Effects of a family-based sensory education on vegetable and fruit variety in children

Several experimental studies implemented in schools have shown that sensory education reduces children’s neophobia and increases their sensory discrimination abilities. However, it is not known whether sensory education has an effect on children’s consumption, particularly on the variety of fruits and vegetables consumed, and whether it is effective when implemented in families.The effect on fruit and vegetable intake of a five months family-based sensory programme was examined in children aged 7–11 (with 32 children in the intervention group and 19 in the control group). The children's parents completed four 24-hour recalls at the beginning and after the intervention to assess their children’s fruit and vegetable intake. Variety indexes were calculated on the basis of the number of different fruits or vegetables consumed during the four 24-hour recalls.The results showed that the vegetable variety decreased in the control group, while it remained stable in the intervention group. No effects of the programme were observed for the fruit variety.The sensory education programme implemented in families prevented the variety of vegetables from decreasing over time. The results of this preliminary study and its long-term effects need to be confirmed by further investigations, with a different methodology than the 24-hour recall.     

Ultrasound assisted-hollow fibre liquid-phase microextraction for the determination of selenium in vegetable and fruit samples by using GF-AAS

A rapid, simple and sensitive cleanup procedure is demonstrated for the determination of selenium in vegetable and fruit samples by using ultrasound assisted-hollow fibre-liquid microextraction (UA-HF-LPME) and graphite furnace atomic-absorption spectrometry (GF-AAS). Method is based on the microextraction of selenium from sample solution into 3.5 μL of organic solvent containing an N-octyl acetamide (OAA) as an extracting agent, which is placed inside the hollow fibre followed by ultrasound irradiation. The parameters that affected the extraction efficiency of selenium from sample solution were investigated. The best optimum conditions for the extraction of selenium were achieved for 15 min of extraction time with 500 rpm of agitation rate at the pH range of 0.8–3.0. The optimised methodology exhibited good linearity between 0.2 and 5 ng mL⁻¹ selenium with relative standard deviations (RSD) from 2.5% to 4.4%. The proposed method has been successfully applied for the determination of selenium from different types of vegetable and fruit samples. The potentiality of the present (UA-HF-LPME) method was compared with ultrasound assisted-single drop microextraction (UA-SDME). Thus, this approach proves that the UA-HF-LPME technique can be applied as a simple, fast and feasible diagnosis tool for the analysis of selenium in vegetable and fruit samples.     

Daily selenium intake in a moderate selenium deficiency area of Suzhou,China

In this study the daily dietary Selenium (Se) intake in Suzhou was investigated to determine whether residents in such a developed region were susceptible to moderate Se deficiency. Concentrations of Se in typically consumed foods in Suzhou were determined. Based on food Se content and the daily per capita consumption, the estimated Se intake in Suzhou was 43.9 ± 3.8 μg day⁻¹. The results revealed that pork and cereals were the major sources of Se daily intake and contributed 24.7% and 22.6% to the daily Se intake, respectively. The Se content in hair of local residents was 389.9 ± 103.6 μg kg⁻¹ for male and 322.9 ± 101.8 μg kg⁻¹ for female. A significant linear correlation between the daily Se intake and the hair Se concentration was established. The hair Se concentration could be used to bioindicate the level of Se intake for longer period.     

Selenium content in selected Slovenian foodstuffs and estimated daily intakes of selenium

Food is the primary source of selenium for man and, since selenium is an essential trace element, the nutritional selenium status is of importance. Data on this topic are currently lacking in Slovenia. In the present study, selenium contents of some selected foods purchased on the Slovenian market were determined and estimation of the daily dietary intake by analysing 20 diet samples collected in four Slovenian Army barracks was made. In determination of the selenium content in selected food, the highest values were found, as expected, in protein-rich food such as fish, meat and eggs (33–686 ng g⁻¹), but lower values in milk and dairy products (12–30 ng g⁻¹) and vegetables and fruits (0.3–77 ng g⁻¹). Analysis of 20 military total daily diet samples, gave an average selenium daily intake of 87 μg.     

