Occurrence of bound 3-monochloropropan-1,2-diol content in commonly consumed foods in Hong Kong analysed by enzymatic hydrolysis and GC-MS detection

The aim of this study was to determine the level of bound 3-monochloropropan-1,2-diol in foodstuffs commonly consumed in Hong Kong, China, by an enzymatic hydrolysis indirect method which proved to be free from interferences. A total of 290 samples were picked up randomly from the local market and analysed. About 73% of these samples were found to contain detectable amounts of bound 3-MCPD. Amongst the 73 food items, bound 3-MCPD was not detected in 13 food items, including extra virgin olive oil, beef ball/salami, beef flank, ham/Chinese ham, nuts, seeds, soy sauce, oyster sauce, butter, yoghurt, cream, cheese and milk. For those found to contain detectable bound 3-MCPD, the content ranged up to 2500 µg kg^?1. The highest mean bound 3-MCPD content among the 14 food groups was in biscuits (440 [50–860] µg kg^?1), followed by fats and oils (390 [n.d.–2500] µg kg^?1), snacks (270 [9–1000] µg kg^?1), and Chinese pastry (270 [n.d.–1200] µg kg^?1). Among the samples, the highest bound 3-MCPD content was in a grape seed oil (2500 µg kg^?1), followed by a walnut flaky pastry (1200 µg kg^?1) and a grilled corn (1000 µg kg^?1). Basically, the results of this study agreed well with other published results in peer-reviewed journals, except for cheese, cream, ham, nuts and seeds.     

香港特区食品安全监管体系及其借鉴

本文通过对香港特区食品安全监管的机构体系、法规标准体系、风险管理和风险交流等方面进行分析研究,比较香港特区与内地食品安全监管体系的差异,研讨我国食品安全监管制度、体制、机制方面存在的不足,分析香港特区食品安全监管可供借鉴的方面,提出完善我国食品安全监管体系的建议。     

Nitrate and nitrite levels in commonly consumed vegetables in Hong Kong

Levels of nitrate and nitrite in 73 different vegetables, a total of 708 individual samples grouped into leafy, legumes, root and tuber, and fruiting vegetables, which are traded mainly in Hong Kong, were measured. Where available, five samples of each vegetable type were purchased from different commercial outlets during the winter of 2008 and summer of 2009. Levels of nitrate and nitrite were determined by ion chromatography and flow injection analysis, respectively. Nitrate and nitrite levels of all samples ranged <4–6300 and <0.8–9.0 mg?kg^?1, respectively. Nitrate concentrations for the different groups, in descending order, were leafy?>?root and tuber?>?fruiting and legume vegetables. More than 80% of vegetables had mean nitrate concentrations less than 2000?mg?kg^?1, but mean nitrate concentrations of three types of leafy vegetables, namely Chinese spinach, Shanghai cabbage and Chinese white cabbage, were >3500?mg?kg^?1. On the other hand, nitrite concentrations were generally low –?<1?mg?kg^?1 on average. Nitrate in vegetables (i.e. Chinese flowering cabbage, Chinese spinach and celery) can be reduced significantly (12–31%) after blanching for 1–3?min, but not after soaking.     

Investigation of pyrrolizidine alkaloids including their respective N-oxides in selected food products available in Hong Kong by liquid chromatography electrospray ionisation mass spectrometry

ABSTRACT

This study determined the levels of pyrrolizidine alkaloids (PAs), including their respective N-oxides, in foodstuffs available in Hong Kong by liquid chromatography-electrospray ionisation tandem mass spectrometry. A total of 234 samples (48 food items) were collected randomly from a local market and analysed. About 50% of samples were found to contain detectable amount of PAs. Amongst the 48 food items, PAs were not detected in 11 food items, including barley flour, beef, cattle liver, pork, pig liver, chicken meat, chicken liver, milk, non-fermented tea, Melissa tea and linden tea. For those found to contain detectable PAs, the summed PA content ranged up to 11,000 µg kg^?1. The highest sum of PA content among the 37 food items calculated with lower bound was cumin seed, then followed by oregano, tarragon and herbs de Provence with ranges of 2.5–11,000, 1.5–5100, 8.0–3300 and 18–1300 µg kg^?1 respectively. Among the samples, the highest sum of PA content was detected in a cumin seed sample (11,000 µg kg^?1), followed by an oregano (5100 µg kg^?1), a tarragon (3300 µg kg^?1) and a herbs de Provence (1300 µg kg^?1). In general, the results of this study agreed well with other published results in peer-reviewed journals, except that the total PAs in honey and specific tea infusion in this study were comparatively lower.     

