Ultrafiltration of metal ions by water‐soluble chelating poly(N‐acryloyl‐N‐methylpiperazine‐co‐N‐acetyl‐α‐aminoacrylic acid)

Water‐soluble copolymers of N‐acryloyl‐N‐methylpiperazine and N‐acetyl‐α‐aminoacrylic acid were synthesized by radical polymerization. The copolymerization yield ranged between 60 and 97%. The FTIR and NMR spectra demonstrated that the copolymerization occurred. The copolymer composition was determined from ¹H‐NMR spectra by comparison of methyl groups from both moieties. The copolymers were richest in AAA units. The metal ion retention properties were investigated by the liquid‐phase polymer‐based retention (LPR) technique at different pH and filtration factors. The affinity for the metal ions depended on the copolymer composition, pH, and filtration factor. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2556–2561, 2002     

Active Compounds in Zingiber officinale as Possible Redox Inhibitors of 5-Lipoxygenase Using an In Silico Approach

5-Lipoxygenase (5-LOX) converts arachidonic acid to lipidic inflammatory mediators such as leukotrienes (LTs). In diseases such as asthma, LTs contribute to a physiopathology that could be reverted by blocking 5-LOX. Natural products with anti-inflammatory potential such as ginger have been used as nutraceuticals since ancient times. 6-Gingerol and 6-shogaol are the most abundant compounds in the ginger rhizome; they possess anti-inflammatory, antioxidant, and chemopreventive properties. In the present study, 6-gingerol and 6-shogaol structures were analyzed and compared with two commercial 5-LOX inhibitors (zileuton and atreleuton) and with other inhibitor candidates (3f, NDGA, CP 209, caffeic acid, and caffeic acid phenethyl ester (CAPE)). The pharmacokinetics and toxicological properties of 6-gingerol, 6-shogaol, and the other compounds were evaluated. Targeted molecular coupling was performed to identify the optimal catalytic pocket for 5-LOX inhibition. The results showed that 6-gingerol and 6-shogaol follow all of the recommended pharmacokinetic parameters. These compounds could be inhibitors of 5-LOX because they present specific interactions with the residues involved in molecular inhibition. The current study demonstrated the potential of 6-gingerol and 6-shogaol as anti-inflammatory agents that inhibit 5-LOX, as they present a high level of performance in the toxicological analysis and could be catabolized by the cytochrome p450 enzymatic complex; however, 6-gingerol was superior in safety compared to 6-shogaol.     

Efficacy of iron-fortified Ultra Rice in improving the iron status of women in Mexico

BACKGROUND: Universal fortification of staple foods with iron has been widely promoted as a cost-effective strategy to reduce iron deficiency in developing-country populations. Nonetheless, relatively few efficacy trials have been reported to date to demonstrate impact on iron status. The Ultra Rice technology provides a means of delivering fortificant iron via rice. OBJECTIVE: The objective of this study was to test the efficacy of rice fortified with microencapsulated, micronized iron pyrophosphate to improve the iron status of women in Mexico in a randomized, controlled intervention trial. METHODS: Nonpregnant, nonlactating women 18 to 49 years of age were recruited from six factories. The women received a daily portion of cooked rice 5 days per week for a period of 6 months, before and after which iron status indicators were determined in venous blood samples. RESULTS: The average intake of iron from the fortificant was 13 mg/day. Mean plasma ferritin concentration and estimated body iron stores were significantly higher, and transferrin receptors were lower, in the iron-fortified rice group following the intervention. Mean hemoglobin concentration also increased in the treatment group, but the increase was significant only when the analysis was restricted to those with baseline hemoglobin < 12.8 g/dL. The absolute reduction in anemia and iron deficiency was 10.3 and 15.1 percentage points, respectively. Total iron intake from fortificant was a significant covariate of change in body iron stores. The overall prevalence of anemia was reduced by 80%. CONCLUSIONS: Fortification of rice with iron using this technology is an efficacious strategy for preventing iron deficiency.     

