Investigation of a food poisoning outbreak due to nitrite contained in cooked peanut [一起因食用煮花生米引起亚硝酸盐中毒的调查报告]

Two workers were hospitalised with similar symptoms. Information was gathered from patients, doctors, colleagues and food seller. Laboratory tests were undertaken on remaining food and vomits. We identified the source food and toxin responsible for this outbreak, and subsequently helped doctors to treat these patients. The intake was estimated to be over the fatal limit but both were fully recovered after treatment. Abstract in Chinese 2001年11月20日，寿光市植物油厂的2名装卸工人因食用花生米引起亚硝酸盐急性中毒，现报告如下。 1 中毒经过 11月20日下午，市植物油厂装卸工人秦×下班后，到本厂职工食堂买了馒头、大米稀饭和少许咸菜，然后到厂外买了1瓶白酒，又到个体菜摊李×处买了2元钱的煮花生米，约400g。17：40与同事江×一同在宿舍内饮酒吃饭，其中花生米大部分被秦×吃掉，江×吃得少。18：30左右秦×在装卸过程中出现双腿发软、恶心、呕吐、呼吸困难、视物模糊，江×随后也出现类似症状，2人被迅速送往寿光市人民医院进行抢救。到医院时已进入昏迷状态，查体可见全身皮肤粘膜青紫、手指脚趾发黑，经吸氧并心电监护、应用美兰静推后，江×症状减轻，于次日出院；秦×因中毒严重，于次日脱离危险，11月23日痊愈出院。……

‘We’ve always cooked kangaroo. We still cook kangaroo. Although sometimes we use cookbooks now’ : Aboriginal Australians and cookbooks

Aboriginal Australians have a long history of eating native animals and plants. Food preparation techniques were handed down through the generations, without any need for cookbooks. But colonisation changed the diets of Aboriginal Australians, introducing us to a processed diet high in salt, sugar and fat, and causing a wide range of diet-related health problems. Over the years, many Aboriginal Australians lost their connections to traditional food preparation practices. In this paper, the authors provide a brief overview of Aboriginal food history and describe a newly-emerging focus on reintroducing native foods. They describe the work of an Aboriginal chef, Dale Chapman, who is actively promoting native foods and creating a native-Western food fusion. Chapman has developed native food recipes and a cookbook, in an effort to make native foods accessible to all Australians. She promotes a future when native foods are part of the identity of all Australians – both Aboriginal and non-Aboriginal.

Quantitative methods to measure pigmentation variation in farmed Giant Tiger Prawns, Penaeus monodon, and the effects of different harvest methods on cooked colour

Cooked prawn colour is known to be a driver of market price and a visual indicator of product quality for the consumer. Although there is a general understanding that colour variation exists in farmed prawns, there has been no attempt to quantify this variation or identify where this variation is most prevalent. The objectives of this study were threefold: firstly to compare three different quantitative methods to measure prawn colour or pigmentation, two different colorimeters and colour quantification from digital images. Secondly, to quantify the amount of pigmentation variation that exists in farmed prawns within ponds, across ponds and across farms. Lastly, to assess the effects of ice storage or freeze-thawing of raw product prior to cooking. Each method was able to detect quantitative differences in prawn colour, although conversion of image based quantification of prawn colour from RGB to Lab was unreliable. Considerable colour variation was observed between prawns from different ponds and different farms, and this variation potentially affects product value. Different post-harvest methods prior to cooking were also shown to have a profound detrimental effect on prawn colour. Both long periods of ice storage and freeze thawing of raw product were detrimental to prawn colour. However, ice storage immediately after cooking was shown to be beneficial to prawn colour. Results demonstrated that darker prawn colour was preserved by holding harvested prawns alive in chilled seawater, limiting the time between harvesting and cooking, and avoiding long periods of ice storage or freeze thawing of uncooked product.

Physiological Factors Influencing Toughness in Cooked Saddletail Snapper (Lutjanus malabaricus)

Saddletail snapper (Lutjanus malabaricus) is a commercially significant tropical species in Australia and has been the subject of consumer complaints of extreme toughness in cooked fillets. Textural and biochemical analyses including collagen and hydroxylysyl pyridinoline (PYD) cross-links concentrations were conducted on 101 commercially harvested Saddletail snapper to identify causes of toughness. Fish age was found to account for 75.6% of observed variation in cooked muscle texture (work done) of Saddletail snapper. A significant linear relationship (P < 0.001) between PYD content and cooked muscle texture was also identified accounting for 50.3% of observed variation. The concentration ratio of PYD to total collagen (TC) ranged from 0.04 to 0.38 mol PYD per mol of TC. Fish size was also found to be a poor indicator of fish age and therefore a poor indicator of the potential risk of toughness of the cooked muscle.