Dietary exposure of Hong Kong adults to fatty acid esters of 3-monochloropropane-1,2-diol

A total of 290 individual food samples were collected in Hong Kong, China, for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters analysis. Most samples were processed food and in ready-to-eat form. The results show that the levels of 3-MCPD fatty acid esters were high in biscuits, fats and oils, snacks and Chinese pastry with mean bound 3-MCPD levels of 440, 390, 270 and 270 μg kg^?1, respectively. The dietary exposures to bound 3-MCPD of average and high adult consumers were estimated to be 0.20 and 0.53 μg kg bw^?1 day^?1, respectively. The primary toxicological concern of 3-MCPD fatty acid esters is its potential to release 3-MCPD in vivo during digestion in the gastrointestinal tract. 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats. Assuming that 100% of the 3-MCPD was released from 3-MCPD fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10% and 26% of the provisional maximum tolerable daily intake (PMTDI) of 3-MCPD established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2 μg kg bw^?1 day^?1), respectively. The results suggest that both average and high adult consumers are unlikely to experience major toxicological effects of 3-MCPD.     

粤港澳大湾区食品监管中口岸通关融合模式研究

目前,粤港澳大湾区一体化建设正在深入推进,但粤港澳大湾区食品监管中的口岸通关融合模式存在如监管标准不一、通关程序繁琐和信息不对称等问题,导致食品监管效率偏低问题日益突出。对此,可以通过统一粤港澳三地食品安全监管标准、构建一体化的口岸通关程序机制、加强信息共享和协同监管等措施推动口岸通关融合模式有效创新。同时,为了强化对粤港澳大湾区食品监管效率提升的配套建设,实践中仍需要进一步提升口岸服务水平,为食品通关提供更加便利的一站式服务。     

从香港盛会看丝绸收藏和研究的国际化趋势

中国古代丝绸文物展和中国古代丝绸学术讨论会首次在香港举行。这次盛会汇集了世界各地丝绸史研究专家，从中了解到，对中国古代丝绸的收藏已受到国外收藏家的重视，同时对中国丝绸史的研究近年来也方兴未艾，呈现出一种国际化的趋势。     

Dietary exposure to non-dioxin-like PCBs of the Hong Kong adult population from a total diet study

Dietary exposure of Hong Kong adults to the sum of the six indicator PCBs (Σ₆ PCBs; PCB 28, 52, 101, 138, 153, and 180) was estimated in this study using the Total Diet Study (TDS) approach. Seventy one commonly-consumed food items of animal origin were sampled in four seasons and prepared as consumed in 2010–2011. The results showed that the main dietary source of Σ₆ PCBs to the adult population was ‘fish, seafood and their products’ which accounted for 84.3% of the total exposure. About 50% of the total exposure was contributed by four fish species: salmon (cooked salmon and salmon sashimi, 19.9%), mandarin fish (14.7%), pomfret fish (8.5%) and yellow croaker (7.5%). Salmon was found to contain the highest mean level of Σ₆ PCBs of 5.7 ng g^?1 fresh weight at upper bound estimation, ranging from 4.4 to 6.3 ng g^?1. The lower bound and upper bound exposure estimates of ?₆ PCBs to the average consumer of the population were found to be 0.68 and 1.38 ng kg^?1 body weight day^?1 respectively while for high consumers, the lower bound and upper bound exposure estimates were 3.08 and 3.84 ng kg^?1 body weight day^?1 respectively. In addition, the dietary exposures to individual indicator PCB congeners were also estimated.     

The effect of food stuffs commonly consumed in egypt on iron absorption and utilisation

The absorption and utilisation of iron in rats fed stewed beans, lentils, fenugreek and wheat bread were measured and compared with that of rats fed on casein. The results showed that ⁵⁹Fe absorption and utilisation were better on the casein diet. Fenugreek promoted absorption and utilisation of iron relative to other food commodities. Stewed beans inhibited both absorption and utilisation of iron. Lentils, in spite of retarding iron absorption, assisted the utilisation. Amino acids and phytate phosphorus content of these ingredients are thought to play a part.     

