Use of FTIR and mass spectrometry for characterization of glycated caseins

Abstract

This study investigates the potential of Fourier transform infrared spectroscopy (FTIR) to monitor glycation-induced changes in protein structure. Aqueous solutions of sodium caseinate and glucose (1:2 w/w, pH 6.7) were heated at 90 degrees C for 0, 10, 20, 40 and 60 min. Evidence for caseinate glycation was obtained by mass spectrometry techniques (electrospray (ESI) and matrix-assisted laser desorption ionisation (MALDI)). FTIR was able to discriminate between glycated and non-glycated sodium caseinate, when the data were analysed by multivariate statistical methods; principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA). The techniques used were complementary and provided different levels of information about the glycated samples.

BITTERNESS AND PHYSICHOCHEMICAL PROPERTIES OF ANGELWING CLAM (Pholas orientalis) HYDROLYSATE

“…According to Amiza et al [25] water holding capacity increased with an increased in degree of hydrolysis. Besides, at higher hydrolysis, polar groups such as COOH and NH 2 increased thus gave significant effects on water absorption and tend to exert better water-holding capacity [22]. In this study the functional group analysis showed that NH group peak was higher in angelwing hydrolysate compared to the flesh thus support the finding by Kristinsson and Rasco [28].…”

“…Therefore, this result is in accordance with the sensory analysis which showed that angelwing hydrolysate was bitter due to the presence of the high peak of N-H groups. Besides, Figure 2 showed angelwing hydrolysate has peak bands at 1640 cm -1 while the flesh has a peak bands at 1654 cm -1 which attributed to the carbonyl (C=0) stretch vibration centered approximately between 1650 cm -1 -1540 cm -1 [22]. These bands indicated the presence of functional compounds strong amide I and II in protein amide group (-CONH 2 ) which this amides of carboxylic acid (RCONH 2 ) were bitter [23].…”

Physicochemical properties and emulsion stabilization of rice dreg glutelin conjugated with κ‐carrageenan through Maillard reaction

“…The most distinctive spectral features for hydroxyl groups were the bands in the regions of 3700–3200 cm −1 and 1100–1000 cm −1 denoting hydroxyl and CO stretching vibration, respectively. Figure shows the FT‐IR spectrum of RDG and conjugate incubation at 60 °C for 24 h. RDG showed all the normal features of a protein spectrum, with strong amide I and amide II features between 1700 and 1500 cm −1 and was identical to findings with amide I and II of sodium caseinate form centered at 1660 and 1530 cm −1 . The absorption band at 3296 cm −1 arises from hydrogen bonding between protein chains and moisture in the protein.…”

Preparation and potential applications of casein–polysaccharide conjugates: a review

“…Fourier‐transform infrared (FTIR) spectroscopy was used to differentiate between glycated and non‐glycated SCN and to provide complementary information about changes in the protein structure of glycated samples.…”

“…Mass spectrometry (MS) techniques are now used for routine analysis and quantification of the degree of glycation in complex protein mixtures . Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) gave evidence for the glycation of SCN with up to four glucose units depending on the heating time …”