Time–intensity characteristics of iron compounds

Discrete-interval time–intensity scaling was used to measure the sensory characteristics of three iron compounds, 0.05 M ferrous sulfate, 0.03 M ferrous chloride and 0.05 M ferrous gluconate. All three compounds exhibited strong and persistent metallic flavors. Ferrous chloride was highest in bitter taste and ferrous gluconate highest in initial sourness and astringency. Evidence of anionic inhibition was seen in that ferrous gluconate was lower in bitterness relative to ferrous chloride. Taste properties decayed rapidly over the 2-min test period but astringency had slower onset, reached a maximum at 60 s and remained at or near the maximum level during the test period. These common iron fortifying agents show complex and different sensory profiles. The sensations that are predominant change over time, with a lingering astringency and metallic taste that may lessen their suitability for use in food fortification.     

Effect of bovine lactoferrin against Carnobacterium viridans

Lactoferrin (LF) alone (8 mg/ml) was able to kill 4 log₁₀ CFU/ml of C. viridans at 4, 10 and 30 °C in all purpose tween (APT) or Lauria broth (LB). In the presence of 2.5% NaCl in each broth system, LF activity shifted from a bactericidal to bacteriostatic effect at all tested temperatures. The addition of sodium bicarbonate (SB) up to 0.16 M did not alter the activity of LF in LB broth containing 2.5% NaCl. However, when 5 mg/ml sodium hexametaphosphate (SHMP) was used with 2.5% NaCl, LF regained some of its bactericidal activity at 30 °C in APT but not in LB broth. This reversal did not occur in APT at 4 or 10 °C. Except for the observation with SHMP at 30 °C, neither sodium lactate (SL) nor SHMP enhanced the bactericidal activity of LF in LB or APT broth containing<2.5% NaCl. It was suggested that 2.5% NaCl in LB and APT broths increased media osmolarity and prevented LF access to binding sites on the contracted cell membrane. This is the first report showing a bactericidal effect of unmodified LF at neutral pH and refrigeration temperatures.     

Consumption of baru seeds [Dipteryx alata Vog.], a Brazilian savanna nut,prevents iron-induced oxidative stress in rats

The protective effect of plant-based foods in human health has been attributed to the presence of bioactive compounds in all parts of the plants. A previous study found a high level of minerals, tannins and phytic acid in the baru nut (Dipteryx alata Vog.), which is a native fruit of the Brazilian savanna. This study investigated the antioxidant activity (AA) of the aqueous and ethyl acetate extracts of the baru nut and the effect of the consumption of this nut on the oxidative status of rats supplemented orally with iron. The AA was evaluated in vitro using the ferric reducing antioxidant power (FRAP), β-carotene/linoleic acid system and free-radical scavenging (DPPH) assays. The total polyphenol concentration was determined spectrophotometrically using the Folin–Ciocalteu reagent. The in vivo study was conducted in male Wistar rats that were fed an AIN-93M diet with or without 10% baru nut or 1% phytic acid and supplemented daily with iron or saline by gavages for 17 days. The liver, heart and spleen were collected for the determination of the malondialdehyde (MDA), carbonyl protein and iron concentrations. The specific activities of catalase, glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in these tissues. A T test was used to compare the results among the rats groups and between the different baru nut extracts (p < 0.05). The aqueous extract of the baru nut contained a higher level of phenolic compounds and a higher antioxidant activity, as measured by FRAP and the β-carotene/linoleic system, relative to the EtOAc extract. The iron supplementation reduced the body weight gain, increased the levels of iron and MDA in the liver and the spleen and increased the carbonyl levels in all three tissues. Consumption of the baru nut reduced the carbonyl levels in the liver, heart and spleen of the iron-supplemented rats (p = 0.002, 0.012 and 0.036, respectively) relative to the heart carbonyl level of rats that were fed the control diet (p = 0.000); it also marginally reduced the iron-induced lipid oxidation in the liver (p = 0.117) and the spleen (p = 0.074). Phytic acid reduced the carbonyl level in the spleen (p = 0.020) and marginally reduced the carbonyl level in the liver (p = 0.098) of iron-supplemented rats. These results demonstrated that the consumption of the baru nut protects tissues against iron-induced oxidative stress, and the phytic acid from the baru nut may be partially responsible for this protective effect; however, other compounds such as phenols may also be involved.     