An industrial approach in the search of natural antioxidants from vegetable and fruit wastes

Eleven fruit and vegetable byproducts and two minor crops were screened for industrial polyphenol exploitation potential by determination of their extraction yield, total phenolic content (TPC, Folin–Ciocalteu), and antioxidant activity (NTZ/hypoxanthine superoxide assay, ferric thiocyanate method). Extracts with the highest activity, economic justification and phenolic content were obtained from apple (TPC maximum 48.6 ± 0.9 mg Gallic acid equivalents g⁻¹ dry extract), pear (60.7 ± 0.9 mg GAE g⁻¹), tomato (61.0 ± 3.0 mg GAE g⁻¹), golden rod (251.4 ± 7.0 mg GAE g⁻¹) and artichoke (514.2 ± 14.9 mg GAE g⁻¹). Apple, golden rod and artichoke byproducts were extracted at pilot plant scale and their antioxidant activity was confirmed by determination of their free radical scavenging activity (DPPH) and the inhibition of stimulated linoleic acid peroxidation (TBA and Rancimat^® methods). The preservative effect of the three extracts (determination of the peroxide value in test crème formulations with 0.1–1.0% extract concentrations) was similar to the established antioxidants Oxynex^® 0.1%, Controx^® KS 0.15%, and butylated hydroxytoluene (BHT) 0.01%. This study demonstrates the possibility of recovering high amounts of phenolics with antioxidant properties from fruit and vegetable residuals not only for food but also cosmetic applications.     

The contribution of fruits and vegetables to dietary intake of polyphenols and antioxidant capacity in a Mexican rural diet: Importance of fruit and vegetable variety

There is mounting evidence of the health-protective role of the consumption of fruits and vegetables, which are the major contributors to dietary polyphenol intake. Lack of knowledge about the consumption of phytochemicals in the Mexican diet makes it difficult to evaluate their health significance. The aim of this study was therefore to estimate the contribution of fruit and vegetable consumption to dietary polyphenol intake and dietary antioxidant capacity in a rural population in Mexico. Despite a low intake of fruits and vegetables (< 400 g/day) in the Mexican rural diet, the mean daily intake of dietary polyphenols (> 800 mg/day) and dietary antioxidant capacity (1000-2000 ??mol trolox equivalents/day) from fruits and vegetables was similar to those determined in the Spanish Mediterranean diet. Local fruits and vegetables consumed in the Mexican rural diet are rich in polyphenols with antioxidant properties and are important source of bioactive compounds and dietary fibers. Fruit and vegetable intake needs to be promoted and lifestyle and environmental factors enhanced to improve the health status of obese Mexican rural populations.     

Determination of atrazine and carbaryl pesticide residues in vegetable samples using a multianalyte dipstick immunoassay format

A dipstick assay for the simultaneous determination of atrazine and carbaryl in vegetable samples was developed. The analytical method involved a fast extraction procedure followed by a multi-strip membrane test. The assay took 10 min, with a detection limit (naked eye) of 10 and 200 µg l^-1 for atrazine and carbaryl, respectively. The cross-reactivities to related compounds tested were negligible except for propazine. Quantification of the pesticides was carried out by measuring the dot colour with a spectrophotometer. IC₅₀ values (inhibition constant at 50% of the maximum binding) of 2.04 μg l^-1 for atrazine and 92.8 μg l^-1 for carbaryl were achieved by this approach. Vegetable samples were extracted with MeOH. The proposed methodology was used to analyse atrazine and carbaryl and check for compliance with European Union maximum residue levels for vegetables. Recoveries (75-105%) were in agreement with those obtained by GC/MS or HPLC. Standard curves using 25% methanol/75% TBS were used for food sample assays using a multi-analyte dipstick. IC₅₀ values were 9.2 μg l^-1 for atrazine and 179.2 μg l^-1 for cabaryl.     

