Microbiological Stability Research Articles

Prolonging the stability of cetuximab (Erbitux®) and panitumumab (Vectibix®): An orthogonal assessment of physicochemical, biological and microbiological properties of original opened glass vials and diluted saline preparations

The two anti-epidermal growth factor receptor monoclonal antibodies (mAbs) cetuximab and panitumumab are the pillars for the treatment of EGFR-positive, KRAS wild-type metastatic colorectal cancers. However, stability data of these mAbs are generally missing or incomplete. Here, we report for the first time an orthogonal analysis of the stability of cetuximab (Erbitux®) and panitumumab (Vectibix®), either undiluted vial leftovers or saline dilutions in polyolefin/polyamide infusion bags. All samples were stored at 2–8 °C protected from light, according to their summary of product characteristics (SmPCs). Alternatively, opened vials and preparations were maintained at 25 °C for 15 h, and then stored again at 2–8 °C protected from light to mimic a temporary interruption of the cold chain. Vial leftovers proved stable up to 180 days when stored according to their SmPCs, while compounded preparations in infusion bags maintained their physiochemical, biological and microbiological stability up to 30 days. Additionally, no changes were detected up to 30 days for the same samples undergoing a thermal excursion. Our results provide additional rationale to the SmPCs, crucial especially in the case of reassignment and pre-preparation of bags. This information will allow hospitals to achieve significant cost savings, and better organization of the entire therapeutic process.

Disinfection of Rainwater for Economic Purposes

Rainwater storage systems are one of the elements of the implementation of sustainable water management. The use of rainwater in households or public buildings reduces the consumption of water supply water for purposes that do not require very good quality water. In crisis situations, rainwater could also be a source of water for drinking and hygiene. In order to use rainwater, it must comply with sanitary quality standards. This paper presents the results of research on the disinfection of rainwater and the possibility of its safe use in the economy as an alternative to tap water. The elements of the proposed pretreatment and disinfection system were selected adequately for the quality of the collected rainwater and its intended use. The aim was to obtain water safe for drinking and hygienic purposes. Rainwater was collected from a roof covered with ceramic tiles, and then subjected to prefiltration, ultrafiltration and disinfection with UV rays. Water before and after treatment was characterized on the basis of a number of microbiological parameters (total number of bacteria at 37 °C and 22 °C; number of coliform bacteria, Escherichia coli, Enterococci, Pseudomonas aeruginosa) and the content of nutrients (TOC, ammonium nitrogen, nitrates, nitrites, phosphates). The use of ultraviolet radiation allowed for the complete removal of indicator bacteria and a significant reduction in the total number of bacteria, from nearly 2500 CFU/mL to 25 CFU/mL for bacteria at 22 °C and from 2010 CFU/mL to 18 CFU/mL for bacteria at 37 °C. The effectiveness of rainwater disinfection, its microbiological stability after disinfection and the time after which the bacterial microflora regenerates, as well as the possibility of using rainwater for drinking and hygienic purposes after disinfection, was determined.

Plant-Based Fermented Beverages: Development and Characterization.

The production of plant-based fermented beverages has been currently focused on providing a functional alternative to vegan and/or vegetarian consumers. This study primarily targeted the development and characterization of fermented beverages made up of hydrosoluble extracts of oats, almonds, soybeans, Brazil nuts, and rice. The fermentation was carried out by lactic cultures of Bifidobacterium BB-12, Lactobacillus acidophilus LA-5, and Streptococcus thermophilus. Plant extracts were fermented at 37 °C for 12 h, with and without sucrose supplementation. The physicochemical and microbiological stability of the extracts was monitored for 28 days at 5 ± 1 °C. The composition of the fermented beverages was subsequently determined. The pH values measured at the beginning and the end of the extracts' fermentation ranged between 6.45 and 7.09, and 4.10 to 4.97, respectively. Acidity indices, expressed as a percentage of lactic acid, ranged from 0.01 to 0.06 g/100 mL at the beginning of the fermentation, and from 0.02 to 0.33 g/100 mL upon fermentation being concluded. Most fermented extracts achieved viable lactic acid bacteria counts exceeding 106 CFU/mL during storage. Sucrose supplementation did not alter the rate of bacterial growth. The findings showed that the complete replacement of dairy ingredients with water-soluble plant extracts is a potential alternative for developing a functional fermented plant-based beverage.

