Development and validation of a food frequency questionnaire.

Regular diet monitoring requires a tool validated in the target population. A 73-item, semiquantitative, self-administered food frequency questionnaire (FFQ), was adapted in French and English from the Block National Cancer Institute Health Habits and History Questionnaire. The FFQ was used to capture usual long-term food consumption among adults living in Quebec. A representative sample of adults aged 18 to 82 (57% female) was recruited by random digit dialling in the Montreal region. Approximately 64% of recruits completed and returned the instrument by mail (n=248). The FFQ was validated in a subsample (n=94, 61% female) using four nonconsecutive food records (FRs). Median energy intakes (in kcal) for men and women, respectively, were FFQ (total sample) 2,112 and 1,823, FFQ (subsample) 2,137 and 1,752, and FR (subsample) 2,510 and 1,830. Spearman correlation analyses between FFQ and FR nutrients were positive (with r ranging from 0.32 for folate to 0.58 for saturated fatty acids) and statistically significant (p<0.001), with better results among women. On average, cross-classification of energy and 24 nutrients from the FFQ and means of four FRs placed 39% into identical quartiles and 78% into identical and contiguous quartiles, with only 4% frankly misclassified. These results suggest that the FFQ is a relatively valid instrument for determining usual diet in Quebec adults.     

Cultural relevance of a fruit and vegetable food frequency questionnaire.

PURPOSE: Canada's multicultural population poses challenges for culturally competent nutrition research and practice. In this qualitative study, the cultural relevance of a widely used semi-quantitative fruit and vegetable food frequency questionnaire (FFQ) was examined among convenience samples of adults from Toronto's Cantonese-, Mandarin-, Portuguese-, and Vietnamese-speaking communities. METHODS: Eighty-nine participants were recruited through community-based organizations, programs, and advertisements to participate in semi-structured interviews moderated in their native language. Data from the interviews were translated into English and transcribed for analysis using the constant comparative approach. RESULTS: Four main themes emerged from the analysis: the cultural relevance of the foods listed on the FFQ, words with multiple meanings, the need for culturally appropriate portion-size prompts, and the telephone survey as a Western concept. CONCLUSIONS: This research highlights the importance of investing resources to develop culturally relevant dietary assessment tools that ensure dietary assessment accuracy and, more important, reduce ethnocentric biases in food and nutrition research and practice. The transferability of findings must be established through further research.     

Food frequency questionnaire for assessing infant iron nutrition.

A food frequency questionnaire (FFQ) was developed and tested for assessing iron nutrition in infants through comparison with a three-day food record (3d-FR) and measures of iron status. Parents of 148 infants aged eight to 26 months completed a 3d-FR and an FFQ. Blood was collected for measures of hemoglobin (Hgb), ferritin, and transferrin receptor (sTfR). Iron deficiency anemia and iron depletion (ferritin < or =12 microg/L) were found in 9% and 26% of infants, respectively. The intakes of energy, total iron, heme and non-heme iron, vitamin C, and dietary fibre determined by the FFQ were associated with the intakes of the same nutrient determined by the 3d-FR (p<0.05). The intakes of energy, total iron, non-heme and heme iron, vitamin C, and fibre were significantly higher when estimated by the FFQ than by the 3d-FR. Total and heme iron intakes determined by the FFQ were significantly associated with serum ferritin, sTfR, and the sTfR:ferritin ratio (p<0.05). However, iron intakes explained <10% of the variability in iron status. Despite relative validity of the FFQ for evaluating differences in energy, iron, vitamin C, and fibre intake compared with a 3d-FR, FFQs need further development before they can be used to advance assessment of iron intake and status in infants.     

Development of a food frequency questionnaire module and databases for compounds in cooked and processed meats

There is ample evidence from basic research and animal carcinogenicity studies that heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are mutagens and carcinogens. However, there was a paucity of human data due to a lack of appropriate investigative tools. We developed the first validated cooked meat module within a food frequency questionnaire (FFQ) in the United States of America and created databases to be used in conjunction with this FFQ to estimate intake of HCAs and benzo[a]pyrene, a marker of PAHs. It became clear that other aspects of meat may also contribute to carcinogenesis; in particular, we are pursuing two additional areas: processed meat and iron exposure in relation to cancer risk. To investigate these hypotheses, we have expanded the cooked meat module to include detailed information on processed meats and fish. In addition, we are developing two databases, one for total iron and heme iron in cooked meat and the other for nitrite, nitrate, and N-nitroso compounds in processed meats. In this report, we will outline the methods used to develop the meat questionnaires, the databases, a software package for generating the intake values, and the methods used to generate nutritional data from nationally representative samples.     

