Casein, the main protein in milk, is a viable protein source for natural emulsifiers, which are frequently utilized in food emulsions. Camel milk casein powders obtained by acid and rennet ...coagulation were investigated and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). These methods gave extensive information regarding crystal structure, surface composition, and secondary and microstructures of the camel caseins, respectively. Therefrom new acknowledgements on morphology and surface composition have emerged, which is necessary to better understand functional characteristics such as emulsifying behaviour (i.e., emulsion’s stability over time and the oil droplet size). The O and C atomic proportions of camel casein surfaces generated by acidification were greater than those obtained through rennet-induced coagulation, whereas the percentage of N atomic was lower, according to XPS measurements. The oxygen to carbon (O/C) ratios on the surface of camel caseins produced by the two coagulation techniques were comparable. But, the enzymatic coagulation method yielded a high (N/C) ratio. The findings suggested that rennet-induced coagulation might influence the C, O, and N components on the surface of camel milk caseins. Furthermore, SEM and XRD data revealed that acid aggregation affected casein micelle’s morphology, resulting in more β-sheet and smooth structures. Rennet camel caseins, on the other hand, have a porous colloidal surface. A correlation between the casein surface composition and the emulsifying stability of the casein powders was observed, whereas the droplet size and stability of emulsions were strongly improved by the rennet-induced coagulation method.
The crude sweet whey is an effluent and a co-product of cooked and pressed cheeses and casein, released into the environment without prior treatment (case of Cheese Dairy Sidi Saada, Yellel, ...Relizane, Algeria) affect the quality of freshwater ecosystems (Oued Mina, Relizane, Algeria).Our study focused on the control of the physical and chemical parameters of crude sweet whey and delactosed whey.The results showed that the applied bioprocess modified the physical and chemical parameters of crude sweet whey such as :density,dry matter,refractive index,viscosity,ash,pH and electrical conductivity, acidity,proteins and lactose; for this purpose these findings depended on the operating conditions, and the composition of the whey put in treatment.
Fenugreek is an herb that has the ability to resist multiple environmental insults, pests, diseases and many pathogens through the synthesis of substances allowing this plant protection, these ...substances are called phytochemical compounds or secondary metabolites. The aim of this study is to characterize these secondary metabolites in the extracts of fenugreek seeds grown in Algeria and compare the phytochemical profile and antioxidant activity of the aqueous extracts obtained by maceration and decoction. We carried out a “phytochemical screening” on both types of extracts in order to highlight the different classes of secondary metabolites and assaying total polyphenols by the method of Follin ciocaltchu, total alkaloids and tannins contained in these aqueous extracts and appreciate their antioxidant activity using the FRAP technique. A characterization of phytochemical molecules of the two types of Fenugreek extracts was done by chromatographic method with HPLC. Several phytochemical groups were identified in the extracts of fenugreek: tannins, saponins, flavonoids, terpenes and reducing nitrogen compounds. Chromatographic analysis of the samples show that 4 phytochemical molecules were identified in the aqueous maceration extract: kaempferol, genistein, vanillin and myrecitine and 3 molecules for the aqueous extract of decoction are: rutin, kaempferol and vanillin. The aqueous extract of decoction was characterized by the total polyphenols content (31.7 ± 0.031 mg GAE / 100 g of extract), total alkaloids (2.12 ± 0.015%) and tannins (9.75 ± 0.06%) that are higher than those obtained in the aqueous extract of maceration: total polyphenols (18.9 ± 0.12 mg GAE / 100g of extract), total alkaloids (1.71 ± 0.02%) and 8.69 ± 0.02% for the tannins. A non-significant difference was marked for antioxidant activity found in both types of extracts (56.90 ± 0.013 mg AAE / 100g decoction extract against 56.37 ± 0.24 mg AAE / 100g maceration extract). In the end we conclude that fenugreek may be a promising plant genetic resource responsible for an important biological activity, except its nutritional and therapeutic properties due to their phytochemical compounds.
Kazein, glavni protein u mlijeku, održiv je izvor prirodnih emulgatora koji se često koriste u prehrambenim emulzijama. U ovom su istraživanju korištene metode rentgenske difrakcije (XRD), rentgenske ...fotoelektronske spektroskopije (XPS) i skenirajuće elektronske mikroskopije (SEM) u svrhu analize i karakterizacije kazeina u prahu dobivenog kiselinskom odnosno enzimskom koagulacijom devinog mlijeka. Spomenute instrumentalne metode rezultirale su opsežnim informacijama o kristalnoj strukturi, površinskom sastavu, odnosno sekundarnoj mikrostrukturi kazeina devinog mlijeka. Iz toga su proizišle su nove spoznaje o morfologiji i sastavu površine, a koje su potrebne za bolje razumijevanje funkcionalnih karakteristika poput sposobnosti emulgiranja i stabilnosti emulzije tijekom vremena i veličini kapljica ulja. Uzimajući u obzir mjerenja pomoću rentgenske difrakcije (XPS), udjeli atoma kisika i ugljika na površini kazeina koaguliranog djelovanjem kiseline bili su veći u usporedbi s kazeinom koji je dobiven enzimskom koagulacijom, dok je udio atoma dušika bio niži. Omjeri kisika i ugljika (O/C) na površini kazeina iz devinog mlijeka dobivenog na dva različita načina koagulacije bili su usporedivi. Međutim, metoda enzimske koagulacije rezultirala je visokim omjerom dušika i ugljika(N/C). Dobiveni rezultati impliciraju da bi enzimska koagulacija mogla utjecati na omjer ugljika, kisika i dušika na površini kazeina devinog mlijeka. Nadalje, rezultati dobiveni SEM i XRD analizom ukazuju da koagulacija kiselinom utječe na morfologiju micele kazeina, što rezultira s više β-nabranih ploča i glatkih struktura. S druge strane, enzimski koagulirani kazein devinog mlijeka pokazuje porozniju koloidnu površinu. Također je utvrđena i korelacija između sastava površine kazeina i sposobnosti emulgiranja kazeinskih prahova, dok su veličina kapljica i stabilnost emulzija značajno poboljšane enzimskom metodom koagulacije.
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