Second order derivative spectrophotometric method for determination of vitamin C content in fruits,vegetables and fruit juices

A second-order derivative UV spectrophotometric method for determination of vitamin C [ascorbic acid (AA)] content in a variety of natural samples is described. The method is based on the measurement of a peak–baseline amplitude in the second derivative of the AA spectrum at 267.5 nm. The following corresponding regression equation was obtained within the concentration range 2×10^-5 to 1×10^-4 M AA (3.5–17.6 g/cm³ AA) in 1.0 M HCl solution: ²D_267.5=2.420×10⁴ c+0.025; the correlation coefficient was 0.9993 and the detection limit 4.2×10^-6 M. The results obtained by analysing 21 different species of fruits, vegetables and juices indicated a possibility for a more extensive application of the proposed method. This method is rapid, simple and requires no pretreatment of the analysed material, which makes it suitable for routine analyses. The reliability of the method was confirmed by comparative determinations with the generally accepted 2,6-dichloroindophenol method.     

Determination of selenium in selected food samples from Argentina and estimation of their contribution to the Se dietary intake

An optimised FI-HGAAS method was applied to determine the total selenium concentrations in selected high consumption food (fish, beef, chicken, milk, rice, wheat flour, egg) and to estimate their contribution to the Argentinean dietary intake, whose information is scarce nowadays. Through several optimisation steps a suitable method was achieved showing satisfactory figures of merit for all matrices. Average recovery was 96%, RSD < 5%, LODs ranged 2.0–7.0 μg kg⁻¹ and the accuracy was assessed using DOLT-3 NRC certified reference material. Meat and eggs showed the highest values (in μg kg⁻¹, beef: 42–153; chicken: 62–205; fish: 94–314; canned tuna: 272–282; eggs: 134–217), minor values were found for wheat flour (22–42), rice: (<22), pasta (47–64) and milk (<7–9). An estimated intake of 32 and 24 μg day⁻¹ for adult men and women, respectively, suggested a deficient Se intake, leading to further comprehensive surveys of Se occurrence in Argentina.     

Distribution of selenium and phenolics in buckwheat plants grown from seeds soaked in Se solution and under different levels of UV-B radiation

Seeds of common buckwheat (Fagopyrum esculentum) were soaked in water, sodium selenate (5, 10 or 20 mg Se^VI/L), or sodium selenite (10 or 20 mg Se^IV/L) solutions. Plants grown from soaked seeds were exposed to reduced UV-B radiation, ambient, or enhanced UV-B. The mass fraction of selenium in leaves was much higher in plants obtained from seeds soaked with selenate (up to 185 ng/g) in comparison to selenite (up to 103 ng/g). In plants obtained from seeds soaked in water, regardless of UV-B levels, the highest concentration of selenium was found in leaves, where the values were between 45 and 66 ng Se/g. In buckwheat leaves 44.5–63.6 mg/100 g d.m. of fagopyrin was found, and in stems 14.3–26.4 mg/100 g d.m.; here no influence of seed soaking solution or UV-B exposure was found. The content of total flavonoids in leaves was 7.8–15.9% and in stems 1.4–4.1%.     

Analytical procedure based on slurry sampling for determining selenium in organic vegetable samples by graphite furnace atomic absorption spectrometry

This paper presents a simple, fast and sensitive method to determine selenium in vegetable samples by graphite furnace atomic absorption spectrometry through the direct introduction of slurries of the samples into the spectrometer’s graphite tube. The limits of detection and quantification calculated for 20 readings of the blank of the standard slurries (5 mg mL⁻¹ of microcrystalline cellulose) were 0.33 and 1.10 μg L⁻¹. The proposed method was applied to determine selenium in samples of organically grown vegetables and its results proved compatible with those obtained from samples mineralized by acid digestion in a microwave oven.     

Sensitive cell-based assay using DCFH oxidation for the determination of pro- and antioxidant properties of compounds and mixtures: Analysis of fruit and vegetable juices

