In-Depth Investigation of the Safety of Wooden Shelves Used for Traditional Cheese Ripening.

The main goal of this research was to characterize the bacterial diversity of the wooden boards used for aging traditional Sicilian cheeses and to evaluate whether pathogenic bacteria are associated with these surfaces. Eighteen cheese dairy factories producing three traditional cheese typologies (PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano) were selected within the region of Sicily. The wooden shelf surfaces were sampled by a destructive method to detach wood splinters as well as by a nondestructive brushing to collect microbial cells. Scanning electron microscopy showed the presence of almost continuous bacterial formations on the majority of the shelves analyzed. Yeasts and fungal hyphae were also visualized, indicating the complexity of the plank communities. The amplicon library of the 16S rRNA gene V3-V4 region was paired-end sequenced using the Illumina MiSeq system, allowing the identification of 14 phyla, 32 classes, 52 orders, 93 families, and 137 genera. Staphylococcus equorum was identified from all wooden surfaces, with a maximum abundance of 64.75%. Among cheese-surface-ripening bacteria, Brevibacterium and Corynebacterium were detected in almost all samples. Several halophilic (Halomonas, Tetragenococcus halophilus, Chromohalobacter, Salimicrobium, Marinococcus, Salegentibacter, Haererehalobacter, Marinobacter, and Idiomarinaceae) and moderately halophilic (Salinicoccus, Psychrobacter, and Salinisphaera) bacteria were frequently identified. Lactic acid bacteria (LAB) were present at low percentages in the genera Leuconostoc, Lactococcus, Lactobacillus, Pediococcus, and Streptococcus. The levels of viable microorganisms on the wooden shelves ranged between 2.4 and 7.8 log CFU/cm2. In some cases, LAB were counted at very high levels (8.2 log CFU/cm2). Members of the Enterobacteriaceae family were detected in a viable state for only six samples. Coagulase-positive staphylococci, Salmonella spp., and Listeria monocytogenes were not detected. Seventy-five strains belonged to the genera Leuconostoc, Lactococcus, Pediococcus, Enterococcus, Lactobacillus, and Weissella. IMPORTANCE This study provides evidence for the lack of pathogenic bacteria on the wooden shelves used to ripen internal bacterially ripened semihard and hard cheeses produced in Sicily. These three cheeses are not inoculated on their surfaces, and surface ripening is not considered to occur or, at least, does not occur at the same extent as surface-inoculated smear cheeses. Several bacterial groups identified from the wooden shelves are typically associated with smear cheeses, strongly suggesting that PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano cheese rind contributes to their final organoleptic profiles.

Migration of substances from food contact plastic materials into foodstuff and their implications for human exposure.

The safety of food contact plastic materials, including PP, PE, PET, PCT, PLA, PBT and cross-linked polyester, was assessed with regard to migrated substances. The migrated concentrations of overall migrants (OMs), terephthalic acid, acetaldehyde, 1,4-butanediol and lead, were determined according to the standards and specifications for utensils, containers and packages in Korea. Food simulants of 4% acetic acid, water and n-heptane were used for the analysis of the substances. The dietary exposures of terephthalic acid, acetaldehyde and 1,4-butanediol were assessed using the dietary concentrations and the food consumption data. As a result, the dietary exposures were considered to be safe comparing to the health-based guidance values. In the case of lead, the margin of exposure (MOE) approach was applied. The MOEs calculated using the UB concentration and mean consumption data were ranged from 3 to 1000, which indicated low concern for health risk. Moreover, in this study, the dietary exposures were estimated by the Korean MFDS and U.S. FDA methods, respectively. As a result, the assessed risks were considered to be low in both cases. Based on the results of current exposure assessments, it could be considered that the food contact plastic materials are properly controlled by the regulatory authorities.

The Effect of Plant Essential Oil and Extracts on Fatty Acid Profile of Virgin Olive Oil Stored in Different Packaging Materials.

