A new micro-plate colorimetric assay was developed for rapid determination of zinc in animal feed, pet food and drinking water. Zinc ion was extracted from sample by trichloroacetic acid and then reacted with 2-(5-Bromo-2-pyridylazo)-5-[N-propyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS) to form a Zn-PAPS complex to be detected by a micro-plate reader at 552 nm. An ion masking formula including salicylaldoxime, deferoxamine and sodium citrate were screened and applied to exclude the interference from other heavy metals and a partitioning correction approach was proposed to eliminate the matrix effect derived from feed sample. The entire procedure can be completed within 40 min and the detection range was 0.038–8.0 μg mL−1 zinc in buffer solution. Moreover, the analysis in real samples revealed the consistency of results by this assay and those by atomic absorption spectrometry analysis. These features highlighted the possibility for this proposed assay to be used for rapid determination of zinc in complex samples.

Objetivos: Se elaboró colación nutraceutica de oca, agua de decocción de hojas y pulpa de guanábana que tenga buena aceptación en la población adulta y del adulto mayor. Métodos: Estudio analítico (cuasi experimental), según métodos recomendados por Román, D. (2009),, Se evaluó la formulación más adecuada según sus proporciones, características fisicoquímicas y sensoriales, de acuerdo a las preferencias y exigencias nutricionales de los adultos mayores (20 personas). Resultados: Existen diferencias significativas en la aceptabilidad de las colaciones nutraceuticas de oca, agua de decocción de hojas y pulpa de guanábana “Nutra-1”, “Nutra-2” con , “Nutra-3”. La prueba de igualdad de medias y prueba de Bonferroni determinó que el elaborado con la formulación “Nutra-3” es la preferida sobre las otras dos colaciones. La colación nutraceutica de oca, agua de decocción de hojas y pulpa de guanábana “Nutra-3”, es un alimento funcional, por su capacidad natural de aportar nutrientes, cuya ingesta de 100 g, cubre el 100% de los requerimientos diarios de ácido ascórbico, 200% de provitamina A, el 30% de fibra dietética y 15% de hierro, para el adulto mayor. En relación a los compuestos polifenoles presentes en el zumo concentrado se aprecia un contenido de 928,12 ± 17,42 mg% (0,828 mg EAG/ g). Conclusiones: La colación nutraceutica de oca, agua de decocción de hojas y pulpa de guanábana “Nutra-3”, tiene efecto favorable sobre el índice aterogénico y acción protectora sobre la salud cardiovascular por su contenido de antioxidantes, fibra alimentaria, principios bioctivos y su efecto hipolipemiante. La La colación nutraceutica de oca, agua de decocción de hojas y pulpa de guanábana, es nutritivo y saludable, cumple con los requisitos de aptitud para el consumo humano directo | Tesis

Children in developing countries often face multiple micronutrient deficiencies. Introduction of zinc‐fortified water can increase zinc intake, but additional recommendations are required to address overall diet nutrient adequacy. We developed and tested food‐based recommendations (FBRs) that included zinc‐fortified water for children aged between 4 and 6 years from rural Kenya to achieve the best possible nutrient adequacy. Dietary intakes of 60 children aged 4–6 years, from Kisumu West district, Kenya, were assessed using a quantitative multipass 24‐hr recall. Linear programming model parameters were derived, including a list of foods consumed, median serving sizes, and distribution of frequency of consumption. By using the Optifood linear programming tool, we developed FBRs for diets including zinc‐fortified water. FBRs with nutrient levels achieving ≥70% recommended nutrient intake (RNI) of the World Health Organization/Food and Agriculture Organization of the United Nations RNI for most of the 12 considered nutrients were selected as the final recommendations for the children. With no FBRs and no zinc‐fortified water, percent RNI coverage range was between 40% and 76% for zinc, improving to 66–101% after introduction of zinc‐fortified water. The final set of FBRs achieved nutrient adequacy for all nutrients except for vitamin A (25% RNI) and folate (68% RNI). Introduction of zinc‐fortified water combined with FBRs will likely improve the nutrient adequacy of diets consumed by children in Kenya but needs to be complemented with alternative interventions to ensure dietary adequacy.

