Chemical Preservation Research Articles

Comparative Study on Structural Differences in Monosaccharide Layers Using PLD and PED Techniques.

To demonstrate the feasibility of obtaining low-molecular-weight organic films (below 200 Da) using non-solvent PVD processes, glucose layers were produced via pulsed laser deposition (PLD) and pulsed electron beam deposition (PED) methods. Glucose was chosen due to its fundamental role in various biological processes, and because this low-molecular-weight compound is a solid at room temperature, which is required for both techniques. The physical and chemical structures of the deposited glucose layers were characterized by optical, scanning electron, and atomic force microscopy, as well as by X-ray diffraction, X-ray photoelectron, and infrared spectroscopy. Both PLD and PED methods resulted in glucose layers with good chemical structure preservation (with minor oxidation observed in PED) while yielding films with distinct physical properties. This opens up the possibility of tailoring organic layers with specific characteristics depending on the application, by choosing the deposition method.

Research Progress on Physical Preservation Technology of Fresh-Cut Fruits and Vegetables

Fresh-cut fruits and vegetables have become more popular among consumers because of their nutritional value and convenience. However, the lower shelf life of fresh-cut fruits and vegetables due to processing and mechanical damage is a critical factor affecting their market expansion, and advances in preservation technology are needed to prolong their shelf life. Some traditional chemical preservatives are disliked by health-seeking consumers because of worries about toxicity. Chemical preservation is inexpensive and highly efficient, but sometimes it carries risks for human health. Biological preservation methods are safer and more appealing, but they are not applicable to large-scale production. Physical fresh-keeping methods have been used for the storage and transportation of fresh-cut fruits and vegetables due to the ease of application. This review discusses current research in fresh-keeping technology for the preservation of fresh-cut fruits and vegetables. Preservation methods include low temperature, modified atmosphere packaging, cold plasma, pulsed light, ultrasonics, ultraviolet light, and ozonated water. As promising alternatives to chemical methods, these novel processes have been evaluated singly or combined with natural preservatives or other methods to extend the shelf life of fresh-cut fruits and vegetables and to provide references and assessments for further development and application of fresh-cut fruit and vegetable preservation technology.

Effects of anticoagulants time storage on stable isotope values of crocodilians’ blood tissues

ABSTRACT Rapid coagulation of reptile blood often hinders its use in studies in remote and difficult-to-access areas, necessitating chemical preservation. Therefore, understanding the potential effects of anticoagulants on the isotopic compositions of blood is essential to avoid issues in interpreting the results for ecological studies. In this study we aimed to verify whether the storage time of the blood tissue in anticoagulants can influence its isotopic compositions of the broad-snouted caiman (Caiman latirostris), an ectothermic top predator from eastern South America. Blood samples were obtained from ten adult females of C. latirostris from a commercial breeding facility in 2015. Samples were stored in vials containing ethylenediaminetetraacetic acid (EDTA) and sodium heparin (SH) and centrifuged after 2 and 8 h to separate red blood cells and plasma. No effect of time was found on the δ13C and δ15N of whole blood, plasma, and red blood cells in contact with the two types of anticoagulants, EDTA and SH. The findings have practical implications for researchers in this field, as they suggest that anticoagulants can be used effectively for at least eight hours under refrigeration.

Fermentation starters and bacteriocins as biocontrol strategies for table olives preservation: a mini-review.

Biopreservation is a powerful strategy to prolong the shelf life of food products by applying naturally occurring microorganisms and/or their metabolites. Current food trends emphasise the need to develop alternatives for chemical or thermal preservation methods. In this line, different fermentation starters from table olives present the potential to control spoilage or pathogen-occurring microorganism in table olives storage. One of the most interesting family used as biopreservative culture is Lactobacillaceae and it has also been used in combination with yeasts as olive fermentation starter. Lactic acid bacteria, from Lactobacillaceae family, are characterised by the production of bacteriocins, proteins with the potential for preserving food by changing the organisation of the membrane of spoilage microorganisms. These bacteriocins-producing bacteria can be directly inoculated, although nanosystem technology is the most promising incorporation strategy. In table olives, the most commonly used starters are Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Saccharomyces cerevisiae, Wickerhamomyces anomalus, among others. These strains with biopreservation characteristics, inoculated alone or in mixed cultures, ensure food safety by conferring the product added value and prolonging product shelf life. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Room temperature storage of myrtle (Eugenia gracillima Kiaersk.) tropical juice: Effects of physical and chemical preservation methods

