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1.
PLoS One ; 19(7): e0303625, 2024.
Article in English | MEDLINE | ID: mdl-38968262

ABSTRACT

The use of smart locker technology has been beneficial for patients with chronic diseases who require regular medication and face challenges accessing healthcare facilities due to distance, time, or mobility issues. This study aimed to assess preferences for utilizing Smart Lockers in accessing and dispensing chronic disease medication among healthcare workers (HCWs) and patients in Nigeria. A descriptive cross-sectional survey was conducted between November 8th and December 4th, 2021, across secondary healthcare facilities in five states of Adamawa, Akwa Ibom, Cross River, Benue, and Niger. Among 1,133 participants included in the analysis, 405 were HCWs and 728 were patients with chronic illnesses. Descriptive statistics, including frequencies and percentages, were used to summarize the data, while chi-square tests were employed to assess significant differences between healthcare workers (HCWs) and patients. Results indicated a strong preference among both HCWs and patients for one-on-one counseling as the preferred method for orientating patients on using Smart Lockers, with 53.8% of HCWs and 58.1% of patients expressing this preference (p = 0.25). Additionally, there was a shared preference for hospitals or clinics as secure locations for Smart Lockers, with 68.9% of HCWs and 71.6% of patients preferring this option (p < 0.05). The majority of participants favored receiving notification of drug delivery via phone call, with 49.1% of HCWs and 48.8% of patients expressing this preference (p = 0.63). There was a significant difference in preferences for access hours, the majority (HCWs: 65.4% and patients: 52.6%) favored 24-hour access (p < 0.05). Participants identified patients with HIV within the age range of 18-40 as the most suitable population to benefit from using Smart Lockers for medication dispensing. These findings offer insights into healthcare policies aimed at enhancing medication access and adherence among patients with chronic diseases in Nigeria. The development of models for using smart lockers to dispense chronic disease medications to chronically ill persons in Nigeria and other populations is recommended.


Subject(s)
Health Personnel , Patient Preference , Humans , Nigeria , Cross-Sectional Studies , Male , Female , Adult , Middle Aged , Chronic Disease/drug therapy , Young Adult , Health Services Accessibility , Adolescent , Aged , Surveys and Questionnaires
2.
PLoS One ; 19(3): e0294936, 2024.
Article in English | MEDLINE | ID: mdl-38451957

ABSTRACT

Smart lockers are automated delivery machines. They have been used in dispensing ARVs and Tuberculosis medication to chronically ill patients in South Africa, Kenya, and Eswatini. However, there is no evidence of smart lockers in dispensing chronic disease medication in Nigeria. This study aimed to assess the acceptability of smart lockers in dispensing chronic disease medication and to describe the barriers to accessing care among patients with chronic diseases medication in 5 states in Nigeria. We conducted a cross-sectional study among healthcare workers and patients living with chronic diseases in five Nigerian states of Adamawa, Akwa Ibom, Cross River, Benue, and Niger between November and December 2021. A total of 1,133 participants were recruited (728 patients and 405 healthcare workers). The results revealed that most patients and healthcare workers agreed that using smart lockers for drug dispensing will lead to reduced transportation costs, hospital waiting times, the workload of healthcare workers, and decongestion of health facilities. The majority of the patients living with chronic diseases (43%) and healthcare workers (51%) showed high acceptability for the use of smart lockers. The use of smart lockers in dispensing chronic disease medication in Nigeria is feasible, and patients and healthcare workers are willing to accept the smart lockers, provided that a patient-centred implementation strategy is developed.


