Two batches of native whey proteins (WP) were subjected to microfluidization or heat denaturation accompanied by microfluidization, followed by spray drying. Powders were assessed for their ...solubility, heat stability, coagulation time, and emulsifying and foaming properties. Effects of denaturation and shearing were examined by particle size analysis, differential scanning calorimetry, reducing and nonreducing sodium dodecyl sulfate-PAGE, and size exclusion-HPLC. Heat treatment significantly decreased solubility, whereas the number of microfluidization passes markedly improved solubility. The combined effect of heat and pressure significantly increased heat coagulation time. Emulsifying activity index substantially increased upon heat denaturation and was further enhanced by microfluidization. Emulsion stability appeared unaffected by the combined treatment, but the concentration of adsorbed protein on fat droplets was significantly increased. Foaming properties were diminished by heating. Particle size distribution patterns, sodium dodecyl sulfate-PAGE, and size exclusion-HPLC revealed disappearance of major WP and creation of relatively higher, as well as smaller, molecular weight aggregates as a result of the 2 treatments. The use of heat and microfluidization in combination could be used to stabilize WP against heat by producing microparticulated species that have different surface and colloidal properties compared with native WP. These results have implications for the use of WP as an additive in heat-processed foods.
► Germination manipulated concentrations of bioactive compounds in selected grains. ► Grain and treatment dependant inhibition of α-glucosidase and α-amylase activities. ► Concentration of bioactives ...mainly increased, especially antioxidants and GABA. ► Barley, sorghum and rye may reduce risk of diabetes and colon cancer.
Germination of seven selected commercially important grains was studied to establish its effects on the nutritional and chemical composition. The changes in the concentration of the nutrients, bioactive compounds and the inhibitory effect of extracts on α-glucosidase and α-amylase activities were investigated. These were measured through proximate analysis, inhibition assays and HPLC. Germinated sorghum and rye extracts inhibited (p<0.05) α-glucosidase activity, whereas barley and sorghum extracts exhibited higher inhibitory activities against α-amylase. Germinated grains contained substantial amounts of total phenolics with rye having significantly higher content compared with the non-germinated grains. Radical scavenging activities of the phenolic extracts were between 13% and 73% for non-germinated and 14% and 53% for germinated. Inositol phosphate (InsP) 4, 5 and 6 were noted in all the grains, but InsP 6 was significantly lower in concentration. This study indicates the potential of germinated barley, sorghum and rye for the development of effective physiologically bioactive compounds for the reduction of the risk of diabetic agents and colon cancer.
Short-chain fatty acids (SCFAs) have been recognized as mediators of immune responses, including pathways of cytokine production. In this study, we investigated the immune-regulatory effects of SCFAs ...on human peripheral blood mononuclear cells (PBMCs) from buffy coat of healthy donors. PBMCs were exposed to varying concentrations of individual SCFAs or of their mixtures of acetate, propionate and butyrate. The productions of interleukin (IL) IL-1β, IL-2, IL-6, IL-10, IL-17, IL-21, IL-23 and transforming growth factor beta 1 (TGF-β1) were assessed. T cell differentiation after exposure to SCFAs was also examined. Compared with lipopolysaccharide (LPS)-stimulated cells (controls), SCFAs slightly decreased TGF-β1 production and reduced IL-6 production; butyrate was more effective than acetate or propionate. SCFAs particularly butyrate caused the induction of CD4+CD25+ regulatory T cells (Treg) rather than Th17 cells. SCFAs may up-regulate the production of anti-inflammatory cytokines in PBMCs, resulting in the induction of CD4+CD25+ Treg cells.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The benefits of probiotics have been recognized and explored for over a century. The pioneering work of Tissier and Moro was elaborated in the Metchnikoff's theory of longevity and converted into ...commercial reality by Shirota and Kellogg in 1930s and German nutritionists with their probiotic therapy in 1950s. Our knowledge about probiotics and their interactions with the host has grown ever since and many potential and even proven mechanisms of action for probiotics have recently been published. Definitely, there is enough clinical evidence to support certain health claims attributed to selected strains of
Lactobacillus and
Bifidobacterium spp. However, substantial work needs to be done to substantiate other potentially beneficial properties including immunomodulation, hypocholesterolemic and anticarcinogenic effects. The aim of this review is to pay the tribute to pioneers in the field and provide an overview of the current state of knowledge about probiotics and their impact on our well-being.
Bioactive compounds released during milk fermentation by proteolytic cleavage of milk proteins have a role beyond their nutritional importance. This study assessed the proteolytic activity of ...Lactobacillus helveticus strains ASCC953, ASCC474, ASCC1188, and ASCC1315 and their ability to release bioactive compounds capable of exerting antioxidative and in vitro anticarcinogenic properties during incubation at 37°C in reconstituted skim milk. The performance of these strains was not affected by the pH decline during fermentation. Soluble extracts of fermented milk by L. helveticus 474 showed the highest free radical (1,1-diphenyl-2-picrylhydrazyl) scavenging activity at 12 h of fermentation, followed by a significant reduction of this activity at 24 h compared with the other strains and control (untreated milk). Skim milk fermented by L. helveticus strains contained compounds with anti-colon cancer activity at varied levels during fermentation. The activity (19.03–50.98% growth inhibition) was greatest in the extract obtained after 12 h of fermentation, which markedly declined (5.4–9.94%) at the end of fermentation. Lactobacillus helveticus 1315 released compounds into the skim milk supernatant with a greater growth inhibition (50.98%) on colon cancer HT-29 cell line than the other strains. More importantly, these compounds had no significant inhibition effect on normal, primary colon cells T4056. Whereas these results suggest that milk fermented by L. helveticus strains may release bioactive compounds with important multifunctional properties, the characteristics and activities of these compounds appear highly strain- and fermentation time-dependent.
