Bioavailability of Iron Produced by the Corrosion of Steel in Apples

The bioavailability of iron formed by the corrosion of low-carbon steel (99% Fe) in contact with Red Delicious apples was measured in a rat model using a depletion-repletion experiment. The percentage of ingested iron converted to hemoglobin iron (Conversion Efficiency) was 74, 57, and 56%, respectively, for daily doses of 110, 190, and 285 μg of this iron. (Conversion Efficiency for FeSO₄ was 46-50%). When compared with FeSO₄= 100, the relative biological value of this iron was found to range from 93–153. Ingestion of one Red Delicious apple that has been exposed to eight large iron nails for 24 hr could provide 10–15 mg iron having good bioavailability.     

Effect of Heat Treatment on Meat Enhancement of Dietary Iron Bioavailability of Meat/Ferrous Sulfate and Meat/Hemoglobin Mixtures Fed to Anemic Rats

The effect of autoclaving on meat enhancement of dietary iron bioavailability was studied. Meat was mixed with FeSO₄ or hemoglobin to obtain ratios of iron from meat to iron from FeSO₄ or hemoglobin of 100:0, 75:25, 50:50, 25:75, and 0:100. One-half of each mixture (except meat:FeSO₄ mixture 0:100) was autoclaved for 90 min at 15 psi. The meat mixtures were lyophilized and formulated into diets to provide approximately 35 mg Fe/kg. Hemoglobin regeneration efficiency (HRE) was determined as the percent iron gained as hemoglobin relative to the iron consumed. Heat increased the HREs of meat/hemoglobin mixtures and of hemoglobin. Heat did not affect the HRE of meat or meat/ferrous sulfate mixtures. Meat did not significantly enhance the bioavailability of total dietary iron.     

Optimization of Extraction of Peanut Proteins with Water by Response Surface Methodology

Water extraction of peanut proteins was optimized to maximize protein extraction, Y₁ and protein concentration in the extract, Y₂. A central composite design involving solids-to-water ratio (X₁), pH (X₂), temperature (X₃) and time (X₄) was used, and second-order models for Y₁ and Y₂ were employed to generate response surfaces. The optimum conditions to obtain Y₁≥ 85% and Y₂≥ 2.5% were X₁= 1:8; X₂= 8.0; X₃= 50 °C; X₄= 30 min. Estimates of Y₁ and Y₂ at the optimum were 85.29% and 2.7%, respectively. Experimental verification gave values of Y₁= 84.39%± 0.78 and Y₂= 2.80%± 0.02. Y₁ and Y₂ were further maximized, as measured by absorbance of solution following centrifugation of the extract, when papain (0.05% g/g peanuts) was added and extraction was carried out at the optimum conditions.     

Optimization of Hexametaphosphate-Assisted Extraction of Flaxseed Proteins Using Response Surface Methodology

Total proteins of defatted low-mucilage flaxseed meals were isolated by extraction with aqueous sodium hexametaphosphate (SHMP). A composite central rotatable design was used to study effects of pH (X₁), meal-to-solvent ratio (X₂) and concentration of SHMP (X₃) on nitrogen extractability (Y₁) and protein recovery (Y₂). Using RSM, quadratic polynomial equations were obtained for Y₁ and Y₂ by multiple regression analysis. All three variables significantly affected nitrogen solubility and protein extractability. The pH was the most effective factor and meal-to-solvent ratio was least. Verification experiments confirmed validity of predicted models. Stationary points for response surfaces were characterized as maxima and they were Y₁=77.6% at X₁= 8.90, X₂= 1:33.6 and X₃=2.75% and Y₂=57.5% at X₁=9.00, X₂=1:33.3 and X₃=2.85%, for nitrogen extractability and protein recovery, respectively.     