In this study, the combined effect of different packaging materials (transparent PET, transparent glass, glass-PET bottle and tin), some aromatic herbs (thyme, rosemary, sage and olive leaf) and also their essential oils (thyme, rosemary and sage) on fatty acid composition of virgin olive oil was investigated during storage period. The initial amounts of the main fatty acids as oleic, palmitic and linoleic acids were determined as 72.89%, 11.89% and 8.96%, respectively. The addition of aromatic plants and essential oils did not effect the fatty acid profile. Also, packaging materials had a minor influence on fatty acids. In the 6th month of storage, the oleic acid contents of olive oils showed the increase in all of samples. The highest increase was observed in olive oil stored in glass-PET (74.30-75.01%), followed by stored in glass bottle (73.41-74.82%). Generally, during the storage, the differences of fatty acid contents were in minor level. The fatty acid composition of olive oils stored under different essential oil and extract concentrations showed partial differences depending on the extract type and concentration.

Mining the Factors Driving the Evolution of the Pit Mud Microbiome under the Impact of Long-Term Production of Strong-Flavor Baijiu.

The mud cellar creates a unique microenvironment for the fermentation of strong-flavor baijiu (SFB). Recent research and long-term practice have highlighted the key roles of microbes inhabiting pit mud in the formation of SFB's characteristic flavor. A positive correlation between the quality of SFB and cellar age was extracted from practice; however, the evolutionary patterns of pit mud microbiome and driving factors remain unclear. Here, based on the variation regularity analysis of microbial community structure and metabolites of samples from cellars of different ages (∼30/100/300 years), we further investigated the effects of lactate and acetate (main microbial metabolites in fermented grains) on modulating the pit mud microbiome. Esters (50.3% to 64.5%) dominated the volatile compounds identified in pit mud, and contents of the four typical acids (lactate, hexanoate, acetate, and butyrate) increased with cellar age. Bacteria (9.5 to 10.4 log10 [lg] copies/g) and archaea (8.3 to 9.1 lg copies/g) mainly constituted pit mud microbiota, respectively dominated by Clostridia (39.7% to 81.2%) and Methanomicrobia (32.8% to 92.9%). An upward trend with cellar age characterized the relative and absolute abundance of the most predominant bacterial and archaeal genera, Caproiciproducens and Methanosarcina. Correlation analysis revealed significantly (P < 0.05) positive relationships between the two genera and major metabolites. Anaerobic fermentation with acetate and lactate as carbon sources enhanced the enrichment of Clostridia, and furthermore, the relative abundance of Caproiciproducens (40.9%) significantly increased after 15-day fed-batch fermentation with lactate compared with the initial pit mud (0.22%). This work presents a directional evolutionary pattern of pit mud microbial consortia and provides an alternative way to accelerate the enrichment of functional microbes. IMPORTANCE The solid-state anaerobic fermentation in a mud cellar is the most typical feature of strong-flavor baijiu (SFB). Metabolites produced by microbes inhabiting pit mud are crucial to create the unique flavor of SFB. Accordingly, craftspeople have always highlighted the importance of the pit mud microbiome and concluded by centuries of practice that the production rate of high-quality baijiu increases with cellar age. To deepen the understanding of the pit mud microbiome, we determined the microbial community and metabolites of different-aged pit mud, inferred the main functional groups, and explored the forces driving the microbial community evolution through metagenomic, metabolomic, and multivariate statistical analyses. The results showed that the microbial consortia of pit mud presented a regular and directional evolutionary pattern under the impact of continuous batch-to-batch brewing activities. This work provides insight into the key roles of the pit mud microbiome in SFB production and supports the production optimization of high-quality pit mud.

Efficacy of different hermetic bag storage technologies against insect pests and aflatoxin incidence in stored maize grain.

