Different Distributions of .ALPHA.-Glucosidases and Amylases in Milling Fractions of Rice Grains

Tsuyukubo, Mika; Ookura, Tetsuya; Mabashi, Yuka; Kasai, Midori

doi:10.3136/fstr.16.523

Cited by 12 publications

(16 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We here discuss the results for these two cultivars in comparison with the previous results for Koshihikari. To describe Koshihikari, we quoted part of the results of the distribution and enzyme behavior in Koshihikari from previous reports (Tsuyukubo et al, 2010;Tsuyukubo et al, 2012) (Fig. 6).…”

Section: Discussionmentioning

confidence: 99%

“…In our previous studies, we revealed the distribution of starch-degrading enzymes in rice grains and their elution behavior during cooking with a specific antibody against each enzyme, including α-glucosidase, α-amylases, β-amylase, pullulanase and isoamylase, in Koshihikari cultivars (Tsuyukubo et al, 2010;Tsuyukubo et al, 2012). We also showed that starch hydrolytic activities and reducing sugar production differ with cooking temperature among Koshihikari, Nipponbare, Habutaemochi, Yumetoiro and Milkyqueen cultivars .…”

Section: Introductionmentioning

confidence: 99%

“…Immunoblot For immunoblots, electrophoresed gels were transferred to nitrocellulose membranes (Bio-Rad) using a transblotting system (Nihon Eido, Tokyo, Japan) as described previously (Tsuyukubo et al, 2010). Transferred membranes were incubated in 20 mM Tris buffered saline (TBS, pH 7.5) containing 0.1% Tween-20 and 5% skim milk for blocking.…”

Section: -0%mentioning

confidence: 99%

See 2 more Smart Citations

Distribution of Starch-degrading Enzymes in Rice Grains of Different Cultivars and Elution Behavior during Cooking

Tsuyukubo

Ookura

Kasai

2013

FSTR

Self Cite

View full text Add to dashboard Cite

Rice grains contain starch-degrading enzymes, including α-glucosidases, α-amylases, β-amylase, pullulanase and isoamylases. We investigated the distribution of these enzymes in raw rice grains, and their elution behavior during cooking in Nipponbare and Habutaemochi cultivars. Different distributions and elution behaviors were observed among the different cultivars. These results suggest that differences among cultivars with regard to activation and starch degradation by these enzymes during rice cooking should be taken into consideration.Keywords: starch-degrading enzymes, immunoblot, rice cooking, elution Abbreviations: PBSD medium, sodium phosphate buffer (pH 7.0) containing DTT and NaCl; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis *To whom correspondence should be addressed. E-mail: ookura@affrc.go.jp IntroductionRice (Oryza sativa) is a major food in Asian countries, including Japan. Extensive studies have been carried out to determine how preferable taste can be achieved in rice cooking. It was found that physical properties, such as stickiness and hardness (Okabe, 1979;Maruyama, 1991;Kainuma, 1992;Okadome et al., 1996;Okadome et al., 1999), and chemical components, such as sugars and amino acids, contribute to the taste of cooked rice (Matsuzaki et al., 1992;Tajima et al., 1992;Ikeda, 2001). The amounts of sugars (reducing sugars and oligosaccharides) and amino acids are correlated with the activities of starch-degrading enzymes and proteases, which are activated during cooking (Maruyama et al., 1981;Kasai et al., 2000;Maruyama, 2002). Kasai et al. measured the amounts of reducing sugars and free sugars, which remained in the rice grains or eluted into the cooking water at the point of soaking, heating and murashi duration. They revealed that reducing sugars and glucose showed the largest increase in a temperature range of 40 − 60℃ during cooking in both rice grains and cooking water. They reported this was due to the activation of enzymes to convert starch to reducing sugars in this temperature range. Mabashi et al. (2010) analyzed the hydrolytic activities of the endogenous starch-degrading enzymes for the soluble starch in the various cultivars, and revealed that 60℃ was the common key temperature in various cultivars for the production of glucose by endogenous enzymes.The enzyme isoforms that exist in dormant rice and degrade starch granules during germination are α-amylases (EC 3.2.1.1) (Mitsui et al., 1996;Yu et al., 1996), β-amylases (EC 3.2.1.2) (Matsui et al., 1975;Yamaguchi et al., 1999), isoamylase (EC 3.2.1.68) , pullulanase (EC 3.2.1.41) (Takeuchi et al., 1999) and α-glucosidases (EC 3.2.1.20) (Takahashi et al., 1971;Matsui et al., 1988). Two studies have demonstrated that rice grains contain more than 10 α-amylase isoforms (Daussant et al., 1983;Mitsui et al., 1996). These isoforms are classified into two groups based on their optimal temperatures: α-amylase I (70℃) and α-amylase II (37℃) (Mitsui et al., 1996). These α-amylase isoforms are strongly induced during germ...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Distribution of Starch-degrading Enzymes in Rice Grains of Different Cultivars and Elution Behavior during Cooking

