Gold nanoparticles (AuNPs) are some of the most extensively studied nanomaterials. Because of their unique optical, chemical, electrical, and catalytic properties, AuNPs have attracted enormous amount of interest for applications in biological and chemical detection and analysis. The purpose of this critical review is to provide the readers with an update on the recent developments in the field of AuNPs for sensing applications based on their optical properties. An overview of the optical properties of AuNPs is presented first, followed by a more detailed literature survey. As the last part of this review, we compare the advantages and disadvantages of each technique, briefly discuss their commercialization status, and some technical issues that remain to be solved in order to move the technique forward (151 references).

Gold nanoparticle-enabled biological and chemical detection and analysis

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables and cereal-based products where these compounds found application.

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Food applications of natural antimicrobial compounds

Research Section Analysis of 200 food items for benzo[a]pyrene and estimation of its intake ίη an epidemiologic study* Ν. Kazerouni a,c,*, R. Sinha a, Che-Han Hsu b,l, Α. Greenberg b,2, Ν. Rothman a "Divi8ion οι CαncCl' Epiden1iology αnd Genetic8, ΝαΙίοnαl Cαncer In8titute, ΝαΙίοnαl Ιn8ιίΙιιΙα ο/' Heαlth, Eχeωtίve ΡΙαΖα South, RIl1 7033, 6120 Execι;tivc Blvd, Rockvillc, MD 20892, USA bDepαrtIl1ent οjΈnvίrοnΙl1entαl SciencC8, Cook c.Όllege, RLifger8 υnίνCI'8ίΙΥ, Nell' Bnln8\vicl(, NJ 08903, USA CDeΡαι'Ιn1ent οι ΡΓeνenιίve Medicine αnd BiOlneuiC8, Unij(JΓmed Scγvice8 υnίνcγ8ίΙγ οjΊlιe ΗeαΙιl1 S(:ienC'e8, 4301 Jone8 BI'i,!ge Roαd, BethC8dα, MD 20814-4799, USA Accepted 1 October 2000 Animal stιιdies have shown that dietary intake of benzo[α]pyrene (BaP), a polycyclic aromatic hydrocarbon (ΡΑΗ), canses increased levels of tumors at several sites, particιιlarly ίη the upper gastrointestinal tract. However, the role of dietary intake of BaP and cancer ίη humans is not clear. We CIeated a BaP database of selected food products that could be lίnl(ed to Food Frequency Qnestionnaires (FFQs) to estimate BaP intake. BaP levels were measnred for each food line-item (composite samples) which consisted of a variety of foods ίη a FFQ. Composite sample parts were derived from the Second National Health and Nutrition Examination Survey (NHANES Π) which represents the most common food items consumed by the general popιιlation. Meat samples were cooked by different techniqnes ίn controlled conditions, and by varions restanrants and fast-food chains. Non-meat products were purchased from the major national supermarket chains. The qnantities of BaP were measnred using a thin-Iayer chromatography (TLC)/spectrofluorometer technique and were highly coaelated with both BaP (radius = 0.99) and sum of carcinogenic ΡΑΗ (1'=0.98) measured by HPLC technique. We lίnl(ed ΟΙΙΓ database to the results from a FFQ and estimated the daily BaP intal<e of varions food items ίη 228 snbjects ίn the Washington, DC metropolitan area. The highest levels of BaP (ιιρ to abont 4 ng BaP/g of cooked meat) were found ίη grilled/barbecued very well done steaks and hamburgers and ίη grilled/barbecued well done chicken with skin. BaP concentrations were lower ίη meats that were grilled/barbecued to medium done and ίη all broiled ΟΓ pan-fried meat samples regardless of doneness level. The BaP levels ίn non-meat items were generally low. However, certain cereals and greens (e.g. I<ale, collard greens) had levels ιιρ to 0.5 ng/g. Ιη our population, the bread/cereal/grain, and grilled/barbecued meat, respectively, contributed 29 and 21 Ρeιτent to the mean daily intal(e of BaP. This database may be helpful ίη initial attempts to assess dietary BaP exposnres ίn stιιdies of cancer etiology. Pnblished by Elsevier Science Ltd. Κcγ\VΟΓds: Po!ycyc!ic aromatic hydrocarbons; Benzo[α]pyrene; Meat; Pork; Chicken; Seafood; Vegetab!es; Fruit; Grains; Fat; Sweets; Pan-fry; Oven-broi1; Gri11; Barbecue; Carcinogenic; Food frequency questionnaire; Cancer AbbI'eviαtion8: ΒαΡ, benzo[α]pyrene; FFQ, Food Frequency Questionnaire; HCA, heterocyc1ic amine(s); ΡΑΗ, p01ycyc1ic aromatic hydrocaΓbοn(s); HHHQ, Hca!th Habits and ΗίstΟΓΥ QιιcstίοnnaίΓC; ng, nanοgΓanι; NHANES ΙΙ, Sccond Nationa! Hca!th and NιιtΓίΙίon Examination Survey; TLC, thin !ayer chromatography; THEES, Tota! Ηηmαη Exposure to Environmenta! Substances. The opinions ΟΓ assertions contained herein are the private ones ο[ the author and are ηοΙ Ιο be constrned as officia! ΟΓ reflecting the views ο[ the United States Department of Defense ΟΓ the Uniforιned Services University of the Health Sciences. * COΓrcsponding aιιthΟΓ. Tcl.: + 1301-594-7296; fax: + 1301-496-1854. E-ιnαil α(/drc8s: kazeroun@exchange.nih.gov (Ν. Kazerouni). \ CLIncnt addΓCSS: DCΡaΓtmcnt ofHospita! and Hca!th CaΓC ΑdnιίnίstΓatίοn, Chnng-Tai Institιιtc ofHca!th Scicnccs and Tcchno!ogy, 11, Po-tzc Lane, Τα1ωn, Taichung, 40605, Taiwan, ROC. 2 Cnrrent address: Department ο[ Chemistry, University ο[ New Hampshire, Dnrham, ΝΗ 03824, USA. 0278-6915/01/$ scc front mattcJ' Pnblishcd by EIscvicJ' Scicncc Ltd. ΡΙΙ: S0278-6915(00)00158-7