The performance of six grain storage technologies for the control of insect pests in maize was evaluated over a 36-week (9-month) storage period. The six technologies used were: two ZeroFly® hermetic bag brands (laminated and non-laminated); Purdue Improved Crop Storage (PICS) bag; non-hermetic ZeroFly® bag; woven polypropylene (PP) bag containing maize grain treated with Actellic Gold® Dust (pirimiphos-methyl 1.6% + thiamethoxam 0.3%) and woven PP bag containing untreated grain. Each bag was filled with 50 kg maize grain and four replicates of each were set up. With the exception of the non-hermetic ZeroFly® bag, 50 live adults of the larger grain borer Prostephanus truncatus and of the maize weevil Sitophilus zeamais, were introduced into all the bags. Insects were not introduced into the non-hermetic ZeroFly® bag to assess its effectiveness in repelling infestation from outside. Parameters recorded were gas composition (oxygen and carbon dioxide) levels inside the bags; weight of flour generated by insect feeding activities; grain moisture level; live adult insect counts; grain damage and weight loss; grain germination rate and aflatoxin level. At termination, the plastic liners of the hermetic bags were examined for perforations. Results show that oxygen depletion and carbon dioxide evolution were faster in ZeroFly® hermetic compared to PICS bags. Throughout the 36-week storage trial, grain damage remained below 4% and weight loss below 3% in all the treatments except in the untreated PP bags in which it increased to 81.1 and 25.5%, respectively. The hermetic PICS, ZeroFly® and Actellic Gold dust-treated PP bags maintained grain germination at 60%, which was lower than the initial 90%, while in untreated control, it reduced to 4.7%. The mean aflatoxin levels fluctuated between 0.39 and 3.56 parts per billion (ppb) during 24 weeks of storage in all the technologies tested, which is below the acceptable maximum level of 10 ppb in maize. Based on the evaluation results, it can be concluded that hermetic PICS and ZeroFly® bags and woven PP bag with Actellic Gold dust-treated grain effectively protected stored maize grain from insect attack and weight losses. Appropriate strategies and mechanisms for the effective and efficient adoption of hermetic storage bag technology at scale would contribute towards global food security.

Low storage temperature for tree ripe mangoes under controlled atmospheres with elevated CO2 concentrations.

BACKGROUND: Tree-ripe mangoes are of a better quality than the more commonly marketed mature-green fruit. However, the postharvest life of tree-ripe mangoes at the chilling threshold temperature for mature-green fruit of 12 °C is insufficient to allow long distance transport for international marketing. Because the chilling sensitivity often decreases as fruit ripen, lower temperatures (5 and 8 °C) in combination with a controlled atmosphere of 5 kPa O2 plus 10 or 25 kPa CO2 were tested to determine whether the quality of tree-ripe mangoes could be maintained longer without chilling injury (CI). RESULTS: Tree-ripe 'Tommy Atkins' and 'Keitt' mangoes were stored for 14 or 21 days, respectively, in air or controlled atmosphere (CA) at 5 or 8 °C. Respiration rates were below 10 mL kg-1 h-1 during CA storage and increased three-fold during a 3-day shelf life period at 20 °C. Ethanol synthesis of fruit stored in 25 kPa CO2 , but not 10 kPa CO2 , increased during storage and remained high during shelf life, indicating physiological stress. Elevated electrolyte leakage and 1-aminocyclopropane-1-carboxylic acid concentrations in both cultivars stored in 25 kPa CO2 also indicated that mesocarp tissues were injured by the higher CO2 level. No CI symptoms were observed in air or CA at either 5 or 8 °C. CONCLUSION: Storage of tree-ripe mangoes in 5 kPa O2 plus 10 kPa CO2 at either 5 or 8 °C best maintained the quality of Tommy Atkins and Keitt fruit for 14 or 21 days, respectively, without evidence of either atmosphere injury or CI. © 2020 Society of Chemical Industry.

How olive washing and storage affect fruit ethanol and virgin olive oil ethanol, ethyl esters and composition.

