Andra-Ionela Ghizdareanu

Interest in non-viable microbial preparations has increased as an alternative to selected technological and safety limitations of live probiotics. Paraprobiotics generally comprise non-viable intact or fragmented microbial cells, whereas the International Scientific Association for Probiotics and Prebiotics (ISAPP) definition of a postbiotic requires a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host. This review critically evaluates mechanisms, clinical evidence, food applications, manufacturing, regulation, and future research priorities. Non-viable microbial preparations can modulate host responses through cell-associated structures, including peptidoglycan, lipoteichoic acids, surface proteins, and exopolysaccharides (EPS), while microbial-derived metabolites such as short-chain fatty acids contribute to barrier and host–microbiota signaling; isolated metabolites, however, should not automatically be classified as postbiotics. Clinical evidence remains preparation- and indication-specific, with stronger evidence for selected preparations such as heat-inactivated Bifidobacterium bifidum MIMBb75 in irritable bowel syndrome (IBS) and more limited or predominantly preclinical evidence for other indications. In food systems, effects on stability, texture, microbial quality, sensory acceptance, and functionality depend on strain, processing, concentration, and matrix. Key barriers include inconsistent terminology, variable inactivation procedures, incomplete characterization, non-standardized dosing, limited long-term clinical evidence, and fragmented regulation. Progress will require reproducible manufacturing, verified residual non-viability, molecular characterization, potency markers, standardized dose reporting, and preparation-specific clinical validation.

The microencapsulation of bioactive compounds from rapeseed oil using sodium alginate, in the presence and absence of an ultrasonic (US) field, is reported. A Box–Behnken experimental design is used to investigate the influence of process parameters on the microencapsulation yield; then, the response surface methodology is applied, to find their values ensuring its optimum yield. The operating parameters investigated are the ratio of sodium alginate to rapeseed oil, the microencapsulation time and the concentration of the calcium chloride solution. The US bath was used at its nominal power, and the microencapsulation temperature was kept at 20 °C, with a thermostat, for all experiments. A detailed study on the comparison of the two microencapsulation techniques (in the presence and absence of the US field) was carried out. Good results were obtained in the presence of the US field for optimal conditions, when the microencapsulation yield was 90.25 ± 0.02%, higher than the microencapsulation process performed in the absence of the US field, 87.11 ± 0.02%. The results also showed that the use of the US field (optimal conditions) led to an increase in encapsulation efficiency, total phenolic content and antioxidant capacity (76.56 ± 0.02%, 324.85 ± 0.01 mg GAE/g and 57.05 ± 0.12 mg/mL). The physicochemical description of microcapsules was performed using modern characterization methods. These results indicate that by increasing the microencapsulation yield of bioactive compounds through sonication, the process aims to achieve a uniform size distribution of microcapsules.

The valorization of cheese whey, a rich by-product of the dairy industry that is rich in lactose (approx. 70%), proteins (14%), and minerals (9%), represents a promising approach for microbial fermentation. With global whey production exceeding 200 million tons annually, the high biochemical oxygen demand underlines the important need for sustainable processing alternatives. This review explores the biotechnological potential of whey as a fermentation medium by examining its chemical composition, microbial interactions, and ability to support the synthesis of valuable metabolites. Functional microorganisms such as lactic acid bacteria (Lactobacillus helveticus, L. acidophilus), yeasts (Kluyveromyces marxianus), actinobacteria, and filamentous fungi (Aspergillus oryzae) have demonstrated the ability to efficiently convert whey into a wide range of bioactive compounds, including organic acids, exopolysaccharides (EPSs), bacteriocins, enzymes, and peptides. To enhance microbial growth and metabolite production, whey fermentation can be carried out using various techniques, including batch, fed-batch, continuous and immobilized cell fermentation, and membrane bioreactors. These bioprocessing methods improve substrate utilization and metabolite yields, contributing to the efficient utilization of whey. These bioactive compounds have diverse applications in food, pharmaceuticals, agriculture, and biofuels and strengthen the role of whey as a sustainable biotechnological resource. Patents and clinical studies confirm the diverse bioactivities of whey-derived metabolites and their industrial potential. Whey peptides provide antihypertensive, antioxidant, immunomodulatory, and antimicrobial benefits, while bacteriocins and EPSs act as natural preservatives in foods and pharmaceuticals. Also, organic acids such as lactic acid and propionic acid act as biopreservatives that improve food safety and provide health-promoting formulations. These results emphasize whey’s significant industrial relevance as a sustainable, cost-efficient substrate for the production of high-quality bioactive compounds in the food, pharmaceutical, agricultural, and bioenergy sectors.