Tropical fruit juices produced from native fruits have been widely marketed by small agribusinesses in the Brazilian semiarid region, necessitating a deeper understanding of the impact of preservation methods on quality parameters. This study aimed to prepare myrtle (Eugenia gracillima Kiaersk.) tropical juice and investigate the effects of physical preservation (90 °C for 60 s) and chemical preservation (potassium sorbate and sodium benzoate) methods. Tropical juice formulations were evaluated after preparation and every 15 days during 60 days of storage in high-density polyethylene bottles at room temperature (25 ± 2 °C). Microbiological parameters, optical microscopy, physicochemical and bioactive parameters, antioxidant capacity, and color parameters were determined. Heat-treated tropical juice showed low counts of all microbiological parameters, but optical microscopy revealed the presence of filamentous fungi after 60 days of storage. Combined use of potassium sorbate and sodium benzoate effectively prevented the development of total yeasts and molds up to 28 days of storage. Bioactive compounds in myrtle pulp contribute to storage stability, mainly total phenolics, estimated at 855.86 mg gallic acid equivalents 100 g−1. The results suggest that it is possible to harness the economic and agroindustrial potential of E. gracillima Kiaersk. fruits for the production of tropical juices, but it is recommended that other technologies be explored, such as aseptic processing or the combined use of physical and chemical methods.

Volatile compounds and quality changes of lesser mealworm larvae: effect of blanching, storage temperature and time

Abstract The impact of blanching and storage temperature (−20 °C and −80 °C) on the formation of volatile organic compounds and changes in quality characteristics of lesser mealworm (Alphitobius diaperinus) larvae was examined over seven weeks. Acid and peroxide values, pH, and colour of lesser mealworm larvae were significantly affected by the studied variables. The changes in these characteristics as well as in the volatile profile indicated occurring lipid oxidation and lipid hydrolysis processes during the storage. The intensity of these reactions was mostly influenced by blanching treatment and storage time, and a lesser extent by storage temperature. It was proposed that changes in composition and intensity of volatiles can be used for rapid quality assessment of lesser mealworm larvae during frozen storage. Thus, the selection of optimum storage conditions for lesser mealworm larvae is important for the prevention of undesirable chemical reactions and preservation of the quality of insect biomass.

Chemical Speciation and Preservation of Phosphorus in Sediments along the Southern Coast of Zhoushan Island

This study investigated the distribution of sedimentary phosphorus (P) species along an area of a rapid current at the southern coast of Zhoushan Island. The objective of this study was to improve the understanding of P cycling in a zone of rapid water cycling. Results showed that the average percentage of each P form to total P (TP) was in the following order: apatite P (Ca-P; 52%) was found in the most abundant, followed by organic P (OP; 16%), exchangeable-P (Ex-P; 14%), detrital P (De-P; 11%), and iron-bound P (Fe-P; 7%). Ca-P showed a trend of an increasing concentration from a location at the west (ZS1 has mean Ca-P = 45.6 mg kg−1) toward the east (ZS2 has mean Ca-P = 82.69 mg kg−1) and south-east (ZS3 has mean Ca-P = 82.17 mg kg−1); De-P also increased from 15.12 mg kg−1 at ZS1 to 22.53 mg kg−1 at ZS2 and 27.45 mg kg−1 at ZS3, but the three bioavailable P species, OP, Ex-P, and Fe-P, decreased from the west toward the east of the coastal area. Results along the cores showed the occurrences of sediment P adsorption and release throughout the time span from the 1930s to the present, with an overall trend of decreasing Ca-P and TP from the bottom to surface sediments. There was a tendency of Ca-P formation at the expense of Ex-P and OP release during transport and organic matter decomposition. The likely impact of climate change in the coastal zone would be an increased temperature resulting in elevated organic matter decomposition and P release.

