A survey study on safety and microbial quality of “gluten-free” products made in Italian pasta factories

The rising prevalence of celiac disease leads to an increased demand of “gluten-free” products. A survey study on the gluten content and on the microbiological quality of “gluten-free” flour, and processing flour products, was carried out from 2010 to 2015 in Northern Italy. Overall 12,419 samples were analyzed, and 94.7% contained a gluten concentration less than 5 mg kg⁻¹ (lower limit of detection). Only 0.1% of samples showed a gluten concentration above 80 mg kg⁻¹ (maximum limit of detection). In the remaining 5.2%, the gluten concentration was between 5 and 80 mg kg⁻¹, underlining how a gluten-free diet completely devoid of gluten is unrealistic. The microbiological quality of these products was investigated.Overall, the majority of samples revealed microbial loads of less than 1 l g CFU g⁻¹ (lower limit of detection). High levels of spoilage bacteria were found in egg-containing products. Total mesophilic bacteria were counted in all analyzed food categories with concentrations up to about 6, 8 and 9 l g CFU g⁻¹ in dry pasta, flours and egg products respectively. Listeria monocytogenes was found only in one sample, whereas Salmonella spp. was never found.Buckwheat flour was the most frequently contaminated product by presumptive Bacillus cereus, with a prevalence of 12.5%. Also, a contamination by Coagulase-Positive Staphylococci was found during this investigation, especially in buckwheat dry pasta and flour and in egg dry pasta, with a prevalence of 54.7%.This study aimed to enhance the knowledge about the “gluten-free” products which are still poorly studied, even if their impact on the food market is increasingly considerable.     

Monitoring survey of patulin in a variety of fruit-based products using a sensitive UHPLC–MS/MS analytical procedure

The mycotoxin patulin is known to be the predominant natural contaminant of apples, apple-based products and a variety of other fruits. Because of its high incidence and harmful health effects, patulin is included with mycotoxins, which are strictly monitored. In this study, a sensitive and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS) method was developed and validated for determination of patulin in a variety of fruit matrices. A combination of the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) procedure along with a solid phase extraction (SPE) clean-up strategy enabled an effective removal of sample matrix and pre-concentration of patulin. This resulted in low limits of quantification ranging from 1 to 2.5 μg/kg, depending on fruit type. In our study, quantification of patulin was based on a stable isotope dilution assay (SIDA) using ¹³C₇-patulin as the internal standard. Data showed that the procedure described, in combination with neat solvent internal calibration, can be used for accurate quantification of patulin regardless the type of fruit. Although the SIDA method allowed omission of matrix-matched calibration, matrix-effects were estimated in order to assess suppression of the patulin signal caused by a variety of fruit samples. The method was fully validated for apples, apple baby food, apple juice, peaches, strawberries and blueberries. The recovery values were in the range from 92 to 109%. Repeatability of the method was below 10% for all tested matrices. The method was applied to the monitoring of patulin in 135 samples of fresh fruits and fruit products and can also be used as an efficient tool for routine monitoring of this contaminant in a variety of fruit-based foods.     

Growth of Listeria monocytogenes in salmon roe – A kinetic analysis

The objective of this study was to investigate the growth kinetics of Listeria monocytogenes in unsalted and salted (3%) salmon roe. Growth curves, developed using inoculated samples incubated at constant temperatures between 5 and 30 °C, were analyzed by curve-fitting to the Huang and Baranyi models using the USDA IPMP 2013. The experimental results showed that L. monocytogenes in salted samples exhibited approximately 40% longer lag times than the cells in unsalted samples under the same temperature condition, while the rates of bacterial growth were not affected by the addition of salt. The Ratkowsky square-root (RSR) model, Huang square-root (HSR) model, and an Arrhenius-type model were all shown suitable for evaluating the effect of temperature on specific growth rates. The estimated nominal minimum growth temperature in the RSR model was −0.5 °C, whereas the minimum growth temperature in HSR model was 2.57 °C. The HSR models may be more suitable for describing the temperature effect in salted salmon roe. The lag times of L. monocytogenes were found to change log-linearly with the specific growth rates. The mean h₀ in the Baranyi model was 0.742 in unsalted samples and 1.193 in salted samples, and did not appear to change with temperature in a systematic manner. In summary, kinetic models were developed for examining the effect of temperature on growth of L. monocytogenes in unsalted and salted salmon roe samples. The results may be used by the food industry and regulatory agencies to estimate the growth of L. monocytogenes in salmon roe, and to conduct risk assessments of this microorganism.     