Enhancing the capacity of food consumption surveys of short duration to estimate long term consumer-only intakes by combination with a qualitative food frequency questionnaire

In principle, a proper risk assessment for a food chemical requires that the time-frame for food chemical intake estimates matches the time-frame for the toxicological assessments upon which the safety statements (ADI, PTW I, etc.) are based. For food additives, the toxicological assessments are based on exposure over a lifetime. While food consumption data cannot be collected over the lifetimes of individuals, the information should reflect habitual intakes as closely as possible. This study investigated the possibility of combining a 3-day food diary with a food frequency questionnaire to estimate mean consumer-only food intakes comparable to estimates based on a 14-day diary. The study population consisted of 948 teenagers and analysis was based on 32 clearly defined foods. For 47% of the foods, the difference was ≤ 1g/day. When expressed as portion sizes, 56% of the foods showed differences representing 14% of an average portion. When between-method differences (portions/day) were plotted against the mean of the methods, the mean between-method difference was 0.02 (± 0.06) portions/ day with limits of agreement of -0.10 to 0.14. This preliminary investigation suggests that the combined 3-day diary and FFQ method provides comparable estimates of mean consumer only intakes to a 14-day diary. Therefore, a qualitative FFQ may be a useful adjunct to a food consumption survey of short duration if estimates of longer term food intakes are required.     

Validation of a Turkish version of the food choice questionnaire

The purpose of this study was to test the validity and reliability of the food choice questionnaire (FCQ) for Turkish consumers. A total of 963 voluntary consumers participated in this study. Confirmatory factor analysis (CFA) with a diagonally weighted least squares estimation method was used to assess the construct validity. Results showed that factor loadings were similar to the original FCQ. CFA results indicated an acceptable fit. Test-retest reliability was tested with intraclass correlation coefficient (ICC) and the ICC values ranged from 0.89 to 0.95. Results show that the Turkish version of FCQ was validated and it appears to be a reliable research instrument.     

Observation versus self-report: validation of a consumer food behavior questionnaire

A reliable and validated set of food safety behavior questions that could be used with confidence when evaluating food safety education programs was identified in this study. A list of 29 food-handling and consumption behaviors rank-ordered within five pathogen control factors by nationally recognized food safety experts was the basis for the development of the behavior questions. Questions were evaluated for reliability and several forms of validity. During a kitchen activity session, 70 graduates of a nutrition education program completed four food preparation tasks while being observed and videotaped. The individuals also participated in an in-depth interview to validate behaviors that could not be observed during the food preparation activity, e.g., refraining from preparing food for others when experiencing diarrhea. Criterion validity was established by comparing questionnaire responses to observed behavior and interview responses. Twenty-eight questions met the validity criterion (> or = 70% agreement between observed and interviewed responses and self-reported responses), with three or more questions from each of five pathogen control factor areas. Observation assessments revealed that hand washing was more likely to be performed prior to beginning food preparation than between working with raw meats and fresh produce. Errors in methods of washing hands, utensils, and preparation surfaces between food preparation tasks were common. Most participants did not use thermometers to evaluate doneness but still cooked to safe internal temperatures. The results provide a tool that educators can use to evaluate food safety programs and will help guide the development of more effective food safety education programs targeting needed improvements in behavioral skills.     

Comparative analysis of zinc status, food products' frequency intake and food habits of 11-year-old healthy children.

Children are particularly vulnerable to zinc (Zn) deficiency during periods of rapid growth and development such as infancy and adolescence. The aim was to find the relationship between food frequency, intake, food habits and zinc status in 11-year-old healthy children from southern Poland. The study group comprised children (n = 157) in the age range 11.0 +/- 0.4 years. The level of Zn in serum, erythrocytes and hair samples was measured using atomic absorption spectrophotometry. The parents of children examined completed a special food frequency questionnaire. The Zn concentration in hair (boys 182.98 +/- 65.63 microg x g(-1), n = 78; girls 203.82 +/- 39.80 microg x g(-1), n = 79; p = 0.0171), erythrocytes (8.60 +/- 2.76 mg x l(-1), n = 50) and blood serum (0.79 +/- 0.15 mg x l(-1)) correlated significantly (p < 0.05) with frequency intake of different products (hair: meat, rolls, fruit juices without additives, brawn, pate, barley, black pudding, fish canned, chips, margarine used for cooking, bacon; erythrocytes: fruits, matured cheese, dishes of meal, white cottage cheese, fruit juices without additives, cakes and cakes with cream, margarine used for bread spread; blood serum: bread, fruits, milk, kefir, yoghurt). The relationship of the Zn amount in food products, food frequency intake and the concentration in different healthy children tissues is influenced by many internal and external factors.     

