Ahsen Rayman Ergün

Foam mat drying is a promising development with the advantages of low cost and can be used as an alternative to drum and spray drying for drying aqueous foods. The economic value and importance of mandarin fruits are increasing day by day due to their rich nutritional content, ease of marketing, easy peeling compared to other citrus fruits, the existence of varieties that ripen at different times, and their resistance to cold. The aim of this study was to optimize the production conditions of mandarin juice foam with response surface methodology, to examine the drying kinetics of hot air and freeze-drying methods, and to express the drying behavior of mandarin juice foams with mathematical modeling. Egg albumen was used as a foaming agent at different concentrations (0, 1.5, and 3% w/w), and carboxymethyl cellulose (0, 1, and 2% w/w) was used as a foam stabilizer. Optimum production conditions were found as a whipping time of 6 min 20 s, an egg albumen concentration of 3% (w/w), and a carboxymethyl cellulose concentration of 2% (w/w). Under the optimized conditions, density, stability, and expansion values of foam were found as 0.262 (g/cm³), 348.955, and 302.516%, respectively. The drying times for temperatures of 50, 60, 70, and −52 °C were determined as 105, 82, 70, and 180 min, respectively. Based on mathematical modeling, the “Page” model was found to be suitable for all temperature values.

The increasing demand for plant-based proteins has intensified interest in alternative legume sources with high nutritional and functional value. Mung bean is a promising protein source; however, limited information is available about the effects of edible coatings and different roasting methods on its quality characteristics. This study investigated the impact of rosemary- and thyme-based coatings combined with oven, microwave, and air-fry roasting on the physicochemical, bioactive, and volatile properties of a high-protein mung bean snack. Rosemary and thyme were chosen as edible coatings because of their well-documented antioxidant and aroma-enhancing properties, making them suitable for improving the functional and sensory quality of legume-based snacks. Coated mung beans were roasted using oven (200 °C, 20 min), microwave (600 W, 8 min), and air-fry (200 °C, 13 min) methods, with the final moisture content maintained below 6%. Moisture, ash, protein, total phenolic and flavonoid contents, antioxidant activity, color parameters, and volatile compounds were evaluated. Air-fried samples exhibited higher phenolic, flavonoid, and antioxidant contents than those of oven- and microwave-roasted samples. Especially, in the rosemary-microwave sample group, the phenolic content was found to be 1447.0 ± 20.02 mg GAE/100 g DM. The highest protein content (25.96%) was observed in the air-fried rosemary-coated samples. Lightness decreased after roasting, while a* and b* values were largely preserved. Coating type and roasting method significantly influenced the volatile profiles, with rosemary- and thyme-coated samples showing higher terpene contents, predominantly limonene. These findings indicate that edible coatings combined with alternative roasting technologies can enhance the nutritional and sensory quality of mung bean-based snacks.

Improved quality and safety can be achieved by UV-C light which is a non-thermal method for fruit juices. Zygosaccharomyces rouxii causes spoilage problems in sugar foods, fruit juices and concentrates. In this research, the effect of UV-C light in different doses (4, 8, 12 J/cm2) was investigated for inactivation of Z.rouxii in apple juice and also some quality properties were evaluated such as color, total phenolic and antioxidant contents. As a result, applying 4 J/cm2 irradiation gave the highest phenolic and antioxidant contents as 229.89±2.19 (mgGAE. mL-1) and 0.032±0.05 (EC50, µg/mL) respectively. Color values significantly affected from the increase in doses of irradiation (P<0.05), The reduction UV-C exposure in Zygosaccharomyces rouxii was achieved as 1.45 log CFU ml-1 for 4 J/cm2 ; 2.09 log CFU ml-1 for 8 J/cm2 and lastly, 1.94 CFU/ml for 12 J/cm2 treatment. These findings indicate that low doses of UV-C irradiation can effectively inactivate organisms while preserving quality characteristics of apple juice.

This study purposed to determine the impacts of chitosan film (CF) (2%, w/v) coating combined with thyme oil (TO) (0.2%, 0.5%, 1%, (v/v)) on the quality properties of black olives during storage (3 months, +4 and 25°C). In the study, film properties (color, elongation at break, tensile strength, Young’s modulus, and scanning electron microscope (SEM)) were analyzed. In the second stage, table olive samples were assessed for physicochemical (% moisture, pH, titratable acidity, color (L*, a*, b* and ∆E*), and microbiological (yeast–mold and total viable count) properties. The average elongation at break, tensile strength, and Young’s modulus values of the obtained film coating samples were 70.02%, 16.66 MPa, 24.05 MPa for the CF; 74.69%, 14.79 MPa, 19.65 MPa for the CF + 0.2% TO; 77.21%, 10.79 MPa, 13.94 MPa for CF + 0.5% TO and 83.78%, 10.40 MPa, 12.69 MPa for CF + 1.0% TO group, respectively. Chitosan film sample was determined the highest tensile strength value and the CF+1% TO sample group was detected with the highest elongation at break. It was determined that the increase in the concentration of TO in the film increased the elongation at break and decreased the Young’s modulus value. Scanning electron microscope (SEM) surface images of group CF film have a homogeneous and uniform structure but added thyme oil occured a heterogeneous appearance. The L*, a*, b*, and ∆E* values increased with the addition of thyme oil and a statistically significant difference was found between samples (P < 0.05). The highest moisture loss was determined in the control (uncoated) group. The highest decrease in yeast–mold and total viable count value was found 4.89 log CFU/g CF + 0.2% TO and 5.21 log CFU/g in CF + 1.0% TO sample at the end of storage period at 4°C in table olives.

