Effect of the protein, citrate and phosphate content of milk on formation of lactulose during heat treatment

1987 ◽  
Vol 54 (2) ◽  
pp. 207-218 ◽  
Author(s):  
Geoffrey R. Andrews ◽  
S. Krishna Prasad
Keyword(s):  
Heat Treatment ◽  
Milk Protein ◽  
Buffering Capacity ◽  
Phosphate Content ◽  
Mechanism Of Formation ◽  
Amino Groups ◽  
Base Catalysts ◽  
Naturally Occurring ◽  
Heated Milk ◽  
Skimmed Milk

SummaryMilk ultrafiltrate and milks of varying protein, citrate and phosphate concentrations were heated in sealed containers. Protein was found not to be involved in the mechanism of formation of lactulose, but increasing the protein content of milk reduced the concentration of lactulose after heating. This was considered to be due to increased condensation of lactose and lactulose with amino groups of the protein, Less lactulose was formed in milk ultrafiltrate than in skimmed milk accorded the same heat treatment, which was attributed to the buffering capacity of the milk protein in skimmed milk. Activation energies for lactulose formation in skimmed milk and in ultrafiltrate were 128 and 131 kJ/mol respectively. Citrate and phosphate catalysed the formation of lactulose. It is proposed that the formation of free lactulose in heated milk and ultrafiltrate proceeds exclusively by the Lobry de Bruyn-Alberda van Ekenstein transformation with the naturally occurring phosphate and citrate acting as base catalysts.

scholarly journals No Glycation Required: Interference of Casein in AGE Receptor Binding Tests

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1836
Author(s):  
Hannah E. Zenker ◽  
Malgorzata Teodorowicz ◽  
Harry J. Wichers ◽  
Kasper A. Hettinga
Keyword(s):  
Heat Treatment ◽  
Milk Protein ◽  
Soluble Form ◽  
Cow’S Milk ◽  
Dot Blot ◽  
Differential Heat ◽  
Cow's Milk ◽  
Inhibition Elisa ◽  
Heated Milk

For the determination of the binding of heated cow’s milk whey proteins such as β-lactoglobulin to the receptors expressed on immune cells, inhibition ELISA with the soluble form of the receptor for advanced glycation end products (sRAGE) and scavenger receptor class B (CD36) has been successfully used in the past. However, binding to heated and glycated caseins in this read-out system has not been tested. In this study, inhibition ELISA was applied to measure the binding of cow’s milk casein alone, as well as all milk proteins together, which underwent differential heat treatment, to sRAGE and CD36, and we compared those results to a dot blot read out. Moreover, binding to sRAGE and CD36 of differentially heated milk protein was measured before and after in vitro digestion. Casein showed binding to sRAGE and CD36, independent from the heat treatment, in ELISA, while the dot blot showed only binding to high-temperature-heated milk protein, indicating that the binding is not related to processing but to the physicochemical characteristics of the casein. This binding decreased after passage of casein through the intestinal phase.

A multi-scale approach to identify the role of heat treatment, milk protein composition and starter culture on the gel formation and the texture defects of acid milk gel

2018 ◽  
Vol 85 ◽  
pp. 299-310 ◽  
Author(s):  
An Thi-Binh Nguyen ◽  
Michaël Nigen ◽  
Luciana Jimenez ◽  
Hassina Ait-Abderahim ◽  
Charles Cunault ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Milk Protein ◽  
Starter Culture ◽  
Protein Composition ◽  
Gel Formation ◽  
Multi Scale ◽  
Acid Milk Gel

scholarly journals The interaction of spermine and pentamines with DNA

1987 ◽  
Vol 244 (1) ◽  
pp. 243-246 ◽  
Author(s):  
H S Basu ◽  
L J Marton
Keyword(s):  
High Temperature ◽  
Melting Temperature ◽  
Conformational Changes ◽  
Thermus Thermophilus ◽  
Total Charge ◽  
Amino Groups ◽  
Carbon Chains ◽  
Naturally Occurring ◽  
Calf Thymus