BACKGROUND: Olives are stored for a short time after harvesting pending processing in the oil mills. Furthermore, olives are often washed prior to fruit storage. In this work we study how washing and storage affect fruit ethanol content and the effect on virgin olive oil ethanol content and quality. RESULTS: Olive storage produced an increase in the fruit ethanol content, achieving values six times higher when storage was in silos. Washing the olives resulted in an increase in fruit ethanol content, although when washed olives were processed immediately no difference was found. The increase in fruit ethanol content during storage was reflected in higher oil ethanol concentration. Similarly, olive washing resulted in oils with higher ethanol concentration. Industrial conditions gave more important increases in oil ethanol content than that from olives processed by hand. For quality parameters all the olive oils were classified as 'extra virgin'. In general, oils showed a slight decrease in some sensory attributes. At industrial scale after 24 h storage oils were classified as 'virgin' because sensory defects were found. CONCLUSION: Olive storage should be avoided or reduced to less than 12 h; if possible, olives should not be washed before storage since this practice favors losses in sensory characteristics and the synthesis of ethanol, a precursor of ethyl esters. © 2020 Society of Chemical Industry.

A new method for matching gold nanoparticle-based time-temperature indicators with muffins without obtaining activation energy.

Time-temperature indicators (TTIs) can monitor the quality and safety of food. A new temperature-time point comparison method was proposed to match TTIs with food. This method omits the step of calculating activation energy (Ea ). It only compares the difference between TTI response time and food shelf life to determine their matching degree. Taking gold nanoparticle-based TTIs and muffins as experimental objects, the new and the traditional matching methods were used to match the absorbance of TTI and the peroxide value of muffins. The two results are not significantly different. TTIs with gelatin solution and gold precursor solution concentration of 150.00  and 2.05 mg/mL, respectively, can show the quality of muffins. TTIs changed from light yellow to pink and finally appeared deep purple. The deep purple represented spoilage and inedibility of muffins. Comparing Ea of food and that of TTIs can preliminarily evaluate their matching degree, improving the experiment efficiency. Hence, it is reasonable to use the traditional matching method in most cases, and use the new method only when Ea of food cannot be obtained. PRACTICAL APPLICATION: The deterioration rate of food is usually calculated by developing kinetic models of characteristic quality parameters. When the reaction rate is unavailable or inaccurate, the activation energy of food cannot be obtained. In this case, it is impossible to match TTIs with food based on the traditional method. This research develops a new matching method and helps TTIs and food to be matched without considering activation energy. It will promote the application of TTIs in more products.

Interactions of Mutiple Biological Fields in Stored Grain Ecosystems.

Biological entities such as fungi in stored grain evolve and interact with the environment in similar fashions as physical fields. An experiment was conducted to study the behavior of the biological field of fungi in stored grain, as well as the interactions between the biological field of fungi and the physical fields of temperature and moisture. A framework of the biological field is presented to describe biological systems in which multiple biological entities co-exist and interact among themselves and with the surrounding environment. The proposed biological field describes the spatio-temporal distribution of a biological entity and its ability of influencing (or being influenced by) the surrounding biotic and abiotic entities through exchange of energy, matter, and/or information. The strength of a biological field of fungi was quantified as the rate of energy conversion by fungi from grain starch to heat. The experimental data showed that the strength of biological field of fungi in stored grain varied in both space and time, with the maximum field strength of 120-133 W m-3 occurred at the location where the biological field of fungi interacted strongly with the temperature and moisture fields.

Assessment of the Risk of Salmonellosis Linked to the Consumption of Liquid Egg Products Made from Internally Contaminated Shell Eggs Initially Stored at 65°F (18°C) Compared with Eggs Stored at 45°F (7°C).