A survey of seasonal variations of aflatoxin M1 in raw milk in Tangshan region of China during 2012–2014

Total 530 samples of raw milk were collected from the dairy farms in the Tangshan region of north China during four seasons each year from 2012 to 2014, and aflatoxin M1 (AFM1) contents were measured using HPLC-MS/MS. The results showed that AFM1 was detected in 280 samples (52.8%) at the range of 10–200 ng L⁻¹, and the mean level of AFM1 was 73.0 ng L⁻¹, which was below the China and US legal limit of 500 ng L⁻¹. The incidences of AFM1 contamination were 27.5% in spring, 39.0% in summer, 71.7% in autumn and 78.9% in winter, respectively. It indicated that seasonal variations should be considered for the AFM1 control particularly during winter season. In comparison with the data from different years, the incidences of AFM1 contamination in raw milk samples were 87.8% with a range of 10.0–160 ng L⁻¹ in 2012, 29.9% with 10.0–190.0 ng L⁻¹ in 2013 and 36.7% with 12.0–111.0 ng L⁻¹ in 2014. Hence, present study exhibits a significant decrease in the incidence of AFM1 contamination in Tangshan region after 2012.     

Transfer of chloramphenicol from milk to commercial dairy products – Experimental proof

The purpose of the study was to investigate the chloramphenicol (CAP) residue in dairy products after experimental CAP transferring from milk to butter, sour cream, white cheese and whey. In order to determine the CAP residue in dairy products, the new approach for the extraction process was developed. The original, simple and fast analytical method is based on QuEChERS and LC-MS/MS. The homogenized sample was extracted and partitioned after the adding of sodium chloride with acetonitrile. The experiment was conducted to check if CAP is transferred from milk to dairy products, and also to check the extraction of CAP from the different dairy matrices. Average recovery ranged from 97.8 to 102.8% and within-laboratory reproducibility was lower than 8.7%. The suggested method is sensitive, the calculated limit of decision (CCα) was from 0.06 to 0.10 μg kg⁻¹ and detection capability (CCβ) from 0.08 to 0.15 μg kg⁻¹. The results of the experiment (butter 4.86 μg kg⁻¹, sour cream 3.5 μg kg⁻¹, white cheese 2.36 μg kg⁻¹ and whey 0.14 μg kg⁻¹) and validation demonstrated that this method is suitable for determination and confirmation of CAP in a variety of dairy product matrices.     

Absence of parasitic nematodes in farmed,harvest quality Atlantic salmon (Salmo salar) in Norway – Results from a large scale survey

A total of 4184 farmed Atlantic salmon (Salmo salar) were sampled and subsequently examined for nematodes between January 2014 and July 2015. The fish originated from 37 salmon farms along the coast of Norway and represented all salmon-producing counties. Samplings took place at processing facilities during regular slaughtering procedures and consisted of 3525 harvest quality salmon processed for human consumption and 659 discarded salmon including runts and fish discarded for other quality defects. Both viscera and musculature (fillets including belly flaps) of the salmon were screened by applying the UV-press method. No nematodes were found in any of the harvest quality salmon. The only nematode findings were from the viscera of three runts (loser fish) originating in southern or western Norwegian farms, and consisted of two Anisakis simplex (s.s.) larvae and three adults of the non-zoonotic species Hysterothylacium aduncum. The absence of nematodes in the harvest quality salmon relates most likely to the diet since healthy and normally developing salmon seem to rely exclusively on the heated and extruded dry-feed, which cannot contain any viable parasites. The runts, however, may feed opportunistically on whatever prey available in the cages, which apparently facilitates the transfer of nematodes. Thus, the present results suggest that the risk of any parasitic nematodes to occur in the flesh of farmed Norwegian salmon intended for human consumption is very low.     

Direct construction of predictive models for describing growth of Salmonella Enteritidis in liquid eggs – A one-step approach

