grau and Hamm (Grau and Hamm, 1952) and by bag method Classification of pork samples according to drip lossORIGINAL SCIENTIFIC PAPERĐurkin1, I., G. Kušec1, G. Kralik1, A. Petričević1, V. Margeta1, D. Hanžek, Z. Maltar1www.meso.hr 61SCIENTIFIC AND PROFESSIONAL PAPERSClassification of pork samples according to drip lossORIGINAL SCIENTIFIC PAPERas described by Kauffman et al. (1992); the former meth-od being termed in this paper as WHC, and the latter as drip loss. Meat samples for WHC and drip loss were taken from longissimus dorsi muscle after 24 hours of cooling; the former were compressed on fi lter paper for planimetry, while the latter were weighed, placed in plastic bags and stored at 6°C for 48 h and then weighed again. The colour of meat was measured by Minolta CR-300 device on cut of m. longissimus dorsi after 15 minutes of blooming and presented as CIE L* values. The measurements of pH45 and pH24 were carried out by digital pH-meter Mettler MP 120-B. All the data were processed using STATISTICA (7.0) for Windows program. Statistical methods applied were descriptive statistics, cluster analysis and traditional discrimination analysis.RESULTS AND DISCUSSION The main parameters of meat quality are presented in Table 1. According to Hofmann et al. (1994), limit value of the initial pH indicating PSE condition of pork is 5.8; L* value exceeding 53 and drip loss value less than 5% sug-gest the same meat quality condition as well. As regards fi nal pH values, different values for differentiation between “normal” and PSE meat were suggested: e.g. 5.5 by For-rest (1998) and 5.7 by van Laack (2000). Water-holding capacity (WHC) measured by the compression method higher than 9 cm2 is also an indication of PSE condition (Blendl et al., 1991). The ability of meat to withhold water, measured by bag method, was expressed as drip loss. Having in mind the above-mentioned threshold val-ues, the meat quality of hogs included in the study was satisfactory. The exception was drip loss measured the bag method, which was too high according to Kauffman et al. (1992) and Warner et al. (1997), but acceptable according to Joo et al. (1999). Variations of measured parameters are similar to those published in expert lit-erature (Ryu and Kim, 2005; Kušec et al., 2005).The signifi cance of meat quality indicators predicting drip loss is presented in Table 2. The highest signifi cance (p<0.05) was found for water-holding capacity (WHC) determined by compression method and fi nal pH values, while initial pH values were on the very limit of statistical signifi cance. The WHC measured by compression was considered in this study as an indicator because its results are known 48h earlier than results of drip loss determination by bag method. Meat paleness expressed by CIE-L* value was not statistically signifi cant (p>0.05) as a predicting indicator of drip loss. Ability of muscles to withhold water was the topic of many discussions in literature (Kušec et al., 2005, Otto et al., 2004). Relation-ship between meat quality indicators were investigated by Kušec et al. (2005) and Kralik et al. (2002). Signifi cant correlation was found between fi nal pH values, water-holding capacity determined by compression method and drip loss determined by bag method. Traditional discriminant analysis model was applied in order to classify meat samples into groups with high and favourable drip loss on the basis of investigated indica-tors of meat quality (pH45, pH24, CIE-L* and WHC). Drip loss limit value of 5% was used in the fi rst analysis (as suggested by Warner et al., 1997) for differentiation of quality groups by dependent variable, whilst in the sec-ond analysis meat samples were classifi ed according to cluster analysis (Table 3). Results of both discriminant analysed are presented in Table 4.From Table 4 it can be seen that classifi cation functions for exudative and non-exudative classes had different accuracy. With the use of the fi rst discriminant method, in the classes with excessive and “normal” drip loss, 58.93% and 65.08% of investigated meat samples respectively, were accurately differentiated. Overall discrimination accuracy was also not high (~62%). The second discrimi-nant analysis (classes determined by cluster analysis) provided better differentiation; almost 99% of samples in T Table 1. Descriptive statistics of investigated meat quality traitsVariable Mean Standarddeviation Minimum MaximumpH24 6.09 0.276 5.43 6.62pH48 