Subject(s)
Health Personnel , Technology , Humans , Cross-Sectional Studies , Nigeria , Chronic Disease
3.
Foods ; 11(12)2022 Jun 20.
Article in English | MEDLINE | ID: mdl-35742010

ABSTRACT

Whey protein isolate (WPI)-derived bioactive peptide fractions (1−3, 3−5, 5−10, 1−10, and >10 kDa) were for the first time used as emulsifiers in nanoemulsions. The formation and storage stability of WPI bioactive peptide-stabilized nanoemulsions depended on the peptide size, enzyme type, peptide concentration, and storage temperature. The highly bioactive <10 kDa fractions were either poorly surface-active or weak stabilizers in nanoemulsions. The moderately bioactive >10 kDa fractions formed stable nanoemulsions (diameter = 174−196 nm); however, their performance was dependent on the peptide concentration (1−4%) and enzyme type. Overall, nanoemulsions exhibited better storage stability (less droplet growth and creaming) when stored at lower (4 °C) than at higher (25 °C) temperatures. This study has shown that by optimizing peptide size using ultrafiltration, enzyme type and emulsification conditions (emulsifier concentration and storage conditions), stable nanoemulsions can be produced using WPI-derived bioactive peptides, demonstrating the dual-functionality of WPI peptides.

4.
Food Sci Nutr ; 5(2): 233-242, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28265358

ABSTRACT

Adansonia digitata (A. digitata) leaves serve as food and has several medicinal uses in many parts of the world. This study evaluated the influence of blanching on the phenolics composition, antioxidant activity, and inhibitory effect of methanol extract of A. digitata leaves on the activities of some key enzymes (α-amylase, α-glucosidase, and aldose reductase) implicated in type 2 diabetes (T2D) in vitro. Reverse-phase HPLC analysis revealed that the leaves had appreciable levels of flavonoids and phenolic acids, including catechin, epicatechin, rutin, quercitrin, quercetin, kaempferol, and luteolin (flavonoids); gallic, chlorogenic, caffeic, and ellagic acids (phenolic acids). Blanching caused significant (P < 0.05) decrease in the flavonoids and phenolic acids contents; DPPH* (2,2 diphenyl-1-picrylhydrazyl radical) and ABTS*+ [2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) radical cation] scavenging ability; reducing power; and Fe2+-induced lipid peroxidation inhibitory capacity of the extract. Similarly, the inhibitory effect of the extract on the activities of α-amylase, α-glucosidase, and aldose reductase was significantly (P < 0.05) reduced due to blanching. Thus, A. digitata leaves extract could be effective for the management of T2D due to its flavonoids and phenolic acids content, antioxidant properties, and inhibitory potency on the activities of α-amylase, α-glucosidase, and aldose reductase. However, blanching militated against the levels of these functional attributes of the leaves and, therefore, may not be recommended for their optimal retention.

5.
J Intercult Ethnopharmacol ; 5(4): 396-402, 2016.
Article in English | MEDLINE | ID: mdl-27757270

ABSTRACT

AIM: To evaluate the phenolics composition and inhibitory effect of the leaves extracts of Ocimum basilicum and Ocimum gratissimum on two key enzymes (pancreatic lipase [PL] and angiotensin 1-converting enzyme [ACE]) involved in obesity and hypertension in vitro. MATERIALS AND METHODS: The phenolics (flavonoids and phenolic acids) were quantified using high-performance liquid chromatography coupled with diode array detection. PL and ACE inhibitory effects; DPPH* and ABTS*+ scavenging activities of the extracts were tested using spectrophotometric methods. RESULTS: O. basilicum had the following major phenolics: Rutin, quercetin, and quercitrin (flavonoids); caffeic, chlorogenic, and gallic acids (phenolic acids); while O. gratissimum had the following major phenolics: Rutin, quercitrin, and luteolin (flavonoids); ellagic and chlorogenic acids (phenolic acids). "Extracts of both plants inhibited PL and ACE; scavenged DPPH* in a dose-dependent manner". O. gratissimum extract was more potent in inhibiting PL (IC50: 20.69 µg/mL) and ACE (IC50: 29.44 µg/mL) than O. basilicum (IC50: 52.14 µg/mL and IC50: 64.99 µg/mL, against PL and ACE, respectively). O. gratissimum also scavenged DPPH* and ABTS*+ more than O. basilicum. CONCLUSION: O. basilicum and O. gratissimum leaves could be used as functional foods for the management of obesity and obesity-related hypertension. However, O. gratissimum may be more effective than O. basilicum.