The objective of this study was to develop a new approach using a one-step approach to directly construct predictive models for describing the growth of Salmonella Enteritidis (SE) in liquid egg white (LEW) and egg yolk (LEY). A five-strain cocktail of SE, induced to resist rifampicin at 100 mg/L, was used to inoculate LEW and LEY. Kinetic studies were conducted isothermally at different temperatures between 8 and 43 °C to generate growth curves at each temperature.This study first solved an inverse problem globally, using the growth curves to estimate the temperature-dependent kinetic parameters, and then applied the parameters to predict growth (a forward problem). Once the growth curves were generated, they were assembled and analyzed using nonlinear regression to determine kinetic parameters of both primary and secondary models in one step, with an objective to minimize the global residual sum of squares (RSS) for the entire data set. For growth in LEW, a three-parameter logistic model was used. For growth in LEY, the Huang model was used as the primary model. The Ratkowsky square-root model was used to evaluate the growth rates.The results showed that the one-step approach resulted in accurate estimation of the kinetic parameters that were used later to successfully predict the growth of SE in LEY and LEW. The estimated nominal minimum growth temperatures of SE were 7.4 °C and 9.9 °C, while the estimated maximum growth temperatures were 45.2 °C and 46.8 °C, respectively, in LEW and LEY. As a validation, the predictive models were tested with independent growth curves of SE in LEY and LEW at 37 °C. The root mean square error (RMSE) was only 0.36 and 0.28 log CFU/ml over a total scale of 8.4 and 7.8 log CFU/ml, respectively, for the growth models of SE in LEY and LEW, suggesting that the one-step approach can generate accurate models for predicting the growth of SE in LEY and LEW. The results from this study can be used to predict the growth of SE and evaluate the safety of LEY and LEW.     

Essential oils as antimicrobials in food systems – A review

Many consumers are demanding foods without what they perceive as artificial and harmful chemicals, including many used as antimicrobials and preservatives in food. Consequently, interest in more natural, non-synthesized, antimicrobials as potential alternatives to conventional antimicrobials to extend shelf life and combat foodborne pathogens has heightened. Aromatic plants and their components have been examined as potential inhibitors of bacterial growth and most of their properties have been linked to essential oils and other secondary plant metabolites. Historically, essential oils from different sources have been widely promoted for their potential antimicrobial capabilities. In this review, mechanisms of antimicrobial action, and the antimicrobial properties of plant essential oils are discussed, including their mode of action, effectiveness, synergistic effects, major components and use in foods.     

Antimicrobial resistance profiles of Listeria monocytogenes isolated from ready-to-eat products in Poland in 2007–2011

The aim of the study was to characterize strains of Listeria monocytogenes isolated from ready to eat (RTE) products collected as part of official food control and monitoring in Poland. A total of 105 L. monocytogenes isolates from RTE products: 54- cakes and 51 – delicatessen products were examined. The presence L. monocytogenes in cakes and delicatessen products was 0.4% and 0.7% respectively suggesting the level of contamination of RTE products with L. monocytogenes is very low.     

Deceit with decapods? Evaluating labelling accuracy of crustacean products in South Africa

Despite the high value of decapod crustaceans, relatively little research has focused on assessing the transparency in the marketing of these species. This study represents the first comprehensive evaluation of the quality of labelling, and the extent of mislabelling, of decapod crustacean products on the South African market. Data collected through surveys of supermarkets and seafood shops in three provinces (KwaZulu-Natal [KZN], Western Cape [WC] and Gauteng [GP]), indicated that the large majority of domestically available crustacean products were imported, but that 18% of these failed to comply with locally applicable country of origin labelling regulations. Voluntary information relating to the scientific name, production method (wild caught or farmed), and capture method of the species was supplied more frequently in supermarkets than in seafood shops, more frequently in the WC and GP than in KZN, and more frequently on shrimp products than on crab and lobster products. DNA sequencing of 77 products collected from the surveyed outlets revealed that 24 (31%) were misrepresented in some way. Species misrepresentations were most pronounced for shrimps, with Litopenaeus vannamei and Pleoticus muelleri being confirmed as the most common substitute species. One shrimp product was found to contain at least three different species, none of which matched the declared species, whereas a product labelled as crab turned out to be a member of the phylum Mollusca rather than the subphylum Crustacea. Overall, these findings demonstrate that the misrepresentation of crustaceans is commonplace on the South African market, signalling the need for a revision of the current seafood labelling and traceability legislation, as well as monitoring and enforcement efforts.     

Alkylated 2,2′-bithiophenes and 2-phenylthiophenes in the composition of pyrolysis products of high-sulfur kerogen

Compounds from the 5-n-alkyl-2,2′-bithiophene, 5-n-alkyl-5′-methyl-2,2′-bithiophene, 5-n-alkyl-2-phenylthiophene, and 5-n-alkyl-2-o-tolylthiophene homologous series were synthesized to prove their presence in the pyrolysis products of sulfur-rich kerogen. A study of the pyrolysis products of sulfur-vulcanized polybutadiene confirmed that these compounds can be formed via the thermal transformation of n-alkyl polysulfur-bound fragments of sulfur-rich kerogen. The earlier proposed scheme that assumes the dependence of the composition of the pyrolysis products of sulfur-rich kerogen on its saturation with sulfide bridges was experimentally corroborated.     