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Analysis of 200 food items for benzo[a]pyrene andestimation of its intake ίη an epidemiologic study

Perfluorochemicals are widely used in the manufacturing and processing of a vast array of consumer goods, including electrical wiring, clothing, household and automotive products. Furthermore, relatively small quantities of perfluorochemicals are also used in the manufacturing of food-contact substances that represent potential sources of oral exposure to these chemicals. The most recognizable products to consumers are the uses of perfluorochemicals in non-stick coatings (polytetrafluoroethylene (PTFE)) for cookware and also their use in paper coatings for oil and moisture resistance. Recent epidemiology studies have demonstrated the presence of two particular perfluorochemicals, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in human serum at very low part per billion levels. These perfluorochemicals are biopersistent and are the subject of numerous studies investigating the many possible sources of human exposure. Among the various uses of these two chemicals, PFOS is a residual impurity in some paper coatings used for food contact and PFOA is a processing aid in the manufacture of PTFE used for many purposes including non-stick cookware. Little information is available on the types of perfluorochemicals that have the potential to migrate from perfluoro coatings into food. One obstacle to studying migration is the difficulty in measuring perfluorochemicals by routine conventional analytical techniques such as GC/MS or LC-UV. Many perfluorochemicals used in food-contact substances are not detectable by these conventional methods. As liquid chromatography-mass spectrometry (LC/MS) develops into a routine analytical technique, potential migrants from perfluoro coatings can be more easily characterized. In this paper, data will be presented on the types of perfluoro chemicals that are used in food packaging and cookware. Additionally, research will be presented on the migration or potential for migration of these chemicals into foods or food simulating liquids. Results from migration tests show mg kg(-1) amounts of perfluoro paper additives/coatings transfer to food oil. Analysis of PTFE cookware shows residual amounts of PFOA in the low microgram kg(-1) range. PFOA is present in microwave popcorn bag paper at amounts as high as 300 microgram kg(-1).