Dietary exposure of Hong Kong secondary school students to total mercury and methylmercury from fish intake

Fish is the main source of dietary exposure to methylmercury (MeHg), which is a public health concern owing to its potential neurotoxicity. To evaluate the public health risk, this study estimated the total mercury (tHg) and MeHg exposure from fish intake in Hong Kong secondary school students. Median tHg and MeHg concentrations of 280 samples purchased from different commercial outlets (covering 89 species of whole fish and three types of canned tuna), together with the local food consumption data of secondary school students obtained by semi-quantitative food frequency questionnaire in 2000, were used to estimate dietary exposure from fish intake for the average and high consumer (95th percentile exposure). For tHg, the median concentration was 63 µg kg^–1 (range 3–1370 µg kg^–1) and estimated exposures ranged 0.5–0.6 µg kg^–1 body weight (bw) week^–1 for an average consumer and 1.6–1.9 µg kg^–1 bw week^–1 for a high consumer. For MeHg, median concentration was 48 µg kg^–1 (range 3–1010 µg kg^–1) and estimated dietary exposures were 0.4–0.5 µg kg^–1 bw week^–1 for an average consumer and 1.2–1.4 µg kg^–1 bw week^–1 for a high consumer. These values are below the respective provisional tolerable weekly intake (PTWI) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA). The health risk is greater for high consumers since MeHg exposures may approach or exceed the PTWI when other dietary sources are taken into account.     

Dietary exposure to antimony,lead and mercury of secondary school students in Hong Kong

The aim of this first study was to determine the dietary exposure of antimony, lead, mercury in foodstuffs consumed by secondary school students in Hong Kong. Around 100 composite food items were purchased and then cooked prior to analysis. Antimony was measured by hydrogen generation (HG)/inductively coupled plasma–mass spectrometry (ICP–MS), while lead was determined by ICP–MS. Total mercury was measured by cold vapour atomic absorption spectrometry. The detection limits for antimony, lead and total mercury were 1, 0.6 and 3 µg kg^?1, respectively. The dietary intake of antimony, lead and total mercury for an average secondary student were estimated to be 0.252, 1.98 and 0.92 µg (kg bw)^?1 week^?1, respectively. The dietary intake of antimony, lead and total mercury for high-consumer secondary student were estimated to be 0.567, 5.09 and 2.33 µg (kg bw)^?1 week^?1, respectively. The main contribution to antimony, lead and mercury were milk, vegetables and seafood, respectively. The Tolerable Daily Intake (TDI) of antimony, as recommended by WHO, is 6 µg (kg bw)^?1 week^?1, while the Provisional Tolerable Weekly Intakes (PTWI) of lead and mercury, as recommended by JECFA, are 25 and 5 µg (kg bw)^?1 week^?1, respectively. The estimated exposure values for secondary school students were compared to these safety reference values. For the relevant population, this study confirms the low probability of health risks from these metals via food consumption.     

Dietary exposure to chloropropanols of secondary school students in Hong Kong

This paper reports levels of 3-monochloropropan-1,2-diol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) in a wide range of food items and estimates their dietary exposure for secondary school students in Hong Kong. Dietary exposure to chloropropanols was estimated using local food consumption data obtained from secondary school students in 2000 and the concentrations of 3-MCPD and 1,3-DCP in food samples taken from the local market. The dietary exposure to 3-MCPD for an average secondary school student consumer was estimated to be 0.063–0.150 µg kg^?1 body weight (bw) day^?1, whilst that for the high consumer was 0.152–0.300 µg kg^?1 bw day^?1. Both estimates fell below the provisional maximum tolerable daily intake of 2 µg kg^?1 bw established by the Joint Expert Committee on Food Additives (JECFA) and amounted to less than 20% of this safety reference value. The dietary exposure to 1,3-DCP for an average secondary school student consumer was estimated to be 0.003–0.019 µg kg^?1 bw day^?1, whilst that for the high consumer was 0.009–0.040 µg kg^?1 bw day^?1. The resulting margins of exposures were of low concern for human health. It could be concluded that both the average and high secondary school student consumers were unlikely to experience major toxicological effects of 3-MCPD and 1,3-DCP.     