Iron content in common Cambodian fish species: Perspectives for dietary iron intake in poor,rural households

Iron deficiency is the most widespread nutritional disorder in Cambodia. Sixteen Cambodian fish species were screened for iron, zinc and calcium contents. Esomus longimanus has a higher iron content (451 mg Fe/kg dry matter, SD = 155, n = 4) than other species. Iron pools were measured as inorganic iron (I-Fe) by the ferrozine method, haem-bound iron (H-Fe) by the acetone method and total iron (T-Fe) by atomic absorption spectrometry. I-Fe + H-Fe accounted for <50% of T-Fe in E. longimanus, indicating a pool of complex bound, probably high-molecular weight non-haem iron (Hm-Fe). In a field study, thirty rural women were interviewed about traditional use of E. longimanus; their cleaning and cooking practices were observed and the amounts of fish consumed were recorded and meal samples were collected for iron analysis. Calculations based on the iron content and a high bioavailability of Hm-Fe showed that a traditional fish meal, sour soup, covered 45% of the daily iron requirement for women.     

Factors influencing ethanol production rates at high-gravity brewing

The aim of this work was to investigate the influences of different fermentation factors on ethanol production rates by Saccharomyces cerevisiae (lager strain), at high-gravity brewing using response surface methodology. An empirical linear polynomial model was developed to describe the behaviour of the dependent variable as a function of significant factors. The resultant functional relationship in terms of coded values for predicting ethanol production rates was: Y=0.421+0.155X₂+0.0575X₂X_3, where Y represents the ethanol production rate (g/lh), and X₂ and X₃ are coded levels for fermentation temperature and nutrient supplementation, respectively. Patterns of yeast growth, decrease in wort gravity and ethanol production were also evaluated at the maximum ethanol production rate (0.694 g/lh). It was concluded that higher ethanol production rates could be achieved by increasing fermentation temperature and supplementing high-gravity worts with yeast extract, ergosterol and Tween 80.     

In-vitro iron dialysability from legumes: Influence of phytate and extrusion cooking

In-vitro iron dialysability from five Italian legumes (mottled bean, white bean, faba bean, chickpea, lentil) and the influence of phytate and extrusion cooking on it were evaluated. Iron dialysability was 2·3 and 2·4% in mottled and white bean respectively, 1·2% infaba bean, 2·7% in chickpea and 1·1% in lentil. After extrusion cooking the flours showed a marked iron contamination and a decrease in iron dialysability, but these changes were significant only for mottled bean. Enzymic phytate removal induced an increase in iron dialysability > 100% in all the raw legumes except mottled bean which showed an increase of only 57%. This finding indicates that, although phytate consistently modifies iron dialysability, it is difficult to identify a quantitative relationship between phytate content and iron dialysability.     

Effect of cooking on protein quality of chickpea (Cicer arietinum) seeds

Amino acid composition and in vitro protein digestibility of cooked chickpea were determined and compared to raw chickpea seeds. Heat treatment produced a decrease of methionine, cysteine, lysine, arginine, tyrosine and leucine, the highest reductions being in cysteine (15%) and lysine (13.2%). Protein content declined by 3.4% and in vitro protein digestibility improved significantly from 71.8 to 83.5% after cooking. The decrease of lysine was higher in the cooked chickpea seeds than in the heated protein fractions, globulins and albumins. The structural modification in globulins during heat treatment seems to be the reason for the increase in protein digestibility, although the activity of proteolytic inhibitors in the albumin fraction was not reduced. Results suggest that appropriate heat treatment may improve the bioavailability of chickpea proteins.     

Carbohydrate composition of raw and extruded pulse flours

Extrusion cooking technology is commercially used in the fabrication of a variety of snack-type and ready-to-eat foods made from cereal grains. However, with the exception of soybean, pulses such as lentil, dry pea and chickpea have not been used for the development of extruded food products. In this study, total carbohydrates, mono-, di- and oligosaccharides, and soluble and insoluble dietary fiber were determined before and after extrusion cooking under specific processing conditions. Concentrations of total available carbohydrates (TAC) in lentil, chickpea and dry pea flours ranged from 625 g/kg to 657 g/kg dry matter. Dry pea showed the highest concentration of TAC, followed by chickpea and lentil. Extrusion processing did not significantly (p < 0.05) affect the TAC content of dry pea and lentil flours. However, extrusion processing decreased the concentration of the raffinose family of oligosaccharides (raffinose and stachyose) in pulse extrudates. Formulated pulse flours demonstrated a beneficial increase in dietary fiber. This research indicates that value-added, nutritious snacks with reduced levels of flatulence factors and higher contents of dietary fiber can be fabricated successfully by extrusion processing of formulations based on lentil, dry pea or chickpea, and represent good alternatives to traditional cereal-based snacks. Also, the commercialization of value-added, pulse-based snacks would increase pulse consumption.     

