## 3 Results
### Quality and Sensory Characteristics of Osmotically Dehydrated Pumpkin

Table 3: Estimated kinetic parameters (\(k_{\textit{order}}\), \(k_{\textit{texture}}\), \(k_{\textit{vitamin}}\), \(k_{\textit{sensory}}\); \(E_{a}\), \(k_{\textit{ref}}\) at \(T_{\textit{ref}}\) = 4 \({}^{\circ}\)C) used for quality deterioration of OD processed pumpkin cuts at 55\({}^{\circ}\)C for 120 min (OD\({}_{\text{SY}}\) whey and OD\({}_{\text{Water}}\)), and stored at isothermal temperature (5, 10, 15\({}^{\circ}\)C) conditions based on instrumental measurement of color and texture, vitamin C, and organoleptically perceived quality (sensory). Figure 2: **(a) Total color change (\(\Delta E\)) by instrumentally measured color parameters \(L\), \(a\), and \(b\), (**b)** texture measured as maximum force (hardness, \(F_{\textit{max}}\), N), (**c**) scores for total sensory quality (scaleThe kinetic reaction rates for color change of OD\({}_{\text{SY\;Whey}}\) and OD\({}_{\text{Water}}\) samples did not present statistically significant differences (\(p<0.05\)) (Table 3). Additionally, no statistically significant differences were observed for OD\({}_{\text{Water}}\) and OD\({}_{\text{SY\;Whey}}\) samples at 5-10 \({}^{\circ}\)C (\(p<0.05\); Table 3). The activation energy \(E_{a}\) for the color degradation of OD\({}_{\text{SY\;Whey}}\) and OD\({}_{\text{Water}}\) samples were calculated as 28.36 and 9.14 kJ/mol, respectively. The texture degradation rates for OD\({}_{\text{SY\;Whey}}\) samples were significantly lower than the texture degradation rates for OD\({}_{\text{Water}}\) samples (\(p<0.05\)). However, the storage temperature effect on texture was not significant for OD\({}_{\text{SY\;Whey}}\) samples. The activation energy \(E_{a}\) for texture degradation of samples ranged from 24.06 (OD\({}_{\text{Water}}\)) to 36.40 (OD\({}_{\text{SY\;Whey}}\)) kJ/mol, respectively. The vitamin C loss rates for OD\({}_{\text{SY\;Whey}}\) samples were significantly lower (up to 40%) than the respective the vitamin C loss rates for OD\({}_{\text{Water}}\) (\(p<0.05\)). The storage temperature effect on vitamin content was significant for both OD\({}_{\text{SY\;Whey}}\) and OD\({}_{\text{Water}}\) samples (\(p<0.05\)). The activation energy \(E_{a}\) ranged from 36.98 (OD\({}_{\text{Water}}\)) to 47.86 (OD\({}_{\text{SY\;Whey}}\)) kJ/mol, respectively. Finally, the reaction rate constants for sensory quality loss of OD\({}_{\text{SY\;Whey}}\) and OD\({}_{\text{Water}}\) samples were not significantly different at temperatures studied. \(E_{a}\) ranged from 20.32 (OD\({}_{\text{SY\;Whey}}\)) to 33.48 (OD\({}_{\text{Water}}\)) kJ/mol (Table 3). In Figure 3, pictures of pumpkin, freshly cut and OD processed at the reference processing conditions (55 \({}^{\circ}\)C for 120 min) in solution of strained yoghurt whey or water (OD\({}_{\text{SY\;Whey}}\), OD\({}_{\text{Water}}\)), are illustrated. In Figure 4a\({}_{1}\),a\({}_{2}\) the scores given for color, in Figure 4b\({}_{1}\),b\({}_{2}\) scores given for texture, and in Figure 4c\({}_{1}\),c\({}_{2}\) scores given for flavor of OD\({}_{\text{SY\;Whey}}\) (figure coding, Index 1) and of OD\({}_{\text{Water}}\) (Index 2) of pumpkin cuts samples are presented. Figure 4: _Cont._  
Figure 3: Pictures of pumpkin cuts (**a**) fresh, (**b**) osmotically treated in SY Whey (OD\({}_{\text{SY\;Whey}}\)), and (**c**) osmotically treated in water (OD\({}_{\text{Water}}\)). According to sensory panelists, \(\text{OD}_{\text{SY\,Whey}}\) and \(\text{OD}_{\text{Water}}\) samples had received similar scores for flavor, initially and during storage. Both OD processed samples were described to retain to a significant level, the initial, fresh-like fruit aroma, and flavor during storage. \(\text{OD}_{\text{SY\,Whey}}\) samples had received significantly higher scores for texture (at the three storage temperatures) and color (at storage temperatures, 5 and 10 \({}^{\circ}\)C), initially and during storage. \(\text{OD}_{\text{SY\,Whey}}\) samples were characterized by improved texture, initially and during storage (high scores for texture and increased hardness values) (Figure 3a-c).