Freeze-dried Material Research Articles

Production and certification of a freeze-dried reference material for human urinary steroids to ensure quality of longitudinal profiling data

Production and certification of a freeze-dried reference material for human urinary steroids to ensure quality of longitudinal profiling data

Phage-Loaded Biomimetic Apatite Powder With Antibiofilm Activity to Treat Bone-Associated Infections.

For decades, calcium phosphate (CaP)-based ceramics have been used for coating of bone and joint substitutes after arthroplasty due to their biocompatible properties. Infections following orthopedic replacement occur in 1%-5% of cases, causing serious complications. Biofilm formation either on the biomaterial's surface or on patient's tissues greatly enhances the resistance against antibiotic treatments and can induce a chronic infection, emphasizing the need for novel antimicrobial delivery systems. In this study, we established a protocol enabling bacteriophage loading during the synthesis of a CaP-based powder. The resulting biomaterial proved to be noncytotoxic against human osteoblastic cells and able to significantly inhibit 24-h matured S. aureus biofilm cultures or even completely eradicate it after 5 days of contact. Additional S. aureus biofilm assays with a freeze-dried material using two different excipients showed that sucrose had a protective role against Remus bacteriophage treatment of S. aureus biofilms, whereas lactose-freeze-dried powder maintained the antibiofilm activity.

Aquivion-Based Spray Freeze-Dried Composite Materials for the Cascade Production of γ-Valerolactone.

The development of multifunctional catalysts is a necessary step to effectively carry out one-pot cascade reactions, such as that from furfural to γ-valerolactone. This research effort faces the challenge posed by the intrinsic limit of how many kinds of catalytic sites a single material can bear. In this work, the application of Spray-Freeze Drying (SFD) as a synthetic technique for the preparation of a wide range of innovative composite multi-functional catalysts is reported. Herein we show that by the proper combination of Aquivion as a highly active Brønsted acid catalyst and metal oxides as both support materials and Lewis acids (LAS) enable to achieve highly unique efficient and effective dual acid composite catalysts that are able to carry out the cascade reaction from furfural to γ-valerolactone. The dual catalytic system comprised of Aq/ZrO2 with 30 % polymer content prepared via spray-freeze drying exhibited GVL yields of 25 % after only 2 h at 180 °C and a remarkably high productivity of 4470 μmolGVL gCat -1 h-1, one of the highest reported results. Mechanistic studies based on experimental and advanced characterisation and spectroscopic techniques, such as, SEM, TEM, 15N MAS NMR and 19F MAS NMR indicate that activity arises from the proper tuning of BAS/LAS (Brønsted Acid Site/Lewis Acid Site) acidic properties.

Drying effects on physicochemical and functional properties of cuttlefish (Sepia officinalis) ink powder

This study investigated the physicochemical, functional, and organoleptic properties of cuttlefish (Sepia officinalis) ink powder prepared by freeze drying and hot air tray drying. Key proximate and physicochemical properties were measured to assess differences due to drying method. In addition, organoleptic tests were conducted on cuttlefish ink powder incorporated into spaghetti sauce. Freeze-dried powders had slightly higher moisture (9.86 %) than tray-dried powders (7.65 %) and more ash (15.04 versus 13.19 %). Both samples had ∼43 % protein, a light-brown to black color and a pH of 5.5–5.6 when rehydrated. There were no differences in loose or tapped density and Hausner ratios of 1.30–1.35 suggest the powders had ‘passable’ flow. Overall protein solubility varied with pH and freeze-dried materials generally had greater solubility. FT-IR showed no differences in peaks derived from organic components. FE-SEM showed both samples had spherical granules that formed 100–200 nm clusters; however, the surface texture of tray-dried powders was rougher than the freeze-dried samples. Consumer tests showed higher overall likability for spaghetti sauce with fresh ink compared to dried ink powders. Differences were attributed more to texture than to flavor or appearance. Cuttlefish ink can be utilized in the food industry, particularly as a natural flavor, food coloring or additive.

