Bacteriological contamination of egg products after thermal preservation processes

Research was carried out to define the hygienic propriety of thermally treated eggs, i.e. eggs treated at pasteurization temperatures and those stored frozen. The average values of the number of the bacteria in the pasteurized yolk and egg white were log 4.9 and 5.1, respectively, those in the frozen-pasteurized yolk and egg white were log 5.5 and 4.8 and in the frozen yolk and white were log 7.0 and 5.9. The contaminants Salmonella spp., Proteus spp., Staphylococcus aureus, Escherichia coli, Clostridium spp., Clostridium perfringens, Pseudomonas spp., Campylobacter jejuni and Yersinia enterocolitica were tested for 306 samples of pasteurized, frozen and pasteurized and frozen products of eggs, egg-yolks and egg-whites. Presence of Salmonella spp. in the pasteurized yolk was 12%, Clostridium spp. 16%, E. coli 16% and Proteus spp. 14%, but in the pasteurized egg white those bacteria were present in 10.8%, 15.3%, 13.8% and 10.0%. Staphylococcus aureus was isolated in yolk at 4.6 and in white 4.0% and Clostridium perfringens 4.0 and 1.5%, respectively. The bacteriological flora indicated that the degree of contamination of egg-products depends directly on the degree of initial contamination and correlates with the technological egg-treatment processes applied

Utjecaj kombiniranog, trajnog hlađenja na fizikalno-kemijske značajke bijelog i crvenog mišićja u pilića.

Research on the influence of combined, continuous chilling on the quality of meat was carried out on young growing broilers of the Hybro line (Euribid, B.V. Boxmeer, Holland). The broilers were 43 to 48 days old with weights ranging from 1465 to 1762 g. The experiments were carried out on 140 samples, on m. iliotibialis lateralis (red muscle) and mm. pectorales superficialis (white muscle). Observed physical properties included temperature measurements, water holding capacity, pH and weight loss of the samples. Water contents in the skin and in the muscles, protein, fat and ash contents were also measured. This research showed that combined, continuous chilling resulted in a temperature decrease of the m. iliotibialis lateralis to 7.64 0C and of the mm. pectorales superficialis to 10.83 0C. Water activity also decreased for both muscles. White muscle had a higher water holding capacity (7.19 cm2) than red muscle (9.40 cm2), and after chilling both muscles showed a reduction in this parameter. Water content in skin and in muscles increased in chilled samples. The results showed a weight gain of 0.92 ± 0.5 % due to absorbed water during the water chilling phase. This method of chilling showed no significant influence on other physical and chemical properties of poultry meat.Istražen je utjecaj kombiniranog, kontinuiranog hlađenja na kakvoću mesa utovljenih pilića linije Hybro (Euribid, B.V. Boxmeer, Nizozemska). Pilići su bili zaklani u dobi od 43 do 48 dana, tjelesne mase 1465-1762 grama. Istraživanje je bilo provedeno na 140 uzoraka, crvenih (m. iliotibialis lateralis) i bijelih (mm. pectorales superficialis) mišića. Istraženi fizikalni pokazatelji obuhvatili su izmjere temperature, sposobnost vezanja vode, pH vrijednost i masu uzoraka. Također, kemijski je analiziran udjel vode u koži i mišićju te udjel bjelančevina, masti i pepela. Rezultati istraživanja pokazali su sniženje temperature m. iliotibialis lateralis (mišić batka) na 7,64 °C, a temperature mm. pectorales superficialis (prsni mišići) na 10,82 °C. Prsni mišići imaju veću sposobnost vezanja vode (7,19 cm2) u usporedbi s mišićima batka (9,40 cm2). Nakon provedenog kombiniranog, kontinuiranog hlađenja, obje skupine istraženih mišića očitovale su smanjenu sposobnost vezanja vode. Udjel vode u koži i mišićima se povećao pri hlađenju uzoraka. Rezultati su pokazali porast mase ohlađenih trupova za 0,92 ± 0,5%. Aktivnost vode za obje vrste istraženih mišića značajno se smanjila nakon hlađenja. Opisani način hlađenja nije utjecao na ostala fizikalna i kemijska svojstva pretraženih mišića pilića

Histološke i kemijske osobitosti mehanički iskoštenog mesa tovnih pilića.

