Food Analysis

The objective of this work was to evaluate the potential of Fourier transform infrared spectroscopy (FTIR) in the characterization and discrimination between immature and mature or ripe coffee beans. Arabica coffee beans were submitted to FTIR analysis by reflectance readings employing attenuated total reflectance (ATR) and diffuse reflectance (DR) accessories. The obtained spectra were similar, but in general higher absorbance values were observed for nondefective beans in comparison to immature ones. Multivariate statistical analysis (principal component analysis, PCA, and agglomerative hierarchical clustering, AHC) was performed in order to verify the possibility of discrimination between immature and mature coffee samples. A clear separation between immature and mature coffees was observed based on AHC and PCA analyses of the normalized spectra obtained by employing both ATR and DR accessories. Linear discriminant analysis was employed for developing classification models, with recognition and prediction abilities of 100%. Such results showed that FTIR analysis presents potential for the development of a simple routine methodology for separation of immature and mature coffee beans.

Background. Iron requirements during the weaning period are the highest per unit body weight during human life, and diet is often insufficient to cover iron needs. For the first time in infant nutrition the absorption of both nonheme and heme iron from a typical weaning gruel after addition of meat with and without ascorbic acid (AA) to improve bioavailability was studied.

This work reports a method for extraction and analysis of thiosultap sodium, thiocyclam, and nereistoxin in pepper. Different extraction methods were tested to attain the best recoveries. The final extraction method combines acetonitrile extraction in an acidic medium with ultrasonic extraction followed by a cleanup step with anhydrous MgSO(4). The analyses were performed on a Linear Ion Trap Quadrupole LC-MS/MS in negative mode for thiosultap sodium and in positive mode for thiocyclam and nereistoxin. Recovery studies carried out on peppers spiked at different fortification levels (20 and 200 μg∙kg(-1)) yielded average recoveries in the range 58-87% with RSD (%) values below 20%. Calibration curves covering two orders of magnitude were performed and they were linear over the concentration range studied (0.001-0.5 mg∙l(-1)). Instrumental detection limits were in the low μg∙kg(-1) range. Stability studies of thiosultap sodium in water were performed by evaluating a 100-μg∙l(-1) solution of this compound in water. It was analyzed over 7 days, after which more than 80% degradation of thiosultap sodium could be observed.

The food niche relationships of a lizard community of an arid zone in the State of Sonora, NW Mexico, were studied during 1982, 1983 and 1984. The species with highly specialized diets showed little variation in food habits during those years, while the opposite occurred with more eclectic predators. The expected correlation between the size of the predator and the size of its prey can also be biased by food specialization. Food niche overlaps, based on analysis of the volume and the taxonomic status of the prey at a family level, were persistently low. The role that food niche partitioning could play in determining the organization of this lizard guild is discussed.

Objective The consumption patterns of beverages and desserts features highly in the current debate surrounding children's nutrition. The aim of this study was to continuously monitor the choice of beverages and desserts made by nearly 1000 children in a school cafeteria.

The influence of human whole saliva on selected alcohols, aldehydes, 3-alkyl-2-methoxypyrazines, and phenols in food-relevant concentrations was investigated. At pH 7.5-8 it was found that the alcohols, methoxyphenols, methoxypyrazines, and 3-hydroxy-4,5-dimethyl-2(5H)-furanone remained unmodified by saliva, whereas aldehydes were reduced to their corresponding alcohols. Generally, the processes were found to be dependent on the salivary activity of the panelists as well as on the concentration of the applied odorants. Reduction of the aldehydes did not occur after thermal treatment of the saliva. These investigations are aimed at finding an explanation for longer lasting aftertaste in humans, as it is induced by some odor-active compounds after the consumption of food materials.

Amaranth oil can be enzymatically modified to match breast milk fat analog requirements. We have developed a structured lipid (SL) from amaranth oil that, in combination with milk fat, delivers recommended amounts of docosahexaenoic acid (DHA) with palmitic acid specifically esterified at the sn-2 position of the triacylglycerol (TAG) backbone. The aim of this study was to study the final fatty acid (FA) contribution and oxidation stability of an infant formula prepared using the structured lipid DCAO (DHA-containing customized amaranth oil). DCAO was included as complementary fat in a "prototype" infant formula, and prepared in parallel with a "control" infant formula under the same processing conditions. The same ingredients but different complementary fat sources were used. A blend of the most commonly used vegetable oils (palm olein, soybean, coconut, and high-oleic sunflower oils) for infant formula was used instead of DCAO in the "control" formula. Additionally, "prototype" and "control" infant formulas were compared to a "commercial" product in terms of FA composition. The oxidative stability index (OSI) of the extracted fats from "prototype," "control," and "commercial" infant formulas were evaluated and compared to the OSI of the substrate fat replacers used. DCAO was the least stable compared to other fat analogs. The use of commercial antioxidants in DCAO containing products should prevent oxidation and therefore increase their stability.