Polysaccharide Hydro-Gel from Arid Plant Seed

There is a limited information on the structure and gelation process in mucilagepolysaccharides because of the complex conformation and non-homogeneity of the constituent polysaccharides that typically show large molecular weights in excess of 1 MDa. Only a few works have been done in this area of characterizing mucilage structure and rheological behaviour for different gel solutions. Exploring this area would surely open the new horizons for drug delivery, soil conditioning and pharmaceutical industry. In this study, we aimed to extract polysaccharides found in P.ovata Seed (Isabgol) via mucilage extraction controlling molecular weight of polymers in hot water extraction stage and tried to formulate gel formation dissolving different conc. of extracted freeze-dried material along with the characterization of gel network through Rheological studies and Dynamic Light Scattering (DLS) studies in different solvents. The study confirmed the relationship between molecular associations, chain relaxation time and entanglement behaviour of P. ovata hot water extracted (HW) solutions using polydispersity index and shear rheology. Moreover, two power law regions obtained for different concentration solution are of great importance because of their wide applications in the industrial prospective.

Synthesis of Chitosan and Ferric-Ion (Fe3+)-Doped Brushite Mineral Cancellous Bone Scaffolds.

Biodegradable scaffolds are needed to repair bone defects. To promote the resorption of scaffolds, a large surface area is required to encourage neo-osteogenesis. Herein, we describe the synthesis and freeze-drying methodologies of ferric-ion (Fe3+) doped Dicalcium Phosphate Dihydrate mineral (DCPD), also known as brushite, which has been known to favour the in situ condition for osteogenesis. In this investigation, the role of chitosan during the synthesis of DCPD was explored to enhance the antimicrobial, scaffold pore distribution, and mechanical properties post freeze-drying. During the synthesis of DCPD, the calcium nitrate solution was hydrolysed with a predetermined stoichiometric concentration of ammonium phosphate. During the hydrolysis reaction, 10 (mol)% iron (Fe3+) nitrate (Fe(NO3)3) was incorporated, and the DCPD minerals were precipitated (Fe3+-DCPD). Chitosan stir-mixed with Fe3+-DCPD minerals was freeze-dried to create scaffolds. The structural, microstructural, and mechanical properties of freeze-dried materials were characterized.

Effect of PEF Treatment on Chosen Properties of Raw and Hot Air- and Freeze-Dried Poultry Meat

The properties of fresh meat, such as high water activity, a slightly acidic reaction, and the availability of carbohydrates and proteins, make it a microbiologically unstable and easily perishable raw material. One of the oldest food preservation techniques is drying. Furthermore, non-thermal food processing techniques such as pulse electric field (PEF) treatment can be used to support the drying process and change the properties of the obtained product. Thus, this study aimed to analyze the impact of pulsed electric field treatment on the hot air-drying and freeze-drying of poultry meat as well as on the quality of the dried meat. The PEF pretreatment and drying methods significantly altered the physical characteristics of the poultry meat. The PEF treatment enhanced the efficiency of freeze-drying by electroporation, reducing drying time and shrinkage. However, in the hot air-drying, the PEF-treated samples prolonged drying, potentially due to muscle structure damage and increased shrinkage. The pretreatment techniques affected the structure of the meat and positively influenced the higher porosity and lower shrinkage. Also, drying decreased the water activity and increased the dry matter content, which ensured the safety of the final product. The freeze-dried material exhibited a higher rehydration rate, improved hygroscopic properties, and better meat color compared to the hot air-dried material. Nevertheless, the selection of the process parameters, for both the pretreatment and drying process, is crucial to ensure a high quality of the dried meat product and should be selected carefully in order to guarantee that the highest quality of the dried product is obtained.

Plant Sample Collection and Shipment for Multi-omic Analyses and Phytosanitary Evaluation.