Tsuyukubo

Ookura

Kasai

2013

FSTR

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, it was shown that RNAi-mediated suppression of α-amylase genes in ripening seeds resulted in fewer chalky grains under high-temperature conditions, and the extent of the decrease in the ratio of chalky grains was highly correlated to decreases in the expression of Amy1A, Amy1C, Amy3A and Amy3B. 32) Furthermore, Tsuyukubo et al (2010Tsuyukubo et al ( , 2012 36,37) have demonstrated that AmyI-1 (Amy1A) and AmyII-4 (Amy3D) proteins existed in the outer layers (100 to 80% fractions) of rice grain (cv. Koshihikari), while α-glucosidase and AmyII-3 (Amy3E) were mainly detected in the inner layers (80 to 0% fractions) by immunoblotting with the specific antibodies.…”

Section: Breaking Test Of Cooked Rice Of Perfect and Chalky Grainsmentioning

confidence: 99%

Characteristics of Opaque and Translucent Parts of High Temperature Stressed Grains of Rice

et al. 2013

View full text Add to dashboard Cite

Global warming is one of the most serious environmental problems we are having today. The average temperature of Japan actually increased about 1 C during the last 100 years. High temperature stress during rice ripening periods causes a decrease in not only grain yield but also grain appearance quality. The presence or absence of chalk appearance is an important quality characteristic in rice. It is widely known that the occurrence of chalky grains of rice including whitecore, white-belly, white-base and white-back kernels is increased by high temperature stress during grain filling. 1)Several research groups have investigated morphological properties of chalky grains, showing that abnormal starch granules were loosely packed in the chalky grains.2-7) The surface of round-shaped starch granules in the chalky grains caused by high temperature stress had so many small pits.3)Interestingly, the feature of the change of granule surface was similar to that occurring during germination.8) The examination of how the chalkiness of rice grains affects the cooking quality is also an important issue. The chalky grains exhibited their characteristic physicochemical properties of the cooked rice different from those of the perfect grains. [4][5][6][9][10][11] From the obtained results, they mentioned that the cooked/steamed rice of chalky grains had undesirable higher hard texture.12) The mechanism of grain chalkiness under high temperature stress is considerably complicated: disorder of photosynthesis, translocation efficiency, sourcesink relationship, and protein expression in ripening seeds may involve in such chalking mechanism. Interestingly however, it has been shown that the environmental temperature at the grain filling stage influenced the starch composition in rice grains. 5,[11][12][13][14][15][16][17] High temperature stress decreased the amylose contents and altered the fine structure of amylopectin, 13,16) suggesting that the unusual expression of

show abstract

“…Isoamylases can debranch glycogen, but rarely attack pullulan, while the pullulanase shows a reverse specificity. Several studies revealed that starch-debranching enzymes not only hydrolyze amylopectin in storage starch during germination, but also play essential roles in amylopectin biosynthesis (Ball et al, 1996;Kubo et al, 1999).In a previous study, we revealed the distribution of enzymes in dormant grains by employing a specific antibody against each enzyme, such as α-glucosidase (against an ONG2 specific peptide), α-amylase, and β-amylase (Tsuyukubo et al, 2010) antibodies. Having clarified the activity profiles of enzymes in rice grains (Mabashi et al, 2009), we encountered difficulty in measuring enzyme activity in cooking water, possibly due to a low abundance of enzymes.…”

mentioning

confidence: 99%

Elution Behavior Analysis of Starch Degrading Enzymes During Rice Cooking with Specific Antibodies

