Bovine colostrum whey: Postpartum changes of particle size distribution and immunoglobulin G concentration at different filtration pore sizes

Bovine colostrum, as vital as it is for calves, is also a valuable source of functional components with rich health benefits for humans. Bovine colostrum whey consists of a large number of bioactive proteins and peptides. The most abundant of these is IgG. Particle size distribution (PSD) is an important feature of many of the processes in the dairy food industries. Despite this, scientific literature on PSD of colostrum whey is scarce. The goal of this research was to describe bovine colostrum whey PSD with an emphasis on postpartum milking time, filtration (pore size 450, 100, and 20 nm), IgG concentration, and lactation number. For this purpose, 4 postpartum milking colostrum samples were sequentially milked from 46 Holstein cows at 12 ± 1 h intervals. Colostrum whey was prepared by renneting and diluted (1:200) for PSD analyses by a Malvern Zetasizer Nano ZS (Malvern Instruments Ltd., Malvern, UK). Immunoglobulin G concentration of these diluted colostrum whey samples were analyzed by an Octet K2 (Molecular Devices LLC, San Jose, CA) system. Linear mixed model analysis revealed significant effects of filter pore size, postpartum milking, and lactation on colostrum whey IgG concentrations. The percentage of particles in the size interval 5 to 15 nm (the hydrodynamic diameter of IgG is around 10 nm) had an intermediate positive correlation (r = 0.50) with IgG concentration. Furthermore, we showed that PSD was associated with IgG concentration, postpartum milking time, and lactation number. The PSD measurement results showed the mean hydrodynamic diameter of 100 nm pore size filtered colostrum whey to be around 10 nm. This, with the IgG concentration results, suggests that even though the size of IgG is around 10 nm, a 100 nm pore size is adequate for membrane-involved IgG separations. In terms of energy efficiency of the filtration process, the use of a larger filter pore size can make a remarkable difference, for example, in pressurizing and cooling costs. Our work contributes to the development of sustainable and widely available colostrum-derived food and feed supplements.This work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 810630 “ERA Chair for Food (By-) Products Valorisation Technologies of the Estonian University of Life Sciences (VALORTECH)” and the Estonian University of Life Sciences research and development base financing (P170195VLTQ). The authors declare no conflict of interest

EFFECT OF PURE Α-AMYLASE UTILIZATION ON THE Β-GLUCAN CONTENT AND THE RHEOLOGICAL PROPERTIES OF OAT-DRINK

The aim of the current study is to investigate the effect of pure α-amylase on the Beta-glucan content, the production yield, and the rheological properties of oat-drink. The results showed the significant increase in the Beta-glucan (0.40 g/ml) in oat-drink treated with pure α-amylase.This publication is supported by basic foundation of Chair of Food Science and Technology (P170195VLTQ) and by project ‘VALORTECH’ received funding from the European Union’s Horozon 2020 research and innovation programme under grant agreement No 810603

Milk protein genotypes and milk coagulation properties of Estonian Native cattle

The genetic variation of ás1-, â- and ê-caseins and b-lactoglobulin was determined and their effects on the rennet coagulation properties were examined using 335 milk samples from 118 Estonian Native (EN) cows. We found 16 aggregate casein genotypes (ás1-, â-, ê-caseins), of which four . namely, BB A2A2 AA (21.2%), BB A1A2 AB (16.9%), BB A1A2 AA (14.4%), and BB A2A2 AB (10.2%) occurred among nearly two-thirds of the analysed cows. Aggregate casein genotype had a significant overall effect on rennet coagulation parameters. Better rennet coagulation properties were found for aggregate casein genotypes CC A2A2 AB and BC A1A2 BB, among frequent genotypes for BB A1A2 AB. Of the cattle breeds raised in Estonia, milk from EN had the best coagulation properties and highest frequency of favourable ê-Cn B allele.

Adipose tissue insulin receptor and glucose transporter 4 expression, and blood glucose and insulin responses during glucose tolerance tests in transition Holstein cows with different body condition.