ABSTRACT: According to the U.S. Food and Drug Administration's (FDA's) rule on "Prevention of Salmonella Enteritidis in Shell Eggs during Production, Storage, and Transportation," shell eggs intended for human consumption are required to be held or transported at or below 45°F (7.2°C) ambient temperature beginning 36 h after time of lay. Meanwhile, eggs in hatcheries are typically stored at a temperature of 65°F (18.3°C). Although most of those eggs are directed to incubators for hatching, excess eggs have the potential to be diverted for human consumption as egg products through the "breaker" market if these eggs are refrigerated in accordance with FDA's requirement. Combining risk assessment models developed by the U.S. Department of Agriculture's Food Safety and Inspection Service for shell eggs and for egg products, we quantified and compared Salmonella Enteritidis levels in eggs held at 65°F versus 45°F, Salmonella Enteritidis levels in the resulting egg products, and the risk of human salmonellosis from consumption of those egg products. For eggs stored 5 days at 65°F (following 36 h at 75°F [23.9°C] in the layer house), the mean level of Salmonella Enteritidis contamination is 30-fold higher than for eggs stored at 45°F. These increased levels of contamination lead to a 47-fold increase in the risk of salmonellosis from consumption of egg products made from these eggs, with some variation in the public health risk on the basis of the egg product type (e.g., whole egg versus whole egg with added sugar). Assuming that 7% of the liquid egg product supply originates from eggs stored at 65°F versus 45°F, this study estimates an additional burden of 3,562 cases of salmonellosis per year in the United States. A nominal range uncertainty analysis suggests that the relative increase in the risk linked to the storage of eggs at higher temperature estimated in this study is robust to the uncertainty surrounding the model parameters. The diversion of eggs from broiler production to human consumption under the current storage practices of 65°F (versus 45°F) would present a substantive overall increase in the risk of salmonellosis.

Direct analysis in real time coupled with quadrupole-Orbitrap high-resolution mass spectrometry for rapid analysis of pyrethroid preservatives in wooden food contact materials.

A methodology is presented for the determination of four pyrethroid (PYR) preservatives in wooden food contact materials (FCMs) using direct analysis in real time (DART) coupled with quadrupole-Orbitrap high-resolution mass spectrometry (Q-Orbitrap HRMS). The sampling mode and critical parameters of the DART-Q-Orbitrap HRMS protocol were systematically investigated. Good linearity was achieved for the four analytes with correlation coefficients all greater than 0.99. The limits of detection (LODs) and limits of quantitation (LOQs) of the method were in the range of 0.04-0.20 mg kg-1 and 0.10-0.50 mg kg-1, respectively. The mean recoveries ranged from 72.1% to 82.7% with relative standard deviations (RSDs) from 5.2% to 11.8% at three spiked levels. The developed method was proved to be suitable for rapid screening of PYRs in complex wooden FCM samples to ensure product safety and consumer health.

Changes in flavor of fragrant rice during storage under different conditions.

BACKGROUND: Because of its high nutritional value and good sensory properties, fragrant rice is very popular all over the world. The aroma and taste of fragrant rice play an essential role in its sensory properties. However, there has been a lack of studies on flavor changes in fragrant rice during storage. RESULTS: Hexanal, nonanal, benzaldehyde, hexadecanoic acid, and methyl ester, were identified as aroma-active compounds in fresh fragrant rice. After storage, more than 100 volatile compounds can be identified. The results indicated that, at high-temperature storage, volatile compounds such as aldehydes, ketones, and furans increased, which led to a deterioration in rice quality. Marker compounds of flavor deterioration, methyl palmitate, 2-methyl-propanoic acid, and 3-hydroxy-2,2,4-trimethylpentyl ester, were determined by principal component analysis. In addition to threonine and proline, the other 14 amino acids contributed to the taste of fragrant rice during storage. Sucrose is the only main contributor to the sweetness of Daohuaxiang 2, whereas glucose and fructose had a little sweet taste contribution during storage. The electronic nose (e-nose) and the electronic tongue (e-tongue) could distinguish samples with different storage conditions. CONCLUSION: Different storage conditions can cause flavor differences in fragrant rice. Especially under high-temperature storage, volatile compounds such as aldehydes, ketones, and furans increase, which is an important reason for the deterioration in the quality of fragrant rice during storage. © 2020 Society of Chemical Industry.

Influence of storage time and elevated ripening temperature on the chemical and sensory properties of white Cheddar cheese.

