scholarly journals Formation and Taphonomic Processes Affecting Starch Granules

Author(s):  
Amanda G. Henry
Author(s):  
Jean-Claude Jésior ◽  
Roger Vuong ◽  
Henri Chanzy

Starch is arranged in a crystalline manner within its storage granules and should thus give sharp X-ray diagrams. Unfortunately most of the common starch granules have sizes between 1 and 100μm, making them too small for an X-ray study on individual grains. There is only one instance where an oriented X-ray diagram could be obtained on one sector of an individual giant starch granule. Despite their small size, starch granules are still too thick to be studied by electron diffraction with a transmission electron microscope. The only reported study on starch ultrastructure using electron diffraction on frozen hydrated material was made on small fragments. The present study has been realized on thin sectioned granules previously litnerized to improve the signal to noise ratio.Potato starch was hydrolyzed for 10 days in 2.2N HCl at 35°C, dialyzed against water until neutrality and embedded in Nanoplast. Sectioning was achieved with a commercially available low-angle “35°” diamond knife (Diatome) after a very carefull trimming and a pre-sectioning with a classical “45°” diamond knife. Sections obtained at a final sectioning angle of 42.2° (compared with the usual 55-60°) and at a nominal thickness of 900Å were collected on a Formvar-carbon coated grid. The exact location of the starch granules in their sections was recorded by optical microscopy on a Zeiss Universal polarizing microscope (Fig. 1a). After rehydration at a relative humidity of 95% for 24 hours they were mounted on a Philips cryoholder and quench frozen in liquid nitrogen before being inserted under frozen conditions in a Philips EM 400T electron microscope equipped with a Gatan anticontaminator and a Lhesa image intensifier.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Rahmawati Rahmawati ◽  
Trimayasari Trimayasari ◽  
Ghozali Akhmad Mustaqim ◽  
Wening Dwi Prastiwi ◽  
Emas Agus Prastyo Wibowo

AbstractSoap facial cleanser is needed to keep the facial skin to keep them clean and healthy. The purpose of this study to make soap cleanser with natural materials such as hard water deposits leri. This is because the use of leri water starch or starch granules of fine particles contained in water leri dansel dust can shed the dead skin on the face because of the essential amino acids contained can regenerate skin cells. In addition, water leri can brighten the face because the leri water oryzanol contain substances that can update the development and formation of the pigment melanin, which is effectively to ward off ultraviolet rays. The process of making soap using the principle of saponification reaction, namely the reaction between the oil and the KOH/NaOH. Facial cleansing soap made in this study is solid soap. Based on the results of quality test, soap solid leri water has a pH of 11.1, saponification number is 33, the water content of 46% as well as respondents to the test aspects of aroma and foam shows good results so this water leri treatment can be an alternative solution to prevent the use of soap facial cleansers that contain harmful chemicals. Keywords: air leri, soap cleanser, saponification  AbstrakSabun pembersih wajah sangat diperlukan untuk menjaga kulit wajah agar tetap bersih dan sehat. Tujuan dari penelitian ini untuk membuat sabun pembersih wajah dengan bahan alami berupa endapan air leri. Penggunaan air leri ini dikarenakan butiran partikel starch atau pati halus yang terdapat dalam air leri dapat merontokkan debu dansel kulit mati pada wajah karena asam amino esensial yang terkandung dapat meregenerasi sel-sel kulit. Selain itu, air leri dapat mencerahkan wajah karena air leri mengandung zat oryzanol yang dapat memperbarui perkembangan dan pembentukan pigmen melanin, yang efektif guna menangkal sinar ultraviolet. Proses pembuatan sabun menggunakan prinsip reaksi saponifikasi, yaitu reaksi antara minyak dan KOH/NaOH. Sabun pembersih wajah yang dibuat dalam penelitian ini ialah sabun padat. Berdasarkan hasil uji mutu, sabun air leri padat memiliki pH 11,1, angka penyabunan sebesar 33 kadar air 46 kadar air 46 % serta uji responden terhadap aspek aroma dan busa yang menunjukkan hasil cukup baik sehingga pengolahan air leri ini dapat menjadi solusi alternative untuk mencegah penggunaan sabun pembersih wajah yang mengandung bahan kimia berbahaya. Kata kunci: air leri, sabun pembersih wajah, saponifikasi 


