Hydrodynamic, thermo-analytical and molecular structural investigations of enzyme interesterified oil and its thermo-oxidative stability by thermogravimetric analysis

This paper deals with the effect of lipase-catalyzed interesterification of oil on hydrodynamic, thermo-analytical, structural properties and its stability. Interesterification of rice bran oil (RBO) and refined, bleached, deodorized palm olein (RBDPO) blend in 1:1 ratio was carried out at 60 ± 1 °C under stirring for 6 h. Results showed that hydrodynamic property of oils decreased from 3.61 × 10−6 in RBDPO to 2.91 × 10−6 m2 s−1 in enzyme interesterified oil (EI) and heat transfer coefficient increased from 221.0 in RBDPO to 250.7 Wm−2 °C−1 in EI over 170–190 °C. Peak melting point of triacylglycerols shifted from 10.36 °C in RBDPO to −4.76 °C in EI. Trisaturated triacylglycerols decreased from 4% in RBDPO to 0.6% in EI. The first step of thermal decomposition started at 190, 212.7 and 238.9 °C for RBDPO, RBO and EI, respectively. Sensory evaluation of poori fried using these oils revealed no significant (p > 0.05) differences in sensory attributes of the fried product

Mass-spectrometric identification of T-kininogen I/thiostatin as an acute-phase inflammatory protein suppressed by curcumin and capsaicin.

Curcumin and capsaicin are dietary xenobiotics with well-documented anti-inflammatory properties. Previously, the beneficial effect of these spice principles in lowering chronic inflammation was demonstrated using a rat experimental model for arthritis. The extent of lowering of arthritic index by the spice principles was associated with a significant shift in macrophage function favoring the reduction of pro-inflammatory molecules such as reactive oxygen species and production and release of anti-inflammatory metabolites of arachidonic acid. Beyond the cellular effects on macrophage function, oral administration of curcumin and capsaicin caused alterations in serum protein profiles of rats injected with adjuvant to develop arthritis. Specifically, a 72 kDa acidic glycoprotein, GpA72, which was elevated in pre-arthritic rats, was significantly lowered by feeding either curcumin or capsaicin to the rats. Employing the tandem mass spectrometric approach for direct sequencing of peptides, here we report the identification of GpA72 as T-kininogen I also known as Thiostatin. Since T-kininogen I is an early acute-phase protein, we additionally tested the efficiency of curcumin and capsaicin to mediate the inflammatory response in an acute phase model. The results demonstrate that curcumin and capsaicin lower the acute-phase inflammatory response, the molecular mechanism for which is, in part, mediated by pathways associated with the lowering of T-kininogen I

Amino acid content of GpA72.

<p>The protein was hydrolyzed with 6N HCl under vacuum at 110°C for 24 h. Amino acid analysis was performed by pre-column derivatization with phenylisothiocynate. The phenylthiocarbomoylamino acids were analyzed using a Pico Tag column (3.9×150 mm)on a Waters HPLC system, equipped with a 1525 binary pump and Waters 2996-photodiode-array (PDA) detector set at 254 nm. Numbers on the peaks are retention times in minutes.</p

Identification of GpA72 as T-Kininogen I by tandem mass spectrometry analysis.

<p>Protein band corresponding to GpA72 was excised and protolysed with trypsin. Extracted peptides were analyzed by liquid chromatography Tandem mass spectrometry using an ion trap mass spectrometer (LCQ Deca XP, Finnigan) as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107565#s2" target="_blank">Methods</a> section. Top panel shows CID spectrum that was matched to ⁶⁶DGAETLYSFK⁷⁵ of T-kininogen 1. Observed b- and y-ions are indicated. Whole protein sequence and the peptides identified by LC-Tandem MS (bold) are shown in the bottom panel. Peptide sequences identified that aid in distinguishing the T-Kininogen I from T-Kininogen II are underlined.</p

Serum levels of T-kininogen I in rats injected with different proinflammatory agents.

<p>Representative native PAGE gel image of sera from rats with hind joint injections of the following: Lane 1: Liquid paraffin oil, Lane 2: Adjuvant containing H37Rv, Lane 3: Turpentine oil; Lane 4: Zymosan; Lane 5: Carrageenan and Lane 6: Collagen.</p

Comparison of the amino acid compositions of GpA72 and α-Cysteine protease inhibitor.

<p>Comparison of the amino acid compositions of GpA72 and α-Cysteine protease inhibitor.</p

HPLC elution profile of the purified fraction of GpA72 Sera from four to six arthritic rats were pooled and subjected to protein purification as described under the methods section.

<p>The single peak eluting at 21.225 min represented GpA72.</p