Sedentary behaviors, like television viewing, are positively associated with overweight among young people. To monitor national health objectives for sedentary behaviors in young adolescents, this project developed and assessed the reliability and validity of a brief questionnaire to measure weekly television viewing, usual television viewing, and computer use by middle school children. Reliability arid validity of the Youth Risk Behavior Survey (YRBS) question on weekday television viewing also were examined. A briej five-item television and computer use questionnaire was completed twice by 245 middle school children with one week apart. To concurrently assess validity, students also completed television and computer use logs for seven days. Among all students, Spearman rorrelations for test-retest reliability for television viewing and computer use ranged from 0.55 to 0.68. Spearman correlations between the first questionnaire and the seven-day log produced the following results: YRBS question for weekday television viewing (0.46). weekend television viewing (0.37), average television viewing over the week (0.47), and computer use (0.39). Methods compurison analysis showed a mean difference (hoursheek) between answers to questionnaire items and the log of-0.04 (1.70 standard deviation [SO]) hours for weekday television,-0.21 (2.54 SO) for weekend television,-0.09 (1.75 SD),for average television over the week, and 0.68 (1.26 SD) for computer use. The YRBS weekday television viewing question, and the newly developed questions to assess weekend television viewing, average television viewing. and computer use, produced adequate reliability and validity for surveillance of middle school students.

The rising prevalence to food allergies in the past two decades, together with the fact that the only existing therapy is avoidance of allergen-containing food next to the implementation of anti-allergic drugs, urges the need for improved performance of current assays to detect potential allergens in food products. Therein, the focus has been on aptamer-based biosensors in recent years. In this paper we report for the first time the selection of aptamers against one of the most important peanut allergens, Ara h 1. Several Ara h1 DNA aptamers were selected after eight selection rounds using capillary electrophoresis (CE)-SELEX. The selected aptamers specifically recognized Ara h 1 and did not significantly bind with other proteins, including another peanut allergen Ara h 2. The dissociation constant of a best performing aptamer was in the nanomolar range as determined independently by three different approaches, which are surface plasmon resonance, fluorescence anisotropy, and capillary electrophoresis (353 7 82 nM, 419 763 nM, and 450 7 60 nM, respectively). Furthermore, the selected aptamer was used for bioassay development on a home-built fiber optic surface plasmon resonance (FO-SPR) biosensor platform for detecting Ara h 1 protein in both buffer and food matrix samples demonstrating its real potential for the development of novel, more accurate aptamer-based biosensors. In conclusion, the reported aptamer holds a great potential for the detection of Ara h 1 in both the medical field and the food sector due to its high affinity and specificity for the target protein.

A sensitive, precise and accurate method has been developed for the simultaneous determination of T-2 and HT-2 toxins in cereal grains at ppb levels using high-performance liquid chromatography (HPLC) with fluorescence detection and 1-antroylnitrile (1-AN) as labeling reagent after immunoaffinity clean-up. Cereal samples were extracted with methanol/water (90:10, v/v), and the extracts were cleaned-up through commercially available immunoaffinity columns containing

Rapid advances in biosensors have recently been reported. This has been possible due to rapid growth in the development of new biomaterials such as conducting polymers, copolymers and sol gels etc and the reported improvements in sensing techniques. Biosensors are miniaturized devices employing biochemical molecular recognition as the basis for a selective analysis. The response generated as a result of biochemical reaction is detected by a transducer to give a signal (optical/electrical/thermal) that can be used with or without amplification for the estimation of the concentration of an analyte in a given test sample. Among the various biosensors, electrochemical sensors, especially amperometric biosensors presently hold a leading position.Due to specificity, portability, simplicity, high sensitivity, potential ability for real-time and on-site analysis coupled with the speed and low cost, biosensors have been projected to have applications in food analysis, environment control, clinical detection, drug and agriculture industries etc. Besides this, biosensors offer exciting opportunities for numerous decentralized clinical applications, ranging from emergency room screening, home self testing and alternative site testing, continuous and real-time in vivo monitoring. New generation of biosensors combining new bioreceptors with the ever-growing number of transducers is emerging. The present paper highlights some of the recent advances in the area of biosensors contributed by our laboratory.