Influence of environmental stresses on the physicochemical stability of orange oil bilayer emulsions coated by lactoferrin–soybean soluble polysaccharides and lactoferrin–beet pectin

Based on layer-by-layer electrostatic deposition, orange oil bilayer emulsions stabilized with lactoferrin (LF)–soybean soluble polysaccharides (SSPS) and lactoferrin (LF)–beet pectin (BP) were prepared. The effect of environmental stresses (ionic strength, pH, freeze–thaw and light) on the physicochemical stability of primary and secondary emulsions was investigated. In the absence of anionic polysaccharides, orange oil emulsion was highly unstable and aggregated at pH 7–9 and NaCl of 0.1–0.5 M. The droplets in LF–SSPS coated emulsion were stable against aggregation at pH range of 3–10 and NaCl concentration less than 0.3 M, while the droplets in LF–BP coated emulsion were stable against aggregation at pH 4–9 and NaCl concentrations of 0–0.5 M. All the primary and secondary emulsions showed the instability after the freeze–thaw treatment and the stability could be improved in the presence of maltodextrin. During the light exposure (0.35 W/m², 45 °C) for 8 h, the bilayer emulsions could protect key volatile compounds (decanal, octanal and geranial) from the oxidation compared with the primary emulsions. These results suggested that the layer-by-layer electrostatic deposition could improve the stability of LF-coated emulsion to environmental stresses.     

Effect of Natural Fermentation on the Chemical and Nutritional Composition of Fermented Soymilk Nono

Changes in the chemical and nutritional composition of naturally fermented soy nono were studied at ambient temperature (27 ± 2°C) for 72h. The differently fermented soy nono samples were collected at 6 h intervals and analysed for chemical, proximate and mineral composition using standard laboratory procedures. Biochemical changes in the fermenting soy nono showed a drop in pH from 6.90 to 4.09 while titratable acidity (lactic acid equivalent) increased from 0.42 to 1.82% after 72 h of natural fermentation. The moisture, carbohydrate and fat contents decreased from 93.45 to 92.70, 1.52 to 0.60 and 2.18 to 0.87 % respectively while total solids, ash and protein contents increased from 6.55 to 7.30, 0.23 to 0.74 and 2.62 to 5.09 % respectively. Results reveal that the calcium, iron and magnesium contents in fermenting soymilk increased from 52.86 to 71.43, 28.00 to 40.00 and 7.66 to 8.87 mg/l respectively within time intervals of 0 to 54 h and then decreased to 65.00, 28.00 and 7.83 mg/l respectively till the end of fermentation period while the zinc content increased from 4.42 to 6.75 mg/l throughout the fermentation period. It was evident that there was increase in protein, calcium, magnesium, zinc and iron contents during natural fermentation of soymilk.     

l-Histidine enhances stability of hemoglobin concentrates by coordinating with free iron

The objective of this investigation was to evaluate the effects of l-histidine on the stability of porcine hemoglobin concentrates during storage. The results indicated that the addition of l-histidine increased the oxyhemoglobin content and a* values but decreased the methemoglobin content and free iron content (P < 0.05) during storage. The addition of iron cation decreased both the oxyhemoglobin content and a* values but increased both the methemoglobin content and free iron concentration (P < 0.05). CD spectra revealed that the free iron content induced the transformation of the hemoglobin secondary structure from an α-helix (close structure) to a β-pleated, β-turn, and random coil arrangement (loose structure), while l-histidine weakened this behavior of the free iron. Infrared spectra demonstrated that the l-histidine coordinated with the free iron (Fe^2 + or Fe^3 +) to give the corresponding complex at 25 °C and pH 7.3. Therefore, l-histidine enhanced the stability of hemoglobin concentrates by coordinating with free iron.     