6.
J Intercult Ethnopharmacol ; 5(2): 122-30, 2016.
Article in English | MEDLINE | ID: mdl-27104032

ABSTRACT

BACKGROUND/AIM: Elevated uric acid level, an index of gout resulting from the over-activity of xanthine oxidase (XO), increases the risk of developing hypertension. However, research has shown that plant-derived inhibitors of XO and angiotensin 1-converting enzyme (ACE), two enzymes implicated in gout and hypertension, respectively, can prevent or ameliorate both diseases, without noticeable side effects. Hence, this study characterized the polyphenolics composition of guava leaves extract and evaluated its inhibitory effect on XO and ACE in vitro. MATERIALS AND METHODS: The polyphenolics (flavonoids and phenolic acids) were characterized using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The XO, ACE, and Fe(2+)-induced lipid peroxidation inhibitory activities, and free radicals (2,2-diphenylpicrylhydrazyl [DPPH]* and 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic [ABTS]*(+)) scavenging activities of the extract were determined using spectrophotometric methods. RESULTS: Flavonoids were present in the extract in the order of quercetin > kaempferol > catechin > quercitrin > rutin > luteolin > epicatechin; while phenolic acids were in the order of caffeic acid > chlorogenic acid > gallic acids. The extract effectively inhibited XO, ACE and Fe(2+)-induced lipid peroxidation in a dose-dependent manner; having half-maximal inhibitory concentrations (IC50) of 38.24 ± 2.32 µg/mL, 21.06 ± 2.04 µg/mL and 27.52 ± 1.72 µg/mL against XO, ACE and Fe(2+)-induced lipid peroxidation, respectively. The extract also strongly scavenged DPPH* and ABTS*(+). CONCLUSION: Guava leaves extract could serve as functional food for managing gout and hypertension and attenuating the oxidative stress associated with both diseases.

7.
Food Chem ; 185: 226-32, 2015 Oct 15.
Article in English | MEDLINE | ID: mdl-25952862

ABSTRACT

This study assessed the ability of canola protein isolate (CPI) and enzymatic hydrolysates (CPHs) to inhibit adipogenic differentiation of C3H10T1/2 murine mesenchymal stem cells in vitro. Cell viability was maintained at concentrations of 60 µg/ml of sample. Cells treated with Alcalase hydrolysate demonstrated a higher reduction in anti-adipogenic differentiation through quantitation by oil-red O staining. qPCR analysis showed that CPI and CPH-treated cells significantly inhibited PPARγ expression, a key transcription factor involved in adipocyte differentiation, as evident in an ∼ 60-80% fold reduction of PPARγ mRNA. Immunofluorescence staining for PPARγ protein also showed a reduced expression in some treated cells when compared to differentiated untreated cells. The 50% inhibition concentration (IC50) of CPI, CPHs and their membrane ultrafiltration fractions on pancreatic lipase (PL) activity ranged between 0.75 and 2.5 mg/ml, (p < 0.05) for the hydrolysed and unhydrolysed samples. These findings demonstrate that CPI and CPHs contain bioactive components which can modulate in vitro adipocyte differentiation.


Subject(s)
Brassica napus/chemistry , Mesenchymal Stem Cells/cytology , Plant Proteins/pharmacology , Protein Hydrolysates/pharmacology , Adipogenesis/drug effects , Animals , Cell Differentiation/drug effects , Cell Survival/drug effects , Cells, Cultured , Lipase/antagonists & inhibitors , Mice , PPAR gamma/analysis , PPAR gamma/genetics
8.
Plant Foods Hum Nutr ; 69(1): 85-91, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24414090

