In this study, we investigated the effects of germination treatment (water soaking) of six-rowed skin barley with different cleaning ratios, on 4-aminobutanoic acid (GABA) production and hardness after boiling. The results indicated that the germination treatment increased the amount of GABA in barley. Moreover, GABA accumulation increased as the amount of barley cleaning decreased. The optimal conditions for germination treatment of six-rowed skin barley, established from the relationship between GABA production and viable cell growth, were determined as water soaking at 25°C for 16 h. This treatment softened the barley after boiling, with a hardness to cleaning ratio of 80% (w/w’, weight remaining after cleaning) germinated barley equivalent to a ratio of 55% of the control barley. Using sensory evaluation, the boiled barley and rice products prepared from the germinated barley were established as soft and easy to eat. GABA, which increased by germination treatment, did not decrease between the boiling and retort treatment processes. These results suggest that the germination treatment increases the GABA content in six-rowed skin barley. Thus, this treatment shows great potential for application in the development of barley products with a reduced amount of barley cleaning.

The suitability of Japanese pear for dried fruit processing at different stages of maturity was compared. Fruit from the varieties ‘Kosui’ and ‘Hosui’ were selected at the usual harvesting time point, as well as one, two and three weeks beforehand. Fruit from the last harvest tended to be more fully ripened, showed decreased pulp firmness, and the Brix value, total sugar concentration and sucrose to total sugar ratio were higher when compared with fruit harvested at earlier stages of maturity. The pH of fruit from the last harvest, however, was about the same as fruit harvested earlier. All fruits were processed using the microwave irradiation of pulp method, followed by hot air drying. This produced high-quality semi-dried fruit, as demonstrated previously. Dried fruits from early harvests were dark in color with a slight hardening of the surface and with a higher breaking force than the dried fruits from the last harvest. Sensory evaluation using the ranking method was conducted among the dried fruits with different maturities. Dried fruits from the early harvests were significantly harder and less sweet than the dried fruits from the last harvest. Interestingly, however, the preference scores of appearance, hardness and taste of dried fruits from one and two weeks before the last harvest were not significantly different from those of dried fruits harvested last, in most cases. All dried fruits, regardless of maturity, showed similar color changes after 12 weeks in storage. We conclude that unripe Japanese pear harvested within about two weeks before the usual harvesting time point is suitable for the drying process. This finding could help to improve the use of fruits affected by typhoon-related fruit drop, and could also lengthen the processing period.

With their high isoflavone content, groundnuts are a novel potential source of isoflavones, but the effective use of this plant has not yet been fully investigated. Therefore, we examined the use of groundnuts as an ingredient in bread, an everyday food item, and evaluated changes in the composition of groundnut isoflavones during processing, as well as the effects of different bread-making methods on the isoflavone composition of the finished product. Significant differences were observed between breads prepared with and without the addition of groundnuts in terms of aroma and sweetness. When incorporated into bread, isoflavone glycosides from groundnuts were converted into their aglycones. This conversion, which may be mediated by β-glucosidase originating from wheat flour, was markedly enhanced in bread made using the sponge-dough method, as compared to the straight-dough method. With regard to sponge-dough production, fermentation in the refrigerator for 24 h resulted in increased conversion of isoflavone glycosides to aglycones relative to dough left to stand at room temperature for 2 h. The present finding that isoflavone glycosides from groundnuts were converted to aglycones in bread dough suggests that the use of groundnuts as a bread ingredient is an effective way to consume the components in their aglycone form.

Time-intensity (TI) assessment was applied for sweetness, sourness and strawberry flavor of commercial strawberry jams. Ten strawberry jams were selected out of 51 products available in Japan. The selected jams covered a wide range of soluble solids concentrations, colors and sensory characteristics. Eleven trained panelists evaluated the sensory attributes of each sample for 90 or 120 seconds using a sliding TI switch. The obtained average TI curves and the TI parameters demonstrated the characteristics of the dynamic flavor intensity of each sample when consumed. In general, the intensity of sweetness was higher in jams with higher concentrations of sugar. However, several jams, which varied widely in the range of soluble solids, had similar average TI curves for sweetness. Thus, sweetness was not decided by only the soluble solids. The data were subjected to principal component (PC) analysis, and PC 1 and PC 2 were interpreted as axes related to the intensities of sourness and sweetness, respectively. In contrast, time-related sensory parameters (i.e. total time and time to maximum intensity) of each attribute contributed to PC 3, indicating time-course assessment of sensory attributes could function in developing precise flavor profiling of strawberry jam.