Assessment of intake inadequacy and food sources of zinc of people in China

OBJECTIVES: To assess the intake inadequacy and food sources of zinc of people in China. DESIGN AND SUBJECTS: Diets of 68 962 subjects aged 2-101 years (urban 21 103, rural 47,859) in the 2002 China National Nutrition and Health Survey were analysed. Dietary intake was assessed using 24-hour recall for three consecutive days. Zinc intake inadequacy was calculated based on values suggested by the World Health Organization. RESULTS: The median zinc intake ranged from 4.9 mg day- 1 (urban girls, 2-3 years) to 11.9 mg day-1 (rural males, 19+ years). The zinc density of urban residents (2-3 to 19+ years) was 5.0-5.3 mg day-1 (1000 kcal)-1, significantly higher than that of their rural counterparts (4.7-4.8 mg day-1 (1000 kcal)-1). Differences in food sources of zinc from cereal grains (27.4-45.1 vs. 51.6-63.2%) and animal foods (28.4-54.8 vs. 16.8-30.6%) were found between urban and rural residents. Zinc from vegetables and fruits (8.2-13.8 vs. 9.7-12.4%) and legumes (1.3-3.3 vs. 2.5-3.4%) was comparable between urban and rural residents. The proportion of zinc intake inadequacy ranged between 2.8% (urban females, 19+ years) and 29.4% (rural lactating women). Rural residents had higher proportions of zinc intake inadequacy than their urban counterparts. Significantly higher proportions of zinc inadequacy were found in the category of phytate/zinc molar ratio >15 for both rural and urban residents. CONCLUSIONS: About 20% of rural children are at risk of inadequate zinc intake, with phytate as a potential important inhibitor. Moreover, lactating women are also considered a vulnerable group.     

Determination of N-nitrosodimethylamine in nonfat dry milk: collaborative study

Ten laboratories participated in a collaborative study of a method for the determination of N-nitrosodimethylamine (NDMA) in nonfat dry milk. NDMA is eluted with dichloromethane from a mixture of Celite, acidic sulfamic acid, and nonfat dry milk (all packed in a chromatography column), concentrated in a Kuderna -Danish concentrator, and finally analyzed by a GC-thermal energy analyzer technique. Ten samples were studied: 6 were naturally contaminated (NDMA levels 0.38-3.56 ppb) and 4 were spiked with known levels (0.96 and 3.2 ppb) of NDMA. The coefficients of variation (CV) of the complete data for the naturally contaminated samples (excluding the 2 samples containing the lowest levels) were 8.5% and 22.5% for repeatability and reproducibility, respectively. The corresponding CVs for the spiked samples were 14.4% and 20.4%, respectively. The percent recoveries of the added NDMA in the spiked samples (at the 2 levels indicated above) were 101.6 +/- 3.2 (omitting 1 outlier) and 95 +/- 2.1, respectively. The method has been adopted official first action.     

Total and inorganic arsenic in marketed food and associated health risks for the Catalan (Spain) population

Inorganic arsenic (iAs) is considered to be a human carcinogen. In this paper, total (As) and iAs contents of 215 food products and drinks (i.e., seafood, fruits and vegetables, meat products, oils and fats, rice and rice products, seasonings, and alcoholic drinks) marketed in Catalonia (Spain) were quantified by inductively coupled plasma-mass spectrometry. The analytical method described was used for different food products, obtaining feasible results without the need to couple LC-ICP-MS for iAs. Daily As and iAs intakes for the average adult Catalan consumer were estimated at 354 and 6.1 μg/day/person, respectively, using consumption data from the Catalan Nutrition Survey (ENCAT). The highest As content was found in seafood, contributing 96% of dietary As intake, whereas rice presented the highest iAs values, corresponding to 67% of dietary iAs intake. As cooking process may affect iAs content, boiled rice was evaluated, showing an iAs reduction (up to 86%) when using higher water volumes (30:1 water/rice ratio) than those used in previous studies. This iAs exposure was slightly below the exposure risk range stated by the European Food Safety Authority (0.3-8 μg/kg of body weight/day), although the possibility of a risk to the population with high rice consumption cannot be excluded.     

