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The bread-making quality of rice flour was evaluated by conducting baking tests using strong wheat flours blended with various quantities of rice flour containing 15% gluten (rice flour). The dough properties and bread qualities obtained from these blends were analyzed. The characteristics of dough and bread changed according to the increase in the blended percentage of rice flour used. The water absorption of blends increased rapidly and the Farinograph characteristics were similar to those of weak flour in that the dough became less pliable and more fragile. The gas retention properties of the dough evaluated using the vacuum expansion method and gassing power after 2 h of fermentation decreased greatly. The appearance and crumb grain of the bread became rough, and the specific loaf volume (SLV) decreased. The upper crust was slightly reddish white, and the crumb grain was somewhat dusty. The sugar and amino acid contents in the bread decreased and the amount of maltose, glutamate, glycine, alanine, and phenylalanine decreased drastically. The texture of the bread was very soft at first, however, the bread rapidly hardened when stored. During the storage, the bread had high cohesiveness and showed high recovery when compressed.

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The present study demonstrated that flavonol 3-glucosidase (f3g) is an important cause of bitter taste generation in tartary buckwheat (Fagopyrum tataricum) flour using the f3g complement test. To screen the f3g deletion line, which must have little bitter taste, an in-gel method to detect individual f3g isozymes in tartary buckwheat seeds was developed. The f3g isozymes in tartary buckwheat seed were stained using a rutin-copper complex on the native-PAGE gel. This method was able to clearly detect as little as 1.4 ng of individual f3g isozymes within 20 min following electrophoresis. With this method, screening of the f3g deletion line can be conducted efficiently and will result in a better taste in tartary buckwheat flour.

The bread-making quality of two domestic flours, Hokushin and Haruyutaka, blended with Victoria INTA, an ES flour, and Harunoakebono, domestic strong flour, was investigated. The baking quality of Hokushin, representative middle-strong flour in Hokkaido, and Haruyutaka, semi-strong flour with prehavest sprouting damage, which is unsuitable domestic flours for bread production, were both improved by blending with Victoria INTA. The results were as follows :(1)With an appropriate blend of ES flour, it was proven that domestic flours with poor bread making quality could be improved and given properties for bread making that are generally attributed to foreign hard flours.(2)The estimation of specific loaf volume of bread made from blends of the flours in this experiment was possible with the following multiple-regressive equation ;X1=0.157 X2+0.251 X3+ 2.38 (X1:specific loaf volume (ml/g) ; X2 : protein content of flour (%) , X3 : breaking force of dough (N) ) . (3)Through analysis by the use of this equation, it was proven that the improvements of bread making quality by blending poor domestic flours with ES flour were principally due to the progress of physical property of the dough, an increase in the breaking force of the dough. (Received Mar. 3 , 2003 ; Accepted May 19, 2003) More than one million tons of flour is used to make bread every year in Japan, and the county is nearly dependent on the importation of wheat for bread production. Although a little wheat for bread making is produced in Japan, it is usually less than 10, 000 tons, and much of it frequently has preharvest sprouting damage that degrades the bread making quality. Since, especially, the Japanese main variety of bread wheat, Haruyutaka, is semistrong wheat with the gluten that is somewhat weaker than strong wheat and it has weak characteristic for the preharvest sprouting damage, the bread making quality of commercial flour of Haruyutaka is rather lower than ordinary strong flour. In general, it is necessary that flour for bread making has strong gluten. However, the preharvest sprouting damage causes partial gluten decomposition by the endo-protease and the softening of gluten and physical property of dough is brought about as the result1), which seem to cause the drastic degradation of bread making quality of Haruyutaka having somewhat weak gluten. The majority of Japanese flours are middle-strong flour with medium strength of gluten that is used to make a Japanese wheat noodle , Udon. Because , Japanese have traditionally eaten the flour as Udon, and Japanese climate is not generally suitable for the cultivation of bread wheat. As the result, the high quality flour for bread is hardly produced in Japan, and it is difficult to make bread of good quality with domestic flours.However, there is a strong consumer demand for bread made with domestic flour in Japan. Some advances are currently being made in breeding for bread wheat in Japan, which may ultimately lead to a better quality bread ; however, it is expected to

