Amylopectin Fine Structure and Rice Starch Paste Breakdown

2001 ◽  
Vol 34 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Xian-Zhong Han ◽  
Bruce R. Hamaker
Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2419
Author(s):  
Yuheng Zhai ◽  
Jiali Xing ◽  
Xiaohu Luo ◽  
Hao Zhang ◽  
Kai Yang ◽  
...  

In this study, the effects of the addition of pectin (PEC) on the physicochemical properties and freeze-thaw stability of waxy rice starch (WRS) were investigated. As PEC content increased, the pasting viscosity and pasting temperature of WRS significantly increased (p < 0.05), whereas its breakdown value and setback value decreased. Differential scanning calorimetry showed that the addition of PEC increased the gelatinization temperature of WRS, but decreased its gelatinization enthalpy. Rheological measurements indicated that the addition of PEC did not change the shear-thinning behavior of WRS–PEC blends, and the storage modulus and loss modulus were positively correlated with PEC content. Moreover, the textural parameter of WRS decreased with the increase in PEC content. Furthermore, the addition of PEC decreased the transmittance of starch paste, but enhanced the freeze-thaw stability of WRS to some extent. These results may contribute to the development of WRS-based food products.


2016 ◽  
Vol 146 ◽  
pp. 253-263 ◽  
Author(s):  
Hongyan Li ◽  
Sangeeta Prakash ◽  
Timothy M. Nicholson ◽  
Melissa A. Fitzgerald ◽  
Robert G. Gilbert

2019 ◽  
Vol 59 ◽  
pp. 104709 ◽  
Author(s):  
Wenhan Yang ◽  
Xiangli Kong ◽  
Yuxue Zheng ◽  
Weixuan Sun ◽  
Shiguo Chen ◽  
...  

2009 ◽  
Vol 50 (1) ◽  
pp. 74-81 ◽  
Author(s):  
A.M. Matalanis ◽  
O.H. Campanella ◽  
B.R. Hamaker
Keyword(s):  

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ling Zhao ◽  
Chunfang Zhao ◽  
Lihui Zhou ◽  
Qingyong Zhao ◽  
Zhen Zhu ◽  
...  

Abstract Background The eating and cooking qualities (ECQs) of rice (Oryza sativa L.) are key characteristics affecting variety adoption and market value. Starch viscosity profiles tested by a rapid visco analyzer (RVA) offer a direct measure of ECQs and represent the changes in viscosity associated with starch gelatinization. RVA profiles of rice are controlled by a complex genetic system and are also affected by the environment. Although Waxy (Wx) is the major gene controlling amylose content (AC) and ECQs, there are still other unknown genetic factors that affect ECQs. Results Quantitative trait loci (QTLs) for starch paste viscosity in rice were analyzed using chromosome segment substitution lines (CSSLs) developed from the two cultivars 9311 and Nipponbare, which have same Wx-b allele. Thus, the effect of the major locus Wx was eliminated and the other locus associated with the RVA profile could be identified. QTLs for seven parameters of the starch RVA profile were tested over four years in Nanjing, China. A total of 310 QTLs were identified (from 1 to 55 QTLs per trait) and 136 QTLs were identified in more than one year. Among them, 6 QTLs were stalely detected in four years and 26 QTLs were detected in at least three years including 13 pleiotropic loci, controlling 2 to 6 RVA properties simultaneously. These stable QTL hotspots were co-located with several known starch synthesis-related genes (SSRGs). Sequence alignments showed that nucleotide and amino acid sequences of most SSRGs were different between the two parents. Finally, we detected stable QTLs associated with multiple starch viscosity traits near Wx itself, supporting the notion that additional QTLs near Wx control multiple characteristic values of starch viscosity. Conclusions By eliminating the contribution from the major locus Wx, multiple QTLs associated with the RVA profile of rice were identified, several of which were stably detected over four years. The complexity of the genetic basis of rice starch viscosity traits might be due to their pleiotropic effects and the multiple QTL hot spots. Minor QTLs controlling starch viscosity traits were identified by using the chromosome segment substitution strategy. Allele polymorphism might be the reason that QTLs controlling RVA profile characteristics were detected in some known SSRG regions.