5.63 0.176 5.38 6.46CIE-L* 46.79 4.898 35.65 59.40WHC, (cm2) 8.31 1.432 4.30 12.50Drip loss, (%) 5.55 2.754 0.98 14.79SS D.F. MS F PIntercept 52.6429 1 52.64288 7.964613 0.005630pH45 25.7736 1 25.77363 3.899425 0.050720pH24 27.7851 1 27.78514 4.203756 0.042628CIE-L* 3.4150 1 3.41504 0.516679 0.473733WHC (cm2) 31.9173 1 31.91729 4.828932 0.030008Error 753.4941 114 6.60960 - -T Table 2. Results of univariate tests of signifi cance for drip loss prediction with meat quality indicators as independent variablesVol. X (2008) siječanj - veljača br. 162SCIENTIFIC AND PROFESSIONAL PAPERSClassification of pork samples according to drip lossORIGINAL SCIENTIFIC PAPERanalysis was used, statistically signifi cant differences were found only in pH45 values, but not in other indicators of drip loss.ZUSAMMENFASSUNGKLASSIFIZIERUNG DER SCHWEINEFLEISCHMUSTER IN BEZUG AUF DIE AUSSCHEIDUNG DER FLEISCHFLÜSSIGKEITDie Untersuchung wurde auf 119 zufällig ausgewählten Schweinehälften durchgeführt, die Schweine waren aus dem Kastratursprung, geschlachtet bei ungefähr 100 kg Lebensmasse in drei Schlachthöfen auf dem Gebiet Ostkroatiens. Es wurden die wichtigsten Eigenschaften der Fleischqualität gemessen: pH45, pH24 , CIE-L* und die Ausscheidung der Fleischfl üssigkeit gemessen durch die Methode der Kompression (WHC) und “die Methode des Säckchens” (Austropfen). Beim Prüfen der statistischen Bedeutsamkeit der Perdiktor(en) für Ausscheidung von Fleischfl üssigkeit wurde die Bedeutsamkeit für WHC und pH24 des Wertes (p<0.05) festgestellt, während für die Werte pH45 und CIE-L* keine statistische Bedeutsamkeit festgestellt wurde. Die Fleischmuster wurden in Gruppen “normales” Fleisch  und “wässeriges” Fleisch mittels zwei Diskriminantanalysen geteilt. Die gesamte Genauigkeit der ersten Analyse war nicht hoch (etwa 62 %), aber nach der Gruppierung abhängiger Variablen nach Cluster-Anal-yse für Prozente der Ausscheidung von Fleischfl üssigkeit stieg die gesamte Genauigkeit auf etwa 77 %. Durch die Anwendung der ersten Diskriminantanalyse des statist-isch bedeutenden Unterschieds (p<0.05) wurden unter der Gruppen “wässeriges” Fleisch und “normales” Fleisch Werte für pH24 und WHC festgestellt. Bei der Anwendung der zweiten Diskriminantanalyse wurde der statistisch bedeutende Unterschied (p<0.05) unter diesen zwei Grup-pen nur für pH45 festgestellt, die anderen Prediktor(en) der Ausscheidung von Fleischfl üssigkeit unterschieden sich untereinander nicht bedeutend (p>0.05).  Schlüsselwörter: Schweinefl eisch, die Eigenschaften der Fleischqualität, Indikatoren, Diskriminantgruppenthe class “normal” meat were accurately differentiated, so that overall accuracy was higher (~77%) in comparison with accuracy of the fi rst discriminant analysis. Accuracy of discrimination in the exudative class was quite low; only 24% of samples were accurately differentiated. Two classes of samples were formed with each discriminant analysis; their principal meat quality traits are presented in Table 5. When the fi rst discriminant analysis was used, the group of exudative samples had signifi cantly lower fi nal pH values and higher water-holding capacity (p>0.05), while the differences between groups in the initial pH and CIE-L* values were not statistically signifi cant (p>0.05). When the second discriminant analysis was used, signifi -cant differences between groups were found only in the initial pH and WHC values (p<0.05).CONCLUSION Based on the study results, following can be concluded: - Among the selected indicators of drip loss assessed by bag method, the highest signifi cance was found for water-holding capacity (WHC) obtained by compression method and fi nal pH values (p<0.05), while the initial pH values were on the very limit of statistical signifi cance. Paleness of meat expressed as CIE-L* value was not statistically signifi cant (p>0.05).