The role of prebiotics and probiotics in promoting gut health is increasingly recognized in food development and nutrition research. This study explored the enhancement of probiotic viability in the food industry through microencapsulated synbiotics, focusing on Lactiplantibacillus plantarum NCIMB 11974 with fructooligosaccharides (FOSs) and inulin as prebiotics. The effect of encapsulation in a chitosan-coated alginate matrix on probiotic survival under simulated gastrointestinal conditions showed a significant effect of 2% FOS concentration on the growth of Lactiplantibacillus plantarum NCIMB 11974. The optimization of microencapsulation parameters by the Taguchi method revealed a 2% sodium alginate concentration, a nozzle size of 200 µm, and a concentration of 0.4% chitosan solution as ideal, producing microcapsules with an estimated average diameter of 212 µm. Viability assessments in simulated gastric juice and simulated intestinal juice showed that chitosan-coated alginate microcapsules notably enhanced probiotic survival, achieving log 8 CFU mL⁻¹ viability in both environments, a marked improvement over the uncoated variant. The study emphasizes the importance of microencapsulation, particularly by sodium alginate and chitosan, as a viable strategy to improve the survival and delivery of probiotics through the digestive system. By improving the stability and survivability of probiotics, microencapsulation promises to expand the use of synbiotics in various foods, contributing to the development of functional foods with health-promoting properties.

The present work aims to study the possibilities of developing silver nanoparticles using natural extracts of grape pomace wastes originating from the native variety of Fetească Neagră 6 Șt. This study focused on investigating the influence of grape pomace extract obtained by two different extraction methods (classical temperature extraction and microwave-assisted extraction) in the phytosynthesis process of metal nanoparticles. The total phenolic content of the extracts was assessed using the spectrophotometric method with the Folin–Ciocâlteu reagent, while the identification and quantification of specific components were conducted through high-performance liquid chromatography with a diode array detector (HPLC-DAD). The obtained nanoparticles were characterized by UV–Vis absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM), along with assessing their antioxidant and antimicrobial properties against Gram-positive bacteria. The data collected from the experiments indicated that the nanoparticles were formed in a relatively short period of time (96 h) and, for the experimental variant involving the use of a 1:1 ratio (v/v, grape pomace extract: silver nitrate) for the nanoparticle phytosynthesis, the smallest crystallite sizes (from X-ray diffraction—4.58 nm and 5.14 nm) as well as spherical or semispherical nanoparticles with the lowest average diameters were obtained (19.99–23 nm, from TEM analysis). The phytosynthesis process was shown to enhance the antioxidant properties (determined using the DPPH assay) and the antimicrobial potential (tested against Gram-positive strains) of the nanoparticles, as evidenced by comparing their properties with those of the parent extracts; at the same time, the nanoparticles exhibited a selectivity in action, being active against the Staphylococcus aureus strain while presenting no antimicrobial potential against the Enterococcus faecalis strain.

