Optimization of enzymatic processes in order to obtain egg white protein hydrolysates as a functional food component applying the high-intensity ultrasound technology

Predmet naučnog istraţivanja doktorske disertacije je razvoj novih netermičkih i enzimskih procesa za proizvodnju proteina belanceta i njihovih hidrolizata sa unapreĎenim tehnološko-funkcionalnim svojstvima kao visokokvalitetnih proteinskih dodataka hrani i napicima...The scope of this academic doctoral research is the development of new non-thermal and enzymatic processes in order to obtain high-qualitiy egg white protein and their hydrolysates with improved technological-functional properties as high-quality protein additives for food and beverages..

Optimization of enzymatic processes in order to obtain egg white protein hydrolysates as a functional food component applying the high-intensity ultrasound technology

Predmet naučnog istraţivanja doktorske disertacije je razvoj novih netermičkih i enzimskih procesa za proizvodnju proteina belanceta i njihovih hidrolizata sa unapreĎenim tehnološko-funkcionalnim svojstvima kao visokokvalitetnih proteinskih dodataka hrani i napicima...The scope of this academic doctoral research is the development of new non-thermal and enzymatic processes in order to obtain high-qualitiy egg white protein and their hydrolysates with improved technological-functional properties as high-quality protein additives for food and beverages..

The synergistic effect of heat treatment on alcalase-assisted hydrolysis of wheat gluten proteins: Functional and antioxidant properties

In order to confirm the gluten potential for inclusion into functional foods, the synergistic effect of the heat treatment and controlled enzymatic hydrolysis on the functional and the antioxidant properties of alcalase-assisted wheat gluten hydrolysates (AWGHs) will be discussed. For this purpose, wheat gluten was heat-treated during 30min at 75 degrees C and intensively hydrolyzed with alcalase at degree of hydrolysis (DH) 16.1%, 22.9%, and 30.2%. All the hydrolysates had excellent solubility over a pH range of 2-12. Emulsifying activity and stability were also improved, while proteolysis was deleterious to foam capacity and stability, water-holding capacity, fat-binding capacity and did not show improvement at higher DH (22.9% and 30.2%). As well, controlled hydrolysis of heat-treated gluten resulted in a remarkable improvement in antioxidant activities. The results show that the heat-treated AWGHs were superior to the untreated hydrolysate in the functional and antioxidant properties tested. Practical applicationsThis report examines existing evidence regarding the wheat gluten proteins (WGP), which is a byproduct from wheat starch processing. It is known that enzymatic hydrolysis is frequently used to improve functional properties of protein hydrolysates and largely dependent on the degree of hydrolysis (DH), which needs to be controlled to elude redundant proteolysis that can deteriorate functionality and cause unfavorable effects. The DH is a substantial factor which affect the hydrolysates' performances and an appropriate selection of protease for WGP hydrolysis will result in maximum biological activity and improved functionalities. Heat treatment is often used to facilitate the proteolysis of proteins. Thus, functional and antioxidant properties of WGP hydrolysates, as a function of heat treatment and the DH were adequately examined in this study and results showed that by combining heat prehydrolysis treatment under controlled conditions, hydrolysates with improved properties can be produced enhancing utilization of WGP in food products

Controlled enzymatic hydrolysis for improved exploitation of the antioxidant potential of wheat gluten

The aim of the study was to find the optimal operational and process parameters for the enzymatic hydrolysis of wheat gluten in a batch stirred bioreactor regarding both degree of hydrolysis and antioxidant capacity of the obtained hydrolysates. It appeared that impeller geometry and agitation speed influenced the mass transfer resulting in enhanced gluten hydrolysis. The highest initial reaction rate (0.83 0.02 min(-1)) and degree of hydrolysis (30.47%) were achieved with the pitched four-bladed impeller and agitation speed of 350-450 rpm, conditions which provided proper balance between requirements for adequate mass/heat transfer and low shear stress. The impact of other process conditions including gluten concentration, temperature, pH and enzyme gluten (E/S) ratio on the enzymatic reaction was investigated by applying a Box-Behnken experimental design from the viewpoint of the degree of hydrolysis (DH) and antioxidant activity. Three models obtained allowed calculation of the hydrolysis degree, and both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulpfonic acid) radical scavenging activity from a given set of reaction conditions with good predictability. The statistical analysis showed that each variable had a significant effect on degree of hydrolysis and the antioxidant capacity of both tested systems. Hydrolysis up to around DH 15% improved DPPH radical scavenging activity, while excessive hydrolysis worsened it. The ABTS activity of the hydrolysates was not associated with the DPPH activity nor with the DH, revealing that it was not possible to fulfill all desirable quality requirements (maximum degree of hydrolysis and protein yield, maximum DPPH and ABTS scavenging activities) by using the Same reaction conditions. Overall, the study might contribute to approve wheat gluten, a by-product of wheat starch industry, as an accessible and cheap source of bioactive compounds for the development of novel nutraceuticals, cosmetics and drugs

Uterine rupture during pregnancy: The URIDA (uterine rupture international data acquisition) study

To describe the characteristics and peripartum outcomes of patients diagnosed with uterine rupture (UR) by an observational cohort retrospective study on 270 patients. Demographic information, surgical history, symptoms, and postoperative outcome of women and neonates after UR were collected in a large database. The statistical analysis searched for correlation between UR, previous uterine interventions, fibroids, and the successive perinatal outcomes in women with previous UR. Uterine rupture was significantly associated with previous uterine surgery, occurring, on average, at 36 weeks of pregnancy in women also without previous uterine surgery. UR did not rise exponentially with an increasing number of uterine operations. Fibroids were related to UR. The earliest UR occurred at 159 days after hysteroscopic myomectomy, followed by laparoscopic myomectomy (251 days) and laparotomic myomectomy (253 days). Fertility preservation was feasible in several women. Gestational age and birth weight seemed not to be affected in the subsequent pregnancy. Data analysis showed that previous laparoscopic and abdominal myomectomies were associated with UR in pregnancy, and hysteroscopic myomectomy was associated at earlier gestational ages. UR did not increase exponentially with an increasing number of previous scars. UR should not be considered a contraindication to future pregnancies

Immobilization of horseradish peroxidase onto kaolin

Kaolin showed as a very perspective carrier for the enzyme immobilization and it was used for the adsorption of horseradish peroxidase (HRP). The effects of the enzyme concentration and pH on the immobilization efficiency were studied in the reaction with pyrogallol and anthraquinone dye C.I. Acid Violet 109 (AV 109). In addition, Fourier transform infrared spectroscopy, scanning electron microscopy and analysis by Brunauer-EmmettTeller were performed for kaolin, thermally activated kaolin and the immobilized enzyme. It has been shown that 0.1 IU of HRP-kaolin decolorized 87 % of dye solution, under the optimal conditions (pH 5.0, temperature 24 degrees C, dye concentration 40 mg/L and 0.2 mM of H2O2) within 40 min. The immobilized HRP decolorization follows the Ping Pong Bi-Bi mechanism with dead-end inhibition by the dye. The biocatalyst retained 35 +/- 0.9 % of the initial activity after seven cycles of reuse in the decolorization reaction of AV 109 under optimal conditions in a batch reactor. The obtained kinetic parameters and reusability study confirmed improvement in performances of k-HRP compared to free, indicating that k-HRP has a great potential for environmental purposes