Plant sample preparation for analyses is a fundamental step in high-throughput omics strategies. Especially for plant metabolomics, quenching of hydrolytic enzymes able to affect metabolite concentrations is crucial for the accuracy of results. Given that DNA is usually less labile than metabolites, most sampling and shipment procedures able to preserve the metabolome are also suitable for preventing the degradation of plant DNA or of DNA of pathogens in the plant tissue. In this article, we describe all the steps of sample collection, shipment (including the phytosanitary issues of moving plant samples), and processing for combined genomics and metabolomics from a single sample, as well as the protocols used in our laboratories for downstream approaches for crop plants, allowing collection of multi-omic datasets in large experimental setups. The protocols have been adjusted to apply to both freeze-dried and fresh-frozen material to allow the processing of crop plant samples that will require long-distance transport. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation of freeze-dried leaf disks for multiplexed PCR or DArT-Seq genotyping Basic Protocol 2: Medium-throughput preparation of pathogen-free nucleic acids for most genotyping-resequencing applications or pathogen detection Alternate Protocol: Low-throughput extraction of high-quality DNA for resequencing using commercial kits Support Protocol: DNA quality control Basic Protocol 3: Preparation of freeze-dried plant material for metabolomics Basic Protocol 4: Preparation of fresh-frozen plant material for metabolomics Basic Protocol 5: Preparation and shipment of metabolite extracts for metabolomic analyses Basic Protocol 6: Sample shipping and long-term storage.

Drought impacts African black beetle feeding on perennial ryegrass

interactions between plants, herbivorous insects and fungal Epichloë endophytes. However, water availability fluctuates, a phenomenon intensified by climate change, challenging the success of NewZealand’s pastoral industry. The impacts of climatic changes, such as intensifying drought, on pastoral insect pests have received little attention. In a no-choice bioassay, African black beetle (ABB) were fed semi-synthetic diets containing freeze-dried foliage material from drought-exposed and well-watered perennial ryegrass containing endophyte strains AR37 or NZCT, or with material free of endophyte (Nil). Diet consumption, beetle weight change, fungal alkaloid concentrations, phytohormones, and NRI (nitrogen reflectance index) concentrations were measured and compared. Except for AR37, ABB consumed more diets containing drought-exposed rather than well-watered material, with a 61% increase in Nil and a 50% increase in diets containing NZCT, though these effects were not accompanied by corresponding ABB weight changes. Here, we discuss the implications of these results on ABB damage in New Zealand pastures in the context of increasing drought and illustrate how spatial patterns of ABB damage could change over the next 75 years. Areas that do not currently have high populations of ABB such as Manawatū-Whanganui, Wairarapa and Marlborough will become increasingly vulnerable to damage.

New anti-α-Glucosidase and Antioxidant Ingredients from Winery Byproducts: Contribution of Alkyl Gallates.

Wine-making activity entails the production of solid and semisolid byproducts (grape stems and pomace and wine lees) that negatively impact the environment and industrial sustainability. Their features as sources of bioactive compounds support valorization procedures for functional and healthy ingredients. This work uncovers the quantitative alkyl gallates (gallic acid esters, C1-C12) profile of fresh (freeze-dried) materials and the effect of oven-drying on their stability by UHPLC-ESI-QqQ-MS/MS. The functionality was established concerning DPPH• scavenging and antihyperglycemic power. Wine lees exerted the highest high-free concentration of galloyl derivatives, ethyl gallate being the most abundant ester (3472.62 ng/g dw, on average). About the impact of the stabilization process, although as a general trend, the thermal treatment reduced the concentration, the reduction dimensions depended on the compound/matrix, remaining in valuable concentrations. Concerning radical scavenging, ze-dried stems and pomace displayed the highest capacity (24.11 and 18.46 mg TE/g dw, respectively), being correlated with propyl gallate (r2 = 0.690), butyl gallate (r2 = 0.686), and octyl gallate (r2 = 0.514). These two matrices exerted α-glucosidase inhibitory activity (1.58 and 1.46 units/L) equivalent to that of acarbose (a recognized α-glucosidase inhibitor). The newly described bioactive phytochemicals in winery residues (galloyl esters) and their correlation with functional traits allow for envisioning valorization alternatives.