射频加热技术在食品工业中的应用

射频加热技术作为一种新型热加工技术,其在食品干燥、杀菌、杀虫、解冻等领域的潜力被广泛开发,并且在这些领域已有部分工业应用。文章综述了射频加热技术机理、在食品领域的应用以及射频加热过程的数学建模方法,指出了射频加热技术目前存在的加热不均匀性等问题及解决方案,并对未来研究的方向进行了展望。     

Sensitivity and specificity of a short questionnaire for food insecurity surveillance in Iran

BACKGROUND: Food insecurity is frequent in both developed and developing countries, affecting from 5% to 25% of the general population. It has considerable health impacts on the physical, social, and psychological status of individuals in communities suffering from food insecurity. OBJECTIVE: The aim of this study was to document the epidemiologic features of food insecurity in the northwest region of Iran and to evaluate the sensitivity and specificity of a short-form (six items) questionnaire for screening of food insecurity in the region. METHODS: This cross-sectional study was conducted on 300 subjects (132 male and 168 female) selected randomly in the Asadabadi area of the northwest of Iran. Information on food consumption was obtained by a 24-hour food-recall questionnaire for 3 days in a week. This information was compared with the data from the Household Food Security Scale (six-item short questionnaire) to assess the applicability of this short scale for the surveillance of food insecurity. Hunger was defined as inadequate intake of energy. Hidden hunger was defined as adequate intake of energy and inadequate intake of one (or more) of four key nutrients (protein, calcium, vitamin A, and vitamin B2). RESULTS: The prevalence of hunger and hidden hunger in the area according to the 24-hour food-recall questionnaire was 26% and 42%, respectively. Only 32% of the study population was secure in terms of having access to all key nutrients. The sensitivity, specificity, and accuracy of the short questionnaire for screening for hunger in the population were 98.7%, 85.5%, and 89%, respectively; and the corresponding values for hidden hunger were 23.5%, 96.9%, and 56.3%. CONCLUSIONS: Our findings indicate that food insecurity is prevalent in the northwest of Iran. The short questionnaire (six items) may be used as a simple, low-cost, rapid, and useful tool for the screening of food insecurity and energy intake in similar areas.     

2002年拉萨市居民肉类和奶类食物消费量及消费频次研究

目的:描述2002年拉萨市居民肉类和奶类食物的消费量和消费频次。方法:利用食物频率表(FFQ)对拉萨市居民调查为期1年的食物消费量和消费频率,计算肉类食物(包括猪肉、牛羊肉、禽肉和动物内脏)和奶类食物(包括鲜奶、奶粉、酸奶和奶酪等)的每日人均消费量和消费频率。结果:2002年拉萨市居民肉类食物的每日人均消费量分别是,猪肉为26.2g,牛羊肉为63.4g,禽肉为11.4g,动物内脏类为1.2g,平均每周的消费次数分别为,猪肉为3.1次,牛羊肉为5.8次,禽肉为1.4次,动物内脏类为0.4次。奶类食物的每日人均消费量分别是,鲜奶为22.9g,奶粉为23.0g,奶酪为27.8,酸奶为19.9g,平均每周的消费次数分别为,鲜奶为2.1次,奶粉为4.2次,奶酪为4.1次,酸奶为1.2次。结论:拉萨市居民牛羊肉的平均每日人均消费量高于其他肉类食物,每周的消费次数也较高。4种奶类食物的消费量相当,以奶粉和奶酪的消费频次高于鲜奶和酸奶。     

Organic food.

"Organic" or "organically grown" foods are commonly represented as "food grown without pesticides; grown without artificial fertilizers; grown in soil whose humus content is increased by the additions of organic matter; grown in soil whose mineral content is increased with applications of natural mineral fertilizers; has not been treated with preservatives, hormones, antibiotics etc." The substitution of "organic" for "chemical" fertilizers during the growth of plants produces no change in the nutritional or chemical properties of foods. All foods are made of "chemicals." Traces of pesticides have been reported to be present in about 20 to 30% of both "organic" and conventional foods. These traces are usually within the official tolerance levels. Such levels are set low enough to protect consumers adequately. Indeed, there is no record of a single case of injury to a consumer resulting from the application of pesticides to food crops at permitted levels.     