In this study, conventional, microwave, and also a combination of these two methods were applied to compare the quality properties of sunflower seeds. Alternative to conventional roasting at 160°C, microwave roasting at two different powers (300W and 600W) and also microwave with conventional roasting treatment (300 W+160°C, 600 W+160°C) were applied to raw sunflower seeds during 5 and 10 min. for each group. The moisture content of roasted seeds was found to be lower than 6%. The results show that the highest protein and fat content were found in the group of combined methods as 21.09±6.64 and 40.55±0.345% respectively. Additionally, the color values were found to be higher, and hardness and sensory characteristics were protected better after roasting compared to the control (unroasted) group. Roasting of microwave at 600W power for 5 min at 160°C was found to be advantageous for the roasting process of sunflower seed via these properties.

In this study, newly formulated gluten-free chips with almond powder were produced. Almond powders were obtained using 3 different drying methods: oven drying, freeze drying, and microwave drying. This study aimed to determine the effect of drying almond powders used in gluten-free chip production using different drying methods and then adding different ratios (10% and 30%) of these powders to the chips on the physicochemical, textural, mineral, and sensory properties of the chips. The physical, textural, mineral, and sensory analyses were then carried out. The moisture content values of the chips with almond powder were < 6.32% and the water activity values were < 0.300. Adding almond powder increased the total fat and protein content of the chip samples. The protein content of the gluten-free chips increased by 34.69-257.14% compared to the control sample and the highest protein content (1.75%) was determined in the samples containing 30% of the almond powder obtained using the microwave drying method. The hardness of the gluten-free chips decreased by increasing the almond powder. The addition of the almond powder to the chip formulation generally increased the B, Cu, Mn, and Zn contents of the gluten-free chips. All chip samples enriched with almond powder showed similar overall acceptability scores (5.00-6.89).

In this study, the effects of a moderate electrical field application and two different blanching methods (conventional and ultrasound) on the frying (deep-frying in oil at 180 °C for 6 minutes and compared to the microwave (400W)) of zucchini slices were investigated. Microwave-fried samples presented a lower moisture content than deep fried ones. The moderate electrical field significantly reduced the oil content before the microwave frying. Greenness (–a*), which is important for the zucchini samples, was found at its best (-3.25) in the combination group of moderate electrical field pre-treated, ultrasound blanched, and microwave fried. Gumminess, cohesiveness, and fracturability of the zucchini slices decreased while chewiness, springiness, and resilience increased after microwave frying. The scores of the sensory test were higher for the ultrasonic blanching and microwave fried sample groups. Besides, these electrical methods were found more advantageous in terms of energy consumption.

The aim of this study was to investigate the effects of electrical pretreatment (40V, 60 sec) and ultrasound blanching (35kHz, 80°C, 2 min) on the drying time, texture, color, and rehydration properties of zucchini which were dried by hot air and freeze dryers to 8% moisture content (wet basis). The synergistic effect of electrical and ultrasonical applications reduced the drying time (36%) to reach the target moisture content in hot air drying and provided fracturable, chewy, and edible hard zucchini chips. The highest lightness value was found as 86.04 at the group blanched ultrasonically and freeze dried chips.The greenness was found at most (-9.31) in the combined group of electrical pretreated, ultrasound assisted blanched and freeze dried sample group. The rehydration capacity of the dried samples increased significantly with the effect of ultrasound compared to the increase with the effect of electroplasmolysis application (P≤0.05). Zucchini chips with higher quality characteristics were produced by these combined applications. The electrical method can be alternatively used for drying pretreatments in the food industry with the advantage of decreasing the processing time and improving the textural and sensorial properties compared to the method of hot drying.

In this study Ginkgo biloba leaf extract which is rich in phytochemical metabolites was used as a pectin substitute in quince jam. The extraction process was performed ultrasonically at 70°C with ethanol that gives the highest flavonoid content. The jam was produced with pectin in the traditional procedure and pectin-free jams were made using two different weight concentrations (0.05% and 0.1%) of Ginkgo biloba extract and compared to the pectin group. Shear stress value decreased when Ginkgo biloba was used as a pectin substitute so the jam becomes softer. Phenolic content 170.09 (mg/g GAE), and antioxidant activity (1.80 mM Trolox/100g) was found highest in the 0.1 g extract group. Lightness and yellowness increased with Ginkgo biloba compared to the pectin group. The jam sample with 0.1 g extract was preferred in sensory tests.