Konstantinos Gkatzionis

Table olives have potential for expansion into Asian markets, where consumer familiarity with these products is still limited. This study investigated sensory perception and emotional responses to table olives among Greek and Indonesian consumers. A total of 242 participants evaluated Kalamata and Green Halkidiki olives using sensory attributes based on the International Olive Council (IOC) protocol and the Check‐All‐That‐Apply (CATA) method for emotions. Greeks associated Kalamata olives, a variety commonly associated with PDO table olives in Greece, more with positive emotions, while Indonesians showed different emotional associations with the two varieties. Greek consumers rated Green Halkidiki higher in overall quality, whereas Indonesian consumers rated Kalamata higher. In Indonesia, Kalamata was more frequently associated with “Adventurous,” “Daring,” and “Aggressive,” while Green Halkidiki was associated with “Steady,” “Friendly,” and “Warm.” These findings suggest that Kalamata olives may have potential for further market testing in Indonesia.

The growing need for sustainable strategies to reduce agro-industrial waste has stimulated interest in valorizing winery by-products as sources of high-value bioactive compounds. Wine lees, rich in phenolic compounds with well-documented antimicrobial activity, remain largely underutilized in the development of functional materials. In most cases, incorporation of bioactive agents relies on physical adsorption, which often results in weak adhesion and limited durability. In this study, phenolic extracts derived from wine lees and grape seed extract were incorporated into bacterial cellulose (BC) to develop bioactive materials with antimicrobial and antioxidant functionality. Two strategies were investigated: (i) direct immersion of BC in phenolic extracts and (ii) incorporation of extracts in BC membranes pre-modified with carboxymethyl cellulose (CMC) to enhance phenolic affinity and retention. The resulting materials were characterized for total phenolic content, antioxidant activity, and antimicrobial performance against bacterial strains (Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus). CMC-pretreated membranes significantly enhanced phenolic incorporation and antimicrobial performance, achieving a 99.9% reduction in E. coli after 24 h, while S. Typhimurium and S. aureus counts were below the detection limit (LOD < 1.0 log₁₀ CFU/mL). These findings demonstrate the potential of wine lees as a sustainable source of bioactive compounds for the development of antimicrobial cellulose-based materials, supporting circular bioeconomy strategies and their potential application in food packaging.

The present study explores the treatment and valorization of carbon-rich, low-cost waste streams—sugar beet molasses, expired rice, and wheat cereal hydrolysates—as substrates for submerged shake-flask cultures of edible ascomycetes (Morchella elata AMRL 63, Tuber aestivum AMRL 364) and basidiomycetes (Lentinula edodes AMRL 126, Agaricus bisporus AMRL 209) within a circular bioeconomy framework. Cultures were conducted under different C/N ratios (20 and 50) with or without the addition of olive oil or its emulsion. Among the tested species, the ascomycetes M. elata AMRL 63 and T. aestivum AMRL 364 outperformed the basidiomycetes in biomass production and substrate utilization. Supplementation with olive oil or its emulsion enhanced mycelial growth and lipid accumulation, while a higher C/N ratio (50) favored exopolysaccharide (EPS) synthesis. Lipid profiles were dominated by oleic (Δ⁹C18:1) and linoleic (Δ^9,12C18:2) acids, with greater unsaturation observed in C/N = 20 cultures. Volatile analysis revealed species-specific aroma signatures, including characteristic truffle and morel compounds. The results underscore the feasibility of using waste streams for sustainable mushroom cultivation.

Composite flours have been increasingly introduced in bakery products, aiming to enhance their nutritional value and reduce overdependence on imported wheat. Crackers are popular snack items, with potential to affect body weight and health status. This study aimed to examine the effects of different flour types, specifically pulses (chickpea, lupin, yellow split pea and cowpea), agricultural by-products (grape seeds and olive stones) and cereals (barley), on flour functionality, dough quality and final product characteristics compared with wheat flour (control) at various substitution levels. The functional properties of the composite flours were associated with the properties of dough and the characteristics of the crackers. Barley flour produced crackers with significantly higher hardness and lightness (L*) compared to the control, whereas chickpea flour had a similar but non-significant trend for both hardness and L* value. In contrast, high-level olive stone formulations yielded softer textures and the highest total color difference (ΔE), followed by grape seed crackers, which also exhibited high ΔE values and reduced hardness. The effects of composite flours on product texture were mediated by water absorption capacity and the compositional characteristics of the added flours. Crackers prepared with composite flours generally resulted in darker and diverse color profiles as well as low water activity and moisture values. Overall, the findings indicate that variations in composite flour type and substitution level influence product quality, allowing targeted modification of specific cracker attributes.