Growth and cocoon production by the earthworm Metaphire houletti (Oligochaeta) in different food sources

 Quantitative observations on the biology of Metaphire houletti were made in cow and horse manure and oak litter in laboratory conditions over a period of 240 days. The study revealed that copulation is not a prerequisite for production of viable cocoons, indicating that M. houletti may be parthenogenetic. The mean growth rate was 2.86 mg worm^–1 day^–1 reaching sexual maturity at 45 days and producing 0.015 cocoons worm^–1 day^–1 (kept singly) and 2.82 mg worm^–1 day^–1, reaching sexual maturity at 45 days and producing 0.03 cocoons worm^–1 day^–1 (kept in batches) in cow manure; 4.08 mg worm^–1 day^–1, reaching sexual maturity at 46 days and producing 0.02 cocoons worm^–1 day^–1 (kept singly) and 2.97 mg worm^–1 day^–1, reaching sexual maturity at 45 days and producing 0.016 cocoons worm^–1 day^–1 (kept in batches) in horse manure; 3.73 mg worm^–1 day^–1 reaching sexual maturity at 45 day and producing 0.023 cocoons worm^–1 day^–1 (kept singly) and 2.73 mg worm^–1 day^–1, reaching sexual maturity at 47 days and producing 0.028 cocoons worm^–1 day^–1 (kept in batches) in oak litter. After an incubation period of 31.9±1.2 days 82% of the cocoons hatched with a mean of 1.12±0.06 hatchlings per cocoon. The earthworms reared in batches did not demonstrate any advantage over those reared singly in all substrates. Higher growth rates were observed in earthworms raised singly than those raised in batches in all substrates. Received: 30 April 1998     

Eating rough: food sources and acquisition practices of homeless young people in Adelaide, South Australia

OBJECTIVE: The aim of this study was to determine the food sources and acquisition practices used by homeless youth in Adelaide. This work is part of a larger study that aimed to examine the extent and nature of food insecurity among homeless youth. DESIGN: Cross-sectional design involving quantitative and qualitative methods. SETTING: Four health and welfare inner-city agencies serving homeless youth in Adelaide, South Australia. SUBJECTS: A sample of 150 homeless youth aged between 15 and 24 years recruited from these agencies. Fifteen were selected via snowball sampling for interview. RESULTS: Use of welfare food sources was high (63%). Food from welfare agencies was supplemented by unorthodox food acquisition methods such as theft (65%), begging for money for food (61%), begging for food items (44%) and asking for help from friends and relatives (34%). Reasons given for non-usage of welfare food services included affordability, access, being too busy, shame or embarrassment. CONCLUSIONS: Food insecurity is a salient issue for some homeless youth in Adelaide. Clarifying food acquisition practices of food-insecure homeless youth is essential for rational planning and improvement of food-related services to meet their needs. Such an understanding also underpins the development of broader public policy responses that improve individual and household skills and resources to acquire food and ensure food security. Nutrition professionals, welfare professionals and policy-makers need to work sensitively with welfare food agencies and others to improve food access and food security for homeless youth.     

Determination of N-nitrosodimethylamine levels in some Canadian 2,4-D amine formulations

Levels of N-nitrosodimethylamine (NDMA) were determined in 112 samples of 2,4-dichlorophenoxyacetic acid, (2,4-D), formulated as the dimethylamine salt, collected over a 2 year period from products on the Canadian market. A sample aliquot is partitioned with dichloromethane, and the co-extracted dimethylamine is removed by cleanup on a silica gel column. The eluates containing NDMA are concentrated, an internal standard of N-nitrosodipropylamine is added, and nitrosamine levels are determined using a gas chromatograph interfaced with a thermal energy analyzer. Recoveries of NDMA and N-nitrosodiethylamine spiked into samples were 103 +/- 16 and 96.3 +/- 9.8%, respectively. Of the 112 samples analyzed, 92 were below 1 part per million (ppm) relative to the amount of 2,4-D in the samples, 16 were between 1 and 5 ppm, and 4 were greater than 5 ppm. The gas chromatographic column used is compared to a conventional packing material for volatile nitrosamine analysis. Formation of NDMA during cleanup and analysis was shown not to occur.     