A method was validated for the multi-residue analysis of 82 pesticides in grapes at ≤25 ng/g level. Berry samples (10 g) mixed with sodium sulphate (10 g) were extracted with ethyl acetate (10 mL); cleaned by dispersive solid phase extraction and the results were obtained by liquid chromatography–tandem mass spectrometry. Reduction in sample size and proportion of ethyl acetate for extraction did not affect accuracy or precision of analysis when compared to the reported methods and was also statistically similar to the QuEChERS technique. The method was rugged (HorRat < 0.5) with <20% measurement uncertainties. Limit of quantification was <10 ng/g with recoveries 70–120% for most pesticides. The method offers cheaper and safer alternative to typical multi-residue analysis methods for grape.

Populations in North India depend on a number of vegetable crops of which Amaranthus spp. is the most important since it is the only crop available in the hot summer months when no other foliage crop grows in the field. However, reports on mineral composition of leaves are rare with absolutely no information on the qualitative improvement of foliage yield with special reference to minerals. Studies on correlation among the minerals as well as with yield and leaf attributes are also lacking. Hence, we report the proximate mineral composition in 30 strains of A. tricolor along with some suggestions for qualitative improvement of the foliage yield with reference to minerals. Our study showed that vegetable amaranth is a rich source of minerals like calcium (1.7±0.04 g/100 g), iron (1233.8±50.02 mg/kg), and zinc (791.7±28.98 mg/kg). The heritability estimates were high for most of the traits, with potassium and calcium showing high values, while comparatively lower values were recorded for magnesium and nickel. Nickel was the only mineral that showed positive correlation with all the minerals, as well as with leaf size and foliage yield. Zinc showed strong positive relationship with iron (0.66**) and manganese (0.74**), and was the only mineral exhibiting significant positive association with foliage yield. This study would be of use in enhancement of selected minerals in different regions according to local preferences and nutrient deficiency prevalent among the populations.

Long-duration space missions require a high-quality, shelf-stable food supply but must also contend with packaging waste after use. We have developed a package, adapted from a military pouch, that enables heating of foods to serving temperature. After the food is consumed, the package may be reused for containment and sterilization of waste, and, potentially, for packaging and sterilizing foods grown on a Mars base. Packages are equipped with electrodes to permit ohmic heating of internal constituents. Heat transfer within the package was modeled using the energy transport equation, coupled with the Laplace equation for electric field strength distribution. The model was verified by temperature measurements during a sample experimental run, and it was used to optimize the package design. Waste sterilization within the package was also studied and confirmed. Mass transfer (electrode component migration) was studied by inductively coupled plasma mass spectrometry; the findings have shown concentrations within products to be well below current daily dietary exposure levels. Microbiological studies for sterilization indicated the need for package redesign to ensure parallel electrode configuration, as well as the use of supplemental external heaters along the nonelectrode walls of the package. Temperature profiles during heating of these packages have been determined.

The commensal microbiota, host immunity and metabolism participate in a signalling network, with diet influencing each component of this triad. In addition to diet, many elements of a modern lifestyle influence the gut microbiota but the degree to which exercise affects this population is unclear. Therefore, we explored exercise and diet for their impact on the gut microbiota. Since extremes of exercise often accompany extremes of diet, we addressed the issue by studying professional athletes from an international rugby union squad. Two groups were included to control for physical size, age and gender. Compositional analysis of the microbiota was explored by 16S rRNA amplicon sequencing. Each participant completed a detailed food frequency questionnaire. As expected, athletes and controls differed significantly with respect to plasma creatine kinase (a marker of extreme exercise), and inflammatory and metabolic markers. More importantly, athletes had a higher diversity of gut micro-...