The in vitro ability of different Saccharomyces cerevisiae – Based products to bind aflatoxin B1

The purpose of this study was to evaluate the ability of Saccharomyces cerevisiae (SC) – based products from sugar cane fermentation (dried yeast – DY, autolyzed yeast – AY, cell wall – CW) and from beer fermentation (brewery dehydrated residue – BDR) to bind aflatoxin B₁ (AFB₁) in phosphate buffer saline (PBS) spiked with 0.5 μg AFB₁ mL⁻¹. All SC cells were heat-killed (121 ° C, 10 min) and then used for checking the effect of contact time (5, 10, 20 and 30 min) on toxin binding capacity. Compared to the CW and BDR treatments, DY and AY had higher (p < 0.05) capability to bind AFB₁ in PBS, although there were no differences (p > 0.05) among the contact times for any product evaluated. The mean percentages of AFB₁ bound by the DY were higher than AY, varying from 96.5% to 99.3% and from 90.4% to 97.5%, respectively, although the differences were not significant (p > 0.05). The SC-based products from sugar cane fermentation have a potential application for reducing levels of AFB₁ in contaminated food products. However, additional studies are needed to investigate the mechanisms involved in the removal process of toxin by SC and factors that affect toxin sequestration aiming the commercial application in food industry.     

Joint geophysical and geochemical evaluation of source rocks – A case study in Sayun-Masila basin,Yemen

Integration of geophysical and geochemical approaches is used for qualitative and quantitative evaluation of source rocks. The Upper Jurassic rocks in the Sayun-Masila basin are used as a case study due to its high hydrocarbon potentiality. Stratigraphically, these rocks could be differentiated from base to top into: Shuqra, Madbi and Nayfa formations. The total organic carbon (TOC) values were determined in the shale and/or carbonate intervals of these formations from four studied wells by the ΔlogR method using sonic, resistivity and gamma-ray log data. Then the discriminant analysis was applied in differentiating source from non-source rocks. Also, the effect of the burial and thermal histories on the organic material maturation and the oil and/or gas generation was studied through the application of two analytical methods, namely, the level of organic metamorphism (LOM) and the time-temperature index (TTI), depending on the corrected temperature logs integrated with the time and depth data. The reliability of the obtained results has been confirmed and combined with the results supplied from geochemical analyses. The Upper Jurassic sediments are found to be oil–prone source rock in a mature stage. The Madbi Formation is considered as the most effective source rock. The burial and thermal histories of the basin in four modeled wells showed that mature oil generation window and hydrocarbon expulsion would have been initiated in the depocenters from Upper Jurassic Madbi Formation source rock during Late Cretaceous to Middle Miocene time.     

Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application – A review

Aflatoxins are mainly produced by certain strains of Aspergillus flavus, which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.     

Performance of ultrasonic – Treated nano-zeolites employed in the preparation of dimethyl ether

Catalytic dehydration of methanol to dimethyl ether was carried out over nano-zeolites and their modified samples via ultrasonic technique. Parent H-Beta and Parent H-Mordenite zeolites are used as synthesized and after sonication. H-Mordenite sonicated for 20 and 120 min whereas H-Beta sonicated for 20 min only. The reaction temperature was varied between 100 and 225 °C at three different contact times. The different catalyst samples were characterized using: XRD, FTIR, TEM, SEM and NH₃-TPD techniques. The results revealed that sonication of parent zeolite samples affects on the unit cell dimensions and their crystal size. FTIR-spectroscopic analysis indicated that sonication may decrease the pore opening and cause framework structure defects. TEM and SEM micrographs showed that sonication broke-up and re-ordered zeolite crystals with longer time resulted in a different morphology relative to parents and also change the particle size. Sonicated samples have a good performance in methanol dehydration with complete conversion and complete selectivity to dimethyl ether at lower temperature relative to the corresponding parent zeolites. TPD results indicated that the concentration of strong acid sites decreased in sonicated H-Mordenite samples leading to an increase of their catalytic activity and the selectivity to DME. On the other hand, ultrasonic treatment of H-Beta sample decreased its catalytic activity.     

