Influence of storage on enzymes in rice grains

Chrastil, Joseph

doi:10.1021/jf00095a008

Cited by 27 publications

(14 citation statements)

References 7 publications

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“…Starch degradation is a complex biochemical process regulated by plant hormones and other metabolites such as sugar availability (Umemura et al, 1998;Loreti et al, 2003). In rice, amylase activity is highly induced during germination (Tanaka et al, 1970); however, this activity begins to appear even earlier, during seed maturation (Baun et al, 1970), and continues even in dry seeds to affect the quality of stored rice grains (Shin et al, 1985;Chrastil, 1990). This study highlighted the importance of amylase activity during germination and early seedling growth under flooded conditions.…”

Section: Discussionmentioning

confidence: 86%

Mechanisms associated with tolerance to flooding during germination and early seedling growth in rice (Oryza sativa)

2008

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Under low oxygen stress, tolerant genotypes germinate, grow faster and more seedlings survive. They maintain their ability to use stored starch reserves through higher amylase activity and anaerobic respiration, have higher rates of ethylene production and lower peroxidase activity as germinating seeds and as seedlings. Relevance of these traits to tolerance of flooding during germination and early growth is discussed.

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Section: Discussionmentioning

confidence: 86%

Mechanisms associated with tolerance to flooding during germination and early seedling growth in rice (Oryza sativa)

2008

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“…Freshness of rice was measured using rice freshness analyzer (Shinsensa, Satake Corporation). The instrument measures the activity of peroxidase as an indicator of the degree of freshness of rice (Chrastil ; Chen and Chen ). The measurements were conducted three times and the average values were presented.…”

Section: Methodsmentioning

confidence: 99%

Physicochemical Properties and Determination of Key Instrumental Quality Measurement Parameters of Frozen‐Cooked Rice by Correlating Consumer Acceptance

Kwak

Kim

Jeong

2015

Journal of Food Quality

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Physicochemical properties and consumer evaluation of frozen-cooked rice made in five rice varieties were investigated. Rice quality evaluation, physicochemical analyses, rapid viscometer analysis, texture measurements and mechanical sensory measurements were conducted. Consumer acceptance test was conducted with 51 consumers. Consumer acceptance ratings were highly correlated with hardness (r = −0.849) and stickiness (r = 0.958) of texture. Toyo taste value was highly correlated with consumer acceptance (r = 0.726), but eating quality measurement was not correlated with consumer acceptance (r = −0.018). Partial least square regression between mechanical parameters and consumer acceptance ratings showed which mechanical measurements have more influence on the determination of consumer acceptance of frozen-cooked rice. There were two positive instrumental indicators -ratio of cracked kernel and stickiness -and two negative onesbreakdown of rapid viscometer analysis and hardness. These mechanical parameters can be used as primary indices to screen rice varieties for high quality frozencooked rice. PRACTICAL APPLICATIONSThere were many mechanical indicators in determining the quality of raw rice and cooked rice. However, there was no study that indicates that mechanical indicators are the key factors representing consumer acceptance of frozen-cooked rice in the overall aspects of these indicators. Four mechanical indicators -ratio of cracked kernel, stickiness, hardness and breakdown of rapid viscosity analysis -showed higher influence on the consumer acceptance of frozen-cooked rice. Applying these indicators would reduce the amount of cultivar screening efforts to select proper rice varieties for frozen-cooked rice processing.

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“…Degradation or complexation of amylose with another component, which resulted in unavailability of amylose to interact with iodine, may contribute to the low amylose content in the yellowed rice. α-Amylase, a starch-hydrolyzing enzyme retaining significant activity after harvest in rice (Chrastil 1990a(Chrastil , 1993a, may hydrolyze amylose under the experimental conditions. On the other hand, oryzenin, a rice storage protein, interacts with amylose or amylopectin during preharvest maturation and storage (Chrastil 1990b(Chrastil , 1991(Chrastil , 1993b.…”

Section: Structural Characterizationmentioning

confidence: 99%

Properties and Structures of Flours and Starches from Whole, Broken, and Yellowed Rice Kernels in a Model Study

Wang

Shephard

et al. 2002

Cereal Chem

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Cereal Chem. 79(3):383-386The objective of this study was to compare the structure and properties of flours and starches from whole, broken, and yellowed rice kernels that were broken or discolored in the laboratory. Physicochemical properties including pasting, gelling, thermal properties, and X-ray diffraction patterns were determined. Structure was elucidated using high-performance sizeexclusion chromatography (HPSEC) and high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The yellowed rice kernels contained a slightly higher protein content and produced a significantly lower starch yield than did the whole or broken rice kernels. Flour from the yellowed rice kernels had a significantly higher pasting temperature, higher Brabender viscosities, increased damaged starch content, reduced amylose content, and increased gelatinization temperature and enthalpy compared with flours from the whole or the broken rice kernels. However, all starches showed similar pasting, gelling, thermal properties, and X-ray diffraction patterns, and no structural differences could be detected among different starches by HPSEC and HPAEC-PAD. α-Amylase may be responsible for the decreased amylopectin fraction, decreased apparent amylose content, and increased amounts of low molecular weight saccharides in the yellowed rice flour. The increased amount of reducing sugars from starch hydrolysis promoted the interaction between starch and protein. The alkaline-soluble fraction during starch isolation is presumed to contribute to the difference in pasting, gelling, and thermal properties among whole, broken, and yellowed rice flours.

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Influence of storage on enzymes in rice grains

Cited by 27 publications

References 7 publications

Mechanisms associated with tolerance to flooding during germination and early seedling growth in rice (Oryza sativa)

Mechanisms associated with tolerance to flooding during germination and early seedling growth in rice (Oryza sativa)

Physicochemical Properties and Determination of Key Instrumental Quality Measurement Parameters of Frozen‐Cooked Rice by Correlating Consumer Acceptance

Properties and Structures of Flours and Starches from Whole, Broken, and Yellowed Rice Kernels in a Model Study

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