ABSTRACT

Faba bean phenolic compounds encompassed phenolic acids, flavonols, proanthocyanidins and anthocyanins. Roasting faba beans for 120 min decreased the total phenolic, flavonoid and proanthocyanidin contents by 42, 42 and 30%, respectively. Roasting beans for 120 min decreased the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, total equivalent antioxidant capacity and ferric reducing antioxidant power by 48, 15 and 8%, respectively. High performance liquid chromatography-post column derivatisation revealed the generation of new phenolic compounds as a result of roasting. Antioxidant mechanism of bean less-polar phenolic compounds was largely based on free radical scavenging activity. The bean phenolic compounds with reducing capability were heat stable. Roasted faba bean extracts (70% acetone, v/v) were fractionated into relatively polar and non-polar fractions; the latter contributed the majority of the antioxidant capacity. The extracts from beans with different seed coat colours differed in their phenolic compositions, which suggest different levels of potential benefits to health. Although roasting initially lowers the bean antioxidant capacity, prolonged roasting at 150 °C for 60 min and longer causes generation of new phenolic compounds and an increased antioxidant capacity. The findings encourage a wider ultilisation of faba beans for human foods particularly in baked/roasted products.


Subject(s)
Antioxidants/pharmacology , Flavonoids/pharmacology , Hot Temperature , Phenols/pharmacology , Plant Extracts/pharmacology , Seeds/chemistry , Vicia faba/chemistry , Antioxidants/analysis , Australia , Biphenyl Compounds/metabolism , Diet , Flavonoids/analysis , Food Handling , Humans , Phenols/analysis , Picrates/metabolism , Plant Extracts/chemistry , Proanthocyanidins/analysis , Proanthocyanidins/pharmacology
9.
Food Chem ; 142: 461-8, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-24001866

ABSTRACT

The Australian grown faba beans of different seed coat colours were either soaked, boiled or autoclaved, and analysed for phenolic contents and antioxidant activity using an array of reagent-based assays. Soaking, boiling and autoclaving were shown to lower the level of active compounds in faba beans. A significant amount of active compounds was leached to the soaking and cooking medium. Boiling was a better method in retaining active compounds in beans than autoclaving. The boiled beans had more active compounds than those of resulting cooking broths, which was the opposite observation when autoclaving. The buff-genotypes had a similar level of active compounds to red- and green-genotypes. The high performance liquid chromatography-post column derivatisation (HPLC-PCD) system detected a dense collection of high antioxidant HPLC peaks ('humps') in extracts of raw, soaked and boiled beans. The present findings encouraged consumption of faba beans together with cooking broth for the maximum potential health benefits.


Subject(s)
Antioxidants/analysis , Cooking/methods , Phenols/analysis , Plant Extracts/analysis , Vicia faba/chemistry , Chromatography, High Pressure Liquid , Color , Hot Temperature , Seeds/chemistry
10.
Food Chem ; 146: 500-6, 2014 Mar 01.
Article in English | MEDLINE | ID: mdl-24176374

ABSTRACT

Antioxidant activities of canola protein hydrolysates (CPHs) and peptide fractions prepared using five proteases and ultrafiltration membranes (1, 3, 5, and 10kDa) were investigated. CPHs had similar and adequate quantities of essential amino acids. The effective concentration that scavenged 50% (EC50) of the ABTS(+) was greatest for the <1kDa pancreatin fraction at 10.1µg/ml. CPHs and peptide fractions scavenged DPPH(+) with most of the EC50 values being <1.0mg/ml. Scavenging of superoxide radical was generally weak, except for the <1kDa pepsin peptide fraction that had a value of 51%. All CPHs inhibited linoleic acid oxidation with greater efficiency observed for pepsin hydrolysates. The oxygen radical absorbance capacity of Alcalase, chymotrypsin and pepsin hydrolysates was found to be better than that of glutathione (GSH) (p<0.05). These results show that CPHs have the potential to be used as bioactive ingredients in the formulation of functional foods against oxidative stress.