Nondestructive monitoring of freeze drying and spray freeze drying endpoint by temperature-pressure method

The determination of the drying endpoint is crucial for the success of the freeze-drying process. However, nondestructive determination methods of the freeze-drying endpoint are often not applicable in spray freeze-drying equipment and process. To address this issue, an integrated spray freeze-drying equipment was developed that atomizes and freezes materials in the drying room through an atomizer, and freezes the frozen particles in the same drying room for vacuum freeze-drying to achieve one-step drying to prepare freeze-dried powder. The temperature and pressure method is used for real-time nondestructive monitoring of the entire drying process while ensuring no pollution in the materials. Experimental studies using pure water and milk as typical materials showed that a heating temperature of 45 °C and a pressure drop to 4.4 Pa can be considered as the drying endpoint, applicable to the monitoring of spray freeze-drying process. The temperature pressure method can be used as a method for judging the sublimation endpoint of spray freeze-drying. The relationship between temperature and pressure of the drying chamber can reflect the dry basis water content of freeze-dried materials.

Proximate Analysis and Antioxidant Properties of Young Plants of Sinapis alba L. Depend on the Time of Harvest and Variety

White mustard plant (Sinapis alba L.) is an easy-to-grow species with low soil requirements and is often sown as a catch crop in Northern Europe to reduce nitrate leaching, especially during the winter. There are studies showing the high nutritional value of mustard seeds, which have a wide application, mainly in food production. Still little is known about the young shoots or plants of different cultivars of white mustard, although in Asian countries, eating them raw is quite common. The aim of the research was to determine the proximate composition, antioxidant activity and polyphenolic compound content in young green plants of the Polish cultivars of white mustard: Borowska (traditional, with a high content of erucic acid and glucosinolates), Bamberka (non-erucic with glucosinolates) and Warta (non-erucic with low glucosinolates content; double-improved). Young plants were harvested in three terms. The first harvest took place at the plover stadium and the next ones at 7-day intervals (31, 38 and 45 day after sowing). In freeze-dried plant material, proximate composition and antioxidant activity with the ABTS and FRAP methods, as well as phenolic compound content, were measured. The highest concentration of protein was measured in cultivars Warta and Borowska after 31 and 38 days of sowing. Harvest time and cultivar affected antioxidant activity and total polyphenol content in young mustard plants. Thirty-eight days after sowing, the examined cultivars of the young plants of mustard had the highest antioxidant activity and total polyphenolic compound content. Green young mustard plants have strong antioxidant properties at the basic level, they are classified as functional foods and are similar to other edible leafy plants such as celery, spinach and Brussels sprouts.

Production and certification of BOTS-1: bovine muscle-certified reference material for incurred veterinary drug residues.

A freeze-dried bovine muscle-certified reference material (CRM), known as BOTS-1 (DOI: https://doi.org/10.4224/crm.2018.bots-1 ), containing incurred residues of commonly used veterinary drugs was produced and certified for the mass fraction of eight veterinary drug residues. Value assignment was carried out using liquid chromatography tandem mass spectrometry (LC-MS/MS) methods in conjunction with isotope dilution and standard addition approaches involving stable isotope internal standards. Data from the National Research Council of Canada (NRC), Canadian Food Inspection Agency (CFIA), United States Department of Agriculture (USDA), and the Federal Office of Consumer Protection and Food Safety in Germany (BVL) were used for value assignment. Results for two drug residues were also obtained through an international inter-laboratory comparison CCQM-K141/P178 organized under the auspices of the International Bureau of Weights and Measures (BIPM). Quantitative NMR (1H-qNMR) was used to characterize primary standards of all veterinary drugs certified. The certified mass fractions of the veterinary drug residues were 490 ± 100µg/kg for chlorpromazine, 44 ± 4.4µg/kg for ciprofloxacin, 3.3 ± 1.4µg/kg for clenbuterol, 9.5 ± 0.8µg/kg for dexamethasone, 57 ± 4.8µg/kg for enrofloxacin, 3.0 ± 0.4µg/kg for meloxicam, 12.4 ± 1.2µg/kg for ractopamine, and 2290 ± 120µg/kg for sulfadiazine with expanded uncertainties quoted (95% confidence) which include the effects due to between-bottle inhomogeneity, instability during long-term storage and transportation, and characterization.

Simultaneous determination of steroid hormones and pharmaceuticals in killer whale (Orcinus orca) faecal samples by liquid chromatography tandem mass spectrometry.