Effect of extract of ginger root and liquorice on the microbiological safety of mutton liver pâté

This work aimed to evaluate the effect of ginger root (Zingiber officinale) and liquorice (Glycyrrhiza glabra) extract in liver pates on their microbiological safety, water activity and pH values. Four samples of pates were produced: control (without extracts), variant 1 (addition of 1% liquorice root and 2% ginger root), variant 2 (2% liquorice root, 3% ginger root), variant 3 (3% liquorice root, 4% ginger root). The number of mesophilic aerobic and facultative anaerobic microorganisms, lactobacilli, moulds, yeasts, Staphylococcus aureus, Escherichia coli, and Salmonella on the day of production and after 1, 3, 6 and 12 months of storage were determined. According to the experimental data, the studied microbiological safety indicators were within the permissible standards during the entire period of storage. The lowest microflora growth was observed in variants 1 and 4. With increasing storage time of the samples, a decrease in the value of water activity and an increase in the pH value was observed. Sensory analysis showed a positive trend in pates' taste, texture, and aroma when introducing sheep fat and plant extracts into the recipe. According to the overall sensory analysis score, variant 2 received the highest score (8.5), while the control sample received the lowest score (7.9). The aroma, consistency and juiciness of the pâtés of variant 2 were significantly better (p <0.05). The studies confirmed the prospects of improving the microbiological stability of liver pâté using different combinations of plant extracts.

FORMULATION AND CHARACTERIZATION OF TABLETS FROM SIMPLICIA AND EXTRACT OF SUNGKAI’S (Peronema canescens Jack) LEAF

Tablets are solid preparations containing medicinal ingredients with or without excipients, usually consisting of one or more active substances. Preparations in tablet form have the best mechanical, chemical, and microbiological stability compared to liquid dosage forms, so they are more resistant to physical damage. This study aims to formulation and characterization of tablet from simplicia and dried extract of sungkai’s (Peronema canescens Jack) leaf by wet granulation which consisted of three formulas, namely F1 without active substances, F2 active substances from sungkai’s leaf simplicia, and F3 active ingredients from dry extracts of sungkai’s leaf. The characterization of the physical properties of tablets includes size uniformity test, weight uniformity test, hardness test, friability test, and disintegration test. The results showed that F1 and F3 tablets showed a good tablet properties, but F2 tablets had 3 tablets that deviated from the tablet weight, namely 12.18%, 6.03% and 9.75%, F2 tablets had an average hardness of 3,413 kg. ie does not fullfill the requirements for tablet hardnes. The friability test for F2 tablets, which is 1.0069%, not accetable for tablet friability. The disintegration test, F2 tablets have a faster disintegration time compared to F1 and F3 tablets.

Soymilk stability increase using polyphenols microcapsules.

Functional beverages have aroused a great interest to the food industry. Among the functional ingredients, there is a growing demand for antioxidant incorporation into foods, which implies a challenge to preserve their bioactivity. The health benefits provided by soymilk can be improved by the addition with microcapsules of polyphenols from peanut skin and this procedure is an alternative to protect these natural and bioactive compounds from environmental factors. The aim of this work was to determine the chemical, antioxidant, microbiological and sensory changes during storage of the product. Soymilk samples were prepared without any addition (C); with peanut skin extract (BEA); and with microcapsules with polyphenols (MCBEA) and stored at 4°C for 30days. Results showed that the addition of polyphenols (free or microencapsulated) improved the chemical, microbiological and sensory stability of soymilk. The BEA and MCBEA had lower values of hydroperoxides, hexanal, bacterial growth, oxidised flavour, and sweet taste than C. The BEA exhibited higher phenol content (819.72mg gallic acid equivalents/L), antioxidant activity (64.66% DPPH inhibition) and colour intensity than MCBEA. The study suggested that polyphenol microencapsulation is a procedure that can protect these sensitive compounds and control their release into this food matrix.