Subject(s)
Antioxidants/chemistry , Brassica napus/chemistry , Plant Proteins/chemistry , Protein Hydrolysates/chemistry , Antioxidants/isolation & purification , Australia , Lipid Peroxidation
11.
J Agric Food Chem ; 61(38): 9176-84, 2013 Sep 25.
Article in English | MEDLINE | ID: mdl-23889116

ABSTRACT

During the extraction of canola oil, large quantities of meal are produced. Extracting biophenols from Australian canola meal (ACM) adds value to an otherwise low-value agro-industrial byproduct. This study examined the biophenol content and the antioxidant activity of ACM, the impact of extraction conditions, and varietal differences. Sinapine was the principal biophenol in ACM. In crude and hydrolyzed extracts, 31 compounds were identified: 2 dihexosides, 2 organic acids, 4 glucosinolates, 17 sinapic acid derivatives, 2 cyclic spermidine alkaloids, caffeic acid and its dihexoside, kaempferol, and its C-glucoside. ACM showed significant free radical scavenging activity in DPPH(•) and ABTS(•+) assays. Sinapine was the chief contributor to ACM antioxidant activity, whereas kaempferol sinapoyl triglucoside isomer was the most potent antioxidant. Biophenol content ranged between 12.8 and 15.4 mg GAE/g DW. Differences among studied cultivars were generally quantitative. The Tarcoola cultivar showed the highest biophenol content and antioxidant activity.


Subject(s)
Antioxidants/analysis , Brassica napus/chemistry , Phenols/analysis , Plant Extracts/analysis , Australia
12.
Food Chem ; 136(3-4): 1435-43, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23194546

ABSTRACT

Heat pre-treated and non heat pre-treated whey protein isolate (WPI) were hydrolysed using α-chymotrypsin (chymotrypsin), pepsin and trypsin. The in vitro antioxidant activity, ACE-inhibition activity and surface hydrophobicities of the hydrolysates were measured in order to determine if peptides with dual functionalities were present. Dual functional peptides have both biological (e.g. antioxidant, ACE-inhibition, opioid activities) and technological (e.g. nanoemulsification abilities) functions in food systems. Heat pre-treatment marginally enhanced the hydrolysis of WPI by pepsin and trypsin but had no effect on WPI hydrolysis with chymotrypsin. With the exception of the hydrolysis by trypsin, heat pre-treatment did not affect the peptide profile of the hydrolysates as analysed using size exclusion chromatography, or the antioxidant activity (P>0.05). Heat pre-treatment significantly affected the ACE-inhibition activities and the surface hydrophobicities of the hydrolysates (P<0.05), which was a function of the specificity of the hydrolysing enzyme. Extended hydrolysis (up to 24 h) had no significant effect on the DH and the molecular weight profiles (P>0.05) but in some instances caused a reduction in the antioxidant activity of WPI hydrolysates. The chymotrypsin hydrolysate showed a broad MW size range, and was followed by pepsin and then trypsin. The bioactivities of the hydrolysates generally decreased in the order; chymotrypsin>trypsin>pepsin. This study showed that by manipulating protein conformation with pre-hydrolysis heat treatment, combined with careful enzyme selection, peptides with dual functionalities can be produced from WPI for use as functional ingredients in the manufacture of functional foods.


Subject(s)
Antioxidants/chemistry , Milk Proteins/chemistry , Protein Hydrolysates/chemistry , Angiotensin-Converting Enzyme Inhibitors/chemistry , Chymotrypsin/chemistry , Hot Temperature , Hydrolysis , Hydrophobic and Hydrophilic Interactions , Pepsin A/chemistry , Trypsin/chemistry , Whey Proteins
13.
Br J Nutr ; 108 Suppl 1: S123-34, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22916808

