Mariana Spinei

The mixture of honey and propolis has become increasingly popular due to its potential functional and antimicrobial properties, generating interest in its stability and quality during storage. This study aimed to evaluate the evolution of physico-chemical and microbiological parameters of honey enriched with different propolis concentrations (0.1%, 0.2%, and 0.3%, w/w) over a 30-day period under controlled storage conditions. Honey samples with and without propolis were stored at 20 °C in the absence of light, and physico-chemical parameters (moisture content, electrical conductivity, pH, and acidity), antioxidant-related indicators (total phenolic content, total flavonoid content, and DPPH radical scavenging activity), and microbiological parameters (the total aerobic viable count, yeast and mold counts, and coliform bacteria counts) were analyzed at defined intervals. The results showed that the monitored physico-chemical parameters remained stable throughout the storage period, indicating good product stability. Antioxidant-related parameters increased proportionally with the concentration of propolis added, reflecting the contribution of phenolic compounds and flavonoids present in propolis. Microbiological analysis confirmed the absence of coliform bacteria in all samples, while a gradual increase in total viable count and in yeast and mold counts was observed in propolis-enriched honey samples during storage. Overall, the findings indicate that honey–propolis mixtures maintain physico-chemical stability, comply with microbiological safety requirements, and exhibit enhanced antioxidant potential during short-term storage. These conclusions are limited to the 30-day storage period investigated and should not be extrapolated to long-term storage stability.

The aim of this study is to evaluate the usefulness of UV-Vis-NIR spectroscopy as a tool for detecting the adulteration of cold-pressed walnut oil and other edible oils (rapeseed, sunflower, and soybean oils) at varying percentages. The spectra were recorded between 200 and 1800 nm, but the analyses focused on 350–1650 nm due to high UV and NIR absorption. Color was determined in CIEL*a*b* coordinates to achieve the differences among the samples. The spectra were submitted to several pre-treatment (none, normalization, SNV, MSC, baseline/detrend, first/second derivative, and 1st-order smoothing) to improve the statistical model’s parameters. The differentiation of the samples was carried out using an unsupervised method (principal component analysis—PCA) and two supervised methods (linear discriminant analysis—LDA and partial least squares linear discriminant analysis—PLS-DA). Partial least squares regression (PLS-R) was used for predicting the degree of adulteration. Separation between the authentic and adulterated samples was visible in the PCA scores plot, primarily along the spectral regions of 420–500 nm (pigment-related absorption band) and 1150–1450 nm (lipid-associated band). PLS-DA was superior to DA for the discrimination of authentic/adulterated samples, with baseline spectra of 350–1650 nm yielding a 100% overall accuracy and near-perfect accuracy with MSC (98.48%). PLS-R was able to predict the adulteration level, depending on the pre-treatment applied.

This study reports the development and characterization of novel active edible films based on apple pectin and honey (80:20, w/w), incorporating raw propolis powder at 0.1%, 0.2%, and 0.3% (w/w, relative to honey) as a natural source of bioactive compounds for sustainable packaging of soluble coffee and matcha powders. The study aims to provide sustainable and functional packaging solutions capable of maintaining the stability and quality of these powdered beverages. The effects of honey and propolis incorporation on the physicochemical, mechanical, optical, and microbiological properties of the films were systematically evaluated. Propolis addition resulted in decreased tensile strength, elastic modulus, and elongation at break, but did not significantly alter the thermal stability of the films, as evidenced by differential scanning calorimetry and thermogravimetric analysis. Increasing propolis concentrations led to higher total phenolic content and significantly improved antioxidant activity, with the 0.3% formulation exhibiting the most pronounced effect. Application tests demonstrated that the honey–propolis-enriched pectin films effectively preserved the sensory attributes and physicochemical quality of soluble coffee and matcha powders. Overall, these results highlight the potential of pectin–honey–propolis films as bioactive carriers and functional materials for active packaging of powdered beverages.

This study investigates the potential use of tomato pomace, a by-product of tomato pulp and seeds, as a functional additive in sunflower and rapeseed oils. The aim was twofold: to improve the oxidative stability of the oils and to enhance their nutritional value for potential food applications. Extractions were performed using different concentrations of tomato pomace (2%, 4%, and 6%) at varying temperatures (40°, 50°, and 60 °C) and stirring speeds (150, 200, and 250 rpm). The resulting samples were evaluated for antioxidant activity, peroxide value, and color characteristics. To further assess oil composition and stability, advanced analytical techniques were employed. Fourier-transform infrared spectroscopy (FTIR) identified key functional groups and structural modifications, while differential scanning calorimetry (DSC) revealed differences in thermal stability across the samples. High-performance liquid chromatography (HPLC), optimized for compound separation and detection, identified several carotenoids, including canthaxanthin, lutein, lycopene, and alpha carotene. Notable differences between extracts made with sunflower versus rapeseed oil were observed, reflecting variations in chemical composition, extraction efficiency, and oil–pomace interactions. In conclusion, the incorporation of tomato pomace into vegetable oils not only enhances oxidative and thermal stability but also enriches the oils with valuable bioactive compounds, supporting their potential use in functional food formulations.