Perfluorochemicals: potential sources of and migration from food packaging Part A Chemistry, analysis, control, exposure & risk assessment

Pickling C. botulinumtoxin formation in finished product Maximum finished product pH in the loin muscle of 5.0 Finished product pH in the loin muscle Collect sample of product from each pickling tank at the end of each pickling cycle and analyze for pH using a pH meter Each pickling tank, each cycle QC personnel Continue pickling process until pH meets the CL Analytical results Daily calibration of pH meter

Food and Drug Administration Center for Food Safety and Applied Nutrition

Biogenic amines are produced by bacterial decarboxylation of corresponding amino acids in foods. Concentration of biogenic amines in fermented food products is affected by several factors in the manufacturing process, including hygienic of raw materials, microbial composition, fermentation condition, and the duration of fermentation. Intake of low amount of biogenic amines normally does not have harmful effect on human health. However, when their amount in food is too high and detoxification ability is inhibited or disturbed, biogenic amines could cause problem. To control concentration of BAs in food, decarboxylase activity for amino acids can be regulated. Levels of BAs can be reduced by several methods such as packaging, additives, hydrostatic pressure, irradiation, pasteurization, smoking, starter culture, oxidizing formed biogenic amine, and temperature. The objective of this review paper was to collect, summarize, and discuss necessary information or useful data based on previous studies in terms of BAs in various foods.

/pdf/biogenic-amines-in-foods-1gscqjxs4e.pdf

Biogenic amines in foods

This study was undertaken to investigate the antimicrobial effect of organic acids against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on whole red organic apples and lettuce. Several studies have been conducted to evaluate organic acids as sanitizers. However, no studies have compared antimicrobial effects of various organic acids on organic fresh produce, including evaluation of color changes of produce. Apples and lettuce were inoculated with a cocktail of 3 strains each of 3 foodborne pathogens provided above and treated with 1% and 2% organic acids (propionic, acetic, lactic, malic, and citric acid) for 0, 0.5, 1, 5, and 10 min. With increasing treatment time and acid concentration, organic acid treatments showed significant reduction compared to the control treatment (distilled water), and differences in antimicrobial effects between organic acids were observed. After 10 min of treatment with 1% and 2% organic acids in apples, propionic (0.92 to 2.75 log reduction), acetic (0.52 to 2.78 log reduction), lactic (1.69 to >3.42 log reduction), malic (1.48 to >3.42 log reduction), and citric acid (1.52 to >3.42 log reduction) exhibited significant (P < 0.05) antibacterial effects against 3 foodborne pathogens compared to the control treatment. In lettuce, propionic (0.93 to 1.52 log reduction), acetic (1.13 to 1.74 log reduction), lactic (1.87 to 2.54 log reduction), malic (2.32 to 2.98 log reduction), and citric acid (1.85 to 2.86 log reduction) showed significant (P < 0.05) effects compared to the control treatment. Changes in sample color subjected to organic acids treatment were not significant during storage.

Practical Application:  It is suggested that organic acids have a potential as sanitizers for organic fresh produce. These data may help the organic produce industry provide safe fresh produce for consumers.

Myung-Sub Chung

Papers

Biogenic amines in foods

Use of Organic Acids to Inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on Organic Fresh Apples and Lettuce

Comparison of indicators of microbial quality of meat during aerobic cold storage.

Combined effects of ultrasound and surfactants to reduce Bacillus cereus spores on lettuce and carrots

Inactivation of foodborne pathogens in powdered red pepper (Capsicum annuum L.) using combined UV-C irradiation and mild heat treatment