Research progress on the effects of postharvest storage methods on melon quality

Background As an important global agricultural cash crop, melon has a long history of cultivation and a wide planting area. The physiological metabolism of melon after harvest is relatively strong; if not properly stored, melon is easily invaded by external pathogens during transportation, resulting in economic losses and greatly limiting its production, development and market supply. Therefore, the storage and freshness of melon are the main challenges in realizing the annual supply of melon, so postharvest storage has received increasing amounts of attention from researchers. Methods This study used academic, PubMed, and Web of Science resources to retrieve keywords related to postharvest storage and melon quality; read, refined, classified, and sorted the retrieved literature; sorted and summarized the relevant research results; and finally completed this article. Results This article reviews the mechanism and effects of physical, chemical and biological preservation techniques on the sensory quality, compound contents and respiratory physiological activities of different varieties of melon fruits. When maintaining normal metabolism and not producing physiological disorders, melon inhibits cell wall metabolism, reactive oxygen species metabolism and the ethylene biosynthesis pathway, etc., to the greatest extent during postharvest storage, thereby reducing the material consumption of fruits, delaying the ripening and senescence process, and prolonging the postharvest life and shelf life. Conclusion The literature provides a theoretical basis for postharvest preservation technology in the melon industry in the future and provides corresponding guidance for the development of the melon industry.

A taguchi approach to assess the effects of LED illumination on quality characteristics of guava RTS

This present study aimed to investigate the impact of light emitting diode (LED) treatment on the microbial and physico-chemical qualities of guava RTS beverage. This study was evaluated on different wavelengths of LED 405 nm, 435 nm, and 461 nm over varying durations of 3 h, 6 h, and 9 h. The results showed that exposure of guava RTS to 405 nm light for 9 h significantly reduced levels of E. coli and S. Enteritidis. The LED treatment also had significant effect on the Vitamin C content and colour values i.e. L* value, and a* value. The study concluded that LED treatment with prolonged time of 9 h at 405 nm can help to mitigate microbial spoilage in guava RTS. This research contributes to the growing field of light-based and chemical free preservation technique in the food and beverage industries, providing insights into novel Non thermal approach for enhancing product quality and safety.

Tricks of the Shade: Preservation of Chemically Developed Shading Papers Based on DuoShade Samples

ABSTRACT From the late 1920s through the early 2000s, artists sometimes utilized chemically developed shading papers, or “chemigraphic” papers, to add dimensional effects to their drawings. These papers were precoated with patterns that were selectively revealed by applying a liquid developer. Drawings on these types of papers often show signs of deterioration, such as discoloration and fading of the developed patterns and staining of the paper support in areas where the developer was applied. This study investigates samples made from Grafix DuoShade chemigraphic papers and developers manufactured in the 1990s. These samples were analyzed to better understand their chemical makeup, deterioration, and preservation needs. The samples were characterized using macro X-ray fluorescence scanning and complementary spectroscopic techniques. To determine optimal storage environments, samples were artificially aged in different storage enclosures and colorimetry was used to compare the artificially aged samples to unaged controls. To determine optimal display environments, the light sensitivity of the samples before and after artificial aging was measured using microfadeometry. Based on the results, preservation recommendations for handling, storage, and display are provided.

Research progress on natural preservatives of meat and meat products: classifications, mechanisms and applications.