We studied the effects of spermine, two naturally-occurring pentamines isolated from the thermophile Thermus thermophilus and one synthetic pentamine on the aggregation and ‘melting’ temperature of calf-thymus DNA and on the B-to-Z transition of poly(dG-me5dC). All pentamines caused aggregation of DNA at much lower concentrations than that of spermine. Concentrations that increased the melting temperature of DNA and induced the B-to-Z transition in poly(dG-me5dC) were different for each pentamine, but were comparable with the concentration of spermine needed to cause these effects. Our results suggest that both the total charge and the distance separating the charge, which is a function of the length of the carbon chains between amino groups, are important for the induction of conformational changes in DNA. The biological role of pentamines in T. thermophilus appears to be related to their ability to promote DNA condensation at high temperature.

Inhibition of the Antibacterial Lactoperoxidase-Thiocyanate-Hydrogen Peroxide System by Heat-Treated Milk

1985 ◽  
Vol 48 (6) ◽  
pp. 494-498 ◽  
Author(s):  
B. EKSTRAND ◽  
W. M. A. MULLAN ◽  
A. WATERHOUSE
Keyword(s):  
Heat Treatment ◽  
Hydrogen Peroxide ◽  
Skim Milk ◽  
Inhibitory Effect ◽  
Sulfhydryl Groups ◽  
Inhibitory Factor ◽  
Casein Micelle ◽  
Heated Milk ◽  
Heat Treated

The antibacterial system, lactoperoxidase-H2O2-SCN− was affected by the presence of heated milk or skim milk reconstituted from powders having received severe heat treatment. This inhibitory effect was related to the increase in exposed sulfhydryl groups and to the redistribution of protein between micellar and whey phases. Chromatographic analyses of heat-treated milk showed that the inhibitory factor was associated with the casein micelle fraction. The inhibition, however, was overcome by addition of unheated skim milk.

Effects of β-lactoglobulin and κ-casein genetic variants and concentrations on syneresis of gels from renneted heated milk

1989 ◽  
Vol 56 (2) ◽  
pp. 297-301 ◽  
Author(s):  
Douglas M. McLean ◽  
Johan Schaar
Keyword(s):  
Genetic Polymorphism ◽  
Complex Formation ◽  
Genetic Variants ◽  
Milk Protein ◽  
Major Influence ◽  
Essential Requirement ◽  
Heated Milk ◽  
Cheese Curd ◽  
Processing Properties ◽  
Β Lactoglobulin

Milk protein genetic polymorphism has a major influence on the composition of milk, and on its processing properties, including yield of cheese (see Schaaret al.1985; McLeanet al.1984, 1987; McLean, 1987). However, there appears to be little information on the effects of milk protein genetic variants on syneresis of cheese curd. The effect of casein composition on syneresis was studied by Pearseet al.(1986), who found that syneresis was affected only by the level of β-casein. Syneresis is an essential requirement in cheese making from renneted or acidified milk, but is undesirable during the storage of products such as yogurt. Milk for yogurt manufacture is preheated to minimize syneresis and to give maximal firmness of the yogurt coagulum (Tamime & Deeth, 1980). Pearseet al.(1985) showed that the reduction of one-third in the extent of syneresis caused by heating artificial micelle milk (AMM) containing βlactoglobulin (β-lg) in natural concentrations was due to sulphydryl-mediated complex formation between β-lg and micellar κ-casein which appeared to interfere with the micelle–micelle interactions responsible for syneresis. The results presented here were part of a study which investigated the effects of κcasein and κ-lg genetic variants and concentrations on syneresis of curd formed from renneted heated AMM.

Use of heated milk protein–sugar blends as antioxidant in dairy beverages enriched with linseed oil

LWT ◽  
2010 ◽  
Vol 43 (9) ◽  
pp. 1373-1378 ◽  
Author(s):  
Hélène J. Giroux ◽  
Jessica Houde ◽  
Michel Britten
Keyword(s):  
Milk Protein ◽  
Linseed Oil ◽  
Heated Milk ◽  
Dairy Beverages
Sign in / Sign up

Export Citation Format

Share Document