Aged cheese is an increasingly popular dairy product. One approach to reduce Cheddar cheese maturation time is by utilizing elevated temperature, despite potential problems including development of imbalanced or off-flavors and negative changes in texture. Therefore, the objective of this study was to evaluate the influence of elevated ripening temperature on chemical and sensory properties of aged white Cheddar cheese. White Cheddar cheese was aged at 7.2, 10, or 12.8 °C for 12 months, with samples evaluated at 2, 5, 8, 10, 11, and 12 months by a trained sensory panel (n = 10). Two consumer sensory panels (n = 120) assessed 8- and 12-month aged cheese for comparison to a commercially available reference sample of the same cheese, aged for 12 months. An electronic tongue methodology was developed for analysis of nonvolatile compounds. Trained panel results showed that 2-month cheeses were described by milkfat flavor and sweet taste, 5-month cheeses were described by nutty aroma and white color, and 8-, 10-, 11-, and 12-month cheeses developed aged characteristics, such as umami and bitter tastes, brothy aroma, and aged flavor. Consumer panel results showed similar overall liking scores for the reference cheese and cheeses aged at 10 or 12.8 °C for both evaluations. The electronic tongue could classify samples according to aging month with a validity value of 92.59%. In conclusion, the electronic tongue served as a valid method of instrumental analysis for Cheddar cheese samples throughout maturation. This study demonstrated that aging white Cheddar cheese for 8 months at an elevated storage temperature of 10 °C produced cheese similar in consumer acceptance to that aged at 7 °C for 12 months. PRACTICAL APPLICATION: This study showed that aged white Cheddar storage at a higher temperature was perceived similarly by consumers as one stored for 1 year at a slightly lower temperature. This may be useful to those in the dairy industry exploring ways to accelerate aging, reducing devoted resources, while still producing an acceptable product. Also, the electronic tongue was effective at distinguishing among aged white Cheddar cheese samples showing another application for this technology.

Low-cost modified-atmosphere hermetic storage structures to reduce storage losses of maize (Zea mays L.) cobs and sorghum (Sorghum bicolor L.) heads.

BACKGROUND: Production and marketing of cereal grains are some of the main activities in developing countries to ensure food security. However, the food gap is complicated further by high postharvest loss of grains during storage. This study aimed to compare low-cost modified-atmosphere hermetic storage structures with traditional practice to minimize quantitative and qualitative losses of grains during storage. The study was conducted in two phases: in the first phase, seven hermetic storage structures with or without smoke infusion were compared, and one selected structure was further validated at scaled-up capacity in the second phase. RESULTS: Grains stored in PVC bag-supported structures (with or without smoke infusion) resulted in low live weevil population, low percentage of damaged grains and reduced weight loss with better retention of crude protein and fat contents. Results from validation study also demonstrated that maize and sorghum stored in improved storage structures experienced, respectively, 9.8% and 10.4% weevil damage as compared with 47.3% and 42.3% when stored in traditional storage structures. The same was true in terms of crude protein and fat contents. CONCLUSIONS: The study demonstrated that storage structures supported with PVC bags are efficient and low-cost structures for reducing storage-related losses and supporting food security efforts as compared to traditional methods. Furthermore, the bags can be made locally and with various storage capacities to store either shelled or unshelled products. © 2019 Society of Chemical Industry.

Effects of temperature on protein phosphorylation in postmortem muscle.