Meat and meat products are highly susceptible to contamination by microorganisms and foodborne pathogens, which cause serious economic losses and health hazards. The large consumption and waste of meat and meat products means that there is a need for safe and effective preservation methods. Furthermore, toxicological aspects of chemical preservation techniques related to major health problems have sparked controversies and have prompted consumers and producers to turn to natural preservatives. Consequently, natural preservatives are being increasingly used to ensure the safety and quality of meat products as a result of customer preferences and biological efficacy. However, information on the current status of these preservatives is scattered and a comprehensive review is lacking. Here, we review current knowledge on the classification, mechanisms of natural preservatives and their applications in the preservation of meat and meat products, and also discuss the potential of natural preservatives to improve the safety of meat and meat products. The current status and the current research gaps in the extraction, application and controlled-release of natural antibacterial agents for meat preservation are also discussed in detail. This review may be useful to the development of efficient food preservation techniques in the meat industry. © 2024 Society of Chemical Industry.

Influence of Chemical preservation and Plant extracts in improving Floral Quality and Longevity of Chrysanthemum indicum L.

Influence of Chemical preservation and Plant extracts in improving Floral Quality and Longevity of Chrysanthemum indicum L.

Application of novel microwave-assisted induction heating technology for extending the shelf life of ready-to-eat rice through microbial, physical, and chemical quality preservation

Microwave-assisted induction heating (MAIH) is a composite heating system that combines top-down microwave irradiation (1000 W, 2450 MHz) with bottom-up electromagnetic induction (1500 W). Rice samples prepared by both MAIH methods (120 °C for 240 s and 100 °C for 300 s) and traditional steam cooking (100 °C for 30 min) were analyzed for microbial count, color, pH value, and hardness during storage at 35 °C, 25 °C, and 4 °C. The results revealed that MAIH-treated rice demonstrated no detectable microbial growth at any storage temperature, whereas steamed rice exhibited microbial growth with increasing aerobic plate counts at 35 °C, 25 °C, and 4 °C after two, four, and sixteen weeks, respectively. Color analysis revealed a decline in L* and W values, with increased b* values over time for all samples at all storage temperatures. The pH values of the MAIH-treated rice remained stable, while steamed rice demonstrated a pH decrease during later stages of storage at 25 °C and 35 °C. The hardness of MAIH-treated rice slowly increased at 25 °C and 35 °C, whereas the steamed rice experienced a notable decrease. At 4 °C, all samples demonstrated increased hardness, with steamed rice having significantly higher values than MAIH-treated rice. Overall, MAIH treatment effectively delayed color, pH, and hardness alterations in rice in comparison to traditional steam cooking during storage. Industrial relevanceThe MAIH equipment is a novel thermal processing technology and provides the efficient pasteurization, reduced processing time, and improved overall quality of ready-to-eat (RTE) rice. Therefore, the MAIH technology is a viable future alternative for thermal processing method that possesses huge potential in the development of RTE rice products.

Investigating the Degradation of Mycenaean Glass Artifacts Using Scientific Methods

Mycenaean vitreous artifacts, such as beads and relief plaques, are highly susceptible to degradation, which can significantly alter their visual characteristics and pose challenges to their taxonomy. The visual manifestation of corrosion on vitreous artifacts, especially glass and faience, has often led to their misclassification, which, in turn, has a significant impact on their interpretation by researchers, often resulting in misleading notions. The present paper constitutes part of an overall study, implemented within the framework of the project, Myc-MVP: Mycenaean Vitreous Production, A Novel Interdisciplinary Approach Towards Resolving Critical Taxonomy Issues, which has employed a combination of established, state-of-the-art scientific methods to analyze and identify the specific compositional changes occurring at different spatial dimensions within surface layers, with the overarching aim of contributing to our understanding of the degradation mechanisms of vitreous artifacts and the relevant implications for the archaeological record. Importantly, these findings will yield useful data in devising strategies for the proper classification, management, and preservation of vitreous artifacts in the future. The present study focuses on investigating the relationship between the compositional changes in a subset of 12 (of the overall 126 objects entailed in the project) corroded vitreous artifacts from Mycenaean contexts in the Aegean and the way these are manifested visually, with the application of X-ray fluorescence and LED microscopy. We aim to decipher the nature of corroded objects with the aid of focused analysis. This study delves into degradation processes in glass artifacts, highlighting preservation variations and environmental influences like burial. Coloration, attributed to copper and cobalt oxide, shows some correlation with preservation quality. These chromophore agents potentially induce thermal stresses and corrosion. The complex interplay between chemical composition, environmental conditions, and preservation status underscores the need for comprehensive research. Analyzing the full artifact set using complementary techniques promises deeper insights for secure material classification and cultural heritage preservation.