Control of foodborne pathogens on fresh-cut fruit by a novel strain of Pseudomonas graminis

The consumption of fresh-cut fruit has substantially risen over the last few years, leading to an increase in the number of outbreaks associated with fruit. Moreover, consumers are currently demanding wholesome, fresh-like, safe foods without added chemicals. As a response, the aim of this study was to determine if the naturally occurring microorganisms on fruit are “competitive with” or “antagonistic to” potentially encountered pathogens. Of the 97 and 107 isolates tested by co-inoculation with Escherichia coli O157:H7, Salmonella and Listeria innocua on fresh-cut apple and peach, respectively, and stored at 20 °C, seven showed a strong antagonistic capacity (more than 1-log unit reduction). One of the isolates, CPA-7, achieved the best reduction values (from 2.8 to 5.9-log units) and was the only isolate able to inhibit E. coli O157:H7 at refrigeration temperatures on both fruits. Therefore, CPA-7 was selected for further assays. Dose-response assays showed that CPA-7 should be present in at least the same amount as the pathogen to adequately reduce the numbers of the pathogen. From the results obtained in in vitro assays, competition seemed to be CPA-7's mode of action against E. coli O157:H7. The CPA-7 strain was identified as Pseudomonas graminis. Thus, the results support the potential use of CPA-7 as a bioprotective agent against foodborne pathogens in minimally processed fruit.     

Analysis of Starch in Food Systems by High‐Performance Size Exclusion Chromatography

Starch has unique physicochemical characteristics among food carbohydrates. Starch contributes to the physicochemical attributes of food products made from roots, legumes, cereals, and fruits. It occurs naturally as distinct particles, called granules. Most starch granules are a mixture of 2 sugar polymers: a highly branched polysaccharide named amylopectin and a basically linear polysaccharide named amylose. The starch contained in food products undergoes changes during processing, which causes changes in the starch molecular weight and amylose to amylopectin ratio. The objective of this study was to develop a new, simple, 1‐step, and accurate method for simultaneous determination of amylose and amylopectin ratio as well as weight‐averaged molecular weights of starch in food products. Starch from bread flour, canned peas, corn flake cereal, snack crackers, canned kidney beans, pasta, potato chips, and white bread was extracted by dissolving in KOH, urea, and precipitation with ethanol. Starch samples were solubilized and analyzed on a high‐performance size exclusion chromatography (HPSEC) system. To verify the identity of the peaks, fractions were collected and soluble starch and beta‐glucan assays were performed additional to gas chromatography analysis. We found that all the fractions contain only glucose and soluble starch assay is correlated to the HPSEC fractionation. This new method can be used to determine amylose amylopectin ratio and weight‐averaged molecular weight of starch from various food products using as low as 25 mg dry samples.     

Changes on Dough Rheological Characteristics and Bread Quality as a Result of the Addition of Germinated and Non-Germinated Soybean Flour

The increasing interest in functional and healthy food products has promoted the use of germinated soybean flour in the manufacture of foods for human consumption. Considering the beneficial effects of soy and its germination, farinograph and extensograph were used to study the effect of adding defatted flour of germinated (32 °C, 72 h) or non-germinated soybean—at different dry protein ratios (0, 0.5, 1.0, 1.5%)—to wheat flour on: water absorption (WA), maximum consistency time (MCT), dough stability (S), maximum resistance to extension (R _max), and dough extensibility (L). Baking tests (straight-dough procedure) were also performed to evaluate the effect of this addition on bread characteristics: loaf volume, texture (firmness, compression force, resilience), color (L*, a*, b*), crumb–grain structure (cell density, mean cell area, shape factor), and consumer acceptance (sensory analysis). Addition of both kinds of soybean flours increased the values of farinographic parameters (WA, MCT, S), although they did not have significant effects (p > 0.05) on extensographic properties (R _max, L). Loaf volume and crumb color were improved as soy flour addition was increased, whereas crust color was not affected (p > 0.05). Texture analysis showed that the addition of soy flour produced breads similar or better than the control, whereas the addition of GSF produced a coarser crumb grain. No detectable differences were found among samples during the sensorial analysis. Germinated soybean flour was better to improve dough breadmaking properties.     