In arsenic-endemic and other areas, food is an important path of exposure to this contaminant. Food is generally consumed in processed form, after a preservation treatment or cooking, which may alter the concentrations and chemical forms of arsenic. This article summarizes and discusses the work so far published on the effect that thermal treatment used in the cooking or processing of food, including sterilization and preservation stages, has on total arsenic and arsenic species contents. It also reviews possible transformations in arsenic species. The studies included use model systems or food products of marine or vegetable origin. Processing may cause a considerable increase or decrease in the real arsenic intake from food. For example, traditional washing and soaking of Hizikia fusiforme seaweed, which has very high inorganic arsenic contents, may reduce the contents by up to 60%. On the other hand, all the arsenic present in cooking water may be retained during boiling of rice, increasing the contents of this metalloid to significant levels from a toxicological viewpoint. This calls for modifications in arsenic risk assessment, hitherto based on analysis of the raw product. It is necessary to consider the effect of processing on total arsenic and arsenical species in order to obtain a realistic view of the risk associated with intake in arsenic-endemic and other areas.

The goal of this study was to examine the possibility of verifying the geographical origin of honeys based on the profiles of volatile compounds. A head-space solid phase microextraction (SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC Â GC-TOF-MS) was used to analyze the volatiles in honeys with various geographical and floral origins. Once the analytical data were collected, supervised pattern recognition techniques were applied to construct classification/discrimination rules to predict the origin of samples on the basis of their profiles of volatile compounds. Specifically, linear discriminant analysis (LDA), soft independent modeling of class analogies (SIMCA), discriminant partial least squares (DPLS) and support vector machines (SVM) with the recently proposed Pearson VII universal kernel (PUK) were used in our study to discriminate between Corsican and non-Corsican honeys. Although DPLS and LDA provided models with high sensitivities and specificities, the best performance was achieved by the SVM using PUK. The results of this study demonstrated that GC Â GC-TOFMS combined with methods like LDA, DPLS and SVM can be successfully applied to detect mislabeling of Corsican honeys.

A new, simple and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of copper and nickel. The metals in the initial aqueous solution were complexed with 2-(2′-benzothiazolylazo)-5-(N, N-diethyl) ...

Food composition databases are critical to assess and plan dietary intakes. Dietary supplement databases are also needed because dietary supplements make significant contributions to total nutrient intakes. However, no uniform system exists for classifying dietary supplement products and indexing their ingredients in such databases. Differing approaches to classifying these products make it difficult to retrieve or link information effectively. A consistent approach to classifying information within food composition databases led to the development of LanguaL™, a structured vocabulary. LanguaL™ is being adapted as an interface tool for classifying and retrieving product information in dietary supplement databases. This paper outlines proposed changes to the LanguaL™ thesaurus for indexing dietary supplement products and ingredients in databases. The choice of 12 of the original 14 LanguaL™ facets pertinent to dietary supplements, modifications to their scopes, and applications are described. The 12 chosen facets are: Product

Organically produced spices and herbs were analyzed for determination of aflatoxin B1 (AFB1) by ELISA using immunoaffinity column. For this purpose 93 organic spices and 37 organic herbs were randomly selected from organic markets and organic shops in Turkey. AFB1 was detected in 58 organic spice and 32 organic herb samples. Among organic spice samples, the maximum value was detected in cinnamon sample (53 g/kg). AFB1 was not detected in thyme samples. AFB1 levels of 41 organic spice samples were above the EU regulatory limit (5 g/kg). Among organic herb samples the highest concentration of AFB1 (52.5 g/kg) was detected in a rosehip sample. AFB1 levels of 21 organic herb samples were above the regulatory limits of the European Union. These results showed that more stringent measures must be taken for the prevention of mold contamination in the production of organic spices and herbs.

A polymerase chain reaction (PCR) was developed for the detection of Clostridium botulinum type A, a cause of human botulism. A two primer set and an oligonucleotide detection probe were used to specifically detect Cl. botulinum type A neurotoxin gene (BoNT/A). After 40 cycles of amplification, detection of a 798 bp amplified DNA fragment was carried out by agarose gel electrophoresis and Southern blot hybridization. This assay was able to detect 12.5 fg of purified target DNA or five bacteria per reaction. The sensitivity in artificially contaminated food samples after an 18 h enrichment step ranges from 10 to 10(3) bacteria per g according to the type of food samples. No cross-reactions were observed with the other Cl. botulinum toxinotypes and other bacteria found routinely in food. This PCR method may provide a suitable and rapid alternative to standard techniques for detection of Cl. botulinum type A in food samples.

