In the proposed squashed cooked rice grain method, a grain of cooked rice is mechanically compressed to 0.1 mm, and the initial staling of cooked white rice is qualitatively and quantitatively determined from image analysis and brightness measurements. The objective of this study was to apply this method to cooked brown rice and characterize the internal appearance of grain and staling of cooked brown rice for three rice varieties. The results showed that this method could be applied to cooked brown rice. A new indicator referred to as “cored rice”, in which the center of the rice grain is not well gelatinized and remains hard, was proposed. The following characteristics of the method were visually and quantitatively characterized: under the same cooking conditions as white rice with a short soaking time, “Kinnoibuki” low-amylose rice with high water absorbency, produced very little cored rice and suppressed staling; when rice was cooked after sufficient water absorption, no cored rice was formed for any brown rice, and the staling of low-amylose “Kinnoibuki” and “Takitate” rice was suppressed. The results of the squashed cooked rice grain method were highly correlated with the degree of gelatinization by the enzymatic method, suggesting that the observations obtained by this method reflect the state of starch gelatinization and retrogradation inside cooked rice grains.

In this study, we investigated the effects of temperature during the ripening period (August temperatures in the production area) on the appearance quality, enzyme activity, taste, and viscoelasticity of rice produced using the “Koshihikari” rice cultivar. (1) The percentage of cracked and broken grains increased with increase in temperature during the ripening period. (2) A positive correlation was found between α-amylase activity and the ratio of immature white grains (r=0.92). (3) The taste and hardness decreased with an increase in temperature during the ripening period.

The water content, sugar content, and physical properties of five commercially available sweet bean paste products were measured and sensory evaluations were conducted. The results showed that most commercially available sweet bean products had a water content of 35 %-50 %. The higher the water content of the sweet bean paste, the harder the texture of the paste, and this leads to reduced sweetness. Because the sweetness level perceived by consumers is influenced by the texture of the sweet bean paste, the amount of sugar to be added must be calculated based on the water content of the sweet bean paste. Generally, a higher water content disperses the sweet bean paste particles, increasing the fluidity and softness of the resulting paste. Conversely, the results obtained for commercially available sweet bean paste products was unexpected. To clarify the reasons for this discrepancy, sweet bean paste samples with adjusted water or sugar content were prepared using the same raw materials. The prepared samples were analyzed in the same manner as the commercially available products. The results showed that as the water content increased, the samples became softer and melted better in the mouth. There was no difference in texture of the prepared samples and the commercially available products. When the water content was adjusted to 40% and the sugar content was increased, the samples became softer, had a smoother texture, and melted better in the mouth. This suggests that the samples with 40 % water content, 40 % sugar content, and high palatability provide consumers with moderate hardness, better melting in the mouth, a smooth texture, and optimal sweetness when used as filling in Japanese sweets and sweetened buns. The “hardness” of the sweet bean paste and its effect on melting sensations in the mouth, texture, and moderate sweetness is an important factor affecting consumer preference. Our findings revealed a relationship between the water and sugar contents of sweet bean paste and consumer preference. In contrast, even at higher water content levels, some samples had the same hard texture as the commercially available products. The hardness of sweet bean paste is considered to be affected primarily by the extent to which the particles in the sweet bean paste are distributed. Therefore, the impact of the manufacturing process and raw materials on the hardness of sweet bean paste should be clarified further. Furthermore, the relationship between the dispersed state of the particles, the physical properties of sweet bean paste, and consumer preferences should be thoroughly investigated.

To investigate the changes in the characteristics of the main inorganic elements in wild game meat during cooking, and to compare the relationship between radiocesium and each inorganic element, the inorganic elements in cooked meat samples were determined after radiocesium analysis. Values for the mean food processing retention factor (F_r), i.e., the ratio of the amount of an element in cooked meat to the amount in raw meat, of K, Na, Mg, and P were 0.8, 0.9, 0.9, and 0.9 for grilling; 0.6, 0.6, 0.7, and 0.7 for boiling; and 0.5, 0.5, 0.7, and 0.7 for steaming, respectively. All of the elements were reduced after cooking. The F_r value was lower for boiling and steaming with water than for grilling. Values for the mean processing factor (P_f), i.e., the ratio of the concentration of an element in cooked meat to the concentration in raw meat, of K, Na, Mg, and P were 1.2, 1.2, 1.2, and 1.2 for grilling; 0.8, 0.8, 1.0, and 1.0 for boiling; and 0.8, 0.8, 1.1, and 1.1 for steaming, respectively. The concentrations of these elements were increased after grilling, and the P_f values were greater than 1.0. K, which was similar to the behavior of radiocesium in cooked meat, including F_r and P_f. The findings showed that K could serve as a proxy for assessing the characteristics of radiocesium in cooked meat.

Genome editing technology can be used to extensively modify genetic information in DNA, and such applications are expected to be widely applied in the fields of medicine and agriculture. In chickens, genome editing of primordial germ cells has made it possible to create genome-edited chickens, which may lead to improvements in breeds that have been difficult to achieve using conventional breeding methods. The development of products derived from genome-edited chickens for the market should be approached with caution, and identification of problems and consumer acceptance should be carefully considered.

The Tsushima-jidori are a native breed of chickens in Tsushima City, Nagasaki Prefecture, and have long been kept as egg-laying hens in garden poultry farms. In order to improve the egg-laying ability of Tsushima-jidori, they were crossed with red eggshell laying hens, which have higher egg-laying ability, and the egg-laying characteristics of the crossed hens were investigated. The crossbred chickens were found to have higher egg-laying ability than the Tsushima-jidori, a more elongated egg shape compared to the red eggshell laying hens, and an eggshell color of pink to almost reddish-brown. The general egg composition showed inherited characteristics of both Tsushima-jidori and red eggshell hens. The large yolk ratio is a characteristic of Tsushima-jidori hens, and hens resulting from crossbreeding with Tsushima-jidori hens inherited the same characteristics. Further, eggshell thickness and strength, and Haugh unit were improved by crossbreeding with red eggshell hens. These results suggest that crossbred Tsushima-jidori hens can inherit characteristics of the original Tsushima-jidori hens while exhibiting high egg-laying ability and producing distinctive eggs.