食品射频灭菌过程加热均匀性调控研究进展

作为一种新型物理灭菌技术,射频(radio frequency, RF)加热具有穿透深度大、传热效率高、无化学残留、适合批量处理等特点,可有效杀灭食品中的致病菌。然而,受物料本身特性参数、射频系统结构、物料周围介质等因素影响,非均匀加热一直是射频灭菌规模化应用面临的主要挑战之一。为进一步明确食品射频灭菌过程均匀性调控的最新研究进展,本文基于射频杀菌的机制及特点,对调控射频加热均匀性的具体措施进行了梳理,包括调控物料介电参数、改变环境介质、优化射频加热系统等,为加热均匀性调控的进一步研究及射频灭菌技术的进一步应用奠定基础。     

A radio frequency identification and sensor-based system for the transportation of food

The damage caused by the degeneration of the quality of perishable products usually results in a great loss to transportation enterprises. To improve the delivery system for perishable products, a real-time monitoring and online decision support system with Radio frequency identification (RFID), a sensor network and a decision rule base has been developed in this study. First of all, the value degeneration process is described, using several mathematical models for handing different ways of perishing. Based on the mathematical models, and data from RFID and the sensor network, the quality of the goods can be predicted by the forecast module. When something abnormal occurs, the warning function will send an alarm signal to the users, then, the rule-based decision module will provide the user with suggestions as how to cope with the abnormality. The results from the simulation have shown that the monitoring and decision support system is an efficient tool for reducing the transportation losses of perishable products for the enterprises in cold chain.     

Analysis of radio frequency (RF) power distribution in dry food materials

The objectives of this research were to investigate the influence of various factors on radio frequency (RF) power distribution in dry food materials, placed in a 12 kW, 27.12 MHz parallel plate RF system, using a validated finite element computer model. The factors investigated were sample size, shape, relative position between the RF electrodes, and dielectric properties (DPs) of the sample and the surrounding medium. Effects of electrode gap and top electrode configuration on the RF power distribution behavior of the sample were also studied. The RF power uniformity in the samples was compared using RF power density uniformity index (PUI). Simulated results showed that the RF power uniformity in cuboid shaped samples, placed on the bottom electrode, first decreased and then increased with the increase in sample size. The sample shape and its vertical position between the fixed gap parallel plate electrodes also affected the RF power distribution and uniformity. A cuboid sample had higher RF power densities at the edges, while an ellipsoid had higher power densities in the center parts. Simulated results showed that the smaller values of DPs resulted in better RF power uniformities in the samples. Reducing the electrode gap improved the RF power uniformity of the sample. While studying the influence of the top electrode configuration on the RF power distribution and uniformity, the results showed that optimum RF power uniformity in a particular sample size could be achieved with a particular top electrode bending position and angle. The results are useful in understanding complex RF heating, designing and scaling up of efficient RF systems.     

Radio frequency reheating behavior in a heterogeneous food: A case study of pizza

Radio frequency (RF) energy could rapidly raise the material bulk temperature with deep power penetration and high energy efficiency. Although many studies on RF treatments have been carried out on different agricultural commodities or food, application of RF energy for studying heating behavior of heterogeneous food matrix is limited. Pizza is typically a heterogeneous food model with a base, cheese matrix and added toppings, and has been rarely evaluated for RF reheating. This study was aimed at using computer simulation for evaluating the RF reheating uniformity of a typical model pizza after baking based on measured thermal and dielectric properties (DPs) of its components (pizza base, cheese, salami and onion). The validation experiments were carried out up to a maximum reheating temperature of 85 °C in a 6 kW, 27.12 MHz RF system. The results showed that both dielectric constant and loss factor of pizza components increased with temperature, and at elevated temperatures, DP values for salami were the highest cheese, onion and pizza base. Both computer simulation and experiment provided similar temperature-time histories (with the maximum RMSE of 0.034 °C) in pizza base, cheese, salami and onion after RF reheating for 7.33 min. The fast RF reheating rate was observed in cooked salami both from the temperature-time history and predicted temperature distribution due to closed dielectric loss to constant value. The high sample temperature resulted in low moisture content. The RF heating uniformity could be improved by moving or rotating pizza and specially locating components in the further studies.     

射频解冻过程中食品加热均匀性影响因素的研究进展

射频加热(radio frequency, RF)技术作为一种新兴加热技术，是一种高效、低能耗的可替代传统加热的热处理方法。该方法在提高工业效率的同时又可保证食品的质量安全性及品质，可满足食品工业中的解冻以及其他加工需求，在食品工业中具有越来越大的应用潜力和发展前景。但解冻过程中存在的“边缘效应”等加热不均匀问题仍是制约该技术的一个瓶颈。本研究对射频解冻及其原理进行了介绍，并总结了影响解冻过程中加热均匀性等问题的因素，包括电磁场、射频功率、电极电压及间隙、食品的介电特性等，以期为射频解冻技术的研究及改善加热均匀性等未来研究发展方向提供参考。     

2003年江苏省食物中毒高发原因重点分析

为了解2003年江苏省食物中毒发生起数比往年有大幅度上升的原因,对造成食物中毒的原因进行了调查,并作了全面的分析,最后提出预防食物中毒的措施与建议。