Rheological properties of goats and cow\u27s acidophilus milk during storage

Cilj rada bio je usporediti reološke osobine gruševa kozjeg i kravljeg acidofilnog mlijeka uz dodatke, te ispitati neke fizikalne i reološke promjene tijekom njihovog skladištenja. Ispitivani su i utjecaji dodatka koncentrata voćnog soka jabuke na stabilnost gruša tijekom skladištenja, kao i njihov utjecaj na održivost proizvoda. Reološke osobine i pH vrijednost gruševa određivane su odmah nakon fermentacije, te poslije 3,6i9 dana skladištenja. Dodatkom obranog mlijeka u prahu povećavala se vrijednost koeficijenta konzistencije u kozjem i kravljem acidofilnom mlijeku. Skladištenjem uzoraka vrijednost koeficijenta konzistencije se povećavala do šestog dana skladištenja, a zatim se smanjivala osobito u kozjem acidofilnom mlijeku. U uzorcima priređenim s koncentratom soka jabuke vidno su bile izražene inhibicije tijekom fermentacije i koagulacije. Unatoč inhibicijama tijekom fermentacije i koagulacije dobiveni gruševi uzoraka priređenih sli 2% koncentrata soka jabuke su visoke kvalitete. Obzirom na pH vrijednosti izmjerene tijekom skladištenja, primijećeno je da koncentrat voćnog soka jabuke djeluje djelomično konzervirajuće na dobivene proizvode.The aim of this paper was to compare rheological properties of goat\u27s and cow\u27s acidophilus milk curds and also to determine physical and rheological changes during storage. The influence of apple juice concentrate addition on the shelf life and curd stability during storage was determined. Rheological properties and pH values of prepared curds were measured after the fermentation and after 3, 6 and 9 days of storage. With addition of skimmed milk powder the consistency coefficient value in goat\u27s and cow\u27s acidophilus milk increased until the sixth day of storage. After that consistency coefficient value was decreased, especially of goat acidophilus milk. Samples prepared with apple juice concentrate showed inhibitions during the fermentation and coagulation. In spite of inhibitions during the fermentation and coagulation, the obtained curds, prepared with 1 and 2per cent of apple juice concentrate, showed high quality. On the basis of pH values measured during the storage, it was noticed that the apple juice concentrate had a partly conservative effect on products

Rheological changes during fermentation of goats and cow\u27s milk using Lactobacillus acidophilus

U radu su praćene promjene reoloških parametara tijekom fermentacije kozjeg i kravljeg mlijeka bakterijom Lactobacillus acidophilus. Reološka svojstva gruša jedan su od osnovnih parametara kvalitete fermentiranih mliječnih proizvoda. Grušanje mlijeka odvija se uslijed snižavanja pH-vrijednosti tijekom fermentacije i uvjetovano je neutralizacijom i demineralizacijom kazeinskog kompleksa i otpuštanjem vode iz micelijske mreže kazeinata uslijed povećane koncentracije H+-iona. Promjene strukture gruša kozjeg i kravljeg mlijeka praćene su sa svrhom uspoređivanja s brzinama njihove fermentacije. I kozje i kravlje mlijeko nenewtonovske su tekućine, koje tijekom fermentacije postupno poprimaju izrazita svojstva karakteristična za pseudo-plastični (tiksotropni) tip tekućim. Formiranje gruša kod kozjeg i kravljeg acidofila započinje u trećem satu fermentacije. Pokazalo se da znatnije promjene reoloških svojstava kozjeg mlijeka nastupaju pri nižim pH vrijednostima od onih kravljeg, a porast prividnog viskoziteta kozjeg fermentiranog acidofilnog mlijeka je ujednačeniji i proporcionalniji padu pH vrijednosti tijekom fermentacije. Na kraju fermentacije kozje acidofilno mlijeko je prividno nižeg viskoziteta od kravljeg pri 22 °C. Tijekom tri dana čuvanja pri 4 °C značajno se poboljšavaju reološka svojstva kozjeg fermentiranog acidofilnog mlijeka koje postaje konzistentnije, dok je promjena konzistencije kravljeg acidofilnog mlijeka tijekom skladištenja neznatna.The changes of rheological properties during goat\u27s and cow\u27s milk fermentation using Lactobacillus acidophilus were observed in this paper. Rheological properties of curd are one of the basic parameters of fermented milk products quality. Milk curdling occurs as a consequence of the pH-value lowering during milk fermentation and it is the result of caseinat complex demineralisation and water molecules discharge from the lactic caseinate owing to the increase of H+-ions concentration. The differences in the curd structure between goat\u27s and the cow\u27s acidophilus milk were attended in the aim to compare those differences with fermentation velocities. Both of them, goat\u27s and cow\u27s acidophilus milk, are nonnewton fluids progressively obtaining characteristic properties of pseudoplastic (ticsotropic) type of fluids during fermentation. Goat\u27s and cow\u27s milk curdling starts in the third hour of fermentation. It was shown that extensive changes of goat\u27s milk rheological properties were starting with the significantly lower pH-value than cow\u27s milk and the increase of apparent viscosity is more steady in goat\u27s acidophilus milk and it is proportional to pH-value fall during fermentation. At the end of the fermentation goat\u27s acidophilus milk has lower apparent viscosity than cow\u27s acidophilus milk at 22 °C. During three storage days at 4 °C Theological properties of goat\u27s acidophilus milk were considerably improved (goats acidophilus milk became more consistent). During storage the consistency change of cow\u27s acidophilus milk is minor

Importance of Determining Vascular Endothelial Growth Factor Serum Levels in Children with Infantile Hemangioma

Background and Objectives: A potential role of vascular endothelial growth factor (VEGF) in the pathophysiology of infantile hemangiomas (IH) is thought to be plausible. The primary objective of this study was to investigate the importance of determining VEGF serum levels at various stages of IH growth in children. Materials and Methods: A nested case–control study was conducted. For the purposes of the researched target group, samples of fifty (N = 50) children with IH without associated diseases at different stages of hemangioma growth (proliferative and involutional stages) were used. The control group consisted of one hundred (N = 100) healthy children comparable in terms of age and sex, in whom the existence of IH and vascular malformations was ruled out via clinical examination. An immunoassay (ELISA) was used to determine VEGF serum levels in hemangioma growth’s proliferation and involution phases. Results: A comparison of serum levels of VEGF in the phases of proliferation and involution in the group of patients with IH did not show a statistically significant difference (p = 0.171). The control group had significantly higher serum VEGF levels than the patient group in both the proliferation phase (p = 0.009) and the involution phase (p = 0.019). In the proliferation phase, a multivariate regression model explained 15% of the variance in the dependent variable, without significant predictor variables, while in the involution phase, it explained 21% of the variance in the dependent variable, and the history of invasive prenatal procedures stood out as a significant predictor variable positively associated with serum VEGF levels (beta coefficient = 0.33; p = 0.043). Conclusions: Although IH is thought to be the result of the dysregulation of angiogenesis and vasculogenesis under the influence of angiogenic factors, especially VEGF, this study did not demonstrate that VEGF serum levels in the proliferation phase of hemangioma growth were higher than those in the involution phase, or in relation to the control group