Development of certified reference materials of lithium chloride solution for water activity

Water activity (a) is used to assess the microbiological stability, shelf life, and safety of food. Water activity meters using electric humidity sensors can measure water activity conveniently. To calibrate water activity meters, certified reference materials (CRMs) of lithium chloride (LiCl) solution for water acidity were prepared by using the gravimetric method. Both the mass balance approach and potentiometric titration were combined to determine the purity of LiCl, and the molality (m) was calculated. The osmotic coefficient (ϕ) was calculated using m and the standard data for ϕ expressed as the Debye–Hückel equation. The certified value of a was calculated using an exponential function of the product of ϕ, m, and molecular mass of water. The certified values and uncertainty (U, k = 2) of two CRMs were 0.250 ± 0.006 and 0.500 ± 0.007, respectively. These two CRMs can be used to calibrate water activity meters and validate analytical methods.

Effects of Thyme Essential Oil Microcapsules on the Antioxidant and Quality Characteristics of Mutton Patties.

This study aimed to assess the stability of thyme essential oil microcapsules (TEOMs) and their impacts on the antioxidant properties and quality of lamb patties. The results demonstrated that gum Arabic effectively enhanced the stability of phenols within the thyme essential oil (TEO), with an optimal core/wall ratio of 1:8. Substituting TEO with TEOMs in lamb patties led to reductions in the thiobarbituric acid content, carbonyl content, sulfhydryl loss, and protein cross-linking. Additionally, the TEOMs positively influenced the mutton patties' color, texture, microbiological stability, and sensory attributes. These findings substantiate the idea that TEOMs exhibit significant potential as a natural preservative to enhance the quality of mutton patties.

Extemporaneous preparation of paediatric oral formulations with sildenafil citrate

The paediatric population is composed of several very different subgroups, each with its own specific characteristics. For this reason, children cannot be considered “small adults”. The development of formulations suitable for children is a complex process, as it must consider the physiological changes that occur during childhood and the impact they have on the absorption of drugs. Sildenafil citrate is a drug with a narrow therapeutic index used in paediatrics to treat pulmonary hypertension. In the present work, technological approaches for extemporaneous preparation of paediatric oral forms containing sildenafil citrate for personalized therapy in children were studied. The prepared formulations were tested for physical and microbiological stability, in-use stability, and determination of active substance content. All tested oral formulations remained unchanged in terms of appearance during the entire period of stability monitoring at the selected storage conditions – room temperature 25 °C ± 5 °C and in a refrigerator at 5 °C ± 2 °C. The established pH values suggest that the formulations remained chemically stable during the stability study. The content of sildenafil citrate in all prepared oral formulations remained above 95% w/v. The microbiological quality of the prepared compositions was confirmed. Rational strategies for preparation of extemporaneous formulations were proposed based on the analysis of experimental data.

An innovative approach: Formulation and evaluation of fermented oat milk using native yoghurt cultures

This study aimed to develop a fermented oat milk product using native yoghurt cultures as a potential alternative to dairy-based yoghurt products. Three samples were prepared; the first sample is the control (FCM: based on cow's milk), the second based on oat milk (FOM) and the third (FOM+MJ) based on oat milk with a portion of melon juice. The physicochemical, microbiological, sensory characteristics, and the nutritive value of the resulting products were evaluated. Results showed the longer microbiological stability of oat-based yogurt. The sensory evaluation indicated that the FOM was the more appreciated by the panelists. Overall, the study demonstrated the feasibility of using native yoghurt cultures to ferment oat milk and produce a product with desirable characteristics. This approach could offer a potential solution for consumers who are lactose intolerant or prefer plant-based products, while still providing the health benefits of traditional yoghurt products.