Reactive oxygen species play a critical role in cardiovascular diseases, inflammatory diseases, neurodegenerative disorders, cancer and aging. Diets rich in foods containing antioxidants, such as fruits and vegetables, could help prevent these pathologies. It is therefore important to properly assay the antioxidant potentials of these antioxidant foods in order to have a guideline for their proper use. Actual in vitro methodologies are often very specific for one mode of action and do not necessarily reflect the normal biological context in which they are used. In this work, we have developed a cell-based assay using 2′,7′-dichlorofluorescin-diacetate (DCFH-DA), a useful indicator of reactive oxygen species (ROS), in order to determine the antioxidant properties of foods, extracts and molecules. Results show a dose-dependent antioxidant activity for pure compounds (in decreasing order of activity: quercetin > caffeic acid > gallic acid > α-tocopherol) and fruit juices (in decreasing order of activity: strawberries > highbush blueberries > kiwis > peaches). These results are in good agreement with results obtained using the ORAC_FL assay. However, the cell-based assay detected a pro-oxidant effect with broccoli and carrot juices which was not observed using the ORAC_FL assay. Mixed isomers of β,α-carotene isolated from carrots were also found to oxidize DCFH about 212% above control-level. Interestingly, the boiling of broccoli and carrot juices inhibits this pro-oxidant effect and restores the antioxidant properties of the juices. Moreover, the boiling of the β,α-carotene mixed isomers causes their partial degradation and significantly inhibits DCFH oxidation about 68%, suggesting that carotenoids present in broccoli and carrot juices are, in part, responsible for their pro-oxidant effects.     

Selenium species in buckwheat cultivated with foliar addition of Se(VI) and various levels of UV-B radiation

Common (Fagopyrum esculentum Moench) and tartary (Fagopyrum tataricum Gaertn.) buckwheat was treated by spraying the leaves with a water solution containing 15 mg Se per litre in the form of sodium selenate in the flowering period. The selenium content in all parts of plant was found to be less than 200 ng g⁻¹ in non-treated and in the range 2700–4650 ng g⁻¹ in selenium treated buckwheat. Exposure to UV-B radiation lead to higher Se accumulation in flowers of both Se enriched cultivars. For speciation analysis enzymatic hydrolysis was carried out, separation and detection of selenium species was performed by high performance liquid chromatography–ultraviolet treatment–hydride generation atomic fluorescence spectrometry (HPLC–UV–HG-AFS). In flowers and leaves, on average 11% of the Se content was soluble and in the form of Se(VI), representing between 0.6% (flowers) and 3% (leaves) of the Se content. The remaining soluble non-amino acid organic Se was not detected by HPLC–UV–HG-AFS. In seeds 93% of the selenium content was found in the extracts and the main selenium species was SeMet with 93 ± 5% relative to the selenium content.     

湿法回流消解-氢化物-原子荧光光谱法测定 营养强化剂中总硒含量

目的建立湿法回流消解-氢化物-原子荧光光谱法测定营养强化剂中总硒的含量。方法采用硝酸-高氯酸(4:1,V:V)作为消解体系230℃回流消解,采用氢化物-原子荧光光谱法进行测定;并考查消解体系、还原剂和掩蔽剂等对荧光强度的影响。结果采用4.0%盐酸作为酸介质,硼氢化钾浓度为2.0%时荧光强度最强。硒在浓度范围为2.0~40.0 ng/mL呈现良好的线性关系,相关系数为0.9999,方法检出限为0.028 ng/mL,加标回收率为93.0%~102.0%,相对标准偏差为2.2%(n=6)。结论该方法试剂用量少、消解速度快、准确度好、灵敏度高,适合于富硒营养强化剂中总硒含量的测定。     

气相色谱-火焰光度检测器法检测果蔬样品中3种二硫代氨基甲酸盐类农药残留

目的建立检测福美铁、丙森锌、代森锰农药残留的气相色谱-火焰光度检测器(硫滤光片)[GC-FPD(S)]测定方法,提高该类农药的检测专一性。方法用带有强螯合作用的碱性缓冲溶液将不溶于水的二硫代氨基甲酸重金属盐转化为可溶于水的钠盐,在离子对甲基化的作用下将二硫代氨基甲酸钠盐转化为可供GC-FPD(S)测定的含硫酯类物质,优化样品前处理技术和色谱检测条件,并进行方法学论证。结果衍生后的二硫代氨基甲酸盐类农药在一定范围内,其浓度的平方与GC-FPD(S)的响应峰高呈良好的线性关系。福美铁、丙森锌、代森锰的最低检出浓度分别为0.1、0.5、0.5 mg/kg,平均回收率为75.3%～94.6%,相对标准偏差最大为14.1%。结论该方法操作简便、定量准确可靠,各项指标均符合农药残留检测的要求。     