Postharvest Physiology and Handling of Guava Fruit.

Guavas are typical tropical fruit with high nutritional and commercial value. Because of their thin skin and high metabolic rate, guavas are highly susceptible to water loss, physical damage, and spoilage, severely limiting their shelf-life. Guavas can typically only be stored for approximately one week at room temperature, making transportation, storage, and handling difficult, resulting in low profit margins in the industry. This review focuses on the physiological and biochemical changes and their molecular mechanisms which occur in postharvest guavas, and summarizes the various management strategies for extending the shelf-life of these sensitive fruits by means of physical and chemical preservation and their combinations. This review also suggests future directions and reference ideas for the development of safe and efficient shelf-life extension techniques.

Magnetic nanocomposite based on chitosan-gelatin hydrogel embedded with copper oxide nanoparticles: A novel and promising catalyst for the synthesis of polyhydroquinoline derivatives

Nanocatalysts are vital in several domains, such as chemical processes, energy generation, energy preservation, and environmental pollution mitigation. An experimental study was conducted at room temperature to evaluate the catalytic activity of the new gelatin-chitosan hydrogel/CuO/Fe3O4 nanocomposite in the asymmetric Hantzsch reaction. All components of the nanocomposite exhibit a synergistic effect as a Lewis acid, promote the reaction. Dimedone, ammonium acetate, ethyl acetoacetate, and other substituted aldehydes were used to synthesize diverse polyhydroquinoline derivatives. The nanocomposite exhibited exceptional efficacy (over 90 %) and durability (retaining 80 % of its original capacity after 5 cycles) as a catalyst in the one-pot asymmetric synthesis of polyhydroquinoline derivatives. Also, turnover numbers (TON) and turnover frequency (TOF) have been checked for catalyst (TON and TOF = 50,261 and 100,524 h−1) and products. The experiment demonstrated several benefits, such as exceptional product efficacy, rapid reaction time, functioning at ambient temperature without specific requirements, and effortless separation by the use of an external magnet after the reaction is finished. The results suggest the development of a magnetic nanocatalyst with exceptional performance. The composition of the Ge-CS hydrogel/CuO/Fe3O4 nanocomposite was thoroughly analyzed using several methods including FT-IR, XRD, FE-SEM, EDX, VSM, BET, and TGA. These analyses yielded useful information into the composition and characteristics of the nanocomposite, hence further enhancing the knowledge of its possible uses.

Microbial, Physicochemical and Sensory Quality of Freshly Extracted Apple and Cucumber Juice Subjected to Preservatives and Storage Conditions

Fruit juices are commonly consumed for their refreshing attribute, nutritive values and health benefits. Fruit juice samples were treated with 0.5 g/ml garlic, 0.5 g/ml ginger, 0.25 g/ml mix of ginger and garlic and 0.05% (w/v) of sodium benzoate respectively where the ginger, garlic and sodium benzoate serve as natural and artificial preservatives. Their effects on the fruit juices were evaluated during 8 days of storage at 4°C and ambient temperature (28±2°C). Juice treated with sodium benzoate had the least microbial contamination while the untreated juice had the highest. The bacterial isolated from the samples were Staphylococcus sp, Bacillus sp. (Most occurring bacteria isolated), Micrococcus sp, and lactobacillus sp. The fungi isolated in the course of the study were Aspergillus sp, Rhizopus sp and Penicillium sp. (The highest occurred fungi isolated). There was a marginal decrease in pH values across treatments in stored juices with juice stored at 4°C showing the least change in pH compared to that stored at ambient temperature. The results obtained show that the preservatives exhibited an antimicrobial effect on the microbial load. The Total titratable acidity of all samples increased with time at ambient temperature and decreased at refrigerated temperature. The ascorbic acid content of both juices samples at storage temperatures decreased after the storage period due to the high sensitivity of vitamin C to oxygen, light, heat, etc. In conclusion, the findings of this study generally indicate that combination of chemical and natural preservation together with refrigeration is suitable for the preservation of fruit juice for a long time. Chemical preservatives can be recommended to be replaced with natural preservatives such as ginger and garlic, since the process is inexpensive and easy. However, preservation of fruit juice at ambient temperature for a long time should be discouraged to reduce microbial contamination.

