Articole din publicaţii naţionale

Reducing sulphite consumption in wines by applying bioprotective yeasts

2026-01-01T00:00:00Z

Reducing sulphite consumption in wines by applying bioprotective yeasts CUPCEA, Nicolai; STURZA, Rodica Consumer demand for “low-sulfite” wines requires alternative microbiological preservation strategies. Non-Saccharomyces yeasts (Metschnikowia pulcherrima and Torulaspora delbrueckii) suppress spoilage organisms through bioprotection (iron chelation, nutrient competition, oxygen depletion) without compromising fermentation. Bioprotective yeasts operate through an elegant ecological principle: inoculated directly into fresh grape must at the prefermentation stage, they rapidly colonize the available microbial niche before indigenous spoilage organisms can establish themselves. Operating at low prefermentation temperatures (10-16°C), these non-Saccharomyces yeasts competitively consume fermentable sugars and nutrients, produce inhibitory metabolites, trigger oxygen-dependent stress responses that suppress acetic acid bacteria and lactic acid bacteria, and establish mechanisms of cell-contact inhibition. Essentially, they perform this protective action without initiating alcoholic fermentation – a role reserved for later inoculated Saccharomyces cerevisiae strains, which take over once the ethanol concentration exceeds the ethanol tolerance threshold (~5% v/v) of the bioprotectors. This study reports the results of field tests conducted under Moldovan conditions, validating the efficacy of bioprotector yeasts on white grape musts from the Codru region (Glera and Fetească Regală varieties). The results demonstrated a 32–50% reduction in sulfites compared to traditional methods. Volatile acidity levels (0.43–0.44 g/L) remained at approximately 40% of the EU quality threshold, demonstrating the successful suppression of acetic acid bacteria and other spoilage microorganisms during the critical pre-fermentative stage. The author would like to thank the Institutional Project, subprogram 020405 “Optimizing food processing technologies in the context of the circular bioeconomy and climate change”, Bio-OpTehPAS, being implemented at the Technical University of Moldova.

Postprandial glycemic response to thermally processed rice: experimental basis for metabolic predictability and stability assessment

2026-01-01T00:00:00Z

Postprandial glycemic response to thermally processed rice: experimental basis for metabolic predictability and stability assessment VÎRLAN, Anna; SIMINIUC, Sergiu; ȚURCANU, Dinu; SIMINIUC, Rodica Postprandial glycemic response is strongly influenced not only by food composition but also by technological processing conditions applied prior to consumption. Rice represents an appropriate experimental model for investigating how domestic thermal processing affects metabolic responses. The aim of this study was to experimentally evaluate the effect of cooking duration on postprandial glycemic response and to establish an in vivo experimental basis for assessing metabolic variability, stability, and predictability. Four rice varieties differing in structural characteristics (three refined varieties and one whole-grain variety) were analysed under two cooking regimes: recommended cooking time and prolonged cooking (+10 min), simulating thermal overprocessing. An in vivo study involving ten healthy participants was conducted. Glycemic response was assessed using glycemic index (GI), incremental area under the glycemic curve (iAUC₀–₁₂₀), postprandial glycemic dynamics (0–120 min), and glycemic load (GL) of a standard 300 g portion. Statistical evaluation was performed using two-factor ANOVA to determine the effects of rice variety and cooking duration. Results showed systematic increases in GI and iAUC₀–₁₂₀ for refined rice varieties following prolonged cooking, indicating enhanced starch digestibility and increased glycemic exposure. In contrast, whole-grain long-grain rice exhibited a differentiated response characterized by reduced iAUC values and maintenance of moderate glycemic load despite extended thermal treatment. ANOVA analysis confirmed significant effects of both variety (F=48.84, p<0.001) and cooking duration (F=7.14, p=0.009), as well as a significant interaction between factors, demonstrating that technological processing effects are variety-dependent. Extended cooking also reduced interindividual variability for some varieties, suggesting partial convergence of metabolic responses. Cooking duration acts as a critical technological determinant of both intensity and stability of postprandial glycemic response. The experimental protocol proved sensitive to technological modification, providing a validated basis for predictive modelling of glycemic response. The research was supported by Institutional Project, subprogram 020405 “Optimizing food processing technologies in the context of the circular bioeconomy and climate change”, Bio-OpTehPAS, being implemented at the Technical University of Moldova.