Potato pulp is an agricultural by-product of the starch industry. To use it for bread-making, experiments were conducted to evaluate the bread-making quality of doughs to which intact potato pulp (IPP) and potato pulp fermented by Rhizopus oryzae NBRC 4707 (FPP) had been added. The use of IPP significantly decreased the baking quality of wheat flour by degrading the dough's physical properties and lowering the gas retention of the dough. The bread-making quality of dough to which potato pulp that had been fermented for 2 days by R. oryzae had been added was significantly better than that of dough to which IPP had been added.In particular, the bread quality, such as specific loaf volume (SLV), aspect and crumb grain, except for staling and color, were good. Increase of the dough's gas retention and gassing power were the primary reasons for its improvement. They seemed to be related to the decomposition of starch and fiber in potato pulp and the moderate pH Iowering of potato pulp by organic acid formed in the fermentation process by R. oryzae. These results suggested that the fermentation with R. oryzae was useful because it improved the utility of potato pulp for bread-making.Keywords: bread, potato pulp, bread-making quality, fermentation, Rhizopus IntroductionPotatoes are a principal rotation crop in Hokkaido, the northernmost island of Japan. Each year, about two million tons of potatoes are produced, and the starch industry uses about one half of them. During the production of starch from potatoes, a large amount of potato pulp is produced, which represents about 10% of the raw material. Potato pulp contains starch, cellulose, hemicelluloses, pectin, protein, amino acid and minerals and has a relatively high nutrient value. Thus, this potato pulp is noticed as the source of compost, fertilizer, a microorganism medium, a dietary fiber, etc (Dongowski et al., 1993; Klingspohn and Schtigerl, 1993;Trojanowski et al., 1995;Mayer and Hillebrandt, 1997). Recently, the functionality of potato pulp as a very cheap dietary fiber has often been noted in Japan. However, though this potato pulp is used in part as compost and organic fertilizer in Japan, it is not sufficiently utilized. The main reasons seem to be as follows: (1) if left untreated, spoilage is very fast; and (2) when utilized for food, the quality of the food is significantly reduced (Mayer and Hillebrandt, 1997).Therefore, to develop the utility of this potato pulp for various food, we examined its treatment with various microorganisms and found that a filamentous fungus, R.oryzae NBRC 4707, caused the potato pulp to ferment rapidly and formed high amounts of lactic acid and ethanol, and that, as a result, the preservation and flavor were improved (Oda et al., 2002;Saito et al., 2003). In this study, to develop a low-cost fiber rich bread, the use of this FPP in bread-making was examined. Experiments were conducted to determine the baking quality of doughs to which various amounts of IPP had been added (various IPP doughs

We examined the relationship between flour/starch properties and the yellow alkaline noodle (YAN) color or physical properties of Kitanokaori, a Hokkaido hard wheat cultivar, and four other samples. Regarding flour properties, Kitanokaori had low polyphenol oxidase (PPO) activity and low amylose content. A time-course experiment showed that a raw noodle sheet made from Kitanokaori had less reduction in color brightness than sheets made from other flour samples that had high PPO activity. This finding suggests that the brightness stability of the Kitanokaori noodle is caused by its low PPO activity. Regarding physical properties and texture, Kitanokaori had high breakdown and low setback viscosity, as measured with a Rapid Visco Analyzer (RVA), and high elastic indices of the starch gel and YAN as a result of the low amylose content. In assessment of the eating quality, the total score of YAN made from Kitanokaori was higher than that obtained from other samples. This was because Kitanokaori had high elasticity and smoothness, which was related to its low amylose content, and the reduction in hardness related to low amylose was suppressed, since the protein properties of Kitanokaori are relatively strong. The results of comparison demonstrated that the superior qualities of YAN made from Kitanokaori could be attributed to the low PPO activity and low amylose content of the flour.

The objective of this study was to evaluate the effects of high-molecular-weight glutenin subunits with different protein contents on the quality of flour. The flour properties of near isogenic lines (NILs), which were substituted with HMWG subunits at the Glu-B1 or Glu-D1 allele, were investigated with four levels of protein content. The effect of the addition of subunits 20 at the Glu-B1 to subunits 5+10 at the Glu-D1 allele on bread-making quality was poor. The strength of the dough was only slightly affected despite the increase in protein content. Subunits 2+12, subunits 4+12 and subunits 2.2+12 at Glu-D1 allele had little effect on dough properties when various protein contents were used, compared with subunits 5+10. Subunits 2.2+12 had the most negative effect on the physical properties of the dough at the Glu-D1 allele. These results clearly showed that each HMWG subunit affected the properties of the dough differently, according to the increase of protein content.Keywords: wheat, high-molecular-weight glutenin, protein content, qualityThe quality and quantity of protein in the flour are important to bread-making quality. Loaf volume is greatly influenced by flour protein content. However, when the quantity of protein is identical, differences in its quality can produce differences in the quality of bread. Flour protein consists of aggregates of glutenin, gliadin, globulin, and albumin. High-molecular-weight glutenin (HMWG) subunits, which are encoded by the Glu-1 loci on the long arms of group 1 chromosomes, play an important role in bread-making quality (Payne et al., 1980). Alleles at three Glu-1 loci represent different effects on bread-making quality. HMWG subunits 5+10 coded by Glu-D1 show a much larger effect on the physical properties of dough than subunits 2+12 (Payne et al., 1981, Moonen et al., 1982. Most Japanese wheat cultivars, which show a poor bread-making quality, shared subunits 2+12, 2.2+12, and 4+12 at Glu-D1 (Nakamura et al., 1999). Near isogenic lines (NILs) are useful tools for analyzing the effects of HMWG subunits because they have the same genetic backgrounds except for some specific characteristics (Payne et al., 1987, Lawrence et al., 1988.We reported the different effects of HMWG subunits with identical protein content on bread-making quality using NILs (Takata et al., 2000). However, the effect of each HMWG subunit with varying protein content on bread-making quality is not fully understood. The objective of this study was to evaluate the effects of HMWG subunits with different protein contents on the physical properties of dough. The flour properties of four kinds of NILs, which were substituted with HMWG subunits at the Glu-B1 allele, and three kinds of NILs, which were substituted with HMWG subunits at the Glu-D1 allele, were investigated with four levels of protein content. The difference in quality was determined among the HMWG subunits which had similar properties. Materialsand and MethodsPlant materials Seven kinds of NILs of the wheat cultivar Harunoakebono, which we...