Effect of storage temperature and high-pressure processing on the preservation of sliced Duroc vacuum-packed dry-cured ham

This study assesses the physicochemical and microbiological stability of Duroc ham slices over a long-term storage (8 months) under various conditions. Thus, three treatments were designed: T4ºC; refrigerated (4ºC ± 1) and non-pressurised vacuum packages; T20ºC; vacuum and not pressurised packages stored at 20ºC ± 2 and high hydrostatic pressure (HHP) + T20ºC; vacuum packages pressurized (600 MPa for 8 min) and stored at 20ºC ± 2. Storage at 20 °C led to higher decrease in lightness over time and lower γ-tocopherol and polyunsaturated fatty acid values from 3 months onwards. But, storage at 20ºC did not increase lipid oxidation or microbiological counts -except for mesophiles at 8 months of storage-, so visual appearance could be the limiting factor of the shelf life. The HHP treatment led to lipid oxidation and γ-tocopherol degradation.

Emerging biotechnologies and non-thermal technologies for winemaking in a context of global warming.

In the current situation, wine areas are affected by several problems in a context of global warming: asymmetric maturities, pH increasing, high alcohol degree and flat wines with low freshness and poor aroma profile. The use of emerging biotechnologies allows to control or manage such problems. Emerging non-Saccharomyces as Lachancea thermotolerans are very useful for controlling pH by the formation of stable lactic acid from sugars with a slight concomitant alcohol reduction. Lower pH improves freshness increasing simultaneously microbiological stability. The use of Hanseniaspora spp. (specially H. vineae and H. opuntiae) or Metschnikowia pulcherrima promotes a better aroma complexity and improves wine sensory profile by the expression of a more complex metabolic pattern and the release of extracellular enzymes. Some of them are also compatible or synergic with the acidification by L. thermotolerans, and M. pulcherrima is an interesting biotool for reductive winemaking and bioprotection. The use of bioprotection is a powerful tool in this context, allowing oxidation control by oxygen depletion, the inhibition of some wild microorganisms, improving the implantation of some starters and limiting SO2. This can be complemented with the use of reductive yeast derivatives with high contents of reducing peptides and relevant compounds such as glutathione that also are interesting to reduce SO2. Finally, the use of emerging non-thermal technologies as Ultra High-Pressure Homogenization (UHPH) and Pulsed Light (PL) increases wine stability by microbial control and inactivation of oxidative enzymes, improving the implantation of emerging non-Saccharomyces and lowering SO2 additions. GRAPHICAL ABSTRACT.

Effect of High-Powered Ultrasound on Bioactive Compounds and Microbiological Stability of Juices—Review

Extending the shelf life of fruit and vegetable juices plays a key role in improving food security. Ultrasonic technology can be an effective method in the process of replacing traditional heat treatment. It offers a number of benefits, such as better product quality expressed as a higher content of bioactive substances and the preservation of the natural sensory characteristics of the juice: consistency, colour, taste and smell. This paper discusses the methods of ultrasound generation, the equipment used and advances in the construction of ultrasound devices. The influence of ultrasounds on the physical and chemical properties of juices was also analysed, with particular emphasis on bioactive substances and the effectiveness of ultrasonic treatment in the inactivation of microorganisms and enzymes. Prospects and trends in the development of ultrasonic techniques that can effectively increase the efficiency of the ultrasonic juice preservation process are also described. Sonication used alone or with other processing techniques makes it possible to achieve a positive effect on the quality of consumed fruit and vegetable juices.

Formulation of an anthelmintic syrup based on the seeds of Carica papaya (Caricaceae)