In evaluation of the suitability of mechanically deboned poultry (MDP) for use in food products, the functional properties of this meat must be taken into consideration. The basic principle of meat separation varies among machines which in turn could affect the functional properties of the MDP produced. The MDP used in this study was produced from broiler carcass, back, wings and necks after commercial cutting. Separation was mechanically performed on a “Beehive” separator, which separates muscular, adipose tissue and skin from cartilage, bone and lymphatic tissues (“offal products”). Histological examination was performed on histological slides, stained with haematoxylin and eosin. Also, analysis of the content of water, lipid, protein, ash and calcium was carried out. Average water content was highest in deboned carcass meat samples (69.14%). Total lipids (20.85%) were highest in deboned back and total proteins (15.57%) in the deboned carcass. In deboned wings the content of total ash was very high (1.65%) as well as the content of calcium (0.29%). In “offal products” the highest average water content was in the whole carcass (59.02%). Total lipids (11.56%) were highest in wings, total proteins (23.88%), total ash (20.19%) and calcium content (7.41%) were highest in the back. Results of chemical analyses confirmed the results of histological examination. This parallel histological and chemical analytic approach could give relevant insights into raw material content, which directly influences the quality of final products.U procjeni mehanički iskoštene peradi (MDP), a u vezi s namjenom kao sirovine za prehrambene proizvode, moraju se promatrati njihove funkcionalne vrijednosti. Osnovno načelo separacije mesa ovisi o svrhovitosti strojeva za separaciju koji mehanički iskošteno meso pripremaju za proizvode u smislu djelotvornih vrijednosti. Mehanički iskošteno meso peradi u ovom radu bilo je proizvedeno od pilećih trupova, krila i vratova nakon komercijalnoga rasjeka. Separacija je provedena na stroju „Beehive“ koji je iskoštio mišićno i masno tkivo te kožu, odvojeno od hrskavice, kosti i limfatičkoga tkiva (nusproizvodi). Histološka su pretraživanja obavljana na mikroskopskim preparatima obojenim hemalaun-eozinom. Kemijskom analizom određen je sadržaj vode, masti, bjelančevina, pepela i kalcija. Srednja vrijednost sadržaja vode bila je najviša u uzorcima iskoštenoga trupa (69,14%). Ukupne masti (20,85%) bile su najviše u iskoštenom mesu leđa, ukupne bjelančevine (15,57%) u iskoštenom mesu trupa. Sadržaj pepela bio je najviši u iskoštenom mesu krila (1,65%), kao i sadržaj kalcija (0,29%). U “nusproizvodu” najviša vrijednost udjela vode bila je u trupu (59,02%). Ukupne masti (11,56%) bile su najviše u “nusproizvodu” krila, a ukupne bjelančevine (23,88%), pepeo (20,19%) i kalcij (7,41%) bili su najviši u leđima. Rezultati kemijskih pretraga u korelaciji su s rezultatima histoloških ispitivanja. Takve uzajamne histološke i kemijske pretrage daju relevantne rezultate u smislu funkcionalnih komponenata sirovine koje izravno utječu na kakvoću završnoga proizvoda

Microbiological effect of preparations for preventing of mastitis, based on active iodine

Istraživanjem smo ustanovili da zbog sigurnosti djelovanja dezinficijensa u laboratorijskim uvjetima radna koncentracija za ZLATOL, JADIP-F i BLINAL, koja bi zaustavila rast bakterijskih kultura u vremenu ekspozicije od 180 sekundi, ne bi smjela biti manja od 2,00%. Uzimajući u obzir bjelančevinastu grešku (utjecaj bjelančevina), radna koncentracija za oba dezinficijensa ne bi smjela biti manja od 5,00%. Tom, koncentracijom mogu se uništiti mikroorganizmi prilikom, dezinfekcije vimena i sisa krava muzara, samo ako se radi precizno ili pod kontrolom, što potvrđuju praktična istraživanja na gospodarstvu muzara u Sadilovcu. Zbog često nepreciznog rada ili mogućih grešaka u somom, postupku "teat dip", moramo uzeti "faktor sigurnosti" 2,5. Tada se dobiva koncentracija od 12,5% koju preporučujemo za primljenu u praksi.With our research we can state that for security of the influence of desinfection in laboratory conditions, the concentration for ZLATOL JODIP-F and BLINAL which would stop the growth of bacterial culture in the exposition time of 180 sec should not be less than 2.00%. Considering the protein mistake, the working concentration for both disinfectants should not be less than 5.00%. By that concentration microorganisms can be destroyed during desinfection of cow udder only if the work is precise or under control which is proved in the practical research on the milk farm in Sadilovac. Owing to the inadequate work or possible mistakes in the "teat dip" procedure we have to take into consideration the "security factor" 2.5%; then we come to a concentration of 12.5% which we advise for practical usage

Ontogenetske promjene morfometrijskih vrijednosti prsne peraje u dobrih dupina (Tursiops truncatus).