BACKGROUND: Phosphorylation is one of the most important post-translational modifications. Currently, many postmortem protein phosphorylation studies in muscle have been related to meat quality such as tenderness and color stability. However, the effects of various storage temperatures (25, 15, 4 and -1.5 °C) on the phosphorylation level of protein are poorly understood. Changes in the protein phosphorylation levels in postmortem ovine muscle at various storage temperatures were determined in this study. RESULTS: The obtained data showed that pH decline rate was significantly inhibited at -1.5 °C from 12 h to 7 days postmortem (P < 0.05). The ATP consumption rate was higher at 25 °C than that at other three temperatures (P < 0.05). Analysis of the temperature, pH and ATP content revealed that the ATP content was related to the phosphorylation levels of individual protein bands. Phosphorylated myofibrillar and sarcoplasmic proteins, such as myosin binding protein C, troponin T3, myosin light chain 1, glucose-6-phosphate isomerase and pyruvate kinase, were mainly involved in glycolysis and muscle contraction. CONCLUSION: The global and specific protein phosphorylation levels can be influenced by the postmortem storage temperature of muscle. Phosphorylation of proteins was correlated with glycolysis and muscle contraction. Certain phosphorylated proteins, such as heat shock proteins, require further study to clarify their effects on meat traits. © 2019 Society of Chemical Industry.

Production and migration of patulin in Penicillium expansum molded apples during cold and ambient storage.

The ability of three Penicillium expansum isolates to produce patulin was first evaluated in YES medium after incubation at 25 °C to select a high patulin producer. Then, a spore suspension of the selected P. expansum 3.78 strain was inoculated onto the surface of Golden delicious apples and incubated at 8 or 20 °C until the mold lesion reached a diameter of 1, 2 or 3 cm. For each lesion size, patulin was quantified from apple samples cut into 1 cm depthwise fractions and widthwise sized cylinders. Maximum patulin concentration, about 80,000 ng/g apple, was obtained at 8 °C for the center and surface sample of the 3 cm diameter lesion. Patulin was systematically found at the highest concentration in the lesions, but still quantified up to one centimeter next to the lesion. Patulin concentrations were not significantly different between the 8 and 20 °C incubation temperature, except for the 3 cm large lesions. Based on these findings, and for lesions less than or equal to 3 cm in diameter, we recommend to consumers to cut off at least 1 cm around and below the mold spot to limit patulin exposure. Apples should also be stored at cool temperatures, below 8 °C, to delay lesion development.

Preparation and characterization of a novel colorimetric indicator film based on gelatin/polyvinyl alcohol incorporating mulberry anthocyanin extracts for monitoring fish freshness.

This work aimed to develop a novel colorimetric indicator film for monitoring of food freshness based on gelatin/polyvinyl alcohol matrix incorporated with anthocyanin extracts from mulberry. The color of anthocyanin extracts solutions obviously changed from bright red to dark green in the pH range of 2.0-11.0. FTIR spectra and isothermal titration calorimetry showed that the anthocyanin extracts were successfully combined with gelatin/polyvinyl alcohol matrix by hydrogen binding and electrostatic interaction, which enhanced the stability of anthocyanin. The scanning electric microscopy showed that the compatibility between polyvinyl alcohol and gelatin were improved owing to the addition of anthocyanin extracts. With the anthocyanin extracts addition from 0 to 45 mg/100 mL mixed solution, the tensile strength decreased from 30.80 to 21.01 MPa and the elongation at break increased from 589.22% to 905.86%. The color response of film in buffer solution of different pH were in accordance with anthocyanin extracts solutions, and its color changes were clearly visible with naked eye. Finally, the film was evaluated by a test on monitoring fish spoilage, which presented visible color changes due to volatile nitrogenous compounds formed over time. These results showed that this developed film could be used as an effective method for the monitoring of food freshness.

Effect of storage conditions on the formation of type A and B trichothecenes in cereal products.