The addition of dietary fibers can alleviate the deteriorated textural properties and water binding capacity (WBC) that may occur when the fat content is lowered directly in the formulas of comminuted meat products. This study investigated the effects of the addition of chitosan or carboxymethyl cellulose (CMC) (2% w/w) to a model meat product. Both dietary fibers improved the water-binding capacity (WBC), while chitosan addition resulted in a firmer texture, CMC lowered the hardness. Chitosan addition resulted in a 2-fold reduction of lipid oxidation products, whereas CMC had no significant effect on oxidation. The effect of chitosan addition on lipid oxidation was evident both in the meat system and after simulated in vitro gastrointestinal digestion. Low-field nuclear magnetic resonance (NMR) relaxometry revealed that the fibers impacted the intrinsic water differently; the addition of chitosan resulted in a faster T₂ relaxation time corresponding to water entrapped in a more dense pore network. Coherent anti-Stokes Raman scattering (CARS) microscopy was for the first time applied in a meat product to study the microstructure, which revealed that the two fibers exerted different effects on the size and entrapment of fat droplets in the protein network, which probably explain the mechanisms by which chitosan reduced lipid oxidation in the system.

A quantum-dot-based immunochromatographic assay (QICA) and a fluorescence quenching immunochromatographic assay (FQICA) were developed to visually detect bisphenol A (BPA). The proposed QICA and FQICA were based on traditional immune competition and on fluorescence resonance energy transfer (FRET) from fluorescence donors (quantum dots) to fluorescence acceptors (colloidal gold nanoparticles), respectively. For the QICA, the concentration of the target negatively correlated with the fluorescent signals, whereas this correlation was positive for the FQICA. The visual limits of detection (LOD) of proposed QICA and FQICA were 10 and 4 μg kg⁻¹ (μg L⁻¹) in samples, respectively. Additionally, the results obtained with the two proposed assays agreed well with those obtained by high-performance liquid chromatography (HPLC), indicating the high accuracy of the proposed assays. These two proposed fluorescence immunochromatographic assays can be applied to rapidly, sensitively, and accurately detect BPA in distillate spirits (42%, v/v), cabbage, grass carp, and river water samples on a large scale.

The usefulness of replacement of caloric sugars by low-calorie sweeteners (LCS) for weight management has been questioned on the grounds that the uncoupling of LCS sweet taste and dietary energy may confuse physiological mechanisms, leading potentially to higher energy and sugar intake. The aim of the present study was to determine whether LCS beverages compared to water, when consumed with meals, differ in their effects on energy and food intake in acute trials and after long-term habituation. Ad libitum food intake of 166 (80 women; 86 men) healthy non-obese adults (BMI between 19 and 28 kg/m²), infrequent consumers of LCS was measured in four 2-consecutive-day testing sessions (Day 1 in the laboratory, Day 2 free-living). During the first 3 sessions, held one-week apart, participants were required to drink either water or commercial non-carbonated LCS lemonade (330 ml) with their main meals (randomised cross-over design). On Day 1, motivational ratings were obtained using visual analogue scales and ad libitum food intakes (amounts and types of foods selected) were measured using the plate waste method. On Day 2, participants reported their ad libitum intakes using a food diary. After Session 3, participants were randomly assigned to the LCS habituation group or to the water control group. The habituation (660 ml LCS lemonade daily vs 660 ml water) lasted 5 weeks. The fourth and final test session measured food intakes and motivational ratings after habituation. Water and LCS beverage did not differ in their effects on total energy intake, macronutrient intakes or the selection of sweet foods and on motivational ratings. Similar results were obtained in both LCS-naïve and LCS-habituated individuals.