2019 ◽  
Vol 204 ◽  
pp. 24-31 ◽  
Author(s):  
Keyu Tao ◽  
Cheng Li ◽  
Wenwen Yu ◽  
Robert G. Gilbert ◽  
Enpeng Li

2018 ◽  
Vol 2 ◽  
pp. e25583
Author(s):  
Magdalena Grenda-Kurmanow

In 2017 the author conducted an international survey among the conservators who have worked with herbaria collections, particularly paper conservators who treated historic herbaria. During the survey the author contacted 25 people from 9 countries. The participants were the conservators who either shared their experience through publications or whose conservation reports were available to the author. Participants were asked to recommend materials used in the conservation of historic herbaria and materials used on a daily basis to mount specimens. The aim of the survey was to list the materials that have direct contact with the surface of the specimens. Therefore the results concentrated mostly on adhesives. Acknowledging that materials recommended for conservation treatment may differ from those used for a typical mounting of a modern specimen, the author presented a traditional conservator’s approach that every modern object (including herbaria) may one day become a valuable part of heritage. This means that all materials used when working with herbaria should be reversible and DNA-safe. The survey revealed that most conservators recommend materials that are very popular in paper conservation: wheat starch paste and methylcellulose at different concentrations, however some suggested using animal glues such as gelatine or isinglass and mixtures of isinglass and starch paste. Other adhesives that were present in the results were two versions of hydroxypropylcellulose, Klucel G and Klucel E, rice starch, shofu, and different PVAs used for mounting (e.g. Hewit M218 and Jade 403). Many conservators expressed their negative approach to popular mounting materials and techniques of mounting by overall adhesion. The survey was a part of the project "Heritage preservation and ethnobotany. Analysis of the influence of conservation treatment on genetic material comprised in historic herbaria“ (project no. 2014/13/N/HS2/03118) funded by the National Science Centre in Poland. The results of the survey served as a basis for the next stage of the project, which was testing samples of herbarium specimens, 'treated' with the chosen materials, for the possible damaging influence on the DNA of specimens. The choice of materials based on the results of the survey, literature and availability of materials (some adhesives used for mounting some decades ago are no longer available). The herbarium samples were made of Arabidopsis thaliana and Fragaria vesca leaves, prepared for the project. After drying and 'treating' with conservation and mounting materials, the samples were artificially aged in a climatic chamber to imitate deterioration processes.


2021 ◽  
Author(s):  
Ling Zhao ◽  
Chunfang Zhao ◽  
Lihui Zhou ◽  
Qingyong Zhao ◽  
Zhen Zhu ◽  
...  

Abstract BackgroundEating and cooking qualities (ECQs) of rice (Oryza sativa L.) is one of the most important economic characters which affecting production and market value. The starch viscosity profile tested by Rapid visco analyzer (RVA) is the direct measure of ECQs that represents the changes in viscosity associated with starch gelatinization. RVA profiles of rice are controlled by a complex genetic system and affected by environment. It is necessary to identify genetic factors controlled the RVA profile characters for development of rice varieties with excellent ECQs. Although it is known that Waxy (Wx) is the major gene control the amylose content (AC) and ECQs, there still have other unknown genetic factors effecting on ECQs.ResultsQuantitative trait loci (QTL) for starch paste viscosity of rice was analyzed using chromosome segment substitution lines (CSSLs) developed from 9311 and Nipponbare with same Wx-b background. With this CSSLs, the effect of major locus Wx could be eliminated and the other locus associated with RVA profile could be identified. QTLs for seven traits of starch RVA profile were tested over 4 years in Nanjing, China. 310 QTLs were identified (from 1 to 55 QTLs for each trait). Among 136 repeated QTLs, 6 QTLs were stable and detected every year. In total of 26 marker intervals detected over 3 years or more, 13 showed pleiotropy with respect to controlling 2 to 6 starch RVA profile properties simultaneously. The stable QTL clusters which we mapped here were overlapped to some of the known starch synthesis–related genes (SSRGs). ConclusionsWithout the effect of major locus Wx, many QTLs associated with RVA profile of rice were identified and some of them were stable. Our study illustrated that the hereditary of rice starch RVA profile is complicated, pleiotropic effects and QTL hot spots are the key factors affecting starch RVA traits.


2010 ◽  
Vol 93-94 ◽  
pp. 675-678
Author(s):  
Varatus Vongsurakrai ◽  
Saiyavit Varavinit

Pregelatinized rice starch (Era-Gel ® ) was prepared by physical modification. The degree of pregelatinization was controlled to an appropriate level. With the addition of small amount of pregelatinized rice starch , a slightly sticky, damped mass was obtained. Pregelatinized rice starch was tested for a potential use as a tablet filler or binder in wet granulation process. Two hydrochlorothiazide formulations were compared. One formulation comprised HCTZ and PRS; the powder mixture was damped with water. The other formulation contained HCTZ, lactose as filter, corn starch as binder and also as tablet disintegrant. In the later case, the powder mixture was damped with starch paste. Both granulations were compressed on an instrumented tablet press. The tablets were evaluated for their hardness, friability, disintegration, and also dissolution. The results indicated that both formulations were comparable in all aspects. It dissolution was found to exceed the USP requirement. It was demonstrated that three components, i.e. , lactose, corn starch paste, and disintegrant could be replaced with only one single material, PRS. It was also found that PRS could perform well in acetaminophen tablet formulation which was a high-dose drug and tended to cap; however, small amount of extra binder and disintegrant were needed. It could be seen that PRS had a great potential use in wet granulation process.


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