- Classifi cation of meat samples into exudative and non-exudative groups by discrimination functions showed different levels of accuracy. When the drip loss value of 5% was used as criterion for division of samples into qual-ity groups, the overall discrimination percentage was not high, but it was increased when the meat quality groups were formed according to cluster analysis of drip loss. - When the fi rst discrimi-nant analysis was used, the exudative and non-exudative meat groups showed statistically signifi -cant differences only in pH and WHC values. When the second discriminant Mean Standarddeviation Minimum Maximum NExudative 9.15 1.87 6.78 14.79 34Non-exudative 4.11 1.40 0.98 6.5 85T Table 3. Descriptive statistics of drip loss clusters (exudative and non-exudative meat)Exudative meat Non-exudative meat Correctly classifi ed (%)Analysis 1 (p=0.471)Analysis 2 (p=0.286)Analysis 1 (p=0.529)Analysis 2 (p=0.714) Analysis 1 Analysis 2Exudative 33 8 23 26 58.93 23.53Non-exudative 22 1 41 84 65.08 98.82Total 55 9 64 110 62.18 77.31T Table 4. Classifi cation matrix obtained by discriminant analysiswww.meso.hr 63SCIENTIFIC AND PROFESSIONAL PAPERSBacteriocinogenic starter cultures vs. Listeria monocytogenesREWIEVREFERENCESBlendl, H., E. Kallweit, J. Scheper (1991): Qualitatanbieten: Schweine-fl eisch, AID, 1103, Bonn.  Forrest, J.C. (1998): Line speed implementation of various pork quality measures. Home page address: http://www.nsif.com/Conferences/1998/forrest.htm. Grau, R., R. Hamm (1952):  Eine einfache Methode zur Bes-timmung der Wasserbindung im Fleisch. Die Fleischwirtschaft, 4, 295-297.Hofmann, K. (1994): What is quality? Defi nition, measurement and evaluation of meat quality. Meat Focus International, 3 (2), 73-82 Joo, S.T., R. G. Kauffman, B. C. Kim, G. B. Park (1999): The relationship of sarcoplasmic and myofi brillar protein solubility to colour and water-holding capacity in porcine longissimus muscle. Meat sci. 52, 297-297. Kauffman, R.G., R. G. Cassens, A. Sherer, D. L. Meeker (1992): Variations in pork quality. NPPC Publication, Des Moines, U.S.A., 1-8. Kralik, G., G. Kušec, H. Gutzmirtl, A. Petričević, D. Grgurić (2002): Correlation between meat colour and some indicators of carcass and meat quality of pigs. Acta Agr. Kapos, 6, 253-258. Kušec, G., Gordana Kralik, D. Horvat, A. Petričević, V. Mar-geta (2005): Differentiation of pork longissimus dorsi muscle regarding the variation in water-holding capacity and correlated traits. It. J. of Anim. Sc., 4 (3), 79-81.Otto, G., R. Roehe, H. Looft, L. Thoelking, E. Kalm (2004): Comparison of different methods for determination of drip loss and their relationships to meat quality and carcass characteristics in pigs. Meat Sc., 68, 401-409. Ryu, Y.C., B.C. Kim (2005): The relationship between muscle fi bre characteristics, post-mortem metabolic rate and meat qual-ity of pig longissimus dorsi muscle. Meat Sci. 71, 351-357.Sellier, P., G. Monin (1994): Genetics of pig meat quality: A review. J. Muscle Foods, 5, 187. Van Laack, R.L.J.M., (2000): Determinants of ultimate pH and quality of pork. Home page address: http://www.nppc.org/Research/00reports/99-129-Laack.htm. Warner, R.D., R.G. Kauffman, M.L. Greaser (1997): Mus-cle protein changes post mortem in relation to pork quality traits. Meat Sci. 45, 339-352.Prispjelo / Received: 26.1.2008.Prihvaćeno / Accepted: 4.2.2008.■Discriminant analysis 1 Discriminant analysis 2pH45 pH24 CIE-L* W.H.C pH45 pH24 CIE-L* W.H.CExudative meat 6.06(0.291)5.59a(0.140)46.76(4.219)8.65a(1.261)6.01a(0.288)5.59(0.154)46.91(4.293)8.85a(1.138)Non-exudative meat6.12(0.261)5.67b(0.198)46.82(5.465)8.01b(1.515)6.13b(0.265)5.65(0.182)46.74(5.143)8.19b(1.485)T Table 5.  Class means and standard deviations (in brackets) of the meat quality traits used in discriminant analysesNumbers in columns with different exponents are statistically different (p<0.05)BACTERIOCINOGENIC STARTER CULTURES    VS. LISTERIA MONOCYTOGENESZdolec1, N., M. Hadžiosmanović1, L. Kozačinski1, Ž. Cvrtila1, I. Filipović1, K. Leskovar2SUMMARY In this paper the use of bacteriocinogenic lactic acid bacteria and bacteriocins in food is presented, in par-ticular regarding their antilisterial activity. Results of most studies are affi rmative to the standardisation of the use of bacteriocinogenic starter cultures, since they enhance 1 Nevijo Zdolec, DSc, DVM, junior researcher - senior assistant; Mirza Hadžiosmanović, DSc, full professor; Lidija Kozačinski, DSc, associate professor; Željka Cvrtila, DSc, assistant professor; Ivana Filipović, DVM, junior research assistant; Institute of Foodstuff Hygiene and Technology, Veterinary Faculty, University of Zagreb, Heinzelova 55, Zagreb; Contact e-mail: nzdolec@vef.hr2 Kristina Leskovar, DVM, Veterinary station Vrbovec, Kolodvorska 68, Vrbovec

Distribuzione dei campioni della carne di maiale secondo il rilascio di succo della carne

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Distribuzione dei campioni della carne di maiale secondo il rilascio di succo della carne

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