Intake and sources of phylloquinone (vitamin K(1)) in 4-year-old British children: comparison between 1950 and the 1990s

OBJECTIVES: To compare dietary intake and sources of phylloquinone (vitamin K1) in 4-year-old British children between 1950 and the 1990s, and report their variation by sociodemographic factors.Design: Nationally representative samples of 4-year-olds from the longitudinal Medical Research Council National Survey of Health and Development (NSHD) (1950) and the cross-sectional National Diet and Nutrition Surveys (NDNS, 1992/93 and 1997). SETTING: Great Britain. SUBJECTS: Subjects were 4599 children born on 3-9 March 1946 (NSHD) and 307 children in the 1990s (NDNS). RESULTS: Geometric mean dietary phylloquinone intake was significantly higher in 1950 (39 mug day(-1), 95% confidence interval (CI) 37, 40) compared with the 1990s (24 mug day(-1), 95% CI 22, 25) (P<0.001). This difference remained when intake was expressed per MJ energy intake and per kilogram body weight, and after accounting for sex, region and occupational social class of the family. In 1950, phylloquinone intake in Scotland was significantly lower than in the rest of Britain. By the 1990s these regional differences had disappeared. Food sources of phylloquinone intake changed significantly between 1950 and the 1990s, with fats and oils contributing more and vegetables less, although vegetables contributed most (60% and 48%, respectively) to phylloquinone intake in both surveys. CONCLUSIONS: Phylloquinone intakes of children have decreased significantly since 1950. With the suggested need for adequate phylloquinone intake for optimal development and maintenance of bone and the cardiovascular system, the substantially lower phylloquinone intakes reported in children of the 1990s, compared with 1950, may have implications for the health of these two systems in later adulthood.     

Toxic potency of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in food samples from Catalonia (Spain)

A surveillance program on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in 29 foodstuff samples produced all over the four provinces in Catalonia (Spain) is presented. The study included the analyses of milk, egg, meat (beef, chicken, and pork), mussel, and olive oil samples. A previously developed method for the simultaneous analysis of the 2,3,7,8-substituted PCDDs/PCDFs and the dioxin-like PCBs, as well as the indicator PCBs, was employed. Total toxicity equivalent (TEQ) values were calculated using the toxicity equivalent factors (TEFs) proposed by the World Health Organization (WHO) for dioxin-like PCBs, PCDDs, and PCDFs. The TEQ(PCDD/F) levels were below the limits proposed in the draft of the EC regulation for food commercialization in the European countries. These limits are the following: 2 pg WHO-TEQ/g fat for pork, 3 pg WHO-TEQ/g fat for milk and chicken, 5 pg WHO-TEQ/g fat for egg and beef, and 3 pg WHO-TEQ/g whole product for fish. The contributions of PCDDs/Fs and dioxin-like PCBs in the total toxicity of the samples were calculated for each matrix. The results showed that the TEQ(PCB) contribution varied from 27% in olive oil samples to 81% in mussel samples. These findings suggest that the regulation of TEQ contents in food should include not only the TEQ(PCDD/F), but also the TEQ(PCB).     

Inhibitory effect of yuzu essential oil on the formation of N-nitrosodimethylamine in vegetables

The inhibitory effect of yuzu (Citrus junos Tanaka) essential oil on the formation of N-nitrosodimethylamine (NDMA) in the presence of vegetables (31 species) or saliva was investigated by HPLC. Most vegetable extracts enhanced the formation of NDMA. However, the formation ratio of NDMA in vegetable extracts was decreased by yuzu oil in the range of 59 to 22%. In the presence of yuzu oil and saliva, its ratio ranged between 62 and 24%. These results indicated that yuzu oil inhibited the formation of NDMA even in vegetables and saliva. The contents of ascorbic acid, nitrate, and nitrite in the 31 vegetable species were 0.3-65 mg/100 g, 3-581 mg/100 g, and 10-750 microg/100 g, respectively. Ascorbic acid and nitrite had little effect on the inhibition or formation of NDMA at their intact levels. Nitrate accelerated the formation of NDMA, and the addition of saliva further enhanced it. The mechanism of inhibition of NDMA formation by alpha-terpinene was studied. It was assumed from the results of LC-MS that a new compound formed by the reaction of alpha-terpinene with nitrite would be a derivative of alpha-terpinene with dinitroso groups. The molecular weight of this compound was 194. It is suggested that terpene hydrocarbons in citrus essential oils would contribute to the decrease of NDMA formation.     