Lactic acid bacteria in cooked hams – Sources of contamination and chances of survival in the product

The aim of this study is microbiological analysis of individual technological operations during the industrial production of cooked hams, focusing on lactic acid bacteria (LAB). Samples were during the course of the entire cooked ham production cycle in May–June (Experiment I) and November–December (Experiment II). A total of 215 samples were taken and subsequently tested. The difference in the occurrence of LAB in meat before thermal processing resulted from the initial level of contamination of the raw material. A reduction to the number of LAB from 4.0 to 5.0 log CFU/g of meat to a value of practically zero occurred during the thermal processing. The LAB population increased during storage of the finished products. A level of 7.0 log CFU/g was reached in slices of ham in the modified atmosphere after three (Experiment I) or two (Experiment II) weeks of storage, respectively. LAB of the genera Leuconostoc (Leuc. carnosum, Leuc. mesenteroides and Leuc. gelidum) occurred most frequently in samples of cooked ham after thermal processing. These species were also isolated from the production environment. Lactobacillus sakei, Lbc. curvatus and Weissella viridescens were other species of LAB that were isolated from samples after thermal processing.     

A New Round of Revamping of Caprolactam Plant in Baling

The caprolactam plant of Baling Petrochemical Company,SINOPEC has been operating continuously for four years without shutdown for overhaul. Debottlenecking has been achieved through optimizing technology and technical innovation. Caprolactam production reached 72kt/a and cyclohexanone production reached 69kt/a with total output value 850 million RMB.     

Occurrence of aflatoxin B1 in food products derivable from ‘egusi’ melon seeds consumed in southwestern Nigeria

Aflatoxin, the toxic secondary metabolite of Aspergillus flavus and Aspergillus parasiticus has been considered as one of the most serious food safety problems in sub Saharan Africa. Egusi melon seeds is susceptible to these fungal infection during postharvest. Therefore, the content of aflatoxin B1 in three food products derivable from ‘egusi’ melon seeds ogiri’ (fermented melon seed condiment), ‘robo’ (melon ball snacks) and egusi soup destined for human consumption in Nigeria in 2005 and 2006 were determined. Aflatoxin B1 was analysed by thin layer chromatography (TLC) with fluorescent detection. The percentage of samples positive for aflatoxin B1 were for 25% robo, 31.8% for ogiri, and 19.5% for ‘egusi’ soup. Aflatoxin B1 ranged from 2.3 to 15.4 ppb in all samples. The overall mean levels of aflatoxin B1 were for 8.9 ppb for ogiri, 9.7 ppb for ‘robo’ and 7.2 ppb for ‘egusi soup’. All positive melon seeds derived food products analysed in this study contained aflatoxin B1 at concentrations much lower than the 20 ppb permissible limit recommended in Nigerian food and suggests that melon seed derived foods present less risk by human exposure to aflatoxin through their consumption. However, it is important to consider these levels in terms of their contribution to overall daily exposure to aflatoxin levels in food. This is the first report of aflatoxin determination in melon seed food products.     

Aflatoxin contamination in unrecorded beers from Kenya – A health risk beyond ethanol

Samples of unrecorded opaque beers (n = 58; 40 based on maize, 5 on sorghum and 13 on other plants) and recorded wines (n = 8) in Kenya were screened for aflatoxins using a rapid ELISA technique followed by confirmation using liquid chromatography-tandem mass spectrometry. Six of the maize beers were obtained from Kibera slums in Nairobi County. Aflatoxin contamination was detected in six unrecorded beers (10%), but in none of the recorded wines. Remarkably, three of the aflatoxin positive samples were from the Kibera slums.The mean concentration of aflatoxins in the positive samples was 3.5 μg/L (range 1.8–6.8 μg/L), corresponding for an average consumption of 500 mL (1 standard drink) to a margin of exposure (MOE) of 36 (range: 15–58), which is considered as ‘risk’. On the other hand, the alcoholic strength of the aflatoxin positive samples had a mean of 4.3% vol (range 3.5–4.8%) corresponding to a MOE of 2.5 (range of 2.2–3.0) for the equivalent consumption volume. While aflatoxins pose a risk to the consumer, this risk is about 10 times lower than the risk of ethanol.The Joint FAO/WHO Expert Committee on Food Additives sets no acceptable daily intake for aflatoxins since they are genotoxic carcinogens and instead recommends for the reduction of aflatoxin dietary exposure as an important public health goal, particularly in populations who consume high levels of any potentially aflatoxins-contaminated food. Nevertheless, ethanol still posed a considerably higher risk in the unrecorded beers examined. However, consumers should be informed about aflatoxins, as these are an involuntary and unknown risk to them. In addition, producers should be educated about measures to reduce aflatoxins in alcoholic beverages.     

Petroleum Asphaltites – a Highly Effective Additive in Production of Carbon Adsorbents

TIt is not possible to eliminate the acute shortage of carbon adsorbents by creating a scientifically substantiated assortment of sorbing materials with defined properties based on traditional stock bases alone. Petroleum residues with the most important natural resource can be used for this purpose. The number increases with the development of heavy, resinous, and mediumsulfur crude oils [13 ].