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The milk fat globule membrane (MFGM) provides infants and adults with several health benefits. These are not derived solely from its unique composition, but also from arrangement of ...lipids in the MFGM that, in the case of newborns, could reach the intestine partially intact. Fluorochromes associated with lipid derivatives were used to prove a fusion process between the MFGM and the cellular membrane of differentiated Caco-2 cells. To explore the mechanism of this interaction, incubations of MFGM with Caco-2 cells were carried out in the presence of fusogenic agents or compounds that block other MFGM interaction pathways with cells. Confocal fluorescence microscopy provided visual evidence of the fusion process. Lastly, determination on the lipid profile of cells after their interaction with MFGM indicated a metabolic rearrangement of lipids leading to accumulation of triacylglycerols.
Brassica carinata defatted flour has been used to prepare protein isolates by alkaline extraction and precipitation at low pH. Different extraction parameters have been tested, and the chemical ...composition and functional properties of the resulting isolates have been analyzed. All the isolates had a protein content above 90% and a well balanced amino acid composition according to FAO standards except for a low content of lysine. The extraction process reduced antinutritional components by more than 90%. Solubility, water and fat adsorption, emulsifying and foaming properties of the original flour and the isolates have been compared. In addition, hydrolysis of
B. carinata protein during extraction using the endoprotease preparation Alcalase was performed, and functional properties of hydrolysates with low and high degrees of hydrolysis were studied and compared with those of the original isolates.
The fatty acid composition of the seed oil from 13 Turkish Asphodeline species was analyzed. The seed oil content ranged between 0.9% and 4.6%, and included 26 different fatty acids from C12:0to ...C22:5. The most abundant saturated, monounsaturated, and polyunsaturated fatty acids were C16:0 (5.7% to 23.7% of their total fatty acid content), C18:1ω9 (11.3% to 30.3%), and C18:2ω6 (49.2% to 66.1%). A. tenuior subsp. tenuiflora, which had the highest content of unsaturated fatty acids, also had the best fatty acid profile from a nutritional point of view. Asphodeline seed oil composition was similar to that of local, related vegetables such as onion seeds. Asphodeline species, which are most frequently grown to use the leaves in salads, may also be a good source of seed oil with good nutritional properties. Results of a cluster analysis using data on the fatty acid composition are consistent with the taxonomic classification of genus Asphodeline.
Brassica carinata protein hydrolysates were obtained by sequential hydrolysis with immobilized trypsin, chymotrypsin, and carboxypeptidase A on glioxyl-agarose supports. The final protein hydrolysate ...with a 36% degree of hydrolysis was made up of peptides smaller than 15
kDa. Three peptide fractions were obtained after gel filtration chromatography and antioxidative, hypocholesterolemic, and inhibitory of angiotensin converting enzyme activities were assayed in comparison with the starting materials (protein isolate and hydrolysate). Total protein hydrolysate achieved the best results in the reduction of micellar cholesterol and fraction II, composed by peptides between 1800 and 1400
Da, showed the best antioxidant and inhibitory of angiotensin converting enzyme activities. These results show that
B. carinata seed proteins may represent an useful source of bioactive peptides after hydrolysis with digestive proteases such as trypsin, chymotrypsin, and carboxypeptidase A.
A new method for fast and easy determination of γ-glutamyl-S-ethenyl-cysteine (GEC) in narbon vetch (Vicia narbonensis L.) seeds was developed as a tool for the selection of low GEC varieties. ...Samples (n=20) were analyzed by reverse-phase HPLC, using isocratic elution and monitoring at 215nm. Calibration curve showed very good linearity of the response between 2.5 and 20μg GEC. The limits of detection and quantification were 0.013 and 0.049mg/mL, respectively. The repeatability (average coefficient of variation (CV)=0.023) and reproducibility (average CV=0.016) of the method were within the recommendations for the validation of HPLC methods. The method yielded similar results in comparison with a previously established method.
A new colorimetric method based on the bleaching of the iodoplatinate ion has been developed for fast and easy determination of γ-glutamyl-
S-ethenyl-cysteine (GEC) in narbon vetch (
Vicia ...narbonensis L.) seeds. The calibration curve showed a good correlation (
r
2
=
0.9959) between absorbance and GEC amounts from 5.5 to 33
μg (10–59.78
μmol/L). The limits of detection and quantification were 1.16 and 3.55
μmol/L, respectively, and no significant interferences from other sulfur-containing compounds were observed. The method showed excellent repeatability (relative standard deviation RSD
=
0.28%), reproducibility (RSD
=
4.4%), and accuracy (94%). Determination of GEC in 20 narbon vetch accessions yielded values that were in agreement with those reported previously using capillary electrophoresis and high-performance liquid chromatography methods. The method could be especially valuable for determination of GEC during the process of production of new low-GEC narbon vetch varieties.
The assay of angiotensin-converting enzyme (ACE) inhibition by food-derived peptides is usually carried out by using soluble ACE in a batch process. The purification of this enzyme from tissues is ...not an easy task, and the resulting preparation loses activity very fast. In addition, ACE commercial preparations are very expensive. In this work the immobilization of ACE, through lysine amino groups, to 4% beads cross-linked (4 BCL) glyoxyl-agarose is described. The amount of immobilized enzyme increased with increasing concentrations of enzyme and with incubation time until a saturation point was reached at 50 mg protein/mL gel and 3.5 hours, respectively. The IC50 values for a noncompetitive sunflower peptide inhibitor were similar for the soluble (30.56 micromolar) and immobilized (32.7 micromolar) enzymes. An immobilized derivative was obtained that was 60 times more stable than the soluble enzyme at 60 °C. This procedure yields a derivative that can be reused and has increased thermal stability compared to that of the soluble enzyme. Thus, ACE immobilization is a good alternative to using soluble freshly prepared or commercial preparations because of economical and practical reasons.
Erophaca baetica is a legume endemic to the Mediterranean region. Although the fruits and seeds are large, the presence of the “locoism” which produces the alkaloid, swainsonine has prevented its use ...as animal feed or for human nutrition. Their protein content and chromatographic profile, amino acid composition, fatty acid composition, and polyphenol contents have been determined in order to explore the potential of the E. baetica seeds as a source of dietary protein with functional components. The protein content was found to be 36% (w/w), and an amino acid analysis revealed a deficiency in sulphur amino acids, tryptophane, and lysine. The low lysine content is probably due to the abundance of alkaloids metabolically derived from this amino acid. Oleic and linoleic acids are the major fatty acids in the seeds. The antioxidant activity of polyphenol extracts was higher than the activity of the polyphenols extracted from most edible legume seeds. Hence, E. baetica seeds represent a promising source of functional and nutritional components on the condition that the anti-nutritional alkaloids are previously removed.
Sunflower protein isolates and the proteases pepsin and pancreatin were used for the production of protein hydrolysates that inhibit angiotensin-I converting enzyme (ACE). Hydrolysates obtained after ...3 h of incubation with pepsin and 3 h with pancreatin were studied. An ACE inhibitory peptide with the sequence Phe-Val-Asn-Pro-Gln-Ala-Gly-Ser was obtained by G-50 gel filtration chromatography and high-performance liquid chromatography C18 reverse phase chromatography. This peptide corresponds to a fragment of helianthinin, the 11S globulin from sunflower seeds, which is the main storage protein in sunflower. These results show that sunflower seed proteins are a potential source of ACE inhibitory peptides when hydrolyzed with pepsin and pancreatin.
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