White spot syndrome virus (WSSV) transmission risk through infected cooked shrimp products assessed by polymerase chain reaction (PCR) and bio-inoculation studies

The aim of the study was to evaluate the resistance of white spot syndrome virus (WSSV) in shrimps (Penaeus monodon) to the process of cooking. The cooking was carried out at 1000C six different durations 5, 10, 15, 20, 25 and 30 min. The presence of WSSV was tested by single step and nested polymerase chain reaction (PCR). In the single step PCR, the primers 1s5 & 1a16 and IK1 & IK2 were used. While in the nested PCR, primers IK1 &IK2 – IK3 & IK4 were used for the detection of WSSV. WSSV was detected in the single step PCR with the primers 1s5 and 1a16 and the nested PCR with the primers IK1 and IK2 – IK3 & IK4 from the cooked shrimp samples. The cooked shrimps, which gave positive results for WSSV by PCR, were further confirmed for the viability of WSSV by conducting the bio-inoculation studies. Mortality (100%) was observed within 123 h of intra-muscular post injection (P.I) into the live healthy WSSV-free shrimps (P. monodon). These results show that the WSSV survive the cooking process and even infected cooked shrimp products may pose a transmission risk for WSSV to the native shrimp farming systems.

Studies on technological problems associated with the processing of cooked frozen prawns. Pt. 1. Preprocess storage conditions of raw material in relation to quality

The chemical and organoleptic properties of prawn held in ice for different days prior to cooking and the changes after freezing and subsequent storage were studied with three different species of prawn viz. Metapenaeus monoceros, Metapenaeus dobsoni and Parapeneopsis stylifera. The optimum period for which the prawn can be kept under ideal conditions of icing prior to cooking has been worked out.

Studies on technological problems associated with the processing of cooked frozen prawns. Pt. 2. Hygienic conditions in relation to bacteriological characteristics

The importance of sanitary practices in the processing of precooked frozen shrimps has been discussed. Several typical examples have been shown to point out the different sources of contamination of the product and the extent to which each of the factors by itself or in combination affect the bacterial quality of the final product. A scheme of processing has also been suggested for controlling the microbial quality.

Fracture and energy partitioning in uncooked and cooked noodles

Humans perform fascinating science experiments at home on a daily basis when they undertake the modification of natural and naturally-derived materials by a cooking process prior to consumption. The material properties of such foods are of interest to food scientists (texture is often fundamental to food acceptability), oral biologists (foods modulate feeding behavior), anthropologists (cooking is probably as old as the genus Homo and distinguishes us from all other creatures) and dentists (foods interact with tooth and tooth replacement materials). Materials scientists may be interested in the drastic changes in food properties observed over relatively short cooking times. In the current study, the mechanical properties of one of the most common (and oldest at 4,000+ years) foods on earth, the noodle, were examined as a function of cooking time. Two types of noodles were studied, each made from natural materials (wheat flour, salt, alkali and water) by kneading dough and passing them through a pasta-making machine. These were boiled for between 2-14 min and tested at regular intervals from raw to an overcooked state. Cyclic tensile tests at small strain levels were used to examine energy dissipation characteristics. Energy dissipation was >50% per cycle in uncooked noodles, but decreased by an order of magnitude with cooking. Fractional dissipation values remained approximately constant at cooking times greater than 7 min. Overall, a greater effect of cooking was on viscoplastic dissipation characteristics rather than on fracture resistance. The results of the current study plot the evolution of a viscoplastic mixture into an essentially elastic material in the space of 7 minutes and have broad implications for understanding what cooking does to food materials. In particular, they suggest that textural assessment by consumers of the optimally cooked state of food has a definite physical definition. © 2007 Materials Research Society.

Inhibition of seafood-borne bacteria in cooked mackerel (Rastrelliger kanagurta) fish meat by lactic acid bacteria

Antagonistic activity of lactic acid bacteria (LAB) namely Streptococcus faecalis, Pediococcus cerevisiae and Lactobacillus casei was tested against seafood-borne bacteria such as Staphylococcus aureus, Bacillus cereus, Escherichia coli, Clostridium perfringens and Listeria monocytogenes. Three lactic acid bacteria such as Streptococcus faecalis, Lactobacillus casei and Pediococcus cerevisiae were coated on cooked mackerel meat, individually and in combination against fish-borne bacteria. S. faecalis inhibited C. perfringens in individual coat by 3.7 log units as compared to control, whereas L. casei did not inhibit C. perfringens. P. cerevisiae inhibited S. aureus by 5 log units. L. casei, inhibited L. monocytogenes by 3.3 log units on the third day of storage as compared to control. On the other hand, S. aureus and B. cereus were inhibited on the third and second day by 4.9 log and 5.2 log units respectively. B. cereus, S. aureus, L. monocytogenes were the most sensitive to all three LAB. C. perfringens was the least inhibited among all the seafood-borne bacteria tried. Multiple LAB or LAB strains in combination showed much earlier inhibitory activity on seafood-borne bacteria than single LAB coat.