ABSTRACT

The functional properties, including antioxidant and chemopreventative capacities as well as the inhibitory effects on angiotensin-converting enzyme (ACE), α-glucosidase and pancreatic lipase, of three Australian-grown faba bean genotypes (Nura, Rossa and TF(Ic*As)*483/13) were investigated using an array of in vitro assays. Chromatograms of on-line post column derivatisation assay coupled with HPLC revealed the existence of active phenolics (hump) in the coloured genotypes, which was lacking in the white-coloured breeding line, TF(Ic*As)*483/13. Roasting reduced the phenolic content, and diminished antioxidant activity by 10-40 % as measured by the reagent-based assays (diphenylpicrylhydrazyl, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) and oxygen radical absorbance capacity) in all genotypes. Cell culture-based antioxidant activity assay (cellular antioxidant activity) showed an increase of activity in the coloured genotypes after roasting. Faba bean extracts demonstrated cellular protection ability against H2O2-induced DNA damage (assessed using RAW264.7 cells), and inhibited the proliferation of all human cancer cell lines (BL13, AGS, Hep G2 and HT-29) evaluated. However, the effect of faba bean extracts on the non-transformed human cells (CCD-18Co) was negligible. Flow cytometric analyses showed that faba bean extracts successfully induced apoptosis of HL-60 (acute promyelocytic leukaemia) cells. The faba bean extracts also exhibited ACE, α-glucosidase and pancreatic lipase inhibitory activities. Overall, extracts from Nura (buff-coloured) and Rossa (red-coloured) were comparable, while TF(Ic*As)*483/13 (white-coloured) contained the lowest phenolic content and exhibited the least antioxidant and enzyme inhibition activities. These results are important to promote the utilisation of faba beans in human diets for various health benefits.


Subject(s)
Chemoprevention , Enzyme Inhibitors , Health Promotion , Plant Extracts/pharmacology , Seeds , Vicia faba , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , Anticarcinogenic Agents/pharmacology , Antioxidants/analysis , Antioxidants/pharmacology , Apoptosis/drug effects , Australia , Cell Line , Cell Line, Tumor , Cell Proliferation/drug effects , DNA Damage/drug effects , Diet , Enzyme Inhibitors/pharmacology , Flavonoids/analysis , Genotype , Glycoside Hydrolase Inhibitors , Hot Temperature , Humans , Lipase/antagonists & inhibitors , Mice , Phenols/analysis , Seeds/chemistry , Seeds/genetics , Vicia faba/chemistry , Vicia faba/genetics
14.
J Food Sci ; 77(1): R25-41, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22260123

ABSTRACT

The production and sale of alcohol-reduced wines, and the lowering of ethanol concentration in wines with alcohol levels greater than acceptable for a specific wine style, poses a number of technical and marketing challenges. Several engineering solutions and wine production strategies that focus upon pre- or postfermentation technologies have been described and patented for production of wines with lower ethanol concentrations than would naturally arise through normal fermentation and wine production techniques. However, consumer perception and acceptance of the sensory quality of wines manufactured by techniques that utilize thermal distillation for alcohol removal is generally unfavorable. This negative perception from consumers has focused attention on nonthermal production processes and the development or selection of specific yeast strains with downregulated or modified gene expression for alcohol production. The information presented in this review will allow winemakers to assess the relative technical merits of each of the technologies described and make decisions regarding implementation of novel winemaking techniques for reducing ethanol concentration in wine.


Subject(s)
Food Technology , Wine/analysis , Wine/microbiology , Ethanol/analysis , Ethanol/metabolism , Fermentation , Food Technology/instrumentation , Glucose Oxidase/genetics , Glucose Oxidase/metabolism , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism
15.
J Food Sci ; 76(1): R16-28, 2011.
Article in English | MEDLINE | ID: mdl-21535703

ABSTRACT

Canola protein isolate has been suggested as an alternative to other proteins for human food use due to a balanced amino acid profile and potential functional properties such as emulsifying, foaming, and gelling abilities. This is, therefore, a review of the studies on the utilization of canola protein in human food, comprising the extraction processes for protein isolates and fractions, the molecular character of the extracted proteins, as well as their food functional properties. A majority of studies were based on proteins extracted from the meal using alkaline solution, presumably due to its high nitrogen yield, followed by those utilizing salt extraction combined with ultrafiltration. Characteristics of canola and its predecessor rapeseed protein fractions such as nitrogen yield, molecular weight profile, isoelectric point, solubility, and thermal properties have been reported and were found to be largely related to the extraction methods. However, very little research has been carried out on the hydrophobicity and structure profiles of the protein extracts that are highly relevant to a proper understanding of food functional properties. Alkaline extracts were generally not very suitable as functional ingredients and contradictory results about many of the measured properties of canola proteins, especially their emulsification tendencies, have also been documented. Further research into improved extraction methods is recommended, as is a more systematic approach to the measurement of desired food functional properties for valid comparison between studies.