Gelation characteristics of tropical surimi under water bath and ohmic heating

Gelation characteristics of tropical surimi, namely threadfin bream (TB), bigeye snapper (BS), goatfish (GF) and lizardfish (LF) prepared in the absence and presence of 10 g kg^?1 egg white proteins were evaluated using either ohmic (OH) or water bath (WB) heating. LF and GF surimi exhibited higher endogenous proteolytic activity than BS and TB. Ohmic heating markedly minimized proteolysis of LF and GF surimi as evidenced by a reduction of trichloroacetic acid (TCA)-soluble oligopeptide content of gels and more retention of myosin heavy chain (MHC). Ohmic heating increased breaking force and deformation of TB and BS surimi by 1.3 and 1.6 times, respectively, as compared to water bath heating. However, TB surimi gels heated by a higher applied voltage gradient of 16.7 V cm^?1 exhibited lower breaking force than those heated at 6.7 V cm^?1. Gels heated ohmically contained lower total sulfhydryl concentration, indicating the greater extent of disulfide bond formation as compared to gels heated in a 90 °C water bath. The rapid heating method with shorter heating time could improve water holding capacity and preserve color of tropical surimi gels when compared to water bath heating.     

Lactobacillus fermentum and Lactobacillus amylovorus as probiotics alter body adiposity and gut microflora in healthy persons

Modification of gut microflora has been reported as altering energy and lipid homeostasis, leading to changes in body composition. We evaluated whether consumption of Lactobacillus amylovorus (LA) and Lactobacillus fermentum (LF) as novel probiotics alters body adiposity through modification of gut microflora. Healthy, but overweight participants (n = 28) consumed yogurt containing 1.39 × 10⁹ colony-forming unit (CFU) microencapsulated LA, 1.08 × 10⁹ CFU microencapsulated LF, or a control yogurt using a randomized, double-blind crossover design. Body composition measurements showed that body fat mass was reduced in all treatments, with the greatest reduction from LA consumption. Bacterial distribution of gut microflora determined a significant reduction in the abundance of Clostridial cluster IV from LA consumption and significant increases in the abundance of Lactobacillus in both LF and LA treatments. The results suggest that modulation of gut microbial composition from probiotic consumption may contribute to altered energy metabolism and body composition.     

Effect of oral administration of water-soluble extract from citrus peel (Citrus unshiu) on suppressing alcohol-induced fatty liver in rats

Water-soluble citrus peel extract (WCE) from Citrus unshiu was studied for its anti-alcoholic fatty liver activities through chronic oral administration to Sprague Dawley (SD) rats. WCE, which was prepared by ultrasound-assisted extraction (UAE), was co-supplemented with ethanol (2.87 ml/rat/day) at low and high dosages (278 and 576 mg/rat/day, respectively) for 6 weeks. Ethanol consumption significantly elevated both total cholesterol (TC) and triglyceride (TG) concentrations in the serum of SD rats; otherwise co-administration of WCE lowered both serum TG and TC levels. Ethanol consumption caused a hepatic lipid content of 227 mg/g liver after 6 weeks whereas co-administration of WCE, especially at high dosage, significantly reduced it to 187 mg/g of liver. Analysis of hepatic fatty acids revealed that WCE suppressed conjugation of oleic acid into TG. These results support probable application of WCE as an anti-alcoholic fatty liver agent.     