Influence of high-pressure–low-temperature treatments on fruit and vegetable quality related enzymes

Recently, high-pressure–low-temperature (HP-LT) treatments, succeeding a regular freezing unit operation, have been shown to inactivate micro-organisms. In this study, we have evaluated the influence of these treatments on the inactivation of quality-related enzymes. The effect of different pressure/temperature combinations (range 0.1–500 MPa/20 to −26 °C) on the activity of pectinmethylesterase, polygalacturonase, lipoxygenase, peroxidase and polyphenoloxidase in model systems, crude extracts and real-food systems was investigated.Present results show that under these HP-LT processing conditions, no or limited enzyme inactivation is obtained for all enzyme systems studied, except for lipoxygenase which can be completely inactivated at high pressure in combination with low temperature. These data suggest that HP-LT treatments, although inactivating micro-organisms, fail to inactivate most food quality related enzymes. Therefore, a blanching unit operation (e.g. a conventional thermal blanching process prior to freezing) is required to prevent enzyme related quality degradation during frozen storage and cannot be replaced by an integrated freezing-HP-LT treatment.     

Determination of ochratoxin A in organic and non-organic cereals and cereal products from Spain and Portugal

The objective of this work was to know the occurrence of OTA in organic and non-organic cereals and cereal products from Spain and Portugal. A method based on extraction with matrix solid phase dispersion (MSPD) using octylsilica (C₈) followed by liquid chromatography coupled with fluorescence detection (LC–FD) was used to determine OTA from the selected samples. Recoveries of OTA from the studied samples spiked at 10 ng/g level ranged from 78% to 89% with a standard deviation of 3.66. The limits of detection and quantification of this method were 0.05 and 0.19 ng/g, respectively. Furthermore, LC–FD after OTA methylation was used to confirm the identity of OTA in all positive samples. This procedure was applied to 83 organic and non-organic samples including rice, wheat, barley, rye, oats and maize from Spain and Portugal. OTA was detected in 22% of the samples, with concentrations ranging from 0.20 to 27.10 ng/g. From the total OTA contaminated samples (n = 18), 72% were organic cereal and 28% were non-organic cereal samples, with mean concentrations of 1.64 and 0.05 ng/g, respectively. The 66% and 34% of contaminated samples were from Spain and Portugal, respectively, with mean concentrations of 0.93 and 0.64 ng/g for each country. Six contaminated samples exceeded the maximum limits (ML) for OTA fixed by European Commission Regulation (5 μg/kg), among them three were from Spain and three from Portugal.     

气相色谱法测定蔬菜、水果中氟环唑的研究

用乙腈提取,GC-ECD毛细柱测定蔬菜、水果中氟环唑残留的方法。质量浓度在0·016～3·95mg·L-1范围内,浓度与峰面积的线性相关系数为0·999以上,蔬菜和水果回收率在89·1%～117%之间,RSD为9·0%和1·1%;精密度的RSD为3·2%和4·9%;重现性的RSD为5·9%和3·4%;检出限:蔬菜在0·37～0·87μg/kg之间,水果在0·64～0·85μg/kg之间。      

Aniline in vegetable and fruit samples from the Canadian total diet study

An isotope dilution method based on solvent extraction followed by GC–MS analysis was developed and used to determine aniline in vegetable and fruit samples collected from the Canadian total diet study. Aniline was not detected in any of the 23 vegetable samples from the 2005 total diet study at a method detection limit of 0.01 mg kg^–1. Among the 16 fruit samples, it was detected only in apple samples, with an average concentration of 0.278 mg kg^–1. Aniline was not detected in apple samples collected in the 2002, 2003, 2006 or 2007 total diet studies, but it was detected in the apple samples collected from the 2001 and 2004 studies, at concentrations of 0.085 and 0.468 mg kg^–1, respectively. The average aniline concentration for the 2001, 2004 and 2005 apple samples was 0.277 mg kg^–1. Good repeatability of the method was observed with replicate analysis of apple samples, with relative standard deviations (RSD) ranging 3.8–21% and an average of 11%.