A highly uncommon odorant, 3-methyl-2-butene-1-thiol was detected by using Gas Chromatography-Olfactometry (GC-O) and unequivocally identified for the first time in wine. A purge and trap sampling technique which provides highly representative extracts for olfactometric analysis was used for the extraction of the volatile fraction of a Spanish red wine made from Prieto Picudo grapes. The identification of the odorant was achieved by multidimensional gas chromatography analysis of the same purge and trap extract. Mass spectrum and retention indices in both polar and non-polar columns allowed knowing unequivocally the identity. To obtain quantitative data a method was validated for the analysis of the compound at ng L À 1 level with acceptable precision. This powerful odorant presented an odor threshold in wine of 0.5-1 ng L À 1 and it has been detected in several Prieto Picudo wines at concentrations slightly above the odor threshold.

Dithiocarbamates are a class of fungicides extensively used in many crops worldwide. The current residue definition of dithiocarbamates in food for compliance with maximum residue limits, at national and international levels, is total residues arising from the use of any or each dithiocarbamate fungicide, determined as CS 2. The analytical method most frequently used to analyze dithiocarbamate residues in food for monitoring purposes was proposed more than 30 years ago. In this method, total dithiocarbamates are decomposed to CS 2 , which is purified and reacted with a cupric reagent. The yellow complex formed is quantified by spectrophotometry. In this paper, a new reaction system for the purification and complexation of CS 2 is proposed. The new system is less fragile than the traditional design, is easier to assemble, and allows for a higher sample throughput, in addition to being of low cost. Recovery of added mancozeb, thiram, or ziram (0.15-8.0 mg/kg) in rice, beans, apple, banana, orange, papaya, tomato, cucumber, and potato ranged from 82 to 120%, with relative standard deviations from 0 to 10% (n) 3 or 5). Analysis of apple, tomato, and papaya samples with field-incurred dithiocarbamate residues showed comparable results using both the traditional and the new reaction systems.

Six Japonica and three Indica rice samples were considered in this study. Total amino acid composition and protein digestibility were studied in relation to protein component while, amylose content, resistant and damaged starch were considered to assess starch characteristics. Results showed a comparable amino acid pattern and carbohydrate but different protein and starch digestibility. Due to the different botanical origin of samples, the amylose content raged between 15.5 and 25.2 g/100 g d. b. to whom corresponded a wide range of pasting temperatures determined by means of Differential Scanning Calorimetry. Principal Component Analysis, used to perform an exploratory data analysis, evidenced the contribution of some amino acids in recognising samples and this evidence could be usefully employed in breeding programs.

In this study, 24 organochlorine pesticide residues in 109 different honey samples collected from stores and open markets in Konya, Turkey were analyzed by gas chromatography-electron capture detection. Aldrin, cis-chlordane, trans-chlordane, oxy-chlordane, 2,4′ -DDE, and 4,4′ -DDE were found in all honey samples. The mean value was 0.0540 μg g − 1 for oxy-chlordane. In the 55 samples of 109, levels of organochlorine pesticide residues of oxy-chlordane were determined as higher than those of Turkish Alimentarius Codex maximum residual limits (MRLs). Other organochlorine pesticide residues also exceeded MRLs except for cis-heptachlor epoxide and α-hexachlorocyclohexane. Since all of the honey samples are found contaminated and most of these samples exceeded MRLs, a control of organochlorine pesticide residues in honey is necessary for consumer health.

Since recent literature has indicated that white lupin (Lupinus albus) may be a useful source of hypocholesterolemic proteins to be used in functional food formulation, our final goal is the development of a fast and automated high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method for the detection and the label-free semi-quantitation of the main lupin globulins in lupin foods and food ingredients. We present here some preliminary results in this direction. As a first step a total protein extract (TPE-WF) from lupin flakes was pre-fractionated by anion-exchange chromatography and each fraction was digested with trypsin and analyzed by HPLC/ESI-MS/MS. Subsequently, the tryptic digest of TPE-WF was directly analyzed by HPLC/ESI-MS/MS without any pre-fractionation. Eventually, in order to test the applicability of the method to real samples, a lupin beverage and two lupin protein isolates were analyzed. Both Mascot and Spectrum Mill MS Proteomics Workbench software were used to identify the protein composition in these samples and Spectrum Mill was used also to test the possibility of developing a label-free semi-quantitation method based on peptide hits. Encouraging results were obtained especially in the detection of the hypocholesterolemic component b-conglutin. a Mascot search results were obtained using MS/MS analyses integrated with a threshold of 1 Â 10 6 . b Proteins characterized by a protein score <60, which is the threshold value suggested by Mascot for best hits. c Tentative assignment as only one peptide was detected. 37 d Proteins characterized by a protein score in the range 13-20.