Inhibitory effects of citrus essential oils and their components on the formation of N-nitrosodimethylamine

Twenty-eight kinds of citrus essential oils and their components were studied for inhibitory effects on the formation of N-nitrosodimethylamine (NDMA). The reaction mixture consisted of dimethylamine and sodium nitrite adjusted at pH 3.6, in addition to essential oils and an emulsifying agent. The quantification was determined by high-performance liquid chromatography monitored at 220 nm. All of the essential oils inhibited the formation of NDMA in the range of 20-85%. The oils of ujukitsu (Citrus ujukitsu Hort. ex Shirai), yuzu (C. junos Tanaka), mochiyu (C. inflata Hort. ex Tanaka), and ponkan (C. reticulata Blanco cv. F-2426) inhibited the formation of NDMA much more effectively than other citrus oils. The inhibitory proportions of components of citrus essential oils such as myrcene, alpha-terpinene, and terpinolene were as high as 80%.     

Inhibitory effects of Orostachys japonicus extracts on the formation of N-nitrosodimethylamine

In Korea, Orostachys japonicus has been used traditionally as a drug and health food. The aim of this study was to investigate possible inhibitory effects of O. japonicus extracts on the formation of N-nitrosodimethylamines (NDMA). Chloroform extraction was the most effective method for recovering the highest number of phenolic compounds and flavonoids; in these extracts the greatest nitrite-scavenging activity and inhibition of NDMA formation occurred at pH 2.5. The chloroform extract was separated into 10 fractions (J1-J10); fraction J4 inhibited NDMA formation by 90.1 +/- 0.4%. This fraction was then separated into five subfractions (J4-1-J4-5) using a silica gel column. Subfractions J4-2 [(+)-catechin] and J4-4 (3,4-dihdroxybenzoic acid) inhibited NDMA formation by 89.5 +/- 0.9 and 77.6 +/- 0.8%, respectively.     

Nectar plant sources for the threatened Apollo butterfly (Parnassius apollo L. 1758) in populations of central Spain

The use of flowers by the apollo butterfly at several sites along the Sierra de Guadarrama (central Spain) is documented. The Apollo butterfly uses a narrow range of flowers as nectar sources. Males feed more frequently on Armeria arenaria, Jasione montana and Carduus carpetanus. Females feed on the same species as males, but incorporate other species in their diet (Jurinea humilis, Thymus bracteata and Anthyllis lotoides). These observations also indicate that Parnassius apollo generally direct their foraging activities towards a limited number of the available plants but that the plants used can differ slightly between sites and change within sites through time. These data on resources for the adult butterflies should serve for the management of the species in future conservation programmes.     

Rapid gas chromatographic method using nitrogen-phosphorus detection for N-nitrosodimethylamine in 2,4-D and MCPA herbicide formulations

A simple and rapid analytical method has been developed for the determination of N-nitrosodimethylamine (NDMA) in amine salts of phenoxy herbicide formulations of 2,4-D and MCPA, plus mixtures of these with mecoprop and dicamba amine salts. Sample preparation consists of direct extraction using pre-packed disposable extraction tubes eluted with dichloromethane followed by cleanup on a disposable silica gel mini-column using ethyl acetate as eluting solvent. Samples are injected on-column for gas chromatography with a Megabore fused silica column; the NDMA is measured by a thermionic specific detector (TSD) that is selective for nitrogen-phosphorus (NP). A detection limit of 0.1 microgram/mL was easily attainable without any concentration step because the solvent volume is minimal. TSD and thermal energy analyzer (TEA) results have been compared and confirmed by gas chromatography/mass spectrometry. Recovery studies were performed as well as a reproducibility study on one of the 2,4-D formulations.     

Ecological history of transhumance in Spain

Transhumance is a traditional livestock practice which permits the complementary exploitation of resources between the highlands and lowlands. It is common to all Mediterranean countries, being for physical and human reasons most fully developed in the Iberian Peninsula. The practice evolved a complex and widespread network of livestock routes (cañadas) in Spain, which were governed by livestock organisations benefiting from special legislation from the 13th century.Designed to cope with the migratory movements of merino sheep, transhumance helped shape a characteristic landscape which has maintained one of the Mediterranean's most complex and interesting ecosystems. Agricultural intensification, the spread of the railway network, urban expansion and industrialisation have led to a drastic reduction in transhumance practices, itself leading to the alteration of the ecosystems these practices had shaped and to an abandonment of the extensive network of drovers' roads.However, periodic migratory movements still continue, although the conservation of the drovers' roads is vital for the maintenance of such activities. These could be complemented by pedagogical and recreational activities to maintain the system and to offer a new view of natural areas and Spanish rural life.