A high-resistance-starch rice diet reduces glycosylated hemoglobin levels and improves the antioxidant status in diabetic rats

Diabetes mellitus is a common problem in developed countries. An improved postprandial hyperglycemic peak is one of the main therapeutic targets in diabetic patients. The Wistar rats with streptozotocin (STZ)-induced diabetes were divided into cornstarch (control) and Japonica rice groups, which were fed 640 g starch/kg diets for 4 weeks. The area (means ± SD) under the glucose curve of cornstarch was 173.8 ± 6.9 and Japonica rice diet was 154.3 ± 8.7 mmol × min/L, and the area (means ± SD) under the insulin curve of cornstarch was 12.9 ± 0.1 and Japonica rice diet was 12.0 ± 0.6 nmol × min/L. The glycosylated hemoglobin levels, serum fructosamine and cholesterol concentrations in diabetic rats fed the Japonica rice diet were significantly lower than the control group (P < 0.05). The decreased malondialdehyde levels and increased superoxide dismutase activity and total radical-trapping antioxidant parameter in plasma were also found in rat fed the Japonica rice diet compared to the control. These results suggested that the diet containing high-resistance-starch Japonica rice might reduce glycosylated hemoglobin levels, serum cholesterol concentrations and raised the antioxidant status in the blood.     

Reuterin,lactoperoxidase, lactoferrin and high hydrostatic pressure treatments on the characteristics of cooked ham

The effect of reuterin, lactoperoxidase system (LPS) and lactoferrin (LF) combined with high hydrostatic pressure (HHP) on the characteristics of sliced cooked ham during 35 days at 4 and 10 °C were investigated. Reuterin and LPS inhibited the growth of total microorganisms during 35 days at 4 and 10 °C, whereas a regrowth at 10 °C was observed when HHP was applied. Combined treatments kept total viable counts below 1.5 log cfu/g after 35 days at 10 °C. Regarding the effect of treatments on colour of cooked ham, LPS alone or in combination with HHP slightly affected L*, a* and b* values, but these changes tended to attenuate during storage. Likely, slight differences were registered in shear strength values among control and treated cooked ham. The accumulation of volatile compounds was reduced in cooked ham treated with LPS and LF in combination with HHP, even under abuse temperature conditions (10 °C).Industrial relevanceLPS applied in combination with HHP was the most effective treatment at reducing the growth of total microorganisms in refrigerated cooked ham with minor changes in its characteristics. The antimicrobial activity of such combined treatment against food-borne pathogens, which has also been reported in RTE foods, points to its usefulness to assure a safe product of sensory characteristics similar to those of untreated cooked ham.     

Iron fortification of skim milk: Minerals and 57Fe Mössbauer study

Reconstituted skim milk was fortified at 2, 5, 10 and 20 mmol Fe kg^?1 with ferric and ferrous chloride iron with or without reversible acidification by injection of CO₂ under pressure. Carbonation improved transfer of iron from the soluble to the colloidal phase and accelerated ferrous iron oxidation. ⁵⁷Fe Mössbauer spectra of the freeze-dried casein micelles collected by centrifugation demonstrated that iron is present in a distorted octahedral coordination and is chelated by phosphate rather than citrate. Milk iron fortification induced several changes in the mineral component of the casein micelles, which are explained by the formation of a ternary complex: inorganic phosphate–iron–organic phosphate.     

Biological potential of extracts of the wild edible Basidiomycete mushroom Grifola frondosa

Partially purified polysaccharides (FP) and hot alkali extract (FNa) obtained from fruiting bodies of the wild basidiomycete Grifola frondosa were examined for their antimicrobial, antioxidant and cytotoxic activity. The structural properties of FP and FNa samples were investigated by FT-IR and high resolution 1H- and 13C-NMR spectroscopy. From a group of various G − and G + bacteria the antibacterial effects were highest against the G + B. cereus. FNa was the better antioxidant shown by the lower EC₅₀ values of DPPH scavenging ability, ferric-reducing antioxidant power and ferrous ion-chelating ability. Ferric-reducing antioxidant power and ferrous ion-chelating ability were mostly linked to total polysaccharides, total- and β-glucan content, as well as total protein content. Both extracts displayed a moderate dose dependent antiproliferative action towards malignant human breast cancer MDA-MB-453, cervical adenocarcinoma HeLa and myelogenous leukemia K562 cells not observed in the non cancer derived MRC-5 fibroblasts. The highest effect was found in HeLa cells for FP extract. The mean diameter of Ca-alginate bead loading FP was 960.7 μm while the mean diameter of beads encapsulating FNa extract was 1051.7 μm.     