In traditional medicine, of Carica papaya (Caricacea) seeds are used as a coarse powder, in maceration or as an aqueous decoction, for the management of helminthiasis. With the aim of contributing to the management of helminthiasis, this study set out to develop a syrup with anthelmintic properties based on Carica papaya L. seeds The aqueous fluid extract was prepared and subjected to phytochemical screening. A syrup based on this fluid extract was prepared and subjected to a physicochemical and microbiological stability control. To assess the effectiveness of the syrup, a pilot study was initiated. The stools of 441 children aged between 5 and 15 years were examined using Kato-katz technique. The secondary metabolites present in the fluid extract were polyphenols (1.2 g EAT/ml), alkaloids, catechic tannins, flavonoids and mucilages. The syrup prepared contained 15.15% of fluid extract and responded favorably to the pharmacotechnical and microbiological tests of the European Pharmacopoeia 9th edition. Only 43 children tested positive for helminth eggs. The syrup based on Carica papaya L fluid seeds extract proved to be comparable to Albendazole on Ascaris lumbricoides (97.46% reduction rate) and on Trichuris trichiura (100% reduction rate) after two administrations of 20 ml 14 days apart. The treatment was also effective against Necator americanus and Tenia sp; but the number of cases of these last two parasitoses was too low to allow any reliable conclusion. Ultimately, the 15.15% syrup of aqueous fluid extract of Carica papaya L. seeds proved a reliable solution for the management of Ascaris lumbricoides and Trichuris trichiura helminthiasis.

Characterization of physicochemical and microbial quality, functional properties, and shelf stability of fermented tigernut-based probiotic beverages

Tigernuts and millet are indigenous underutilized crops in West Africa that have versatile applications in food processing. These crops are rich in fermentable carbohydrates, resistant starch, fiber, and micronutrients, making them ideal candidates for pre- and probiotic (synbiotic) foods. This study utilized whole tigernuts in a dairy–millet-based fermented beverage called brukina, turned it to a synbiotic, and assessed the functional and physicochemical profiles, microbial quality, and shelf stability of the beverage. The tigernut–millet agglomerate was prepared by incorporating cellulose-hydrolyzed tigernut fibrous (TNF) cake and non-hydrolyzed TNF (10% and 15%, respectively) into millet and allowing to ferment for 12 and 24 h. Brukina produced from composite tigernut milk: dairy in a ratio of 40%:60% was inoculated with the probiotic Lacticaseibacillus casei after pasteurization. The beverage was analyzed for physicochemical, proximate, and functional properties and microbiological stability at 5°C and 25°C. The obtained data were subjected to analysis of variance (ANOVA) in Minitab version 17 using a general linear model to determine the variability, interactions, and significance of the measured product characteristics. The agglomerate water absorption capacity (l/g) ranged from 0.70 ± 0.17 to 0.89 ± 0.17, bulk density (g/l) from 0.55 ± 0.04 to 0.63 ± 0.00, and swell index (%) from 1.62 ± 0.08 to 1.80 ± 0.06. The agglomerate prepared from dough and fermented for 12 h had excellent functional characteristics and was selected for synbiotic brukina production. Moisture content of the product decreased (p < 0.001) with tigernut incorporation ranging from 78.85% to 70.45%, while sodium, phosphorus, protein, total carbohydrate, and crude fiber increased with tigernut incorporation (p < 0.05). Synbiotic brukina supported the growth of L. casei attaining 11 log CFU/mL with a corresponding increase in lactic acid production and was microbiologically safe at 5°C and 25°C for 5 days compared to unpasteurized and uninoculated probiotic control (p < 0.05). The addition of whole tigernuts and L. casei to brukina enhanced its nutritional content with a shelf stability of 3 days.

Influence of sodium nitrite microcapsules on the physicochemical properties, microbiological stability, and mathematical modeling during the shelf life of mortadella

Influence of sodium nitrite microcapsules on the physicochemical properties, microbiological stability, and mathematical modeling during the shelf life of mortadella

Feasibility of Enzymatic Protein Extraction from a Dehydrated Fish Biomass Obtained from Unsorted Canned Yellowfin Tuna Side Streams: Part I.

