A comparison of the heat stability of fresh milk protein concentrates obtained by microfiltration, ultrafiltration and diafiltration

2019 ◽  
Vol 86 (3) ◽  
pp. 347-353 ◽  
Author(s):  
Isis Rodrigues Toledo Renhe ◽  
Zhengtao Zhao ◽  
Milena Corredig

AbstractThe objective of this work was to evaluate the impact of changes during membrane filtration on the heat stability of milk protein concentrates. Dairy protein concentrates have been widely employed in high protein drinks formulations and their stability to heat treatment is critical to ensure quality of the final product. Pasteurized milk was concentrated three-fold by membrane filtration, and the ionic composition was modified by addition of water or permeate from filtration (diafiltration). Diafiltration with water did not affect the apparent diameter of the casein micelles, but had a positive effect on heat coagulation time (HCT), which was significantly longer (50 min), compared to the non diafiltered concentrates (about 30 min). UHT treatments increased the particle size of the casein micelles, as well as the turbidity of retentates. Differences between samples with and without diafiltration were confirmed throughout further analysis of the protein composition of the unsedimentable fraction, highlighting the importance of soluble protein composition on the processing functionality of milk concentrates.

2016 ◽  
Vol 60 ◽  
pp. 59-66 ◽  
Author(s):  
Yuting Xu ◽  
Dasong Liu ◽  
Hongxu Yang ◽  
Jie Zhang ◽  
Xiaoming Liu ◽  
...  

2017 ◽  
Vol 84 (4) ◽  
pp. 471-478 ◽  
Author(s):  
Lata Ramchandran ◽  
XiaoXia Luo ◽  
Todor Vasiljevic

Modulating conditions during ultrafiltration of skim milk appears to be a feasible strategy to obtain milk protein concentrates (MPC) with tailored functionalities. Adjustment of pH and process temperature attenuated properties of casein micelle resulting in enhanced emulsification capacity. Additional pre-treatment options such as addition of calcium chelators can further impact on the functionality of MPC by modifying the calcium distribution and casein micelle integrity. The objective of the project was to establish effects of pre-treating skim milk with calcium chelators (EDTA or citrate) in concentrations between 10 to 30 mmprior to UF on the physical properties of the feed, corresponding retentates and dried MPC, including particle size, zeta potential and calcium distribution in skim milk and the corresponding retentates, as well as the physical functionalities such as solubility, heat stability and emulsifying properties. Addition of calcium chelators (EDTA or citrate), at levels 20–30 mmconcentrations reduced casein micelle size as well as total, soluble and ionic calcium contents that resulted in MPC with enhanced solubility and heat stability. The emulsion capacity was, however, improved only with EDTA at 10 mmconcentration. The enhanced functionality is attributed to the reduced particle size resulting from the removal of calcium from the retentate that could modify micellar casein to an extent sufficient to cause such improvements.


2021 ◽  
Vol 12 (6) ◽  
pp. 2605-2616
Author(s):  
Teresa Francis Wegrzyn ◽  
Alejandra Acevedo-Fani ◽  
Simon M. Loveday ◽  
Harjinder Singh

The gastric digestion behaviours of blended protein beverages containing different ratios of casein, whey protein and soya protein that were heat-treated at 60 °C or 80 °C were investigated using an in vitro dynamic human gastric simulator.


Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1476
Author(s):  
Jian Zhang ◽  
Ai Zhao ◽  
Shiyun Lai ◽  
Qingbin Yuan ◽  
Xiaojiang Jia ◽  
...  

Our knowledge related to human milk proteins is still limited. The present study determined the changes in multiple human milk proteins during the first six months of lactation, investigated the influencing factors of milk proteins, and explored the impact of milk proteins on infant growth. A total of 105 lactating women and their full-term infants from China were prospectively surveyed in this research. Milk samples were collected at 1–5 days, 8–14 days, 1 month, and 6 months postpartum. Concentrations of total protein and α-lactalbumin were measured in all milk samples, and concentrations of lactoferrin, osteopontin, total casein, β-casein, αs−1 casein, and κ-casein were measured in milk from 51 individuals using ultra performance liquid chromatography coupled with mass spectrometry. The concentration of measured proteins in the milk decreased during the first six months of postpartum (p-trend < 0.001). Maternal age, mode of delivery, maternal education, and income impacted the longitudinal changes in milk proteins (p-interaction < 0.05). Concentrations of αs−1 casein in milk were inversely associated with the weight-for-age Z-scores of the infants (1 m: r −0.29, p 0.038; 6 m: r −0.33, p 0.020). In conclusion, the concentration of proteins in milk decreased over the first six months postpartum, potentially influenced by maternal demographic and delivery factors. Milk protein composition may influence infant weights.


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