Characterization and quantification of γ-oryzanol in grains of 16 Korean rice varieties

Waxy and non-waxy rice starches from japonica type Korean rice varieties were esterified with different levels of octenyl succinic anhydride (OSA), and the molecular structure of amylopectin (AP), digestibility, and emulsion stability were investigated. As OSA levels increased, the degree of substitution, granule size, peak and final viscosities, emulsion stability, and short chain of AP increased. However, the gelatinization temperature and enthalpy, and digestibility decreased. All OSA esterified starches showed a new band at 1723 cm−1, but maintained A-type crystallinity. The DP6-12 of AP in waxy rice starch (WRS) was higher than that in non-waxy rice starch (NRS) with increasing OSA levels. Because the amylose and long chain of AP accessed easily with OSA groups, the digestibility of NRS was lower than that of WRS. The emulsion stability was higher in WRS than in NRS. From the above results, it is suggested that amylose should have a higher affinity with OSA esterification than AP and that the emulsion stability should increase in WRS, but the digestibility should decrease in NRS after OSA modification.

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Testing the simulation capability of APSIM-ORYZA under different levels of nitrogen fertiliser and transplanting time regimes in Korea

Australian Journal of Experimental Agriculture ◽

10.1071/ea05363 ◽

2007 ◽

Vol 47 (12) ◽

pp. 1446 ◽

Cited By ~ 12

Author(s):

Xike Zhang ◽

Jae-Hong Lee ◽

Yahya Abawi ◽

Young-ho Kim ◽

David McClymont ◽

...

Keyword(s):

Management Practices ◽

Field Experiments ◽

Agricultural Research ◽

Cropping System ◽

Measured Data ◽

Rice Varieties ◽

Early Maturing ◽

Photoperiod Sensitive ◽

Korean Rice ◽

Management Issues

APSIM-ORYZA is a new functionality developed in the APSIM framework to simulate rice production while addressing management issues such as fertilisation and transplanting, which are particularly important in Korean agriculture. To validate the model for Korean rice varieties and field conditions, the measured yields and flowering times from three field experiments conducted by the Gyeonggi Agricultural Research and Extension Services (GARES) in Korea were compared against the simulated outputs for different management practices and rice varieties. Simulated yields of early-, mid- and mid-to-late-maturing varieties of rice grown in a continuous rice cropping system from 1997 to 2004 showed close agreement with the measured data. Similar results were also found for yields simulated under seven levels of nitrogen application. When different transplanting times were modelled, simulated flowering times ranged from within 3 days of the measured values for the early-maturing varieties, to up to 9 days after the measured dates for the mid- and especially mid-to-late-maturing varieties. This was associated with highly variable simulated yields which correlated poorly with the measured data. This suggests the need to accurately calibrate the photoperiod sensitivity parameters of the model for the photoperiod-sensitive rice varieties in Korea.

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Influence of sowing methods on biometric indicators of domestic and international rice varieties

E3S Web of Conferences ◽

10.1051/e3sconf/202124402029 ◽

2021 ◽

Vol 244 ◽

pp. 02029

Author(s):

R. Tellyaev ◽

M. Ergashev ◽

B. Kodirov ◽

A. Kholboev

Keyword(s):

Rice Varieties ◽

South Korean ◽

Korean Rice ◽

Selection Of

This article presents the results of a study on the introduction of South Korean rice varieties, the influence of transplanting methods on the biometric indicators of local and foreign varieties, as well as the selection of varieties adapted for transplanting method using mechanization.

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