Content of biogenic amines and polyamines in some species of European wild-growing edible mushrooms

The content of eight biologically active biogenic amines and polyamines were determined in fruiting bodies of 17 species of wild-growing edible mushrooms picked during 3 consecutive years. An analytical procedure, using freeze-dried samples, derivatisation with dansyl chloride and HPLC quantification had to be adapted in its extraction step due to the slimy character of the analysed mushrooms. No histamine and cadaverine were determined. Tyramine and tryptamine occurred at very low levels, usually up to 5 mg kg⁻¹ fresh matter, whilst phenylethylamine contents varied widely from an undetectable level to 38 mg kg⁻¹. Putrescine was the amine of the highest content, sometimes exceeding 150 mg kg⁻¹ fresh matter, mainly in species of the family Boletaceae. The contents of spermidine were considerably higher than those of spermine, usually at levels of tens mg kg⁻¹ fresh matter and sporadically above 100 mg kg⁻¹. Thus, mushrooms are raw food materials with very high spermidine content. The highest spermidine levels occurred in spore-forming parts of fruiting bodies. In Xerocomus badius, statistically significant effects of the year of harvest, age and parts of the fruiting body and of their interactions on the contents of phenylethylamine, putrescine and spermidine were found.     

Selenium content in selected Portuguese foodstuffs

In the present study, selenium contents for some selected food items commonly consumed in Portugal are presented. Food items, i.e., meat, fish, eggs, dairy products, cereals, fruits and vegetables were sampled from two representative markets of two different regions of Portugal territory. The selenium concentrations in the various food items have been determined by using nuclear activation analysis (NAA) in both versions instrumental (INAA) and replicate sample (RSINAA) through the short-lived nuclide ^77mSe that features a half-life time of 17.5 s. The highest values were found for meat, fish and eggs (87.6–737 μg kg⁻¹); lower values were obtained for vegetables and fruits (1.7–24.9 μg kg⁻¹).     

Determination of Nitrite and Nitrate in Brazilian Meats Using High Shear Homogenization

Nitrate and nitrite are usually added to processed meat products to protect against the growth of microorganisms. Two sample preparation methodologies using either manual grinding (with a mortar and pestle) or mechanical high shear homogenization were investigated and compared. The results showed that high shear homogenization was the most suitable for the extraction of nitrite and nitrate from ham, salami, and bacon samples, achieving high extraction recoveries (>98%) together with low relative standard deviations (RSDs) for the samples analyzed. Analyses were performed using capillary electrophoresis. A running buffer consisting of 60 mmol L⁻¹ tetraborate and 0.2 mmol L⁻¹ cetyltrimethylammonium bromide enabled separation of the analytes in <5 min. In validation experiments, good repeatability was obtained for both migration times (<0.8% RSD) and peak areas (<1.1% RSD). Analytical curves for nitrite and nitrate were linear (r > 0.998) in the 0.2- to 2.5-mg L⁻¹ and 0.5- to 5-mg L⁻¹ concentration ranges, respectively. The limits of detection were 0.15 mg L⁻¹ for nitrite and 0.17 mg L⁻¹ for nitrate. The method developed was applied to the analysis of different kinds of meats (sausage, ham, salami, bacon, and others) produced in Brazil. The ranges of concentration found were 17.3–46.4 mg kg⁻¹ (nitrite) and 69.9–198.1 mg kg⁻¹ (nitrate). The contents of nitrate and nitrite in the samples were below the Brazilian legislation limit values (150 and 300 mg kg⁻¹ for nitrite and nitrate, respectively).     

Sulfite content in some Brazilian wines: analytical determination and estimate of dietary exposure

