Neighbourhood fruit and vegetable availability and consumption: the role of small food stores in an urban environment

OBJECTIVE: Previous studies on the relationship of dietary intake to the neighbourhood food environment have focused on access to supermarkets, quantified by geographic distance or store concentration measures. However, in-store food availability may also be an important determinant, particularly for urban neighbourhoods with a greater concentration of small food stores. This study synthesises both types of information - store access and in-store availability - to determine their potential relationship to fruit and vegetable consumption. DESIGN: Residents in four census tracts were surveyed in 2001 about their fruit and vegetable intake. Household distances to food stores in these and surrounding tracts were obtained using geographical information system mapping techniques. In-store fruit and vegetable availability was measured by linear shelf space. Multivariate linear regression models were used to measure the association of these neighbourhood availability measures with consumption. SETTING: Four contiguous census tracts in central-city New Orleans. SUBJECTS: A random sample of 102 households. RESULTS: Greater fresh vegetable availability within 100 m of a residence was a positive predictor of vegetable intake; each additional metre of shelf space was associated with 0.35 servings per day of increased intake. Fresh fruit availability was not associated with intake, although having a small food store within this same distance was a marginal predictor of fruit consumption. CONCLUSIONS: The findings suggest the possible importance of small neighbourhood food stores and their fresh produce availability in affecting fruit and vegetable intake.     

Demographic, familial and trait predictors of fruit and vegetable consumption by pre-school children

OBJECTIVE: To examine the contribution to fruit and vegetable eating in children of potential predictive variables within the domains of demographics, parental feeding practices and personality traits. DESIGN: Cross-sectional survey. SETTING: Questionnaires were distributed to parents through 22 London nursery schools. SUBJECTS: Questionnaires were completed and returned by 564 parents or principal caregivers of 2-6-year-old children. RESULTS: Significant predictors of children's fruit and vegetable intake emerged from all three domains examined. Demographic variables associated with child's vegetable consumption were mother's education and child's age and gender. Only ethnicity was significantly associated with fruit consumption. Parental consumption, breast-feeding and early introduction to fruit and vegetables were related to intake of both. Family meal times were associated with higher intake of vegetables, but not of fruit. Two characteristics of children themselves (food neophobia and enjoyment of food) were strongly related to the consumption of fruit and vegetables. Subsequent multivariate analyses revealed that parental intake and child food neophobia independently predicted intake of both foods. In the presence of these, fruit consumption was affected by breast-feeding and early introduction to fruit, whereas vegetable consumption was related only to child's gender and enjoyment of food. CONCLUSIONS: These findings may be used to inform future interventions aimed at increasing children's consumption of fruit and vegetables. Parents should be made aware of the possible impact of their own behaviour on the eating habits of their children.     

A school salad bar increases frequency of fruit and vegetable consumption among children living in low-income households

OBJECTIVE: To measure change in fruit and vegetable (F&V) consumption among elementary-school children after the introduction of a salad bar programme as a lunch menu option in the US Department of Agriculture's (USDA) reimbursable lunch programme in Los Angeles Unified School District (LAUSD). DESIGN: A cross-sectional sample of children was interviewed before and after a salad bar intervention (1998 and 2000, respectively) utilising a 24-hour food recall questionnaire. Frequencies of F&V consumption were calculated. SETTING: The evaluation took place in three LAUSD elementary schools participating in the salad bar programme and the USDA reimbursable lunch programme. SUBJECTS: Three hundred and thirty-seven children in 2nd-5th grade (7-11 years old). RESULTS: After the salad bar was introduced, there was a significant increase in frequency (2.97 to 4.09, P < 0.001) of F&V consumed among the children studied. The increase in frequency of F&V consumed was almost all due to an increase during lunch (84%). Mean energy, cholesterol, saturated fat and total fat intakes were significantly lower in the children after the salad bar was introduced in the schools compared with the intakes in the children before the salad bar was introduced.Conclusion: A salad bar as a lunch menu option in the USDA reimbursable lunch programme can significantly increase the frequency of F&V consumption by elementary-school children living in low-income households.     

光对采后果蔬叶绿素降解动力学研究

叶绿素对光不稳定,易降解,为探讨引起该类色素降解的主要因素,并在生产、加工及贮藏中予以克服和避免,更好地保证产品在货架期内的感官品质,提高经济效益。该试验利用紫外分光光度计、全自动色差计(CIE-L*a*b*)和高效液相色光谱法定量分析叶绿素光降解的变化情况,并对叶绿素光降解动力学过程进行了分析。结果表明:叶绿素光降解反应符合一级动力学模型;紫外线对叶绿素有很强的破坏作用,可见光中蓝光、红光对该色素降解作用次之,而红外线对叶绿素破坏作用较小;光照强度为500、1000、1500、2000、2500、3000、3500、4000、4500、5000 lux,温度为25℃的条件下,叶绿素降解半衰期分别为16.9、14.1、11.5、9.8、8.8、8.2、7.1、6.0、5.2、4.0 h;相同条件下叶绿素a的降解速率约为叶绿素b降解速率的3～4倍;叶绿素在温度60℃以下降解不明显;氧气在叶绿素光降解过程中有着非常重要的作用。本试验结果对绿色果蔬包装材料的选择和产品感官品质控制有一定的参考价值。     

Evaluation of brief dietary questions to estimate vegetable and fruit consumption - using serum carotenoids and red-cell folate

OBJECTIVE: To evaluate responses to self-administered brief questions regarding consumption of vegetables and fruit by comparison with blood levels of serum carotenoids and red-cell folate. DESIGN: A cross-sectional study in which participants reported their usual intake of fruit and vegetables in servings per day, and serum levels of five carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and lycopene) and red-cell folate were measured. Serum carotenoid levels were determined by high-performance liquid chromatography, and red-cell folate by an automated immunoassay system. SETTINGS AND SUBJECTS: Between October and December 2000, a sample of 1598 adults aged 25 years and over, from six randomly selected urban centres in Queensland, Australia, were examined as part of a national study conducted to determine the prevalence of diabetes and associated cardiovascular risk factors. RESULTS: Statistically significant (P<0.01) associations with vegetable and fruit intake (categorised into groups: /=4 servings per day) were observed for alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and red-cell folate. The mean level of these carotenoids and of red-cell folate increased with increasing frequency of reported servings of vegetables and fruit, both before and after adjusting for potential confounding factors. A significant association with lycopene was observed only for vegetable intake before adjusting for confounders. CONCLUSIONS: These data indicate that brief questions may be a simple and valuable tool for monitoring vegetable and fruit intake in this population.     

果蔬产品品质无损检测技术的研究进展

该文较为全面地介绍了国内外基于果蔬产品物理特性的无损检测技术的研究现状及方法,如电学特性检测技术、光学特性检测技术、声波振动特性检测技术、核磁共振(NMR)技术、电子鼻技术、撞击技术以及一些其他技术与方法,并对未来的发展方向予以了展望,认为综合应用多种高科技技术进行果蔬产品的无损检测与分选是未来发展的趋势。