Various berries and fruit types of less common fruit species are known to contain antioxidants. Consumption of high amounts of antioxidant flavonoids, which display a variety of biological properties, including antiproliferative and anti-inflammatory activity, may have a positive impact on human health, particularly for the prevention of cancer and other inflammatory diseases. In these studies, based on the hypothesis that the fruit extract with the highest content would possess significantly higher health benefits, flavonoid-rich extracts were obtained from some less common fruit species -Blue Honeysuckles (Lonicera Kamtschatica and Lonicera edulis, Turcz. ex. Freyn), Saskatoon berry (Amelanchier alnifolia Nutt.) and Chinese Hawthorn (Crataegus pinnatifida BUNGE) -grown from germplasm held at the Mendel University of Agriculture and Forestry in Brno, Czech Republic and then characterized in terms of biological value based on the results from a relative antioxidant capacity assessment. The antioxidant content

Anemia and micronutrient deficiencies are common among Indian schoolchildren. We assessed the effectiveness of micronutrient fortification of meals cooked and fortified at school on anemia and micronutrient status of schoolchildren in Himalayan villages of India. In this placebo-controlled, cluster-randomized study, 499 schoolchildren (6-10 y) received either multiple micronutrients (treatment group) or placebo (control group) as part of school meals (6 d/wk) for 8 mo. Both groups were dewormed at the beginning of the study. The micronutrient premix provided 10 mg iron, 375 mg vitamin A, 4.2 mg zinc, 225 mg folic acid, and 1.35 mg vitamin B-12 for each child per day (;75% recommended dietary allowance). Blood samples drawn before and after the intervention were analyzed for hemoglobin, ferritin, retinol, zinc, folate, and vitamin B-12. Baseline prevalence of anemia (37%), iron deficiency anemia (10%), low serum ferritin (24%), retinol (56%), zinc (74%), folate (68%), and vitamin B-12 (17%) did not differ between groups. Postintervention, fewer in the treatment group had lower serum retinol [odds ratio (OR) (95% CI): 0.57 (0.33-0.97)] and folate [OR (95% CI): 0.47 (0.26-0.84)] than the control group. The serum vitamin B-12 concentration decreased in both groups, but the magnitude of change was less in the treatment than in the control group (P , 0.05). Total body iron (TBI) increased in both groups; however, the change was greater in the treatment than in the control group (P , 0.05). Micronutrient fortification of school meals by trained school personnel was effective in improving vitamin A, folate, and TBI status while also reducing the magnitude of a decrease in vitamin B-12 status.

Two sensitive, selective, and precise methods for the determination of pyriproxyfen and pyridalyl insecticide residues in tomatoes have been developed. The first method is HPLC with UV detection in which pyriproxyfen and pyridalyl were extracted with ethyl acetate and acetone, respectively, followed by cleanup using column chromatography. The recoveries ranged from 86.03 to 94.55 for pyriproxyfen and 95.08 to 99.38% for pyridalyl in tomato samples. The LOD of the method was 0.217 ppm for pyriproxyfen and 0.1866 ppm for pyridalyl. The second method depends on direct fluorometric determination of pyriproxyfen and pyridalyl in acetic and sulfuric acid at excitation and emission wavelengths of 320 and 646 nm, respectively. The recoveries of pyriproxyfen and pyridalyl in tomato samples ranged from 88 to 98% and 86 to 93%, respectively. The LOD of the method was 0.146 ppm for pyriproxyfen and 0.078 ppm for pyridalyl. Both methods were applied successfully to determine residues and rate of...

Staphylococcus aureus is a gram-positive, enterotoxin-producing coccus. It is a hardy organism and known to survive over a wide range of water activities, pH values, and temperatures. The objective of this study was to model the survival or gradual inactivation of S. aureus ATCC 13565 in intermediate moisture foods (IMFs). Various initial concentrations (∼10 1 , 10 2 , 10 3 , and 10 4 CFU/g) were used to inoculate three different IMFs (beefsteak, bread, and chicken pockets). Viable counts were determined up to 60 days using tryptic soy agar. Inoculum size did not influence the survival or gradual inactivation of S. aureus in these foods. The rate of change (increase or decrease) in log CFU/day was calculated for every consecutive pair of data points and by linear regression for each inactivation curve. Both consecutive pair and linear regression rates of change were fit to logistic distributions (with parameters α and β) for each food. Based on the distribution parameters, survival or gradual inactivation of S. aureus was predicted by computer simulation. The simulations indicated an overall decline in S. aureus population over time, although a small fraction of samples in the consecutive pair simulation showed a slight population increase even after 60 days, consistent with the observed data. Simulation results were compared to predictions from other computer models. The models of Stewart et al. were fail-safe, predicting the possibility of significant growth only after >3,000 days. The USDA pathogen modeling program predictions were found to be fail-dangerous, predicting declines at least four times faster than observed.