Brazilian wines of different regions and that commercially available in the city of Campinas, SP, were analysed for their contents of sulfites. Dietary exposure to sulfites from Brazilian wines was also assessed by combining sulfite levels determined analytically with three hypothetical scenarios of daily wine consumption: 150, 300, and 450 mL. In all samples, the concentration of sulfites was below the maximum permitted level (MPL) of 350 mg L⁻¹ set in the Brazilian legislation with most samples (88%) containing residual sulfite below 150 mg L⁻¹. The dietary exposure to sulfites from regular consumption of 150 mL of national white wines containing sulfites at the mean level of 122.0 mg L⁻¹ covered 44% of the Acceptable Daily Intake (ADI) established by JECFA for these preservatives (0.7 mg kg⁻¹ bw). For high regular consumption (450 mL per day) of white wines, the dietary exposure could reach 131% of the ADI. In the case of national red wines (SO₂ mean level of 71.3 mg L⁻¹) the dietary exposure was lower, ranging from 26 to 76% of the ADI for 150 and 450 mL of daily consumption, respectively. The present study indicates that although sulfite levels in national wines is usually below the MPL (mean of 98.5 mg L⁻¹) a regular moderate consumption of 150 mL per day could lead to a dietary exposure of 15 mg of sulfites (0.25 mg kg⁻¹ bw in a 60-kg adult), covering one-third of the ADI. A regular heavy consumption (450 mL per day) would cover the full ADI.     

Determination of Degradation Rate of Acaricide Fenpyroximate in Apple, Citrus, and Grape by HPLC-DAD

Fenpyroximate, a widely used acaricide around the world, was recently registered for control of mites in Egypt. Hence, only limited data are available on the dissipation rate of fenpyroximate under field conditions. In this study the dissipation rate of fenpyroximate after one application on apple, citrus and grape was estimated. Samples were prepared by an optimized quick, easy, cheap, effective, rugged, and safe (QuEChERS) analytical method before quantification by high performance liquid chromatography with diode array detector (HPLC-DAD). The initial deposit of fenpyroximate residue of 1.63, 0.33, 0.49 and 1.75 mg kg⁻¹ on apple, citrus, grape fruits and grape leaves, respectively after 7 days of application degraded to 0.14 mg/kg (91.41%), 0.09 mg kg⁻¹ (72.7%), 0.08 mg kg⁻¹ (83.6%) and 0.07 mg kg⁻¹ (96.0%), respectively. Pre-harvest interval (PHI) and maximum residue limit (MRL) were: 7 days and 0.3 mg kg⁻¹ for apple, 3 days and 0.2 mg kg⁻¹ for citrus, 3 days and 0.2 mg kg⁻¹ for grape fruits, and 14 days and 0.2 mg kg⁻¹ for grape leaves. Dissipation rate for all fruits followed first order kinetics with half-lives (t _1/2) of 2.03, 2.42, 1.56 and 2.75 days for apple, citrus, grape fruits and grape leaves, respectively. We suggested that a waiting period of at least 3 days before harvesting the citrus and grape fruits and 7 days for apple and 17 days for grape leaves after fenpyroximate application at recommended dose that may be considered quite safe from point of health hazards due to the toxic effect of residues.     

High-Performance Liquid Chromatography Analysis and Assessment of Benzoic Acid in Yogurt, Ayran, and Cheese in Turkey

Among food sources, particular attention is paid to milk and dairy products, due to its nutritional importance. Benzoic acid is extensively used in the preservation of foods. A reliable method for the determination of benzoic acid in some dairy products, such as yogurt, ayran, and cheese using high-performance liquid chromatography and UV detection was validated. The peak of benzoic acid was measured at a wavelenght of 226 nm. Samples were purchased from supermarkets in Turkey in the period 2009–2010. All dairy product samples were produced from cow’s milk. The levels of benzoic acid in cheese, yogurt, and ayran samples were in the range of 3.17 to 56.77 mg kg⁻¹, 8.94 to 28.30 mg kg⁻¹, and 1.54 to 16.57 mg L⁻¹, respectively. The results show that benzoic acid widely occurs in milk products in Turkey at the low levels.     