The aim of the present study was to investigate and compare the morphometric characteristics of the flippers in male and female bottlenose dolphins (Tursiops truncatus) of various ages. We investigated the right flippers of 64 bottlenose dolphinc specimens - 36 males and 28 females, in an age span of from 6 months to 28 years. Two numeric indices were suggested in order to establish the numerical relationship between the external measures of the flipper and the total body length of each animal. The index of the flipper measurements (IxF) directly showed the differences in flipper sizes in the investigated dolphins, whereas the index of the flipper measurements and the total body length (IxBL) displayed the differences in the flipper size in relation to the body length of the studied dolphins. By comparing these indices in dolphins of different ages, noticeable variations in flipper dimensions during total body growth were observed. In bottlenose dolphins, both flipper indices were highly correlated with the animal’s body length. The mean value of the index of the flipper measurements and the total body length (IxBL) was somewhat higher in female bottlenose dolphins. Both the flipper indices were highly correlated with the animal’s age, and our results suggest that the flipper grows until the tenth year of age, after which it does not change substantially until the 25th year of age. After that age the flipper size starts to decrease.Cilj ovog istraživanja bio je usporedba morfometrijskih obilježja prsne peraje u mužjaka i ženki dobrih dupina različite dobi. Istražene su desne prsne peraje od 64 dobra dupina (Tursiops truncatus) - 36 mužjaka i 28 ženki u dobnom rasponu od 6 mjeseci do 28 godina. Predložena su dva numerička indeksa kojima bi se utvrdila numerička povezanost između vanjskih mjera prsne peraje i ukupne dužine tijela svake životinje. Indeks mjera prsne peraje (IxF) izravno pokazuje razlike u veličini prsne peraje istraženih dupina, dok indeks mjera prsne peraje i ukupne dužine tijela (IxBL) pokazuje razlike u veličini prsne peraje u odnosu na ukupnu dužinu tijela istraženih dupina. Usporedbom tih indeksa u dupina različite dobi utvrđene su varijacije u dimenzijama prsne peraje tijekom ukupnog rasta tijela životinje. U dobrih dupina, oba indeksa bila su u visokoj korelaciji s ukupnom dužinom tijela. Srednja vrijednost indeksa mjera prsne peraje i ukupne dužine tijela bila je nešto veća u skupini ženki istraženih dupina. Oba indeksa bila su u visokoj korelaciji s dobi životinje te naše istraživanje pokazuje da prsna peraja u dupina raste do dobi od 10 godina, nakon čega se značajno ne mijenja do dobi od 25 godina. Nakon te dobi, veličina prsne peraje počinje se smanjivati

Utjecaj različitih postupaka obrade goveđih crijeva na njihovu morfološku strukturu.

After manual and machine cleaning of beef intestines, the structure of the intestinal layer was examined. Examination was performed using a histological technique and included 60 intestinal sets of fattened beef (Simmental breed), 10 months of age and with an average slaughter weight of 248.05 kg. Intestines are considered to be edible by-products and therefore are used as natural casings for high quality sausages. The aim of this study was to determine differences between duodenum and colon layers that remain after manual and machine cleaning. Our results showed that machine cleaning is a better method of intestinal treatment than manual cleaning. Machine cleaning yields better results in uniformity of cleaned intestines and in an absence of lesions in the muscular layer. These criteria of technological treatment were absent when cleaning was conducted manually.Na crijevima 60 tovnih goveda simentalske pasmine, u dobi od 10 mjeseci i prosječne klaoničke mase 248,05 kg, istražena je uz pomoć histološke tehnike građa dijelova crijevne stijenke nakon ručnog i strojnog čišćenja. Budući da se crijeva kao jestivi nusproizvodi sve više rabe kao prirodni ovitci za izradu visokokvalitetnih kobasičarskih proizvoda, naša su istraživanja bila usmjerena na utvrđivanje razlika u slojevima stijenke tankoga (duodenum) i debeloga (colon) crijeva preostalihnakon strojne i ručne obrade. Rezultati naših histoloških analiza upućuju na činjenicu da je strojna obrada crijevnih kompleta pokazala bolje rezultate u smislu uniformnosti očišćenih crijeva bez pojave mikrooštećenja u mišićnom sloju što je od bitnog značenja za njihovu kakvoću u odnosu na histološku sliku crijevne stijenke nakon ručne obrade koja nije ispunila navedene kriterije tehnološke obrade

A study of chemical profiles and appearance of white crystals in Istrian dry-cured ham: effect of desalting

In order to find out the effect on physical-chemical profile of Istrian dry-cured ham with particular regard to the appearance of white crystals in the muscles, raw salted legs were desalted by soaking the legs in cold water for 24 hours. The 20 raw hams taken from 10 slaughtered hogs (Swedish Landrace breed) and processed in the traditional Istrian manner were used. After salting and pressing, the raw hams were divided into two groups: 1) the 10 left legs of each hog were desalted (D); 2) the 10 right legs were not desalted (N). Following this, both groups of legs were subjected to continuous processing. Samples for chemical analysis and counting of white spots were taken from the 20 legs (10 N and 10 D) from 10 hogs, each weighing 12 to 15 kg. Chemical analysis of muscle tissue showed a highly significant difference (P<0.0001) in the salt quantity in the N (6.85%) and D (5.31%) dry-cured hams, as expected. Desalting affected the level of calcium which was higher (P=0.0124) in the D hams (0.27 g) than in the N hams (0.22 g). Desalting did not affect the free amino acid content, with the exception of methionine which was lower (P=0.0041) in D (0.14 g) than in N hams (0.17 g). Desalting affected the level of two free fatty acids as follows: heptadecanoic acid was higher (P=0.0203) in N (0.18%) than in D hams (0.24%) and DPA was higher (P=0.0373) in N (0.49%) than in D hams (0.39%). By counting the white precipitates, it was established that the regularity of appearance of the precipitate was noted on both the D and N hams, such that where there was no precipitate on the right N ham, nor was their any on the left D ham of the same hog. However, desalting only lead to a slight decrease in the appearance of precipitates (average of 0.7 points), but it is certain that desalting reduces the salt content in the legs, which affects some physical- chemical changes in the ham tissues during processing