This study presents for the first time a scalable process for the extraction of valuable proteins starting from samples of unsorted mixed tuna scraps which were previously dehydrated by an industrial patented process. The aims of this work were both to avoid the onerous sorting step of tuna leftovers, which generally consists of isolating skin and bones for collagen/gelatin extraction, and to improve the logistic of managing highly perishable biomass thanks to the reduction in its volume and to its microbiological stabilization. In view of a zero-waste economy, all the protein fractions (namely, non-collagenous proteins NCs and ALKs, gelatin, and hydrolyzed gelatin peptides, HGPs) isolated in the proposed single cascade flowchart were stabilized and preliminarily characterized. The extraction flowchart proposed allows one to obtain the following most promising compounds: 1.7 g of gelatin, 3.2 g of HGPs, and 14.6 g of NCs per 100 g of dehydrated starting material. A focus on oven-dried gelatin was reported in terms of proximate analysis, amino acid composition, color parameters, FT-IR spectrum, pH, and viscoelastic properties (5 mPa·s of viscosity and 14.3 °C of gelling temperature). All the obtained extracts are intended to be exploited in food supplements, feed, fertilizers/plant bio-stimulants, packaging, and the cosmetic industry.

High hydrostatic pressure improved properties of peanut sprout juice and its effect on resveratrol

HHP was a nonthermal technology which was widely used in food processing. In this study, HHP was used to process the peanut sprout juice and microbial load, physicochemical properties and antioxidant capacities of peanut sprout juice were found to be improved during 90-day storage. Compared with heat treatment (HT, 95 °C, 10 min), the treatment at 400–600 MPa resulted in greater microbiological stability. No more than 2 lg CFU/g of total plate count (TPC) was observed at 600 MPa for 5 min during a 90-day storage period at 4 °C. The significant negative correlation between the total number of colonies and resveratrol was confirmed, which has bactericidal and bacteriostatic effects. Additionally, resveratrol treated with HHP would degrade and generate new degradation products like p-methylphenol, resorcinol, oxidized resveratrol with higher DPPH scavenging rate, which resulted the higher antioxidation capacity in HHP treated peanut sprout juice. In a word, this study focused on the effect of HHP on peanut sprout juice and the possible degradation behavior of the bioactive resveratrol with HHP treatment, providing a promising processing technology for peanut sprout juice with higher quality.

The effect of form and method of flavoring on microbiota of olive oil.

Flavoring olive oil is an increasing trend in olive oil processing. Growing consumer interest in flavored olive oils by natural material brings the need to evaluate the key limiting factors which is its microbiological stability. The present research compares the microbiological quality of olive oil flavored by 3 flavors (rosemary, garlic, and lemon), prepared by 3 methods to determine changes during storage. The comprehensive microbiological analyses (total number of microorganisms [TCM], anaerobic sporulates, yeasts, molds, bacteria of the family Enterobacteriaceae, bacteria of the genus Salmonella spp., Clostridium botulinum, and lactic acid bacteria) were conducted during 12 months of storage. The best results in TCM were observed in the oil flavored by fresh garlic (0.24 log CFU/mL). The highest counts of anaerobic sporulates were detected in the dried rosemary olive oil (1.10 log CFU/mL). The flavoring materials have significantly higher counts of microorganism than flavored oils (p < .05). The obtained results demonstrated that microorganisms are capable to survive in flavored olive oil and the method of flavoring can affect their growth in a selective way according to the chemical characteristics.

Development of a Carvedilol Oral Liquid Formulation for Paediatric Use.

Carvedilol (CARV) is an 'off-label' β-blocker drug to treat cardiovascular diseases in children. Since CARV is nearly insoluble in water, only CARV solid forms are commercialized. Usually, CARV tablets are manipulated to prepare an extemporaneous liquid formulation for children in hospitals. We studied CARV to improve its aqueous solubility and develop an oral solution. In this study, we assessed the solubility and preliminary stability of CARV in different pH media. Using malic acid as a solubility enhancer had satisfactory results. We studied the chemical, physical, and microbiological stability of 1 mg/mL CARV-malic acid solution. A design of experiment (DoE) was used to optimize the CARV solution's preparation parameters. A 1 mg/mL CARV solution containing malic acid was stable for up to 12 months at 25 °C and 30 °C and 6 months at 40 °C. An equation associating malic acid with CARV concentrations was obtained using DoE. Microbiological data showed that the use of methylparaben was not necessary for this period of time. We successfully developed an aqueous CARV solution suitable for paediatrics and proven to be stable over a 12-month period.