Migration of ε-caprolactam from nylon cooking utensils: validation of a liquid chromatography-ultraviolet detection method

A large amount of modern cooking utensils are made of nylon. This is the generic name of polyamides that are polymers having characteristic amide linkages. Caprolactam is the monomer used in the synthesis of nylon 6. This work presents the validation of an LC-UV method for the determination of caprolactam in the aqueous food simulant 3% acetic acid (w/v) employing capryllactam as internal standard. LC–MS/MS was the confirmation technique. The obtained detection and quantification limits were satisfactory regarding caprolactam specific migration limit; these were 0.6 and 2 mg kg⁻¹, respectively. The working range was 2–30 mg kg⁻¹ and the correlation coefficients (r) were in all cases at least 0.999. The intra-day repeatability was between 2.5 and 4.8% depending on the validation level. The global mean recovery was 100.6% with a RSD (%) of 5.0%. Different nylon cooking utensils were analyzed for the migration of caprolactam in the food simulant acetic acid 3% p/v. Conditions used were repeated exposure to the simulant for 2 h at 100 °C, and the results obtained after the third exposure were in compliance regarding Directive 2002/72/EC. With the aim of identifying the polymer used in these utensils, IR spectra were also obtained for all samples.     

Polycyclic aromatic hydrocarbons (PAHs) in traditional and industrial smoked beef and pork ham from Serbia

Smoked beef and pork ham samples were analysed during process of smoking (after packing and storing) for the presence of the 16 EU priority PAHs via Fast GC/HRMS method. This study showed that there are differences in PAH contents between final smoked beef ham samples from traditional smokehouse (TS) (3.9 μg kg⁻¹) and industrial smokehouse (IS), (1.9 μg kg⁻¹). Also there is a difference in PAH contents in final smoked pork ham samples (4.9 μg kg⁻¹, TS; 4.2 μg kg⁻¹, IS). In beef and pork ham samples from the same smokehouse different PAH contents were observed during smoking. The highest content of examined PAHs in all beef and pork ham samples during smoking showed benzo[c]fluorene (BcL) (beef ham: from 0.3 μg kg⁻¹ to 1.5 μg kg⁻¹; pork ham: from 0.2 μg kg⁻¹ to 2.1 μg kg⁻¹).The maximum level for benzo[a]pyrene (BaP) of 5 μg kg⁻¹ in smoked meat products was not exceeded in any samples. Correlation statistic analysis (P < 0.05) of obtained contents from samples both from TS and IS showed that BaP is a good marker both for 16 EU priority PAHs and 12 IARC probably and possibly carcinogenic PAHs (IS: R _BaP/Σ16PAHs = 0.95, R _BaP/Σ12PAHs = 0.96; TS: R _BaP/Σ16PAHs = 0.71, R _BaP/Σ12PAHs = 0.88).     

Contaminant metals in black scabbard fish (Aphanopus carbo) caught off Madeira and the Azores

Total mercury, cadmium and lead concentrations were measured in black scabbard fish (Aphanopus carbo), caught off Madeira and the Azores archipelagos (Portugal). The metal contents were expressed in mg kg⁻¹ wet weight. The mean mercury levels in liver were 4.50 and 2.37 whereas, in skin, such values were 0.59 and 0.36 (Madeira and Azores, respectively). On average, the muscle content was around 0.9 in fish from both areas. Cadmium maximum levels in muscle and skin were found in Azores samples (0.09 and 0.11, respectively). Mean lead contents in all samples were always below than 0.10. In general, the results obtained did not allow the establishment of any relationship between metal accumulation and fish weight or length. According to the permissible WHO and FAO levels, these results, suggest that this species does not represent a risk for human consumption if the liver is excluded and the edible part consumed with moderation.     

Biogenic amines assessment during different stages of the canning process of skipjack tuna (Katsuwonus pelamis)

The present research focused on the biogenic amines (BAs) formation in skipjack tuna (Katsuwonus pelamis) throughout the whole canning process. In agreement with its wide employment on this species, on‐board brine immersion freezing (BIF) was tested as post‐mortem processing. The study included fish samples corresponding to different stages of the canning process such as frozen, thawed, cooked and canned; after cooking, two kinds of tuna muscles were considered, that is, whole fillets (main product) and grated muscle (off‐product arising from small pieces). For the BAs (tryptamine, putrescine, cadaverine, histamine, spermidine and spermine) assessment, an HPLC‐DAD method was developed and validated in skipjack tuna samples, in agreement with different parameters such as suitability, linearity, limits of detection and quantification, precision, accuracy and robustness. Tuna submitted on‐board to BIF procedure provided low levels of spermine and spermidine (up to 27.6 mg kg^?1), while contents on the remaining BAs maintained below the limit of detection. Throughout the different stages of the canning process, skipjack tuna showed a low formation of most BAs; interestingly, histamine content was found below 10.6 mg kg^?1 level. The highest values were obtained for spermidine, these related to cooked grated tuna (from 22.6 to 66.7 mg kg^?1) and canned grated tuna (from 70.6 to 104.4 mg kg^?1). Values for pH assessment in all kinds of tuna samples corroborated the results obtained for BAs determination. BIF procedure proved to be an amenable post‐mortem processing to guarantee the quality of canned skipjack tuna.     