We projected changes in weather extremes, hydrological impacts and vulnerability to food insecurity at global warming of 1.5°C and 2°C relative to pre-industrial, using a new global atmospheric general circulation model HadGEM3A-GA3.0 driven by patterns of sea-surface temperatures and sea ice from selected members of the 5th Coupled Model Intercomparison Project (CMIP5) ensemble, forced with the RCP8.5 concentration scenario. To provide more detailed representations of climate processes and impacts, the spatial resolution was N216 (approx. 60 km grid length in mid-latitudes), a higher resolution than the CMIP5 models. We used a set of impacts-relevant indices and a global land surface model to examine the projected changes in weather extremes and their implications for freshwater availability and vulnerability to food insecurity. Uncertainties in regional climate responses are assessed, examining ranges of outcomes in impacts to inform risk assessments. Despite some degree of inconsistency between components of the study due to the need to correct for systematic biases in some aspects, the outcomes from different ensemble members could be compared for several different indicators. The projections for weather extremes indices and biophysical impacts quantities support expectations that the magnitude of change is generally larger for 2°C global warming than 1.5°C. Hot extremes become even hotter, with increases being more intense than seen in CMIP5 projections. Precipitation-related extremes show more geographical variation with some increases and some decreases in both heavy precipitation and drought. There are substantial regional uncertainties in hydrological impacts at local scales due to different climate models producing different outcomes. Nevertheless, hydrological impacts generally point towards wetter conditions on average, with increased mean river flows, longer heavy rainfall events, particularly in South and East Asia with the most extreme projections suggesting more than a doubling of flows in the Ganges at 2°C global warming. Some areas are projected to experience shorter meteorological drought events and less severe low flows, although longer droughts and/or decreases in low flows are projected in many other areas, particularly southern Africa and South America. Flows in the Amazon are projected to decline by up to 25%. Increases in either heavy rainfall or drought events imply increased vulnerability to food insecurity, but if global warming is limited to 1.5°C, this vulnerability is projected to remain smaller than at 2°C global warming in approximately 76% of developing countries. At 2°C, four countries are projected to reach unprecedented levels of vulnerability to food insecurity. This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels’.

Con la finalidad de evaluar la estructura trófica a nivel de los grupos funcionales de alimentación y la calidad biológica del agua del río Cardenillo, se establecieron tres estaciones de muestreo en la parte mediabaja del río, separadas por una distancia aproximada de dos kilómetros. En cada estación la unidad de esfuerzo de recolecta fue de una hora y las giras de campo se realizaron dos veces al mes durante el período de junio a noviembre de 2015. Para la recolecta de los especímenes se utilizó una red tipo D-Net (500 µm), y pinzas entomológicas. La asignación de los grupos funcionales de alimentación se realizó con la literatura especializada para taxones neotropicales. El grupo funcional de alimentación dominante fue el de los colectores-recolectores. La calidad biológica del agua según el índice BMWP´-Pan., corresponde a aguas de calidad buena y según el índice EPT corresponde a aguas buenas sin impacto.

A simple and rapid dispersive solid-phase extraction method coupled with furnace atomic absorption spectrometry detection was developed for selective separation and preconcentration of ultra-trace amounts of lead ions using modified magnetic graphene oxide such as the pseudo imprinted polymer sorbent in real water and food samples. Some effective parameters in the extraction of lead were selected and optimized. The optimum experimental conditions of the proposed method were: pH, 5.0; amount of absorbent, 1 mg; eluent type and its volume, 50 μL of 0.4 mol L⁻¹ hydrochloric acid; sample solution volume, 30.0 mL. Under the optimum conditions, a high preconcentration factor of 600 was obtained for 30.0 mL of sample solution. The relative standard deviation for seven 20 ng L⁻¹ replicates of lead was 2.4% and the detection limit was 0.18 ng L⁻¹. The proposed method was applied for the determination of lead ions in real water and food samples, and its accuracy was assessed through the analysis of a certified reference water (ERA 1340) and recovery experiments.