Tsuyukubo

Ookura

Tsukui

et al. 2012

FSTR

Self Cite

View full text Add to dashboard Cite

Rice grains contain starch degrading enzymes, including α-glucosidases, α-amylases, β-amylases, pullulanase and isoamylases. To investigate the elution behavior of these enzymes from rice grains into cooking water during rice cooking, we separated cooking water from rice grains after soaking (20℃) and when the temperature reached 40℃ and 60℃ during cooking. Immunological detection of these enzymes in rice grains and cooking water was carried out with SDS-PAGE and immunoblot. Bands corresponding to pullulanase, α-glucosidase, isoamylase 1, and α-amylase E were detected in both rice grains and cooking water at each temperature. Bands corresponding to α-amylases A + B and H were not detected in rice grains, but were detected in the cooking water at each temperature. The β-amylase band was detected in rice grains but was not detected in cooking water. These results suggest that the amount of enzyme eluted into cooking water depends on enzyme localization and quantity in rice grains.Keywords: rice, starch degrading enzymes, immunoblot, rice cooking, elution Abbreviations: PBSD medium, sodium phosphate buffer (pH 7.0) containing DTT and NaCl; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis *To whom correspondence should be addressed. E-mail: ookura@affrc.go.jp IntroductionRice (Oryza sativa) is a major food in Asian countries, including Japan. Extensive studies have been carried out to determine how a preferable taste can be achieved in rice cooking. It was found that physical properties such as stickiness and hardness (Maruyama, 1991;Kainuma, 1992), and chemical components such as sugars and amino acids contribute to the taste of cooked rice (Matsuzaki et al., 1992;Tajima et al., 1992;Ikeda, 2001). The amounts of sugars (reducing sugars and oligosaccharides) and amino acids correlate with the activities of starch-degrading enzymes and proteases, which are activated during cooking (Maruyama et al., 1981;Kasai et al., 2000;Maruyama, 2002).The enzyme isoforms present in dormant rice, which degrade starch granules during germination, include: α-amylases (EC 3.2.1.1) (Mitsui et al., 1996;Yu et al., 1996), β-amylases (EC 3.2.1.2) (Matsui et al., 1975;Yamaguchi et al., 1999), isoamylases (EC 3.2.1.68) (Fujita et al., 1999), pullulanase (EC 3.2.1.41) (Takeuchi et al., 1999), and α-glucosidases (EC 3.2.1.20) (Takahashi et al., 1971;Matsui et al., 1988). Two studies demonstrated that rice grains contain more than 10 types of α-amylase isoforms (Daussant et al., 1983;Mitsui et al., 1996). These isoforms are classified into two groups on the basis of their optimum temperature: α-amylase I (70℃) and α-amylase II (37℃) (Mitsui et al., 1996). These α-amylase isoforms are remarkably induced during germination (Alpi and Beevers, 1983; Perata et chi (Hokkaido University, Japan). The polyclonal antibody against isoamylase 1 was kindly provided by Dr. Nakamura (Akita Prefectural University, Japan).Rice Sample Brown rice (Oryza sativa L., cv. Koshihikari) was purchased from Uonuma in Niigata in 2008 and stored at 4℃ u...

show abstract

Different Distributions of .ALPHA.-Glucosidases and Amylases in Milling Fractions of Rice Grains

Cited by 12 publications

References 45 publications

Distribution of Starch-degrading Enzymes in Rice Grains of Different Cultivars and Elution Behavior during Cooking

Distribution of Starch-degrading Enzymes in Rice Grains of Different Cultivars and Elution Behavior during Cooking

Characteristics of Opaque and Translucent Parts of High Temperature Stressed Grains of Rice

Elution Behavior Analysis of Starch Degrading Enzymes During Rice Cooking with Specific Antibodies

Contact Info

Product

Resources

About