In this study, X-ray microtomography (μCT) was used for the image analysis of the microstructure of 12 types of Italian aerated chocolate chosen to exhibit variability in terms of cocoa mass content. Appropriate quantitative 3-dimensional parameters describing the microstructure were calculated, for example, the structure thickness (ST), object structure volume ratio (OSVR) and the percentage object volume (POV). Chemical analysis was also performed to correlate the microstructural data to the chemical composition of the samples. Correlation between the μCT parameters acquired for the pore microstructure evaluation and the chemical analysis revealed that the sugar crystals content does not influence the pore structure and content. On the other hand, it revealed that there is a strong correlation between the POV and the sugar content obtained by chemical analysis. The results from this study show that μCT is a suitable technique for the microstructural analysis of confectionary products such as chocolates and not only it does provide an accurate analysis of the pores and microstructure but the data obtained could also be used to aid in the assessment of its composition and consistency with label specifications.

ANTRACT: A carotenoid database for individual and multicomponent foods has been compiled that contains values for the five most common carotenoids (a-carotene, 3carotene,-cryptoxanthin, lycopene, lutein) in 2,458 fruits, vegetables, and multicomponent foods containing fruits and vegetables. The database was used to estimate intakes of specific carotenoids for 19-to 50-year-old women (n = 1,102), using food consumption data obtained from dietary recalls in the US Department of Agriculture Continuing Survey of Food Intake by Individuals, 1986. The major contributors of acarotene were carrots consumed as a single food or as an ingredient in multicomponent foods. Carrots, cantaloupe, and broccoli were the main sources of-carotene. Orange juices and blends, oranges, and tangerines were important contributors of-cryptoxanthin. Tomatoes and tomato products consumed as single foods or as ingredients in multicomponent foods provided most of the dietary lycopene. Contributors of lutein + zeaxanthin included collard, mustard, or turnip greens; spinach; and broccoli. The per capita consumption of total carotenoids (the sum of the five specific carotenoids) among these women was approximately 6 mg/day.

Accurate estimates of energy and nutrient intake of individuals and populations are contingent on the reliability of information obtained about food intake, food composition, and portion size. This article reviews issues related to the definition, determination, and use of portion sizes in dietary assessment and public education. Food frequency questionnaires USDA FDA Pyramidz2 Food labelzx Willett et al.b.3z Block et al.2.33 Grains and cereals Bread Crackers Rice, cooked Cereal, ready-to-eat Cereal, cooked Whole fruit Juice Fresh, frozen, or canned Raw leafy Carrots, raw Potato French fries Tomato juice Beef Hamburger Poultry Fish Dairy Milk Cheese Fats, sweets Butter Cookies Doughnuts Alcohol Wine Fruit Vegetables Meat 1 slice 3-4 small 4 oz 1 medium elass I a Standard portion sizes vary by weight and size of items. Harvard University Health Professionals Follow-up Study, 1990 questionnaire. Food Guides Historical Background. For nearly a century, the USDA has published food guides to help the public select healthful diets.I5 In its earliest efforts to suggest portion sizes, the agency recommended that families purchase specific quantities of foods to supply nutrients then known to be essential. Quantities were expressed by weight, volume, or 100kcal portions; 80,000 kcal (800 100-kcal portions) was the figure used to meet the weekly needs of an average family of two adults and three children. USDA advised families to obtain these portions through specific food purchases, such as 14 lb potatoes, 2 lb turnips, and 14 qt milk per week.16 Later, USDA specified yearly amounts of foods needed by men and women.17 Although portion sizes could be estimated from such figures, they were not stated explicitly. USDA first defined daily portions during World War 11. It recommended consumption of one or two