We describe a non-invasive method for profiling selected hormones, pharmaceuticals and personal care products (PPCPs) in killer whales (Orcinus orca) based on analysis of faecal samples by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method targets 21 compounds of interest including glucocorticoids, mineralocorticoids, androgens, estrogens, progestogens, selective serotonin uptake inhibitors and an antibacterial/antifungal agent. This method is suitable for routine simultaneous determination of target compounds in killer whale faecal samples as well as validation of immunoassays for the detection and measurement of steroid hormones in faeces. The optimized method involves extraction of freeze-dried faecal material with reagent alcohol and water followed by isolation of the analytes using solid phase extraction with hydrophilic-lipophilic balance cartridges and liquid-liquid extraction with methyl tertiary-butyl ether. Reconstituted extracts were analysed by LC-MS/MS using an electrospray ionization interface. Method limit of quantification ranged from 0.06 to 45.2ng/g in freeze-dried faecal samples. Except for sertraline, triclosan and estradiol (which was not recovered at the lowest spiked concentration), average intra- and inter-day precisions were within 10%, and average recoveries were between 89.3% and 129.3%, for faecal samples spiked with 5.3, 26.7 or 133ng/g of each analyte. The method was applied successfully to the analysis of hormones and PPCPs in whale faeces during which 17α-hydroxyprogesterone, a common intermediate in steroid biosynthesis that cross-reacts with precursors and sulphated conjugates in immunoassays, was identified and quantified in all samples.

Quantification of structures in freeze-dried materials using X-ray microtomography

The structure of a freeze-dried material is essential for its ability to preserve and protect biologics such as proteins, cells and other sensitive structures. The structure of a typical freeze-dried matrix can be described as pores surrounded by thin walls where the walls are the encapsulating material (for e.g. cells).The objective of this investigation is to evaluate X-ray microtomography (µCT) as a characterization method to quantifying the matrix of a freeze dried material, and compare it to scanning electron microscopy (SEM). The material consists of maltodextrin, freeze-dried below or above the glass transition temperature of the maximal freeze concentration (Tg′) and after applying annealing.The SEM images have high resolution and provide an excellent view of the sample. However, it is challenging to perform any image analysis and to ensure that a representative section is presented. The µCT images provide a rather uniform contrast between material and void, allowing for a simple grey-level thresholding when separating structure from the background. A robust image analysis procedure allows the results extracted from a representative sample volume to be evaluated. Further image analysis has been focused on understanding the thickness of the encapsulating structures by estimations of volume-weighted averages of inscribed spheres within the walls.The results show two types of structures: A large pore structure of around 20–100 µm separated by thin walls around 2–3 µm thick, and a finer structure consisting of smaller pockets of air (< 10 µm) packed in a honeycomb like structure. The structures of the samples dried below and above Tg′ have smaller and thinner structures, while material dried after annealing has larger and thicker structures. The structures display comparably small differences between the different drying protocols despite the quite different drying conditions.

Development of the certified reference material of chromium in freeze-dried human urine

To develop the certified reference material in freeze-dried human urine. Normal human urine was collected, mixed and filtered as a matrix, then the urine was prepared by adding standard, mixing, sub-packaging, and freeze-drying; After the homogeneity and stability were tested by inductively coupled plasma mass spectrometer, the urine were determined by two methods in seven independent laboratories and the uncertainty of the certified reference material was evaluated. The minimum sample intake of the developed certified reference material was 0.50 mL, and the homogeneity was good. The freeze-dried material was stable for 12 months at ≤4 ℃, and the reference material was stable at 4 ℃ after reconstitution for the 7 d. The standard value and uncertainty of the two levels were(16.0±1.0) μg/L and(30.7±2.1) μg/L(k=2), respectively. The certified reference material of chromium in freeze-dried human urine in this research met the national certified reference material requirements and could be used for the quality control of the detection of chromium in laboratory human urine.