Bioactive peptides are food derived components, usually consisting of 3-20 amino acids, which are inactive when incorporated within their parent protein. Once liberated by enzymatic or chemical ...hydrolysis, during food processing and gastrointestinal transit, they can potentially provide an array of health benefits to the human body. Owing to an unprecedented increase in the worldwide incidence of obesity and hypertension, medical researchers are focusing on the hypotensive and anti-obesity properties of nutritionally derived bioactive peptides. The role of the renin-angiotensin system has long been established in the aetiology of metabolic diseases and hypertension. Targeting the renin-angiotensin system by inhibiting the activity of angiotensin-converting enzyme (ACE) and preventing the formation of angiotensin II can be a potential therapeutic approach to the treatment of hypertension and obesity. Fish-derived proteins and peptides can potentially be excellent sources of bioactive components, mainly as a source of ACE inhibitors. However, increased use of marine sources, poses an unsustainable burden on particular fish stocks, so, the underutilized fish species and by-products can be exploited for this purpose. This paper provides an overview of the techniques involved in the production, isolation, purification, and characterization of bioactive peptides from marine sources, as well as the evaluation of the ACE inhibitory (ACE-I) activity and bioavailability.
The presence of acids in a lactose-containing system can affect its crystallization. The crystallization kinetics of lactose solutions were investigated as affected by lactic, citric, or phosphoric ...acid at a concentration of 0.05, 1, or 4% (wt/wt) as compared with that of pure lactose. The crystallization behavior of lactose was affected differently by the presence of all 3 acids and was mostly concentration dependent. The presence of 1 and 4% citric or phosphoric acid reduced the crystal yield significantly (≥18%) as compared with that of pure lactose (∼82%). Thermographic analysis of lactose crystals showed that the presence of 1% lactic, 0.05 and 1% citric, and 4% phosphoric acids in the lactose solutions induced the formation of amorphous lactose. X-Ray diffraction analysis revealed that the lactose crystallized mainly into α-lactose monohydrate, stable anhydrous α-lactose, and anhydrous crystals containing α-lactose and β-lactose in a molar ratio of 5:3 and 4:1. Average size of the lactose particles, comprising of several crystallites, declined depending on the type of the acids and their concentration, but size of a single crystallite was not altered. The findings suggested that the lactose crystallization and crystal properties are governed by the lactose-water interactions, which can be influenced by the presence of acids in a concentration-dependent manner.
Prawn allergy is one of the most common food-borne allergies and current prevention is by avoidance. This review paper summarised different methodologies for the extraction, identification and ...quantification of prawn protein allergens, reported in various research studies. Following extraction, allergenic components have been analysed using well-established methodologies, such as SDS-PAGE, Immunoblotting, ELISA, CD Spectroscopy, HPLC, DBPCFC, SPT etc. Moreover, the preference towards Aptamer-based technique for allergenicity analysis has also been highlighted in this review paper. The summary of these methodologies will provide a reference platform for present and future research directions.
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•Effective separation and visualization of proteins depend on SDS PAGE gel concentrations.•Sandwich ELISA is more precise than indirect and Inhibition ELISA for allergenicity quantification.•Aptamers provides more specific immunogenic reaction for allergens than antibodies.•Allergenic proteins can be isolated by reversed-phase, anion-exchange and hydrophobic interaction HPLC methods.•This review paper will provide a better platform for present and future research direction on allergenic prawn proteins.
The search for alternative preservatives is on the rise due to safety issues linked with the application of synthetic antioxidants and the extensive increase in bacterial resistance to several ...conventional antibiotics. Therefore, the quest for finding suitable alternatives including bioactive peptides has received attention. This article reports a comprehensive insight concerning antioxidative and antibacterial peptides derived from milk proteins, a prolific source of peptides having various bioactivities. Caseins and whey proteins have also been evaluated for antioxidative and antibacterial potential using the BIOPEP database. A notable number of potentially active peptides are present in milk proteins. Technological approaches are here reported for the production of these peptides. The findings of this review show potentiality of utilizing dairy derived antioxidative and antibacterial peptides in the development of a superior alternative to the current generation of preservatives and therapeutic agents, as well as a functional ingredient in dietetic or pharmaceutical applications.
The main aim of the study was to assess the effect of microparticulation at low pH on the functionality of heat-denatured whey proteins (WP). Spray-dried, microparticulated WP (MWP) powders were ...produced from 7% (wt/wt) WP dispersions at pH 3, acidified with citric or lactic acid, and microfluidized with or without heat denaturation. Nonmicroparticulated, spray-dried powders produced at neutral pH or pH 3 served as controls. The powders were examined for their functional and physicochemical properties. Denatured MWP had an approximately 2 orders of magnitude reduction in particle size compared with those produced at neutral pH, with high colloidal stability indicated by substantially improved solubility. The detection of monomeric forms of WP in PAGE also confirmed the particle size reduction. Microparticulated WP exhibited enhanced heat stability, as indicated by thermograms, along with better emulsifying properties compared with those produced at neutral pH. However, MWP powders created weaker heat-induced gels at neutral pH compared with controls. However, they created comparatively strong cold acid-set gels. At low pH, a combination of heat and high hydrodynamic pressure produced WP micro-aggregates with improved colloidal stability that affects other functionalities.
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