The possible transfer and accumulation of novel DNA and/or proteins in food for human consumption derived from animals receiving genetically modified (GM) feed is at present the object of scientific dispute. A number of studies failed to identify GM DNA in milk, meat, or eggs derived from livestock receiving GM feed ingredients. The present study was performed in order to: (i) develop a valid protocol by PCR and multicomponent analysis for the detection of specific DNA sequences in milk, focused on GM maize and GM soybean; (ii) assess the stability of transgenic DNA after pasteurization treatment and (iii) determine the presence of GM DNA sequences in milk samples collected from the Italian market. Results from the screening of 60 samples of 12 different milk brands demonstrated the presence of GM maize sequences in 15 (25%) and of GM soybean sequences in 7 samples (11.7%). Our screening methodology shows a very high sensitivity and the use of an automatic identification of the amplified products increases its specificity and reliability. Moreover, we demonstrated that the pasteurization process is not able to degrade the DNA sequences in spiked milk samples. The detection of GM DNA in milk can be interpreted as an indicator of fecal or airborne contamination, respectively, with feed DNA or feed particles, although an alternative source of contamination, possibly recognizable in the natural environment can be suggested. Further studies, performed on a larger number of milk samples, are needed to understand the likely source of contamination of milk collected from the Italian market.

In the present study, the jackfruit volatile compounds were established using solid-phase microextraction (SPME) and gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). Qualitative and quantitative analyses were carried out using 5 g samples with divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibre at 30 1C for 10 min. Rapid spectral acquisition rate of 10 spectra/s by the GC-TOFMS permitted identification and quantification of compounds having chromatographic peak widths of only a fraction of second. For SPME-GC-TOFMS analysis, the total time was approximately 18 min. Thirty-seven compounds were identified from five jackfruit cultivars. The main jackfruit volatile compounds were: ethyl isovalerate, 3-methylbutyl acetate, 1-butanol, propyl isovalerate, isobutyl isovalerate, 2-methylbutanol, and butyl isovalerate. These compounds were consistently present in all the five cultivars and this suggests the compounds contributed to the sweet and fruity note of jackfruit. Principal component analysis (PCA) applied to the data, differentiated the five jackfruit cultivars according to their unique flavour compounds and explained 88% of the total variance.

Analysis of organic acids in strawberry-tree (Arbutus unedo) honey showed the presence of an unknown acid as the main constituent. This compound was isolated and identified as homogentisic acid (2,5-dihydroxyphenylacetic acid) by MS and NMR techniques. Its average content in honey was 378 ( 92 mg/kg. Analysis of nectar confirmed the floral origin of the compound found in honey. Since this acid was not detected in any of the different monofloral honeys, it could be used as a marker of strawberry-tree (A. unedo) honey.

The proposed method for ascorbic acid: AA (Vitamin C) determination is based on the oxidation of AA to dehydroascorbic acid with the CUPRAC reagent of total antioxidant capacity assay, i.e., Cu(II)-neocuproine (Nc), in ammonium acetate-containing medium at pH 7, where the absorbance of the formed bis(Nc)-copper(I) chelate is measured at 450 nm. The flavonoids (essentially flavones and flavonols) normally interfering with the CUPRAC procedure were separated with preliminary extraction as their La(III) chelates into ethylacetate (EtAc). The Cu(I)-Nc chelate responsible for color development was formed immediately with AA oxidation. Beer's law was obeyed between 8.0 × 10 −6 and 8.0 × 10 −5 M concentration range, with the equation of the linear calibration curve: A 450 nm = 1.60 × 10 4 C (mol dm −3 ) − 0.0596. The relative standard deviation (R.S.D.) in the analysis of N = 45 synthetic mixtures containing 1.25 × 10 −2 mM AA with flavonoids was 5.3%. The Cu(II)-Nc reagent is a lower redox-potential and therefore more selective oxidant than the Fe(III)-1,10-phenanthroline reagent conventionally used for the same assay. This feature makes the proposed method superior for real samples such as fruit juices containing weak reductants such as citrate, oxalate and tartarate that may otherwise produce positive errors in the Fe(III)-phen method when equilibrium is achieved. The developed method was applied to some commercial fruit juices and pharmaceutical preparations containing Vitamin C + bioflavonoids. The findings of the developed method for fruit juices and pharmaceuticals were statistically alike with those of HPLC. The proposed spectrophotometric method was practical, low-cost, rapid, and could reliably assay AA in the presence of flavonoids without enzymatic procedures open to interferences by enzyme inhibitors.