Analytical procedure based on slurry sampling for determining selenium in organic vegetable samples by graphite furnace atomic absorption spectrometry

This paper presents a simple, fast and sensitive method to determine selenium in vegetable samples by graphite furnace atomic absorption spectrometry through the direct introduction of slurries of the samples into the spectrometer’s graphite tube. The limits of detection and quantification calculated for 20 readings of the blank of the standard slurries (5 mg mL⁻¹ of microcrystalline cellulose) were 0.33 and 1.10 μg L⁻¹. The proposed method was applied to determine selenium in samples of organically grown vegetables and its results proved compatible with those obtained from samples mineralized by acid digestion in a microwave oven.     

Fish and food safety: Determination of formaldehyde in 12 fish species by SPME extraction and GC–MS analysis

The formaldehyde (FA) content in different fish products was evaluated using a solid phase microextraction (SPME)-GC–MS method based on fiber derivatisation with pentafluorobenzyl-hydroxyl-amine hydrochloride. LOD and LOQ values of 17 and 28 μg kg⁻¹, respectively were calculated. Fish quality was assessed by the analysis of 12 species (sea-fish, freshwater-fish and crustaceans), revealing variable FA levels. Fresh, deep frozen, canned, boiled and roasted fish were analysed; cooking always produced a decrease in the analyte content. Fish belonging to the Gadidae family were the samples with the highest FA concentration (from 6.4 ± 1.2 mg kg⁻¹ to 293 ± 26 mg kg⁻¹), in four cases out of 14 exceeding the value of 60 mg kg⁻¹ proposed by the Italian Ministry of Health. Storage on ice was also investigated, showing moderate FA production also at temperature around 0 °C. FA contents lower than 22 mg kg⁻¹ were finally found in all the other samples.     

Occurrence of Aflatoxins and Ochratoxin A in Baby Foods in Portugal

Infants have a more restricted diet and they generally consume more food on a body weight basis than adults. Therefore, the significance and potential health risk of any contaminant in foods consumed by infants is increased and diligent attention must be paid to this particular area. The present study aims to determine the occurrence of aflatoxin M₁ (AFM₁), aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) in processed cereal-based foods (flours) and infant formulae (milk powder) available in the Portuguese market, both sold as conventional and organic origin. Mycotoxin determination was carried out using a method previously applied to duplicate diet samples. This method employed chloroform extraction, liquid–liquid extraction, immunoaffinity column (IAC) cleanup and HPLC analysis with fluorescence detection after post-column derivatisation. Quantification limits were 0.014, 0.004 and 0.028 μg kg⁻¹ for AFM₁, AFB₁ and OTA, respectively. These toxins could only be quantified in 12 of 27 analysed samples (15 positive results): two samples with AFM₁, two samples with AFM₁ and OTA, one sample with AFB₁ and OTA and seven samples with OTA. Positive results concerned four for AFM₁ (26%), one for AFB₁ (7%) and ten for OTA (67%). For these samples, contents ranged between 0.017–0.041 μg AFM₁ kg⁻¹, 0.034–0.212 μg OTA kg⁻¹, and one sample had a value of 0.009 μg AFB₁ kg⁻¹. Considering the presented results, we could provisionally conclude that the presence of these mycotoxins in baby foods does not constitute a public health problem. These are the first results concerning the occurrence of mycotoxins in marketed baby foods in Portugal and this is the first study using the HPLC method, proposed for duplicate diets, in baby food sample analysis.     