Does the age of milk affect its mid-infrared spectrum and predictions?

Milk of dairy species commonly undergo standardized official analyses, these that may require chemical preservation and transportation to a certified laboratory. In this context, storage duration is an important factor that can potential affect both milk chemical analyses and its mid-infrared spectrum. We analysed milk samples at different time points/ages to assess repeatability and reproducibility of mid-infrared predicted traits (e.g., fat and protein). Using spectral data, we also evaluated the ability of spectroscopy coupled with chemometrics to discriminate samples according to their age. Although the main components of milk remained consistently reproducible across age (days), changes in the spectrum due to sample aging and deterioration of the matrix were detectable. Using a discriminant analysis, we achieved a classification accuracy of 77% in validation. Predicting milk age using mid-infrared spectra is feasible, allowing for sample monitoring within circuits where maximum reliability is needed, e.g., bulk or individual milk samples for legal/official use or payment systems.

Chemically robust functionalized covalent organic framework for the highly efficient and selective separation of bromine.

Effective sequestration of bromine holds great promise for the chemical industry's safe expansion, environmental preservation, and public health. However, attaining this goal is still challenging due to the serious drawbacks of existing adsorbents such as limited capacity, low retention efficiency, and sluggish uptake kinetics. Herein, we report a strategy-driven systematic study aimed at significantly enhancing multiple host-guest interactions to obtain functionalized covalent-organic frameworks for the efficient sequestration of bromine. Results showed that the presence of specific quantities of selective binding sites of the porous frameworks afford stronger host-guest interactions and therefore higher bromine adsorption capacities. The developed framework exhibits high bromine sorption capacity of up to 5.16 g g-1 in the vapor phase and 8.79 g g-1 in the aqueous phase under static adsorption conditions with fast kinetics, large distribution coefficient (Kd ∼105 mL g-1), high retention efficiency and reusability. Moreover, the adsorbent is able to sequestrate trace bromine (from 13 ppm to below 4 ppm) from aqueous medium with fast adsorption kinetics (86.3% within less than 3 h) and demonstrates the selective extraction of bromine over iodine under both static and dynamic conditions. These results were further utilized to demonstrate recycling-selective and highly efficient bromine capture from a real-water system, exhibiting excellent scalability and affordability, as exemplified using COF membranes in a continuous flow-through process.

Придание аэробной стабильности кукурузному силосу при химическом консервировании

Aerobic stability of corn silage, as well as other types of silage, can be achieved by chemical preservation. Currently, mainly organic acids and their salts are used as chemical preservatives. The highest preservative effect is provided by undissociated forms of acids. Dissociation occurs most intensely in a reaction environment close to neutral and is significantly inhibited in an acidic environment. To give silage aerobic stability, the chemical preservative must have fungicidal and static properties, since the main initiators of aerobic decomposition are yeast. Of the organic acids, propionic acid has such properties to the highest extent, and acetic acid to a somewhat lesser extent. Other representatives of organic acids with fungicidal properties not inferior to propionic acid are benzoic, sorbic, acrylic and others. Salts of these acids also have similar properties. The use of mixtures of acids and salts significantly enhances their preservative effect, provided that their components interact synergistically. In addition to these mixtures, the fungicidal effect of a mixture of monoglycerides: monopropionate and monobutyrate has recently been established. Unlike biological products, the fungicidal effect of chemical preservatives manifests itself from the first days of use.