Analysis of selected functional properties, resource demands, and energy consumption of freeze‐dried vegetable snacks

The study aimed to investigate a possibility of using fruits (apple and blackcurrant) pomace as carrier agents in freeze-dried snacks and analyze selected properties of obtained products in comparison to snacks with addition of pectin as traditional carrier in terms of physical and functional characteristics modification. The addition of fruits pomace powders caused significant porosity and hygroscopicity reduction. The type of carrier also affected color and structure of the freeze-dried snacks. Moreover, applied additives influenced textural properties inducing products with fruits pomace powders brittle and more fragile in comparison to material with pectin. Reformulation did not affect energy consumption that was determined mostly by freeze drying (90%), but replacement of hydrocolloid with fruit pomace powders may reduce environmental impact of freeze-dried products. Considering obtained findings and possibilities resulting from application of pomace in new food products, further research is needed, especially in terms of influencing nutritional value and storage properties by such additives. Novelty impact statement The manuscript is focused on the newest approach in food technology related to management of food waste and by-products as additives modifying properties of freeze-dried materials. Our study included examination of the impact of fruits pomace powders as carrier agents in freeze-dried fruit and vegetable snacks in relation to traditional hydrocolloid carrier on selected properties that are important in terms of stability and attractiveness of food products. Second part of the study was assessment of resource demand of manufacturing such products aimed on the possibilities of environmental impact reduction.

The Effect of Composition, Pre-Treatment on the Mechanical and Acoustic Properties of Apple Gels and Freeze-Dried Materials.

This study aimed to determine the effect of the addition of apple juice concentrate (AJC) on the properties of agar gel and dried materials. Agar gels with the addition of apple juice concentrate in the range of 5–20% were prepared with or without the addition of maltodextrin. The gels were also soaked in the solution of AJC. The water content, water activity, densities, some mechanical and acoustic descriptors of gels, and the freeze-dried gels were analysed. The porosity and shrinkage of dried products were also investigated. The addition of AJC significantly changed mechanical and acoustic properties of gels. The hardness of gels decreased with a higher addition of concentrate. Dried samples with a lower concentration of sugars (the lower addition of AJC) were characterised by lower shrinkage and higher porosity, as well as crispness and glass transition temperature. The investigated mechanical and acoustic properties of dried gels showed the addition of apple concentrate at the level of 5% to agar solution was optimal.

In vitro bioaccessibility and activity of basil (Ocimum basilicum L.) phytochemicals as affected by cultivar and postharvest preservation method – Convection drying, freezing, and freeze-drying

The effects of convection drying, freezing, and freeze-drying, on phytochemicals content, in vitro activity and bioaccessibility of sweet basil, cinnamon basil, red rubin basil, and lemon basil were investigated. For evaluation of bioaccessibility, rosmarinic acid content, phenolic content, and antioxidant potential of samples before and after gastric and intestinal steps of digestion were determined.Results showed that the content, activity and bioaccessibility of basil phytochemicals varied depending on the cultivar as well as the applied postharvest preservation. It was found that the frozen and freeze-dried plant materials were characterized by a higher phenolic level and antioxidant activity compared to the convection dried. However, in general, convection drying allows obtaining samples with higher bioaccessibility of phytochemicals compared to the low-temperature processed samples.These findings highlight the need for evaluation of basil cultivars and postharvest preservation methods regarding phytochemicals bioaccessibility, which might help in the classification in terms of pro-health quality.

A field-friendly alternative to freeze-drying faeces for glucocorticoid metabolite analyses of African wild dogs (Lycaon pictus)

Endocrine studies using faeces as hormone matrix have become increasingly popular to examine adrenocortical activity in wildlife. A prerequisite for this approach is to minimize alteration of faecal glucocorticoid metabolite (fGCM) composition post-defecation. This is done by freezing the collected material as soon as possible after collection, and removing moisture from the frozen faecal samples afterwards (usually by freeze-drying). In remote areas, freeze-drying opportunities are often limited, and in the case of the African wild dog (Lycaon pictus), established assays revealed that fGCM concentrations remain comparable for only ∼24h post-defaecation. In the present study, three cost-effective drying treatments (exposure to sunlight, placement in a solar oven, and use of a food dehydrator) were investigated as alternatives to the golden standard of freeze-drying faeces.•In comparison to freeze-dried material, African wild dog faecal samples dried through sunlight exposure, a solar oven, and use of a food dehydrator revealed no significant differences in respective fGCM concentrations measured.•A food dehydrator would be the preferable option to dry African wild dog faeces if limited electrical supply is available. This technique dries faeces the fastest, and negates any reliance on weather conditions.