Subject(s)
Brassica rapa/chemistry , Dietary Proteins/isolation & purification , Seed Storage Proteins/chemistry , Seed Storage Proteins/isolation & purification , Seeds/chemistry , Dietary Proteins/administration & dosage , Emulsifying Agents , Food, Fortified/analysis , Gels , Seed Storage Proteins/administration & dosage
16.
J Agric Food Chem ; 57(15): 7022-9, 2009 Aug 12.
Article in English | MEDLINE | ID: mdl-19588923

ABSTRACT

An Acacia victoriae trypsin inhibitor (AvTI) was purified from the seeds of prickly wattle (A. victoriae Bentham) by salt precipitation, ion exchange, and gel filtration chromatography and then characterized by electrophoresis and N-terminal amino acid sequencing. AvTI had a specific activity of 138.99 trypsin inhibitor units per milligram (TIU mg(-1)), which was 21-fold higher than that of the salt precipitate. A molecular mass of 13 kDa was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions, which also indicated that AvTI may consist of two polypeptide chains linked by at least one disulfide bond. Although only a single peak was resolved by ion exchange and reverse phase high-performance liquid chromatography (RP-HPLC), native-PAGE and isoelectric focusing revealed the presence of three isoforms possessing acidic pI values of 5.13, 4.76, and 4.27, respectively. N-Terminal amino acid sequencing analysis of native and reduced AvTI showed two sequences with a high degree of homology with a typical Kunitz-type trypsin inhibitor. All isoforms had considerable trypsin inhibitory activity but showed relatively very low inhibition against alpha-chymotrypsin.


Subject(s)
Acacia/chemistry , Plant Proteins/chemistry , Plant Proteins/isolation & purification , Trypsin Inhibitors/chemistry , Trypsin Inhibitors/isolation & purification , Amino Acid Sequence , Molecular Sequence Data , Molecular Weight , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Seeds/chemistry , Sequence Alignment
17.
J Agric Food Chem ; 51(10): 3127-34, 2003 May 07.
Article in English | MEDLINE | ID: mdl-12720403

ABSTRACT

The yield, protein content, proteolytic activity, and substrate specificity of crude and partially purified extracts from dried and fresh Australian cardoon (Cynara cardunculus L.) flowers were determined. Crude water extracts had high yield but low protein content and proteolytic activity, whereas citric acid extracts had low yield but high protein content and proteolytic activity. Fresh flower extracts gave higher yield and proteolytic activity but lower protein content in comparison with dried flower extracts. Purification with ammonium sulfate resulted in significantly increased proteolytic activity for water extracts from both fresh and dried cardoon flowers, whereas the proteolytic activity of citric acid extracts did not change significantly after purification. Irrespective of extraction method, all extracts had higher proteolytic activity against ovine whole and kappa-caseins compared to their bovine counterparts, showing optimal activity at 37 degrees C and pH 6.0. Separation of purified extracts by ion-exchange liquid chromatography yielded three active fractions, each of which when assayed with sodium dodecyl sulfate capillary electrophoresis revealed two subunits with molecular masses of 15.5 and 33.1 kDa, respectively.


Subject(s)
Chymosin , Cynara/enzymology , Endopeptidases/isolation & purification , Endopeptidases/metabolism , Plant Extracts/chemistry , Ammonium Sulfate , Animals , Caseins/metabolism , Cattle , Chymosin/metabolism , Citric Acid , Flowers/enzymology , Hydrogen-Ion Concentration , Proteins/analysis , Substrate Specificity , Temperature , Water
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