Diet with linseed oil and organic selenium yields low n‐6/n‐3 ratio pork Semimembranosus meat with unchanged volatile compound profiles

The aim of this was to improve n‐6/n‐3 ratio without affecting the volatile compounds profiles of pork. Different feeding strategies were designed for 60 Polish Landrace pigs with the goal to enhance the health attributes of Polish pork. Composition, colour, hardness, fatty acid contents and volatile compound profiles of the semimembranosus muscles were determined. Results showed that with the basic diet with the addition 3% of linseed oil, 100 mg kg^?1 of vitamin E and 1 mg kg^?1 of organic selenium, the level of polyunsaturated fatty acids (PUFA) in the meat samples was increased by 26% (P ≤ 0.05) as compared to the control. Principal component analysis (PCA) demonstrated that the aroma profile of semimembranosus muscles from pigs fed with the diet supplemented with 3% of linseed oil and 1 mg kg^?1 of organic selenium was close to that of control. Results demonstrated that healthy functional meats could be produced by designing feeding strategies.     

Determination and Evaluation of the Mineral Composition of Chinese Cabbage (Beta vulgaris)

Inductively coupled plasma optical emission spectrometry was used to determine the elements present in Chinese cabbage (Beta vulgaris). The accuracy of the method was confirmed by analysis of a certified reference material of spinach leaves. The study involved 57 samples that were collected in 13 Brazilian cities. Average concentrations of elements found per gram of Chinese cabbage were as follows: 3.44 mg g⁻¹ sodium, 5.09 mg g⁻¹ potassium, 1.25 mg g⁻¹ phosphorous, 0.85 mg g⁻¹ calcium, 0.49 mg g⁻¹ magnesium, 2.79 μg g⁻¹ manganese, 9.50 μg g⁻¹ iron, 0.74 μg g⁻¹ copper, 14.28 μg g⁻¹ zinc, and 6.44 μg g⁻¹ strontium. Principal component analysis and hierarchical cluster analysis demonstrated that there is no systematic difference in the mineral composition between the cabbage samples that were analyzed.     

Iodine content of cooked and processed fish in Turkey

This study evaluates the effects of different cooking (grilling, frying and steaming) and processing (smoking, salting, marinating and drying) methods on iodine contents of valuable marine and freshwater fish species commonly consumed in Turkey. The highest mean iodine content of cooked fish was determined to be 3.760 mg kg^?1, 2.788 mg kg^?1, 5.831 mg kg^?1 and 6.161 mg kg^?1 in grilled anchovy, horse mackerel, Atlantic Bonito and whiting, 0.914 mg kg^?1, 1.452 mg kg^?1, 3.106 mg kg^?1 in steamed bluefish, red mullet. The highest mean iodine content of processed fish was determined to be 2.149 mg kg^?1 in smoked mackerel, 0.701 mg kg^?1 in salted Bonito, 1.128 mg kg^?1 in dried horse mackerel and 7.283 mg kg^?1 in marinated anchovy. This iodine values are also above the Upper Tolerable Nutrient Level of 100–150 μg day^?1 iodine.     

Study of phenolic composition and sensory properties of red grape varieties in danger of extinction from the Spanish region of Castilla-La Mancha

This paper reports on a study of the profiles of different phenolic compounds (anthocyanins, flavonols, hydroxycinnamic acids and stilbenes) of five minor red grape varieties from the Spanish region of Castilla-La Mancha (Bobal, Moravia Agria, Moravia Dulce, Rojal and Tortosí) and a traditional variety from this growing region (Cencibel) as reference. Grape skin extracts of each variety were analysed by High Performance Liquid Chromatography coupled to Diode Array Detector (HPLC–DAD). The content of grape skins in anthocyanins (21.1–453 mg kg⁻¹), flavonols (26.9–288 mg kg⁻¹) and hydroxycinnamic acids (6.80–18.2 mg kg⁻¹) showed differences according to mainly varietal origin, although other important factors have to be taken into account such as the degree of ripeness, berry size or vintage year. In all the studied varieties, the major anthocyanin was malvidin 3-glucoside (>40%) with the exception of Rojal variety, which major one was peonidin 3-glucoside together with cyanidin 3-glucoside. Moravia Dulce and Rojal varieties contained more than 46% of quercetin 3-glucuronide; the rest of them contained less than 27%. No relation was found between profiles of hydroxycinnamic acids in the studied samples and their variety or year of vintage. All the studied grapes presented high concentrations of stilbenes that could be interesting due to the health benefits.     