Effect of processing on water absorption and softening kinetics in chickpea (Cicer arietinumL) seeds

The processing effect on the physical properties of chickpea seeds (kabuli type cv Athenas) is reported. Soaking of chickpea seeds in different solutions (distilled water, 0·5% NaHCO₃ and 0·5% CaCl₂) is characterised by a rapid water absorption followed by a decrease in the hydration rate to saturation point. An improvement in chickpea softening rate and water absorption during cooking, with previous 12 h soaking in 0·5% NaHCO₃, was observed. The presence of Ca²⁺ ions delayed the softening process in chickpea seeds. Physicochemical changes associated to the soaking and cooking process necessary for reducing cooking time are discussed. The texturometer method was estimated as a suitable objective method for the evaluation of the cooking degree in chickpea seeds. © 1998 Society of Chemical Industry     

In Vitro Assay of Iron in Fortified Rice Analogues

A simple in vitro assay for the determination of soluble iron in fortified rice analogue/natural rice blends is described. The soluble iron, measured as an indicator of iron bioavailability, is quantified by FerroZine? colorimetry of the supernatant obtained after simulated gastric (pepsin) and intestinal (pancreatin) digestions. Method suitability was defined by assessments of linearity (R ² average=0.9999±0.0001, and low standard residual average=+0.6±0.9 %; n=17), precision (day-to-day RSD values [n=3 days] ranged from 5.3 % to 75 % for concentrations from 0.017 to 0.585 mg per 100 g of fortified rice analogue/natural rice blend), accuracy (spike recovery=97.5±0.4 %, n=4, spiking level=0.2 to 0.8 mg/l; and linear response of the digest plot [R ²=1.0000] vs. the standard solution plot [R ²=1.0000]), and selectivity (absence of interference from Ca, Mg, Mn, and Zn; reagent blank correction for minimal bias by Cu). The assay provides for a reliable quantification of the soluble iron in fortified rice analogue/natural rice blends. The assay is regarded not as a substitute for in vivo determination of iron absorption, but instead as a tool for identifying formulation, extrusion, and storage issues that are worthy of formal in vivo study. In this connection, application of the assay to fortified rice analogue/natural rice blends and to experimental rice flour preparations has identified potential agents of iron absorption enhancement (e.g., NaFeEDTA at only 2 % of total iron), and of iron absorption inhibition (zinc).     

Optimisation of serine protease extraction from mango peel (Mangifera Indica Cv. Chokanan)

This study investigated the possible relationship between the enzyme extraction variables, namely amount of buffer (25–75 ml, X₁), temperature (−20, 25 °C, X₂) and mixing time (1–3 min, X₃) on total protein (Y₁), total activity (Y₂), specific activity (Y₃), storage stability (Y₄), temperature stability (Y₅) and pH stability (Y₆) of serine protease from mango peel. It was found that there was significant (p < 0.05) fit of the response surface models for all the response variables investigated. There was indication of high coefficient of determination (R²) values (between 0.954 and 1.000) in the regression models describing variations of the response variables. It was found that there was no significant (p > 0.05) difference between the experimental and predicted values. This ensured that the response surface models used to indicate property changes of serine protease as a function of enzyme extraction conditions were sufficient.     

Bioavailability of Zinc and Iron from Mature Winged Bean Seed Flour

The relative bioavailability of zinc and iron from mature winged bean (Psophocarpus tetragonolobus) flour was determined utilizing standard rat bioassay procedures. Weight gain of rats after 21 days and total bone (tibia) zinc resulting from zinc addition to the standard diet as zinc carbonate or from zinc endogenous to winged bean flour were compared. The relative bioavailability of winged bean zinc was calculated to be 85% (P < 0.05) and 93% (N.S.) when weight gain and log tibia zinc were the criteria of evaluation. The results of the hemoglobin repletion assay indicated that iron from winged bean was 89% (N.S.) as bioavailable iron from ferrous sulfate.     