Five varieties of vegetable oil underwent oleogelation with two types of wax as follows: beeswax (BW) and rice bran wax (RW). The oleogels were analyzed for their physicochemical, thermal, and textural characteristics. The oleogels were used in the bun dough recipe at a percentage level of 5%, and the textural and rheological properties of the oleogel doughs were analyzed using dynamic and empirical rheology devices such as the Haake rheometer, the Rheofermentometer, and Mixolab. The thermal properties of beeswax oleogels showed a melting peak at a lower temperature for all the oils used compared with that of the oleogels containing rice bran wax. Texturally, for both waxes, as the percentage of wax increased, the firmness of the oleogels increased proportionally, which indicates better technological characteristics for the food industry. The effect of the addition of oleogels on the viscoelastic properties of the dough was measured as a function of temperature. All dough samples showed higher values for G′ (storage modulus) than those of G″ (loss modulus) in the temperature range of 20–90 °C, suggesting a solid, elastic-like behavior of all dough samples with the addition of oleogels. The influence of the beeswax and rice bran oleogels based on different types of vegetable oils on the thermo-mechanical properties of wheat flour dough indicated that the addition of oleogels in dough recipes generally led to higher dough stability and lower values for the dough development time and those related to the dough’s starch characteristics. Therefore, the addition of oleogels in dough recipes inhibits the starch gelatinization process and increases the shelf life of bakery products.

The influence of particle size intervals (Vitis vinifera var. Băbească Neagră) was analyzed in terms of the proximate composition, functional properties, and physicochemical parameters. The aim was to study the effect of the formulation variables (extract from grape pomace with different particle size intervals and gelatin doses—7, 8.5, and 10 g) on the mechanical properties (hardness, cohesiveness, adhesiveness, springiness, and gumminess), color, and sensorial, microbiological, and phytochemical parameters. The jelly candy formulated with grape pomace extract (<125 μm) and 7 g of gelatin showed the highest total phenolic content (156 mg GAE/g) and antioxidant activity (65.8% inhibition), while grape pomace jellies with a particle size of ≥125–<200 μm and different concentration of gelatin presented the greatest sensory acceptance in terms of sweetness, taste, odor, elasticity, color, and overall acceptability of the resulting jelly. The concluding observation was supported by the microbiological analysis, which also showed that there is no growth in jelly samples except the jelly candies prepared with a ≥200–<300 μm particle size interval of grape pomace extract.

The yield, physicochemical and rheological parameters of grape pomace pectin (Fetească Neagră and Rară Neagră) obtained by conventional extraction (CE) were compared to those acquired by pulsed ultrasound-assisted extraction (PUAE). Extraction temperature (70–90 °C), pH (1–3) and time (1–3 h) were considered as independent variables for CE, while amplitude (20–100%), pH (1–3) and time (20–60 min) for PUAE. The optimal conditions for maximum yield and physicochemical parameters of pectin samples extracted by CE were temperature of 90 °C, pH 1.9 for 164 min (9.96% yield, 79.91 g/100 g of galacturonic acid (GalA) content, 81.28% of degree of esterification (DE) and 5.52 × 10⁴ g/mol of molecular weight (M_w) for Fetească Neagră (FN) pectin; 11.08% yield, 80.05 g/100 g of GalA content, 80.86% of DE and 5.59 × 10⁴ g/mol of M_w for Rară Neagră (RN) pectin), while for PUAE they were amplitude of 100%, pH 1.8 for 60 min (8.83% yield, 80.24 g/100 g of GalA content, 81.07% of DE and 4.19 × 10⁴ g/mol of M_w for FN pectin; 8.94% yield, 78.64 g/100 g of GalA content, 80.04% of DE and 4.23 × 10⁴ g/mol of M_w for RN pectin). The yield and physicochemical parameters of CE pectin were higher than PUAE pectin. The FT-IR spectra of pectin samples revealed the occurrence of polysaccharide compound, while rheology characteristics confirming its application in different food products.