Factors Affecting the Stability of the Vitamin A from Cod Liver Oil in Cereal Feeds

1950 ◽  
Vol 40 (3) ◽  
pp. 415-427 ◽  
Author(s):  
A. W. Halverson ◽  
E. B. Hart
The Analyst ◽  
1933 ◽  
Vol 58 (683) ◽  
pp. 65 ◽  
Author(s):  
H. N. Griffiths ◽  
T. P. Hilditch ◽  
J. Rae

1939 ◽  
Vol 18 (5) ◽  
pp. 345-349 ◽  
Author(s):  
R.C. Holder ◽  
S.K. Ford

2007 ◽  
Vol 98 (2) ◽  
pp. 422-430 ◽  
Author(s):  
R. A. Ayah ◽  
D. L. Mwaniki ◽  
P. Magnussen ◽  
A. E. Tedstone ◽  
T. Marshall ◽  
...  

Postpartum vitamin A supplementation of mothers and infants is recommended, but the efficacy has been questioned. In this double-blind, placebo-controlled trial, Kenyan mother–infant pairs were randomised to maternal vitamin A (400 000 IU) or placebo < 24 h postpartum, and infant vitamin A (100 000 IU) or placebo at 14 weeks. Milk retinol was determined at weeks 4, 14 and 26, and maternal and infant serum retinol at weeks 14 and 26. Infant retinol stores were assessed at week 26, using a modified relative dose response (MRDR) test. Among 564 women, serum retinol at 36 weeks gestation was 0·81 (sd 0·21) μmol/l, and 33·3 % were < 0·7 μmol/l. Maternal serum retinol was not different between groups, but milk retinol was higher in the vitamin A group: (0·67 v. 0·60 μmol/l; 0·52 v. 0·44 μmol/l; 0·50 v. 0·44 μmol/l at 4, 14 and 26 weeks, respectively). When expressed per gram fat, milk retinol was higher in the vitamin A group only at 4 weeks. Infant serum retinol was not different between groups. However, although most infants had deficient vitamin A stores (MRDR>0·06 %) at 26 weeks, vitamin A to infants, but not mothers, resulted in a lower proportion of infants with deficient vitamin A stores (69 v. 78 %). High-dose postpartum vitamin A supplementation failed to increase serum retinol and infant stores, despite modest effects on milk retinol. Infant supplementation, however, increased stores. There is a need for a better understanding of factors affecting absorption and metabolism of vitamin A.


2021 ◽  
pp. 1-36
Author(s):  
Vahideh Angardi ◽  
Ali Ettehadi ◽  
Özgün Yücel

Abstract Effective separation of water and oil dispersions is considered a critical step in the determination of technical and economic success in the petroleum industry over the years. Moreover, a deeper understanding of the emulsification process and different affected parameters is essential for cost-effective oil production, transportation, and downstream processing. Numerous studies conducted on the concept of dispersion characterization indicate the importance of this concept, which deserves attention by the scientific community. Therefore, a comprehensive review study with critical analysis on significant concepts will help readers follow them easily. This study is a comprehensive review of the concept of dispersion characterization and conducted studies recently published. The main purposes of this review are to 1) Highlight flaws, 2) Outline gaps and weaknesses, 3) Address conflicts, 4) Prevent duplication of effort, 5) List factors affecting dispersion. It was found that the separation efficiency and stability of dispersions are affected by different chemical and physical factors. Factors affecting the stability of the emulsions have been studied in detail and will help to look for the right action to ensure stable emulsions. In addition, methods of ensuring stability, especially coalescence are highlighted, and coalescence mathematical explanations of phenomena are presented.


2017 ◽  
Vol 73 (7) ◽  
pp. 618-625 ◽  
Author(s):  
Nicole Balasco ◽  
Luciana Esposito ◽  
Luigi Vitagliano

The protein folded state is the result of the fine balance of a variety of different forces. Even minor structural perturbations may have a significant impact on the stability of these macromolecules. Studies carried out in recent decades have led to the convergent view that proteins are endowed with a flexible spine. One of the open issues related to protein local backbone geometry is the identification of the factors that influence the amplitude of the τ (N—Cα—C) angle. Here, statistical analyses performed on an updated ensemble of X-ray protein structures by dissecting the contribution of the major factors that can potentially influence the local backbone geometry of proteins are reported. The data clearly indicate that the local backbone conformation has a prominent impact on the modulation of the τ angle. Therefore, a proper assessment of the impact of the other potential factors can only be appropriately evaluated when small (φ, ψ) regions are considered. Here, it is shown that when the contribution of the backbone conformation is removed by considering small (φ, ψ) areas, an impact of secondary structure, as defined byDSSP, and/or the residue type on τ is still detectable, although to a limited extent. Indeed, distinct τ-value distributions are detected for Pro/Gly and β-branched (Ile/Val) residues. The key role of the local backbone conformation highlighted here supports the use of variable local backbone geometry in protein refinement protocols.


2013 ◽  
Author(s):  
J. Rick Griffin ◽  
James R Johnstone ◽  
Terry E Cotter ◽  
Ashleigh E O'Brien

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