Development of a cooked rice model for bibimbap and resulting physico-digestive properties

A cooked rice model for bibimbap was developed using response surface methodology (RSM). The ratio of brown rice (X ₁), high amylose rice (X ₂) based on a white rice ratio of 1.0, and the ratio of water to total rice weight (X ₃), were independent variables. Stickiness (Y ₁), elasticity (Y ₂), and overall acceptability by sensory testing (Y ₃) of cooked rice were dependent variables. Optimal RSM conditions were white rice:brown rice:high amylose rice=1:1.07:0.56, and the ratio of water to total rice weight was 1.6. Coefficient of determination (R ²) values of response surface equations were 0.909, 0.930, and 0.956 for Y ₁, Y ₂, and Y ₃, respectively (p<0.05). Experimental values measured under optimal conditions coincided with predicted values. Rapidly digestive starch (RDS) and expected glycemic index (eGI) values determined using the optimized rice model were much lower than for control white rice only.     

Preparation,characterization, bioavailability in vitro and in vivo of tea polysaccharides–iron complex

The task of this study was to prepare a complex of tea polysaccharides (TPS) with ferric iron and research its bioavailability in vitro and in vivo. Optimum condition for preparing tea polysaccharides–iron complex (TPIC) was as follows: TPS and FeCl₃ with a weight ratio of 1:2.4, reacted in a water bath at 60 °C for 3 h, generating an iron content for TPIC of 14.60 %. The digestion in vitro experiment showed that availability of TPIC was sufficient. Then, iron bioavailability in vivo of TPIC was evaluated by the rat hemoglobin-repletion bioassay with ferrous sulfate (FeSO₄) as the positive control. Results indicated that at the end of 21 days’ iron regeneration phase, the values of hemoglobin (Hb) concentration, free erythrocyte protoporphyrin (FEP), serum iron (SI) concentration, and mean cell hemoglobin (MCHC) of rats supplemented with FeSO₄ and TPIC increased quickly to those of normal ones. If the bioavailability of FeSO₄ was given 100 % with Hb concentration, SI concentration and MCHC as the evaluation index, respectively, bioavailability of TPIC were in the range of 101.85–116 %. These results demonstrate that TPIC is a good iron supplement source for increasing uptake and bioavailability in the body.     

Response surface studies on cholesterol reduction in egg yolk using #ps01β-cyclodextrin

The effects of β-cyclodextrin (BCD) and reaction time on the recovery of cholesterol from egg yolk were studied at 25°C based on response surface methodology. The developed response model is of the form: Y = 5.585 + 429.77 X _c + 0.534 X _t ², where Y is the predicted cholesterol recovery (%), X _c is the BCD/egg yolk ratio (kg/kg) and X _t is the reaction time (h). Cholesterol recovery increased with the both BCD/egg yolk ratio and reaction time and there was no optimum value. The model predicted a cholesterol recovery of 94.5% at a BCD/egg yolk ratio of 0.163 over a reaction time of 6 h whereas experiments showed a cholesterol recovery of 87.7%.     

Effect of controlled atmospheres on the insect Callosobruchus maculatus Fab. in stored chickpea

Callosobruchus maculatus (Fab.) is the principal pest of the stored chickpea. The larvae of this insect feed on the grain, causing considerable damage that produces qualitative and quantitative losses. For control of this species, pesticides such as phosphine and methyl bromide have been used; the latter was withdrawn from use due to the reduction of the ozone layer. Therefore, it is important to develop novel, safe, and economical control alternatives such as Controlled Atmospheres (CA). In this study, the mortality was determined on four developmental states of C. maculatus, employing CA at different concentrations (50, 70, and 90% CO₂ with 10, 6, and 3% O₂, respectively) during 48, 72, and 120 h. 100% mortality of adult insects was observed with 50% CO₂ at 48 h. Cases of third instar exhibit higher resistance to CA than adults, with 18.9% mortality at 48 h. There were no significant differences in tests on water absorption, cooking time, texture, and color. Finally, the chickpea germination obtained was 93.5% with 90% CO₂ exposure during 120 h. In this latter treatment, significant differences were not presented between control and CA treatments. On comparison of means of vigor, the treatments are favored in terms of weight, rootlet number, plumule and radicle growth with the increase of CO₂ concentration and exposure time. In conclusion, the effect of CA was lethal on C. maculatus, did not affect chickpea quality, and it favored chickpea vigor.     