Vitamin A stability in triple fortified salt

A triple fortified salt (TFS) containing vitamin A, iron and iodine was produced and studied under two controlled climatic conditions: 40 °C, 60% and 100% relative humidity (RH) for three months. The stability of commercially available vitamin A products and the effect of different iron and iodine compounds on vitamin A stability were investigated. The highest vitamin A stability was observed in premixes made with vitamin A palmitates stabilized in a solid matrix. Our best TFS formulation retained 65 ± 2% of vitamin at 60% RH. The highest retention at 100% RH was 45 ± 1%. The TFS containing vitamin A acetate retained a maximum of 48 ± 5% at 60% RH. Introduction of all three micronutrients into one premix particle resulted in reduced vitamin A retention to ∼10% at 60% RH. Vitamin A was more stable with ferric sodium EDTA than with any other iron compound. The source of iodine did not significantly affect vitamin A retention.     

Suitability of Protein-Rich Extract from Okra Seed for Formulation of Ready to Use Therapeutic Foods (RUTF)

Protein-rich extract (PRE) was made from okra (Abelmuscus esculentus) seeds. Three versions of feed A, B, and C were formulated using: as sources of protein, A – protein-rich extract from okra seed, B – dehulled and de-fatted okra seed flour (34% protein), C – casein. Each of the feeds was fed to a group of six rats (21 days old mice) for 21 days. The weights of the rats and their droppings were taken at 3-day intervals so were the weights of feed consumed. After 21 days, the rats were decapitated and blood samples harvested. The blood was used for the haematological tests. Liver and heart toxicity indicator including aspartate amino transferase (AST) and alanine amino transferase (ALT) were assayed. Ready-to-use therapeutic food (RUTF) prepared with PRE of okra seeds was formulated and organoleptically assessed in comparison to a standard product. The results showed protein efficiency ratio for A, B, C to be 0.33, 0.14 and 0.47 respectively. The mean weights of the droppings are 2.6, 1.9 and 1.5 respectively, showing significant difference (p ≤ 0.01). The serum AST was 56.5, 72 and 24 (IU/L) respectively. For ALT it was 16.5, 3.1 and 11 respectively. There was no significant difference between the RUTF as well as weaning foods formulated and the standards in terms of overall acceptability (p ≤ 0.01).     

Lactoferrin-based nanoparticles as a vehicle for iron in food applications – Development and release profile

This study aims at developing and characterizing bovine lactoferrin (bLf) nanoparticles as an iron carrier. bLf nanoparticles were characterized in terms of size, polydispersity index (PdI), electric charge (ζ-potential), morphology, structure and stability over time. Subsequently, iron release experiments were performed at different pH values (2.0 and 7.0) at 37 °C, in order to understand the release mechanism. bLf (0.2%, w/v) nanoparticles were successfully produced by thermal gelation (75 °C for 20 min). bLf nanoparticles with 35 mM FeCl₃ showed an iron binding efficiency value of approximately 20%. The nanoparticles were stable (i.e. no significant variation of size and PdI of the nanoparticles) for 76 days at 4 °C and showed to be stable between 4 and 60 °C and pH 2 and 11. Release experiments at pH 2 showed that iron release could be described by the linear superposition model (explained by Fick and relaxation phenomenon). On the contrary, the release mechanism at pH 7 cannot be described by either Fick or polymer relaxation behaviour. In general, results suggested that bLf nanoparticles could be used as an iron delivery system for future food applications.     

