Studies on functional propertiesof a protein concentrate produced from the seeds of bakul (Mimusops elengiL.; Sapotaceae) have been carried out. Solubility of the protein was minimum at pH 4.0. Water and oil holding capacities of the seed protein concentrate were 1.70 g g-1and 3.23 g g-1, respectively. Minimum foaming capacity, minimum emulsifying activity, minimum emulsion stability and maximum foam stability were found at pH 4.0. Moreover, emulsion stability of the protein concentrate was high (above 88.3%) over the pH range of 2-10.
Authors:R. Rodríguez Madrera, R. Pando Bedriñana and B. Suárez Valles
Simultaneous optimization of protein, soluble and insoluble dietary fibre, total phenolic content, and antioxidant activity was carried out in apple pomace by using response surface methodology (RSM) and solid state fermentation. A central composite design (CCD) was used to optimize the content of nutritional and functional properties, and two factors were studied: time and temperature of fermentation. The fermentation of apple pomace under the best conditions (29.5 ºC and 4.9 days) allowed the depletion of fermentable sugars, an increase the contents of protein and insoluble dietary fibre (36% and 23%, respectively), while soluble dietary fibre, total phenolic content, and antioxidant activity remained constant.
Authors:R. Briones-Martínez, M. Juárez-Juárez, M. Oliver-Salvador and M. Cortés-Vázquez
DSC was used to study the extent of denaturation of hemisphaericin and mexicain hydrolysates from corn gluten, soybean and
sunflower meals. It was observed that the defatted meals studied exhibited only one broad peak transition. The data obtained
demonstrated that the partial protein denaturation found with hemisphaericin or mexicain is correlated to modifications of
functional properties. The two enzymes display different modes of action, according to the protein source.
Authors:M. Włodarczyk-Stasiak, A. Mazurek, J. Jamroz, U. Pankiewicz and R. Kowalski
The aim of the study was to analyse the influence of the type of osmotic substance (sucrose, glucose, xylitol, trehalose, and sorbitol) on the physicochemical properties of freeze-dried fruit (pear and pineapple). Controlling the functional properties of freeze-dried fruit after osmotic dehydration with aqueous solutions at water activity of aw=0.90 is presented. Decrease in the water adsorption index (WAI) was recorded for all dehydrated samples. The largest decrease (for pears and pineapples by 25 and 65%, respectively) was observed in osmoactive solutions containing trehalose. Considerable increase in the FAI was recorded in samples of dehydrated pineapple. In osmoactive trehalose solutions that increase hardly reached 46%, whereas in sorbitol and xylitol its value elevated to 39% and 13%, respectively. Regardless of the osmoactive sweetener applied prior to freeze-drying, an increase in specific surface area (SBET) of dried materials was observed. For dehydrated pears, SBET ranged from 96 to 697 m2 g−1, and for pineapple, from 115 to 938 m2 g−1. Osmotic dehydration before lyophilisation of fruit samples weakened rehydration relative to the control. The dehydration carried out with osmoactive sweeteners, that is, sorbitol, xylitol, and trehalose, allows obtaining a product with good functional properties that can be successfully used for supplementation of dietary products, in particular for diabetics.
Authors:S. Sirilun, C. Chaiyasut, D. Kantachote and P. Luxananil
The aims of this study were to isolate LAB from Thai plant-derived foods and beverages and to examine in vitro probiotic properties including b-glucosidase enzyme activity. Lactobacillus plantarum SC 359 selected from Thai pickled soybean was significantly (P<0.05) the best to perform β-glucosidase enzyme activity (0.396 U ml−1 at 18 h of incubation) out of the 227 tested strains. The strain survived in 0.30% (w/v) bile salt and had high tolerance to acidic pH with survival rates at a 2 h period of 72.24%, 85.52%, 92.64%, and 93.38% at pH 2.0, 3.0, 4.0, and 5.0, respectively. The SC 359 strain showed proteolytic and lipolytic activities. Moreover, the selected strain displayed strong antagonistic activities against Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Salmonella Typhi, Shigella sonnei and Candida albicans ATCC 90028. The strain was susceptible to ampicillin, chloramphenicol, erythromycin, gentamicin, kanamycin, rifampicin, streptomycin, tetracycline, and vancomycin. In addition, the selected strain significantly inhibited the adherence to Caco-2 cells of E. coli, S. Typhi and Sh. sonnei (P<0.05) by 33.50 to 73.37%. The strain could obstruct the adherences of pathogens by elimination, competition, and displacement with pathogen adherences 33.62–53.92%, 26.63–59.23%, and 49.41–66.50%, respectively. Based on the results, the selected strain could be applied as functional starter for Thai fermented plant-derived foods and beverages.
Authors:Jana Niemz, Stefanie Kliche, Marina C. Pils, Eliot Morrison, Annika Manns, Christian Freund, Jill R. Crittenden, Ann M. Graybiel, Melanie Galla, Lothar Jänsch and Jochen Huehn
Using quantitative phosphopeptide sequencing of unstimulated versus stimulated primary murine Foxp3+ regulatory and Foxp3− conventional T cells (Tregs and Tconv, respectively), we detected a novel and differentially regulated tyrosine phosphorylation site within the C1 domain of the guanine-nucleotide exchange factor CalDAG GEFI. We hypothesized that the Treg-specific and activation-dependent reduced phosphorylation at Y523 allows binding of CalDAG GEFI to diacylglycerol, thereby impacting the formation of a Treg-specific immunological synapse. However, diacylglycerol binding assays of phosphomutant C1 domains of CalDAG GEFI could not confirm this hypothesis. Moreover, CalDAG GEFI−/− mice displayed normal Treg numbers in thymus and secondary lymphoid organs, and CalDAG GEFI−/− Tregs showed unaltered in vitro suppressive capacity when compared to CalDAG GEFI+/+ Tregs. Interestingly, when tested in vivo, CalDAG GEFI−/− Tregs displayed a slightly reduced suppressive ability in the transfer colitis model when compared to CalDAG GEFI+/+ Tregs. Additionally, CRISPR-Cas9-generated CalDAG GEFI−/− Jurkat T cell clones showed reduced adhesion to ICAM-1 and fibronectin when compared to CalDAG GEFI-competent Jurkat T cells. Therefore, we speculate that deficiency in CalDAG GEFI impairs adherence of Tregs to antigen-presenting cells, thereby impeding formation of a fully functional immunological synapse, which finally results in a reduced suppressive potential.