Response surface optimisation for the extraction of phenolic compounds and antioxidant capacities of underutilised Mangifera pajang Kosterm. peels

The optimum extraction conditions for highest recovery of total phenolics content (TPC) and antioxidant capacities (AC) were analysed for Mangifera pajang peels (MPP), using response surface methodology. The effects of ethanol concentration (X₁: 20–80%), extraction temperature (X₂: 30–65 °C) and liquid-to-solid ratio (X₃: 20–50 mL/g) on the recovery of total phenolics (Y₁) and antioxidant capacity (Y₂) were investigated. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolic content (R² = 0.9966, p < 0.0001) and antioxidant capacity (R² = 0.9953, p < 0.0001). The optimum extraction conditions for TPC were 68%, 55 °C and 32.7 mL/g, and for AC were 68%, 56 °C and 31.8 mL/g, respectively. Predicted values for extraction of TPC and AC agreed well with the experimental values. Liquid chromatography–mass spectrometry of the optimally obtained extracts from MPP revealed the major phytochemicals as mangiferin, gallic acid, catechin and epicatechin.     

Optimisation of the solvent extraction of bioactive compounds from Parkia speciosa pod using response surface methodology

Central composite design was employed to optimise the buffer-to-solids ratio (X₁: 20–50 ml/g), incubation temperature (X₂: 35–55 °C) and time (X₃: 100–200 min), obtaining extracts from Parkia speciosa pod with high total phenolic and flavonoid contents and high antioxidant activities. Analysis of variance showed that the contribution of a quadratic model was significant for the responses. An optimisation study using response surface methodology was performed and 3D response surfaces were plotted from the mathematical models. The optimal conditions based on combination responses were: X₁ = 20 ml/g, X₂ = 35–36 °C and X₃ = 100–102 min. These optimum conditions yielded total phenolic contents of 664–668 mg gallic acid equivalents/100 g, total flavonoid contents of 47.4–49.6 mg pyrocatechol equivalents/100 g, %DPPH_sc of 81.2–82.1%, %ABTS_sc of 78.2–79.8% and FRAP values of 3.2–3.3 mM. Close agreement between experimental and predicted values was found. This methodology could be applied in the extraction of bioactive compounds in the natural product industry.     

Functional properties of pasteurized samples of Aloe barbadensis Miller: Optimization using response surface methodology

Functional properties (FPs) of pasteurized extracts of Aloe barbadensis Miller, rich in bioactive polymer acemannan and cell wall polysaccharides, were optimized using response surface methodology. Box–Behnken design was applied to evaluate the effects of three independent variables: age of plant (X₁ = 3–5 years), pasteurization temperature (X₂ = 65–85 °C), and pasteurization time (X₃ = 15–35 min) on swelling (Sw), water retention capacity (WRC), and fat adsorption capacity (FAC). Analysis of variance showed that the contribution of quadratic models was significant for the responses. From response surface plots, age of plant, time and temperature exhibited independent and interactive effects on Sw, WRC and FAC properties. The optimal conditions to obtain alcohol insoluble residues (AIRs) from pasteurized samples with the highest values for the FPs analysed were: (1) X₁ = 3.6 years, X₂ = 65 °C, X₃ = 15 min for Sw; (2) X₁ = 4.0 years, X₂ = 75.3 °C, X₃ = 20.5 min for WRC; (3) X₁ = 4.0 years, X₂ = 70.1 °C, X₃ = 15 min for FAC. These optimum conditions allowed the obtention of AIRs from pasteurized aloe samples exhibiting: (1) Sw of 308.0 mL g^?1 AIR; (2) WRC of 30.0 g H₂O g^?1 AIR; and (3) FAC of 33.9 g Oil g^?1 AIR. A close agreement between experimental and predictive values was found. These results may be used for the pasteurization process of A. barbadensis Miller in industry.