Determination of Histamine in Some Foods by Isotachophoretic Method with Simple Sample Preparation

A one-dimensional capillary isotachophoretic method in cationic system of the separation has been applied for histamine determination in food samples. The proposed electrolyte system consisted of 0.01 M potassium hydroxide with l-valine to pH = 9.9 as the leading electrolyte and 0.02 M 2-amino-2-hydroxymethyl-propane-1,3-diol adjusted to pH = 8.3 with 0.1 M hydrochloric acid as terminating electrolyte. Proposed method was characterized by linearity range 5–50 mg L⁻¹ and R ² = 0.9982, accuracy (recoveries ranged from 95% to 102%), detection (2.10 mg L⁻¹), and quantification (7.01 mg L⁻¹) limits. The sample preparation for proposed electrophoretic method included only simple extraction with trichloroacetic acid with filtration and derivatisation stage are avoided. The histamine concentration was determined in meat (turkey, chicken, beef and pork) and meat products (ripened sausage and dry-cured ham), fish (smoked salmon and mackerel), and different kind of mildew and mold ripened cheeses samples. The histamine content ranged from not detected level for fresh meat to 29.63 mg 100 g⁻¹ for cheese samples. The reversed phase HPLC was applied as reference method and the F-Snedecor test and the t test were employed to compare the precision and accuracy of the both methods. Positive correlations were found between the two analytical methods for histamine determination in food products. The obtained results indicate that the proposed electrophoretic method is simple, precise, accurate, and convenient.     

ACE inhibitory and antihypertensive properties of apricot almond meal hydrolysate

Apricot almond meal was hydrolyzed simultaneously with Neutrase and N120P proteases. The hydrolysate almond peptide (AP) was fractionated into three ranges of molecular weight (AP-I, >5 kDa; AP-II, 1–5 kDa; AP-III, <1 kDa) using an ultrafiltration membrane bioreactor system. The AP-III brought about a high angiotensin-I-converting enzyme (ACE) inhibitory activity with IC₅₀ value of 0.138 mg mL⁻¹ and the content of hydrophobic amino acid of AP-III was 50.08%. Lineweaver–Burk plots suggested that AP-III acts as a non-competitive inhibitor to inhibit ACE. And we evaluated the stability and in vivo antihypertensive activity of AP-III. Multiple dose oral administration (100 mg kg⁻¹ body weight (BW), 400, 800 mg kg⁻¹ BW) to spontaneously hypertensive rats led to a significant decrease in blood pressure for AP-III. Additionally, the gel filtration and RP-HPLC were used to separate ACE inhibitory peptides from the hydrolysate. The results suggested that the peptide derived from apricot almond protein may have potential applications as functional food.     

Correlation between sensory and chemical markers in the evaluation of Brazil nut oxidative shelf-life

Sensory analysis is one of the most suitable processes for measuring oxidative damage and determining the shelf-life of nuts, but it is an expensive and time-consuming methodology. Thus, our objective was to correlate sensory data and chemical markers obtained during the accelerated oxidation of Brazil nuts and to determine the chemical parameters values associated with the sensory shelf-life of the nuts as established by the consumers. Brazil nuts were kept at 80 °C for 21 days. At intervals of 2 days, the oxidized odor of the samples was analyzed by nine trained panelists using a discriminative scale, and the oil was extracted to quantify the chemical parameters. A high (r > 0.95) and significant correlation (p < 0.05) was observed between the sensory data and the hydroperoxide concentration (PV), para-anisidine value (pAV), hexanal content, and α- and γ-tocopherol concentrations. When compared with fresh samples, sensory identification of oxidized odor occurred on the 4th day, noticeably earlier than changes in chemical markers (12th day). Consumers rejected the nuts after 12 days of storage, which corresponded to PV = 18.8 meq kg⁻¹ oil, pAV = 7.68, hexanal = 48.95 μmol 100 g⁻¹ oil, α-tocopherol = 15.01 mg kg⁻¹ oil, and γ + β-tocopherol = 73.88 mg kg⁻¹ oil. Our study suggests that simple spectrometric methods, such as PV and pAV, can be used to estimate the oxidative shelf-life of nuts based on sensory analysis.