This study investigated the combined alkaline and enzymatic hydrolysis of eggshell membranes for obtaining ingredients for food and cosmetic applications. 1.25 N NaOH and Alcalase 2.4 L protease were used for eggshell membrane hydrolysis. The characterization of the hydrolysates consisted of the determination of the degree of hydrolysis, oligopeptides, and free amino acids obtained through eggshell membrane hydrolysis. The degree of hydrolysis was 14.23%. Analytical techniques such as reversed-phase liquid chromatography coupled with mass spectrometry, hydrophilic interaction liquid chromatography, and FT-IR spectroscopy revealed the presence of oligopeptides, dipeptides, and amino acids, including alanine, lysine/glutamine, glutamic acid, histidine, proline, valine, hydroxyproline, and phenylalanine. Electrophoretic analysis demonstrated protein fractions within the molecular weight range of approximately 14 kDa to 70 kDa in all samples.

Annually, considerable amounts of polluted water are produced due to industrialization based on processing in various industries. The purpose of this study refers to a process of obtaining a photocatalytic system with a structure of metal oxides in the field of ultrasound, used in the advanced treatment of wastewater resulting from the pharmaceutical and agricultural industries. These photocatalytic systems allow wastewater to be treated in a relatively short time, being quickly recovered and reused repeatedly. To quantify the efficiency of the photocatalyst in treating wastewater, experiments were carried out in the presence of sunlight, in the absence and presence of the photocatalyst, with a methylene blue solution.

The objective of this study was to investigate the effects of enzymatic hydrolysis using α-amylase from Bacillus amyloliquefaciens on the mechanical properties of starch-based films. The process parameters of enzymatic hydrolysis and the degree of hydrolysis (DH) were optimized using a Box–Behnken design (BBD) and response surface methodology (RSM). The mechanical properties of the resulting hydrolyzed corn starch films (tensile strain at break, tensile stress at break, and Young’s modulus) were evaluated. The results showed that the optimum DH for hydrolyzed corn starch films to achieve improved mechanical properties of the film-forming solutions was achieved at a corn starch to water ratio of 1:2.8, an enzyme to substrate ratio of 357 U/g, and an incubation temperature of 48 °C. Under the optimized conditions, the hydrolyzed corn starch film had a higher water absorption index of 2.32 ± 0.112% compared to the native corn starch film (control) of 0.81 ± 0.352%. The hydrolyzed corn starch films were more transparent than the control sample, with a light transmission of 78.5 ± 0.121% per mm. Fourier-transformed infrared spectroscopy (FTIR) analysis showed that the enzymatically hydrolyzed corn starch films had a more compact and solid structure in terms of molecular bonds, and the contact angle was also higher, at 79.21 ± 0.171° for this sample. The control sample had a higher melting point than the hydrolyzed corn starch film, as indicated by the significant difference in the temperature of the first endothermic event between the two films. The atomic force microscopy (AFM) characterization of the hydrolyzed corn starch film showed intermediate surface roughness. A comparison of the data from the two samples showed that the hydrolyzed corn starch film had better mechanical properties than the control sample, with a greater change in the storage modulus over a wider temperature range and higher values for the loss modulus and tan delta, indicating that the hydrolyzed corn starch film had better energy dissipation properties, as shown by thermal analysis. The improved mechanical properties of the resulting film of hydrolyzed corn starch were attributed to the enzymatic hydrolysis process, which breaks the starch molecules into smaller units, resulting in increased chain flexibility, improved film-forming ability, and stronger intermolecular bonds.

This study aims to characterize the pectic oligosaccharides (POSs) generated from enzymatically hydrolyzed citrus peel pectin using a selected enzyme. Pectinex Ultra AFP was used to depolymerize citrus peel pectin into POSs. The POSs were analyzed using high-performance liquid chromatography (HPLC) and liquid chromatography coupled with a mass spectrometer (LC/MS) methodology to determine the composition of monosaccharides and the average molar mass distribution based on the retention time. The identified fractions were predominantly neutral sugars (rhamnose, glucose, and galactose) and acidic sugars (galacturonic acid), with corresponding mole percentages of 8.67%, 10.28%, 74.33%, and 6.72%, respectively. The degree of polymerization (DP) was in the range of DP3–DP8, containing three (trimers) to eight (octamers) monomeric units. The low DP indicates an advanced degree of enzymatic hydrolysis of pectin up to the level of pectic POSs.