不同烹调方式对植物源食物营养成分及抗氧化活性的影响

植物源食物是人类饮食中至关重要的组成部分,提供人体所必需的多种营养成分,特别是多数植物源食物具有强抗氧化活性,可有效预防人体氧化损伤所引起的衰老和疾病。植物源食物的基本营养成分及抗氧化活性在加热烹调过程中会发生变化。本文旨在综述几种烹调方式对植物源食物营养成分组成和抗氧化活性的影响。     

加压毛细管电色谱法测定不同烹饪方式食品中丙烯酰胺含量

目的 建立加压毛细管电色谱法检测食品中丙烯酰胺含量的分析方法,并依据所建立的方法研究不同烹饪方式下食品中丙烯酰胺含量变化的规律。方法 样品经1.0 mol/L NaCl溶液提取后,以乙腈-15 mmol/L pH 4.7磷酸钾缓冲液（15:85,V:V）为流动相,在电压强度＋2 kV条件下,外标法峰面积定量。结果 丙烯酰胺标准溶液在0.05~5.00 μg/mL浓度范围内线性良好,相关系数r2为0.9991,检出限为0.3 μg/g,定量限为1.5 μg/g,加标回收率达到96.3%～98.6%。通过研究发现蒸、煮2种方式对丙烯酰胺含量的影响较小,而炸和烤对淀粉质及肉类食品中的丙烯酰胺含量影响较大。结论 此法可以准确、快速的测定不同烹饪方式食品中的丙烯酰胺含量。     

Iodine content in bread,milk and the retention of inherent iodine in commonly used Indian recipes

Iodine deficiency disorders (IDD) is still a major public health problem and iodized salt remains the most effective means to control IDD in India. Few reports indicate that vegans have inadequate iodine intake while at the same time concerns are being raised on the implementation of universal salt iodization in the country. Therefore, we investigated the iodine content in bread, milk and commonly used Indian recipes prepared without iodized salt and the retention of inherent iodine therein. Results showed considerable iodine content in bread (25 μg/100 g) and milk (303 μg/L) as a positive fallout of universal salt iodization. Iodine content in 38 vegetarian recipes prepared without iodized salt was very low (2.9 ± 2.4 μg/100 g). Retention of inherent iodine (65.6 ± 15.4%) and iodine from iodized salt (76.7 ± 10.3%) in the same recipes was comparable. Thus, universal salt iodization programme remains the single most important source of dietary iodine for the Indian population.     

食物在烹饪过程中有害物质形成与减控技术研究进展

各式各样的烹饪方式在赋予食物不同风味的同时,也会在烹调过程中产生一些有害化合物,如丙烯酰胺、多环芳烃、醛、苯等,这些有害化合物会损害人体健康。本文系统介绍了食物不同烹饪方式（水基烹饪、油基烹饪、熏烤腌制和其他烹饪方式）的优缺点;综述了食物在不同烹饪过程中有害物质的形成与减控技术,以期为食物在烹饪过程中有害物质的控制以及产品品质的提升提供理论依据。     

The antecedents of successful buyer–supplier relationships in strategic networks of the Hong Kong clothing industry

Abstract

There has long been a research interest in dyadic business relationships. However, the antecedents of strategic networks have not yet been fully understood, especially within contexts that are indiscernible and capricious with respect to competitive and cooperative interaction. Building on the previous strategic network studies, this paper focuses on the antecedents of collaborations between the Asian manufacturers and their suppliers within a strategic network. In-depth interviews were conducted, and qualitative data were collected from senior executives at five well-known Hong Kong clothing companies. Based on these interviews, we developed a conceptual framework that included eight antecedents that are applicable to successful networks for the Hong Kong clothing industry. Finally, implications for managerial practice emphasize how to develop a successful strategic network, along with its antecedents.     

Tannin content of foods commonly consumed in India and its influence on ionisable iron

The tannin content of a number of foods and diets commonly consumed in India has been determined. Most of the tannin in legumes resides in the seed-coat. Decortication of seeds reduced tannin to a low level with a significant increase in ionisable iron. Germination of the legumes also resulted in a decrease in tannin and an increase in ionisable iron. Diets consumed in different parts of the country had tannin contents ranging from 1.5 to 2.5 g. Much of this appeared to be contributed by spices. A high level of tannin in these foods is associated with low ionisable iron. It is suggested that besides phytates, tannin may be an important factor responsible for the low absorption of iron from habitual diets in India.     

Mercury and methylmercury levels in the main traded fish species in Hong Kong

This survey was undertaken to determine the levels of aflatoxins in melon seeds. Among 65 samples analyzed by liquid chromatography (LC), the results showed that aflatoxin B₁ (AFB₁) was the major toxins in melon seeds, detected in 58 samples (89.2% of the total) at an average concentration of 8.5?ng?g^?1. The level of AFB₁ in 12 samples exceeded the maximum tolerated level for AFB₁ in Iranian (5?ng?g^?1) regulations; in other words, 18.5% of samples were unfit for human consumption.