Characterization of liposomes as delivery systems for polyphenols

2026-01-01T00:00:00Z

Characterization of liposomes as delivery systems for polyphenols POPOVICI, Violina Polyphenols are valuable bioactive compounds widely recognized for their strong antioxidant, anti-inflammatory, and health-promoting properties. However, their incorporation into food systems is often limited by low stability, sensitivity to environmental factors (light, oxygen, temperature), and reduced bioavailability during gastrointestinal digestion. Liposomal encapsulation represents a promising strategy to protect polyphenols, improve their stability, and enhance their bioaccessibility in functional food applications. In this study, polyphenol-loaded liposomes were characterized in terms of particle size distribution, antioxidant activity during in vitro digestion, and storage stability. The obtained liposomal systems exhibited particle sizes ranging between 126.17±3.17 and 198.78±2.48 nm, confirming their nanoscale structure and suitability for incorporation into food matrices. The stability of polyphenol-loaded liposomes during storage is influenced by factors such as lipid oxidation, membrane permeability, and potential interactions between encapsulated compounds and the phospholipid bilayer. Although a gradual reduction in the concentration of encapsulated polyphenols may occur over time due to oxidative and hydrolytic processes, the liposomal structure contributes to maintaining a significant level of antioxidant activity. The protective phospholipid matrix reduces direct exposure of polyphenols to environmental stress factors, thereby enhancing their overall stability compared to non-encapsulated forms. The obtained results confirm that liposomes function as efficient delivery systems for polyphenols, enhancing their stability, digestive behavior, and functional properties. These findings support the potential application of liposomal encapsulation in the development of fortified and functional food products with improved nutritional value and bioactive compound retention. The research was supported by the State Project for Young Researchers 25.80012.5107.10TC “Stabilization of Plant-derived Bioactive Compounds by Liposomal Encapsulation”, running within Technical University of Moldova.

The impact of sodium chloride concentration on the technological and textural properties of bread

2026-01-01T00:00:00Z

The impact of sodium chloride concentration on the technological and textural properties of bread BOEȘTEAN, Olga; CODINĂ, Georgiana Gabriela; CARACACI, Corina; BULGARU, Viorica; GHENDOV-MOȘANU, Aliona The aim of this research was to evaluate the influence of various concentrations of sodium chloride (NaCl) on bread quality by analyzing the changes occurring in physical and textural properties, as well as in the technological behavior of the dough and the final product. Five bread samples were obtained, differentiated by their NaCl content: 0%, 0.4%, 0.8%, 1.2%, and 1.6%. Each sample was evaluated in terms of: specific volume, crumb porosity, technological losses during baking and cooling, and textural properties. Increasing the NaCl concentration led to noticeable changes in bread properties: specific volume and porosity decreased as the salt level increased, due to the inhibition of yeast activity and reduced gluten extensibility. The salt-free control sample exhibited the highest porosity (72.53%), while the salted samples ranged between 67.76% and 72.12%; technological losses decreased during both baking (from 14.94% to 14.15%) and cooling (from 3.86% to 2.58%). This trend is associated with improved water retention and strengthening of the gluten network in the presence of salt; textural properties were significantly affected: at low NaCl concentrations, hardness decreased, whereas at higher levels (1.2–1.6%), both hardness and chewiness increased considerably, indicating the formation of a denser and more rigid internal structure. Elasticity remained constant (~1.00), while cohesiveness showed a slight decrease, from 0.696 in the control sample to 0.651 in the 1.6% NaCl sample. Salt exerts a substantial influence on the physical, technological, and textural properties of bread. High NaCl concentrations (>1.0–1.2%) inhibit fermentation, reduce bread porosity and volume, and lead to the formation of a denser and more rigid crumb. In contrast, moderate salt additions contribute to maintaining an optimal balance between firmness, porosity, and overall structural quality. The research was supported by a grant from the Ministry of Education and Research, CCDI-UEFISCDI, project number PN-IV-PCB-ROMD-2024-0135, within PNCDI IV and NARD, 25.80013.5107.22ROMD.