Production of nutraceutics from chestnut burs by hydrolytic treatment

Chestnut (Castanea sativa) burs (CB) were processed by solvent extraction (with ethanol, toluene–ethanol or n-hexane) and/or isothermal autohydrolysis, and the potential as nutraceutics of the solubilized fractions of dietary fiber and antioxidants was evaluated. Among the studied alternatives, the most suited consisted on ethanol extraction, which yielded 21.0 g gallic acid equivalents (GAE)/100 g ethanolic CB extract, with EC_50,DPPH = 0.38 g/L. Ethanol-extracted CB were treated with water at 120 °C, and the soluble fraction was mixed with ethanol to precipitate 8.8 g soluble fiber/100 g CB, with a Water Retention Capacity of 2.4 g/g and an oil absorption capacity of 23.7 g/g. The mother liquors from the above precipitation stage were concentrated and extracted with ethyl acetate to yield an organic phase containing soluble phenolics with high antioxidant activity (EC_50,DPPH = 0.103 g/L) at a yield of 7 g/100 g CB. When the aqueous phase before the ethyl acetate extraction was treated with sulfuric acid, an additional antioxidant fraction (EC_50,DPPH = 0.395 g/L) was obtained. The properties and characteristics of these extracts produced make them good candidates to be used as active ingredients.     

Metabolite profiling of ginsenoside Re in rat urine and faeces after oral administration

Following oral administration of ginsenoside Re, the compound and its metabolites were identified and quantified in rat urine and faeces by liquid chromatography coupled with triple quadrupole mass spectrometry (LC–MS/MS). Ginsenoside Re (200 mg/kg) was orally administered to rats by gastric intubation, and urine and faeces samples were then collected during the next 24 h using metabolic cages. Samples were prepared by solid phase extraction and analysed by LC–MS/MS. The precursor-product ion pairs used for LC–MS/MS analysis were: m/z 945 → 475 for ginsenoside Re, 799 → 637 for ginsenoside Rg1, 783 → 475 for ginsenoside Rg2, 637 → 475 for ginsenosides Rh1 and F1, 475 → 391 for protopanaxatriol, and 779 → 641 for digoxin (internal standard). The major ginsenosides excreted in urine were ginsenosides Re and Rg1, and only minimal amounts of ginsenosides Rg2 and Rh1 were found. Greater amounts of ginsenoside metabolites were detected in the faeces samples; biotransformation to ginsenoside Rg1 was predominant but further deglycosylated metabolites including ginsenoside F1 and protopanaxatriol were additionally detected. The total recovery of ginsenosides over 24 h was approximately 46%.     

Effect of Boiling and Frying on the Total Carbohydrate,Vitamin C and Mineral Contents of Irish (Solanun tuberosum) and Sweet (Ipomea batatas) Potato Tubers

In a study aimed at ascertaining whether boiling or frying best conserves nutrients; since the two methods are commonly adapted in Nigeria, the effect of boiling and frying on total carbohydrate, vitamin C and mineral contents of Irish (Solanum tuberosum) and sweet (Ipomea batatas) potato tubers were investigated. The determination of total carbohydrate was carried out using the phenol-sulphuric acid method and the spectrophotometric method was used to determine vitamin C content at 520 nm. The minerals evaluated are iron, zinc, magnesium, sodium, calcium and copper. These were determined by the atomic absorption spectrophotometric method. There was no significant difference (p > 0.05) in the total carbohydrate content of the boiled and fried sweet and Irish potatoes compared with their raw tubers. There was significant difference (p < 0.05) in the vitamin C content of the boiled and fried potato tubers. Boiling and frying of Irish potato resulted in a loss of 37.34 mg/100 ml (63.90%) and 30.44 mg/100 ml (53.90%) vitamin C respectively. Boiled sweet potato lost 51.16 mg/100 ml (72.37%) and fried lost 43.05 mg/100 ml (60.90%) of vitamin C. The mineral compositions of the boiled and fried Irish and sweet potatoes were significantly different (p < 0.05) from their raw tubers. Boiling retained more iron and copper while frying retained more zinc, magnesium, sodium and calcium in both Irish and sweet potato tubers. Boiling retained more carbohydrate while frying retained more vitamin C and minerals.