A method for the preparation of cooked-peeled-frozen prawns

Several consignments of cooked-peeled-frozen prawns exported from India were rejected last year due to high total plate count (TPC) at 30°C. The specified temperature of incubation for TPC in our country is 37°C. Hence the effect of incubation at 30 and 37°C on TPC was studied. It is seen that the count is higher on incubation at 30°C. A method for production of cooked-peeled-frozen prawns conforming to the specification for TPC at 30°C is standardized and is reported. It consists of recooking the cooked-peeled prawns followed by packing and freezing without further contamination. The method minimizes batch to batch or sample to sample variation in TPC.

Comparison of the volatile components of two cultivars of potato cooked by boiling, conventional baking and microwave baking

Tubers of two cultivars (Estima and Maris Piper) of potato were cooked by three different procedures, ie boiling, conventional baking and microwave baking. Peeled and sliced tubers were boiled, while intact potatoes were baked in their skins. Flavour components from the boiled slices and the flesh of the baked tubers were isolated by headspace adsorption onto Tenax and analysed by gas chromatography-mass spectrometry (GC-MS). For all cooking procedures, Estima gave stronger isolates than Maris Piper. The two main sources of flavour compounds (regardless of cooking procedure) were lipid degradation and the Maillard reaction and/or sugar degradation. The ratio (yield derived from lipid)/(yield derived from Maillard reaction and/or sugar) decreased from 8.5-9.1 (boiling) to 2.7-3.4 (microwave baking) and to 0.4-1.1 (conventional baking). Quantitative and qualitative differences among the cooking procedures are explained in terms of the variations in heat and mass transfer processes that occurred. Each cooking procedure resulted in a unique profile of flavour compounds. (C) 2002 Society of Chemical Industry.

Comparison of consumer perception and acceptability for steaks cooked to different endpoints: Validation of photographic approach

Photographs have been used to enhance consumer reporting of preference of meat doneness, however, the use of photographs has not been validated for this purpose. This study used standard cooking methods to produce steaks of five different degrees of doneness (rare medium, medium well, well done and very well done) to study the consumer’s perception of doneness, from both the external and internal surface of the cooked steak and also from corresponding photographs of each sample. Consumers evaluated each surface of the cooked steaks in relation to doneness for acceptability, ‘just about right’ and perception of doneness. Data were analysed using a split plot ANOVA and least significant test. Perception scores (for both external and internal surfaces) between different presentation methods (steak samples and corresponding photos), were not significantly different (p > 0.05). The result indicates that photographs can be used as a valid approach for assessing preference for meat doneness.

Arsenic in groundwater and its influence on exposure risks through traditionally cooked rice in Prey Vêng Province, Cambodia

Arsenic (As) contamination of communal tubewells in Prey Vêng, Cambodia, has been observed since 2000. Many of these wells exceed the WHO As in drinking water standard of 10 µg/L by a factor of 100. The aim of this study was to assess how cooking water source impacts dietary As intake in a rural community in Prey Vêng. This aim was fulfilled by (1) using geostatistical analysis techniques to examine the extent of As contaminated groundwater in Prey Vêng and identify a suitable study site, (2) conducting an on-site study in two villages to measure As content in cooked rice prepared with water collected from tubewells and locally harvested rainwater, and (3) determining the dietary intake of As from consuming this rice. Geostatistical analysis indicated that high risk tubewells (>50 µg As/L) are concentrated along the Mekong River's east bank. Participants using high risk tubewells are consuming up to 24 times more inorganic As daily than recommended by the previous FAO/WHO provisional tolerable daily intake value (2.1 µg/kgBW/day). However, As content in rice cooked in rainwater was significantly reduced, therefore, it is considered to be a safer and more sustainable option for this region.

Arsenic Bioaccessibility in Cooked Rice as Affected by Arsenic in Cooking Water

Rice can easily accumulate arsenic (As) into its grain and is known to be the highest As-containing cereal. In addition, the As burden in rice may increase during its processing (such as when cooking using As-polluted water). The health risk posed by the presence of As in cooked rice depends on its release from the matrix along the digestive system (bioaccessibility). Two types of white polished long-grain rice, namely, nonparboiled and parboiled (total As: 202 and 190 mu g As kg(-1), respectively), were cooked in excess of water with different levels of As (0, 10, 47, 222, and 450 mu g As L-1). The bioaccessibility of As from these cooked rice batches was evaluated with an in vitro dynamic digestion process. Rice cooked with water containing 0 and 10 mu g As L-1 showed lower As concentrations than the raw (uncooked) rice. However, cooking water with relatively high As content (>= 47 mu g As L-1) significantly increased the As concentration in the cooked rice up to 8- and 9-fold for the nonparboiled and parboiled rice, respectively. Parboiled rice, which is most widely consumed in South Asia, showed a higher percentage of As bioaccessibility (59% to 99%) than nonparboiled rice (36% to 69%) and most of the As bioaccessible in the cooked rice (80% to 99%) was released easily during the first 2 h of digestion. The estimation of the As intake through cooked rice based on the As bioaccessibility highlights that a few grams of cooked rice (less than 25 g dry weight per day) cooked with highly As contaminated water is equivalent to the amount of As from 2 L water containing the maximum permissible limit (10 mu g As L-1).