INTRODUCTION AND OBJECTIVE: Mycotoxins are toxic metabolites produced by certain types of fungi, causing pathological changes in humans and animals. The aim of this study was to assess the degree of contamination of selected cereal grains, bran and cereal products intended for children, with mycotoxins using GCxGC-TOF-MS technique. The study involved mycotoxins belonging to the type A and B trichothecenes group, including T-2 toxin (T-2), HT-2 toxin (HT-2), scirpenol (SCI), 15-monoacetoxyscirpenol (15-MAS), diacetoxyscirpenol (DAS), triacetoxyscirpenol (TAS), fusarenon-X (FUS-X), nivalenol (NIV), deoxynivalenol (DON), 3-acetyl-DON (3-Ac-DON), 15-acetyl-DON (15-Ac-DON). The study also assessed the effect of conditions in which the samples were stored, including temperature (6°C and 28°C) and time (14 and 28 days), on fungal growth and mycotoxin production. Among all studied compounds, only DAS and HT-2 toxins were detected in tested samples, with the exception of products intended for children. Measured HT-2 mycotoxin content in tested samples was in the range 83.9 - 196.4 µg kg -1. RESULTS AND CONCLUSIONS: Experiments with storage conditions showed a statistically significant increase in the HT-2 toxin level after 14 days of storage in all samples, irrespective of temperature. Prolonged storage (additional 14 days) did not cause significant changes in the HT-2 content. Further analyses showed a statistically significant effect of storage temperature on HT-2 toxin levels only in cereal products intended for children after both 14 and 28 days. Interestingly, lower temperature (6°C) was more optimal then higher temperature (28°C) for the HT-2 toxin production. No significant effect of storage temperature on HT-2 level was observed for cereal grains and bran.

Acacia, cherry and oak wood chips used for a short aging period of rosé wines: effects on general phenolic parameters, volatile composition and sensory profile.

BACKGROUND: There is a restricted knowledge about the potential impact of the use of different wood chip species on the rosé wine aging process. Thus, the aim of this work was to evaluate the general phenolic parameters, aroma composition and sensory profile of rosé wines during a short maturation (20 aging days) in contact with wood chips from oak, acacia and cherry. In addition, the different wood chips were added to a rosé wine without a previous clarification process (unfined wine) and to a rosé wine submitted to a clarification process (fined wine). RESULTS: For the brief maturation time considered, the use of different wood chips induced a tendency for an increase of phenolic content, in particular for unfined rosé wine aged in contact with acacia chips. For volatile composition, the differentiation was clearer for aldehyde compounds group. Regarding sensorial overall appreciation the panel test preferred the unfined rosé wine aged in contact with acacia wood chips. CONCLUSIONS: The results show that, in general, the use of different wood chip species (acacia, cherry and oak) for a brief maturation time of rosé wines could play an important role in rosé wine characteristics, in particular in their phenolic composition. © 2019 Society of Chemical Industry.

Investigation of diversity and dominance of fungal biota in stored wheat grains from governmental warehouses in West Bengal, India.

BACKGROUND: Fungal infestation is a leading cause of qualitative and quantitative deterioration of stored wheat grains. Limited information is available on the spatial distribution of fungal biota associated with stored wheat grains in India. Fungi were isolated and characterized from nine stored wheat grain samples in three warehouses of the Food Corporation of India, located in three agro-climatic zones (Paschim Medinipur, Bankura and Purulia) of West Bengal in India. RESULTS: Maximum density and fungal diversity were observed in dichloran glycerol agar (DG-18) medium and the number increased with the increase of storage duration. Samples collected from Purulia showed maximum fungal diversity than that from Bankura and Paschim Medinipur. A total of 284 fungal isolates were obtained, classified into 29 operational taxonomic units (based on amplified ribosomal DNA restriction analysis of 18S and internal transcribed spacer sequences), and identified as 24 different fungal species. The majority of fungal isolates belonged to Aspergillus flavus (35%) followed by Rhizopus oryzae (13%) and Eurotium amstelodami (9%). Aspergillopepsin O (PEPO) gene and aflatoxin biosynthetic pathway gene, nor-1, were amplified by polymerase chain reaction (PCR) from 91% and 71% of Aspergillus flavus isolates, respectively, indicating their aflatoxin producing ability. Aflatoxin production was further confirmed by ammonia vapour test, thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). CONCLUSION: The presence of toxigenic fungi in stored wheat grain emphasizes the necessity of quarantine measures of stored grains before placing them in the public domain to save consumers from health hazards. © 2019 Society of Chemical Industry.