2013 ◽  
Vol 38 (10) ◽  
pp. 1920-1929
Author(s):  
Xiu-Shan TAN ◽  
Jian-Jie BI ◽  
Jin-Hua WANG ◽  
Bao-Xing YE

2018 ◽  
Vol 18 (1) ◽  
pp. 10-15
Author(s):  
Wang Yi-Wei ◽  
He Yong-Zhao ◽  
An Feng-Ping ◽  
Huang Qun ◽  
Zeng Feng ◽  
...  

In this study, Chinese yam starch-water suspension (8%) were subjected to high-pressure homogenization (HPH) at 100 MPa for increasing cycle numbers, and its effect of on the physicochemical properties of the starch was investigated. Results of the polarizing microscope observations showed that the starch granules were disrupted (i.e. greater breakdown value) after HPH treatment, followed by a decrease in cross polarization. After three HPH cycles, the crystallinity of starch decreased, while the crystal type remained unaltered. Meanwhile, the contents of rapidly digestible starch and slowly digestible starch were increased. On the contrary, resistant starch content was decreased. Our results indicate that HPH treatment resulted in reduction of starch crystallinity and increase of starch digestibility.


2021 ◽  
Vol 85 (3) ◽  
pp. 634-642
Author(s):  
Qiuyun Li ◽  
Sen Li ◽  
Xiao Guan ◽  
Kai Huang ◽  
Fengbo Zhu

ABSTRACT Soaking is an essential step in the processing of various rice products. In this study, the influences of vacuum soaking on hydration, steaming, and physiochemical properties of rice were investigated. Results showed that vacuum soaking accelerated water absorption as well as affected the mobility and density of water protons inside rice during soaking. Vacuum soaking could considerably shorten the optimal steaming time from 58 to 32 min and reduce the adhesiveness of steamed rice. Microstructure analysis of rice revealed that porous structure was formed on rice surface and the arrangement of starch granules became loosened after vacuum soaking. Moreover, vacuum soaking slightly reduced the relative crystallinity of rice starches without altering the crystalline type. The gelatinization temperature as well as the peak and trough viscosity was also decreased after vacuum soaking. Our study suggested that vacuum soaking was conducive to improve the soaking and steaming properties of rice.


1993 ◽  
Vol 39 (4) ◽  
pp. 367-376 ◽  
Author(s):  
T. A. McAllister ◽  
Y. Dong ◽  
L. J. Yanke ◽  
H. D. Bae ◽  
K.-J. Cheng ◽  
...  

The ruminal fungi Orpinomyces joyonii strain 19-2, Neocallimastix patriciarum strain 27, and Piromyces communis strain 22 were examined for their ability to digest cereal starch. All strains digested corn starch more readily than barley or wheat starch. Orpinomyces joyonii 19-2 exhibited the greatest propensity to digest starch in wheat and barley, whereas the digestion of these starches by N. patriciarum 27 and P. communis 22 was limited. Media ammonia concentrations were lower when fungal growth was evident, suggesting that all strains assimilate ammonia. Fungi formed extensive rhizoidal systems on the endosperm of corn, but O. joyonii 19-2 was the only strain to form such systems on the endosperm of wheat and barley. All strains penetrated the protein matrix of corn but did not penetrate starch granules. Starch granules from all three cereals were pitted, evidence of extensive digestion by extracellular amylases produced by O. joyonii 19-2. Similar pitting was observed on the surface of corn starch granules digested by N. patriciarum 27 and P. communis 22, but not on wheat and barley starch granules. The ability of ruminal fungi to digest cereal grains depends on both the strain of fungus and the type of grain. The extent to which fungi digest cereal grain in the rumen remains to be determined.Key words: ruminal fungi, cereal grain, starch digestion, ruminant.


2021 ◽  
Author(s):  
Rini Hardiyanti ◽  
S. Suharman ◽  
M. Zulham Efendi Sinaga ◽  
I. Putu Mahendra ◽  
Adrian Hartanto

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