Glucose uptake in tissues is mediated by insulin receptor (INSR) and glucose transporter 4 (GLUT4). The aim of this study was to examine the effect of body condition during the dry period on adipose tissue mRNA and protein expression of INSR and GLUT4, and on the dynamics of glucose and insulin following the i.v. glucose tolerance test in Holstein cows 21 d before (d -21) and after (d 21) calving. Cows were grouped as body condition score (BCS) ≤3.0 (thin, T; n = 14), BCS = 3.25 to 3.5 (optimal, O; n = 14), and BCS ≥3.75 (overconditioned, OC; n = 14). Blood was analyzed for glucose, insulin, fatty acids, and β-hydroxybutyrate concentrations. Adipose tissue was analyzed for INSR and GLUT4 mRNA and protein concentrations. During the glucose tolerance test 0.15 g/kg of body weight glucose was infused; blood was collected at -5, 5, 10, 20, 30, 40, 50, and 60 min, and analyzed for glucose and insulin. On d -21 the area under the curve (AUC) of glucose was smallest in group T (1,512 ± 33.9 mg/dL × min) and largest in group OC (1,783 ± 33.9 mg/dL × min), and different between all groups. Basal insulin on d -21 was lowest in group T (13.9 ± 2.32 µU/mL), which was different from group OC (24.9 ± 2.32 µU/mL. On d -21 the smallest AUC 5-60 of insulin in group T (5,308 ± 1,214 µU/mL × min) differed from the largest AUC in group OC (10,867 ± 1,215 µU/mL × min). Time to reach basal concentration of insulin in group OC (113 ± 14.1 min) was longer compared with group T (45 ± 14.1). The INSR mRNA abundance on d 21 was higher compared with d -21 in groups T (d -21: 3.3 ± 0.44; d 21: 5.9 ± 0.44) and O (d -21: 3.7 ± 0.45; d 21: 4.7 ± 0.45). The extent of INSR protein expression on d -21 was highest in group T (7.3 ± 0.74 ng/mL), differing from group O (4.6 ± 0.73 ng/mL), which had the lowest expression. The amount of GLUT4 protein on d -21 was lowest in group OC (1.2 ± 0.14 ng/mL), different from group O (1.8 ± 0.14 ng/mL), which had the highest amount, and from group T (1.5 ± 0.14 ng/mL). From d -21 to 21, a decrease occurred in the GLUT4 protein levels in both groups T (d -21: 1.5 ± 0.14 ng/mL; d 21: 0.8 ± 0.14 ng/mL) and O (d -21: 1.8 ± 0.14 ng/mL; d 21: 0.8 ± 0.14 ng/mL). These results demonstrate that in obese cows adipose tissue insulin resistance develops prepartum and is related to reduced GLUT4 protein synthesis. Regarding glucose metabolism, body condition did not affect adipose tissue insulin resistance postpartum

A Tool For Explaining The Differences on Renneting Characteristics of Milks From Different Origins: The Surface Hydrophobicity Approach

The differences between renneting characteristics of raw milk samples from different origins (bovine, ovine, caprine, buffalo) were investigated by protein surface hydrophobicity approach. 8-Anilinonaphthalene-1-sulfonic acid (ANS) binding method was used to evaluate surface hydrophobicity of raw milk samples and rennet precipitates. The following surface hydrophobicity parameters were calculated: number of surface hydrophobic sites (F (max)), dissociation constant of the fluorescent ANS-protein complex (K (d)), binding affinity of ANS to protein surface (1/K (d)), the average tightness of binding of ANS to the protein (F (max)/K (d)), turnover number (k (cat)), and protein surface hydrophobicity index (PSHI). The number of hydrophobic sites on the protein surface was found to be highest in cow milk, whereas ovine milk samples had the lowest number of hydrophobic sites and binding affinity to ANS. Protein content was not found directly related to the number of surface hydrophobic sites. The binding affinity of the proteins to ANS was greater in buffalo milk. PSHI was found to be the highest for bovine milk and the lowest for ovine milk. Renneting period was interpreted in two phases (enzymatic phase and flocculation phase) for each origin via ANS partition curves of rennet precipitates. Same trends between bovine-ovine and caprine-buffalo milks were observed during renneting. Buffalo milk completed both of two phases and total renneting period significantly earlier than the milks from the other origins. The hydrophobic parameters of proteins were found to play a key role on coagulation properties.Wo