Precipitation during aging in N-containing austenitic stainless steels

Two different N-containing austenitic stainless steels were aged at temperatures from 600 to 800 °C for 10 to 1000 min in order to study the precipitation kinetics. In general, the fastest precipitation occurred in the aged steel with higher content of interstitial solutes, named 24Cr–15Ni–4Mn–0.32N–0.04C steel. Time-temperature-precipitation, TTP, diagrams showed that the intergranular precipitation of M₂₃C₆ and M₂N preceded to the intragranular precipitation of M₂N and M₂N and η phase in the aged 24Cr–15Ni–4Mn–0.32N–0.04C and 12Cr–12Ni–10Mn–5Mo–0.24N–0.02C steels, respectively. Besides, the presence of cellular precipitation of austenite and M₂N was observed to occur in the aged 24Cr–15Ni–4Mn–0.32N–0.04C steel.     

Stabilizing large‐scale generalized systems on parallel computers using multithreading and message‐passing

We discuss the parallelization of an efficient algorithm for the partial stabilization of large‐scale linear control systems in generalized state‐space form. The algorithm is composed of highly parallel iterative schemes that appear in the computation of certain matrix functions. Here we evaluate different approaches to exploit parallelism at two levels, based on threads and processes. Our experimental results on a cluster of symmetric multiprocessors and a CC‐NUMA platform show that the efficiency of the matrix operations underlying the iterative schemes carry over to the parallel implementation of the stabilization algorithm. Copyright © 2006 John Wiley & Sons, Ltd.     

Food purchase patterns indicative of household food access insecurity,children’s dietary diversity and intake,and nutritional status using a newly developed and validated tool in the Peruvian Amazon

Food security, defined as the capacity to acquire preferred food at all times, can manifest in many dimensions. Following a mixed methods approach used in India and Burkina Faso, we developed a 58-item experience-based measure in the Peruvian Amazon, based on investigator observations, relevant literature, and pre-testing with community field workers. The tool encompasses seven dimensions of food security and included measures of (1) food purchases, frequency of purchase, and location of acquisition, (2) food expenses, (3) coping mechanisms, (4) preparation of leftover food, (5) food safety (refrigerator access), (6) fishing intensity and (7) selling food. The survey was piloted among 35 randomly selected families from the Malnutrition Enteric Disease (MAL-ED) birth cohort in Santa Clara, Peru and the surrounding communities. Subsequently, based on a focus group discussion, a pile-sorting exercise, and pilot results, we reduced the survey to 36 items to be collected monthly among 203 MAL-ED households from November 2013 to January 2015. Validity and reliability were then assessed using principal component analysis and exploratory factor analysis, revealing four groups of purchase and coping strategy behaviors: (1) Sweets and sugary items, (2) Less preferred, (3) More preferred, and (4) Minimum meal. Internal consistency of the final 22-item scale had an acceptable cutoff of Cronbach’s α of 0.73. Criterion and construct validity of the factor groups revealed there were: (1) food purchase patterns that were distinctive to quality and quantity aspects of the Household Food Insecurity Access scale, (2) unique correlations of child’s intake of fats, animal source protein, fiber and other micronutrients, (3) household purchase patterns from the “more preferred” group (fish, red meat) associated with child’s weight-for-age. Food purchase and frequency, and context-specific behaviors at the household level can be used as surrogates for dietary intake patterns and nutritional status among children. Food purchase and frequency measurement is a quick, objective, non-intrusive survey method that could be used as an indicator for acute changes in household food security status with appropriate pilot testing and validation.