In this study, baked rice donuts with added psyllium seed husk were manufactured and their quality and retrogradation characteristics were investigated. Control (Con) was made only with wheat flour; Psyllium seed husk in the amount of 8, 12, 16 and 20 grams was added to make rice donuts (P8, P12, P16 and P20). Higher amounts of psyllium seed husk reduced the moisture loss and baking loss, and increased the moisture content and water holding capacity of the donuts. The specific volume of Con was the highest of all the groups. As the amount of psyllium seed husk increased, the lightness and yellowness of the crumb decreased, and the redness of the crumb increased. Hardness also increased as the amount of psyllium seed husk increased. The hardness of P16 was the most similar to that of Con. The scanning electron microscopy images also identified that the structure of the donuts got denser as the amount of psyllium seed husk increased. Rate constant (k) of the rice donuts with psyllium seed husk were lower than that of Con. In conclusion, it is considered that P16 is the sample that is the most similar to Con in terms of texture, but the retrogradation was more retarded in P16 than Con.

Pumpkin (Cucurbita moschata Duch.) seed is rich in protein and sulfur-containing amino acids. Tofu is a protein gel made from soybean, which is rich in lysine but lacking in sulfur-containing amino acids. This study was conducted to investigate the use of pumpkin seeds in tofu manufacture and to determine its quality and texture characteristics. Soybean was substituted with pumpkin seed to obtain pumpkin seed tofu at the following ratios: 10%, 30%, 50%, and 70% (P10, P30, P50 and P70). Tofu manufactured only with soybean was used as a control (Con). The higher rate of pumpkin seed substitution significantly decreased the moisture content and yield rate (p<0.05). In contrast, pH value and turbidity were significantly increased with the increase in the amount of pumpkin seed (p<0.05). The L-value (81.74~79.04), a-value (－0.19~－3.89) and b-value (12.40~9.84) of samples significantly decreased with the amount of pumpkin seed (p<0.05). No significant difference in syneresis was found among the samples (p<0.05). The hardness tended to decrease with the increase in the amount of pumpkin seed. The microstructure analysis revealed that the pore size of pumpkin seed tofu was smaller than that of Con. These results suggest that the pumpkin seed protein is a useful ingredient in the manufacture of tofu. Increasing the pumpkin seed substitution levels improves the texture of tofu.

As the consumption of wheat has increased recently, the number of people who have digestive problems resulting from gluten in wheat has also increased. Teff has an attractive nutritional profile, as it not only gluten-free but also high in dietary fiber, protein, iron, and calcium. Seven samples were prepared for this study. The quality characteristics of gluten-free noodles were evaluated based on pH, salinity, water absorption, turbidity, color, texture properties, tensile strength, and SEM. The pH value was the highest in TF100 with a pH of 6.66 and the lowest in the control with a pH of 6.42. Salinity showed no significant difference among all samples, and it ranged from 0.02~0.04% (p<0.05). Water absorption was the highest in TFX with a value of 66.11%, and the lowest in the control with a value of 44.81%. Turbidity showed no significant difference among all samples, and it ranged from 0.14~0.21 O.D. (p<0.05). While the lightness and yellowness values decreased with an increase in teff flour content, the redness value tended to decrease. The color difference value was the highest in the sample group without gluten. Based on the texture profile analysis, the hardness was highest in the control with a value of 46.74 N and lowest in TF100 with a value of 18.34 N. The springiness showed no significant difference among all samples. The cohesiveness was highest in the control with a value of 0.92 N. The chewiness decreased with an increase in teff flour content. Although the control with gluten had the highest tensile strength at 3.42 kg/cm2, TFX had considerable tensile strength at 2.30 kg/cm2. This study demonstrated the processability of gluten-free noodles using teff flour.

An agricultural waste, pomegranate (Punica granatum L.) peel is known to be rich in total phenolics, which are flavonoids having strong antioxidant effects. In this study, pomegranate peel sponge cakes were prepared with varying ratios of freeze dried pomegranate peel powder (0, 1, 3, 5, 7% (w/w)) to examine their effect on quality characteristics, retrogradation and antioxidant activities. The specific gravity and moisture contents of 3, 5, and 7% pomegranate peel powder showed higher values than the control and 1% group. Addition of pomegranate peel powder increased the batter yield, while there was a significant decrease in baking loss. Increasing pomegranate peel powder content significantly decreased the lightness (L) (from 75.03 to 57.04) and pH values, whereas redness (a), yellowness (b) and ΔE were increased. Increasing concentration of the peel powder also increased the hardness and chewiness, while the springiness and cohesiveness decreased. Considering the Avrami equation, Avrami exponene (n) decreased from 1.8055 (control) to 0.9199 (7% pomegranate peel powder). Time constant (1/k) was lowest in control (at 17.64) and highest in the 7% group (39.84). Total polyphenol, flavonoid content, DPPH and ABTS radical scavenging activities significantly increased with increments in the content of pomegranate peel powder. A sensory evaluation by the 7-point scaling method showed that the sponge cake containing 7% pomegranate peel powder had the highest scores in color, flavor, sweetness, chewiness and overall acceptability. Hence, it is considered that sponge cake supplemented with 7% pomegranate peel powder is the most appropriate for quality characteristics, retrogradation and antioxidant activities.