Social media has developed into a leading advertising platform, with Instagram likes serving as visual cues that may influence consumer perception and behavior. The present study investigated the effect of Instagram likes on visual attention, memory, and food evaluations focusing on traditional Greek food posts, using eye-tracking technology. The study assessed whether a higher number of likes increased attention to the food area, enhanced memory recall of food names, and influenced subjective ratings (liking, perceived tastiness, and intention to taste). The results demonstrated no significant differences in overall viewing time, memory performance, or evaluation ratings between high-like and low-like conditions. Although not statistically significant, descriptive trends suggested that posts with a higher number of likes tended to be evaluated more positively and the AOIs likes area showed a trend towards attracting more visual attention. The observed trends point to a possible subtle role of likes in user’s engagement with food posts, influencing how they process and evaluate such content. These findings add to the discussion about the effect of social media likes on information processing when individuals observe food pictures on social media.

Introduction: Jaw muscles are essential for chewing and swallowing, generating electrical signals measurable through electromyography (EMG). In food science, EMG is increasingly being used to link food texture with consumption. Objective: This study aimed to analyze chewing EMG data using signal processing and machine learning, to explore its relationship with sensory evaluation. Methods: Participants tasted three gels with identical flavors but different colors (green, red, yellow) while EMG data were recorded. Three machine-learning classification algorithms analyzed the EMG patterns to detect potential color-based preference differences. Results and Discussion: No strong relationship was found between EMG data and gel preferences, although the approach shows promise for investigating muscle function in food choice. Challenges arose from limited taste variability and data set size. Conclusión: This research underscores EMG’s potential in studying muscle function and foodrelated behavior, despite limitations in using EMG data with machine learning for preference prediction.

Functional flours, high in bioactive compounds, have garnered increasing attention, driven by consumer demand for alternative ingredients and the nutritional limitations of wheat flour. This study explores the thermal stability of phenolic compounds in various functional flours using visible, near and shortwave-infrared (Vis–NIR–SWIR) spectroscopy (350–2500 nm), integrated with machine learning (ML) algorithms. Random Forest models were employed to classify samples based on flour type, baking temperature, and phenolic concentration. The full spectral range yielded high classification accuracy (0.98, 0.98, and 0.99, respectively), and an explainability framework revealed the wavelengths most relevant for each class. To address concerns regarding color as a confounding factor, a targeted spectral refinement was implemented by sequentially excluding the visible region. Models trained on the 1000–2500 nm and 1400–2500 nm ranges showed minor reductions in accuracy, suggesting that classification is not solely driven by visible characteristics. Results indicated that legume and wheat flours retain higher total phenolic content (TPC) under mild thermal conditions, whereas grape seed flour (GSF) and olive stone flour (OSF) exhibited notable thermal stability of TPC even at elevated temperatures. These first findings suggest that the proposed non-destructive spectroscopic approach enables rapid classification and quality assessment of functional flours, supporting future applications in precision food formulation and quality control.

The sensory and physicochemical properties of three different recipes for apple cream filling were investigated, focusing on their potential to enhance consumer appeal in pastry applications. Two of the recipes incorporate dried apple cubes (AP1, 48% and AP2, 38% w/w, respectively), while the third recipe (PD) features a cube-free formulation with higher quantities of sugar, potato starch, xanthan gum, dextrose, cinnamon and malic acid. The study evaluated the impact of ingredient composition and processing techniques on sensory attributes. The results indicate that AP1 and AP2 resulted in higher moisture, ash and fiber content but lower viscosity, pH values and emulsion stability compared to PD. All samples exhibited pseudoplastic behavior. The AP2 sample exhibited the most hydrophilic behavior. FT-IR spectra have shown three main peaks, i.e., O-H (3300–3320 cm⁻¹), C=O (1640–1730 cm⁻¹) and C-O (1025–1030 cm⁻¹) stretching vibrations. AP1 and AP2 significantly enhanced hardness and cohesion, providing a more engaging sensory experience. PD offers a smoother, creamier texture with lower inhomogeneity compared to AP1 and AP2 samples, making it ideal for consumers who prefer a uniform mouthfeel. This research demonstrates the critical role of formulation choices in tailoring sensory and physicochemical properties of apple cream fillings to meet diverse consumer preferences.