Iodine-binding in Granular Starch: Different Effects of Moisture Content for Corn and Potato Starch

2008 ◽  
Vol 60 (3-4) ◽  
pp. 165-173 ◽  
Author(s):  
Debora Saibene ◽  
Henry F. Zobel ◽  
Donald B. Thompson ◽  
Koushik Seetharaman
2016 ◽  
Vol 8 (2) ◽  
pp. 61
Author(s):  
Virna Muhardina ◽  
Lukmanul Hakim ◽  
Zaidiyah Zaidiyah ◽  
Anshar Patria ◽  
Ismail Sulaiman

Sweet potato starch characteristic of local variety using heat moisture treatment with different level of moisture content and temperatureThe aim of this study is to modify local variety sweet potato starch (cream flesh color) in order to produce the optimal dried-noodle based starch. Native starch was maintained in varied water content (20%, 25% and 30%) and heat moisture treatment (HMT) by exposing the starch in high temperature, i.e. 90oC, 95oC, 100oC and 110oC for 3 h. The treated starch was analyzed using some parameters such as: swelling power, solubility, SEM (scanning electron microscopy) and total dietary fiber. Based on this study, swelling power shows decreasing as increasing both HMT temperature and starch water content. In other hand, solubility shows not significant different among all treatments. The treated-starch granule which is exposed to high temperature has irregular shape compared to granule in lower temperature. Furthermore, total dietary fiber shows significant different among the starch moisture content and the temperature treatment. HMT modification at 100oC and starch water content of 30% is chosen as the best results


2019 ◽  
Vol 33 (7) ◽  
pp. 915-937 ◽  
Author(s):  
Mahla Pirouzifard ◽  
Roghiye Ashrafi Yorghanlu ◽  
Sajad Pirsa

In this study, biodegradable/antioxidant active film based on potato starch was provided. Composite films of potato starch/Zedo gum/ Salvia officinalis essential oil were provided in different percents of Zedo gum (0.5–1.5%) and S. officinalis essential oil (0–500 µl). The characters of composite film, including physical, mechanical, and antioxidant properties were studied. The results showed that adding different amounts of Zedo gum and essential oil to starch film causes a significant decrease ( p < 0.05) in moisture content, solubility, and film water vapor permeability (WVP). The film containing 1.5% gum and 500 µl of essential oil had minimum moisture content, solubility, and WVP. Results showed that the addition of Zedo gum significantly increased the thickness and opacity of the films and reduced the transparency of the films. Increasing the essential oil is significant on the film opacity and leads to a decrease in the passage of light from the films. By adding different amounts of gum, the antioxidant content of the films was significantly increased compared to the control film (pure starch film). Also, increasing the concentration of essential oil in the film composition caused a significant increase in the antioxidant activity of the films ( p < 0.05). Modified starch films containing 1.5% gum (without essential oil) with 62.64% antioxidant activity and film with 1.5% gum and 500 µl essential oils with 68.35% antioxidant activity had the highest antioxidant activity. The addition of salvia essential oil and Zedo gum significantly decreased the elongation and tensile strength of the potato starch film ( p < 0.05). Finally, the potato starch composite film containing Zedo gum and salvia essential oil showed excellent physical and antioxidant properties and had an excellent ability to be used in the food packaging industry.


2017 ◽  
Vol 31 (4) ◽  
pp. 515-523 ◽  
Author(s):  
Sławomir Obidziński ◽  
Magdalena Joka ◽  
Olga Fijoł

Abstract This paper compares the densification work necessary for the pressure agglomeration of fine-grained dusty nettle waste, with the densification work involved in two-stage agglomeration of the same material. In the first stage, the material was pre-densified through coating with a binder material in the form of a 5% potato starch solution, and then subjected to pressure agglomeration. A number of tests were conducted to determine the effect of the moisture content in the nettle waste (15, 18 and 21%), as well as the process temperature (50, 70, 90°C) on the values of densification work and the density of the obtained pellets. For pre-densified pellets from a mixture of nettle waste and a starch solution, the conducted tests determined the effect of pellet particle size (1, 2, and 3 mm) and the process temperature (50, 70, 90°C) on the same values. On the basis of the tests, we concluded that the introduction of a binder material and the use of two-stage agglomeration in nettle waste densification resulted in increased densification work (as compared to the densification of nettle waste alone) and increased pellet density.


2009 ◽  
Vol 26 (No. 6) ◽  
pp. 413-420 ◽  
Author(s):  
A. Landfeld ◽  
M. Houška ◽  
K. Hoke

A precise design of the equipment for thermal sterilisation of rice, potato starch, and oat flakes by dry heat requires the knowledge of the relevant values of physical properties of these products. Water activity and enthalpy are presented as functions of temperature and humidity. Water activity was measured as a function of the moisture content and temperature in the desorption process that reproduces the real conditions existing during dry heat processing in the pilot rotating steriliser equipment. The heat of evaporation can be predicted from these data as a function of the moisture content of these products. DSC (differential scanning calorimetry) method was used for measuring the enthalpy of these products as a function of temperature during desorption of moist products starting from various levels of the moisture content. The total energy Ec necessary for heating the product and evaporation of the given amount of water can be calculated.


Author(s):  
Marcin Mitrus ◽  
Agnieszka Wójtowicz ◽  
Tomasz Oniszczuk ◽  
Ewa Gondek ◽  
Leszek Mościcki

Abstract The aim of the work was to investigate the effect of extrusion-cooking process conditions on the structure and pasting properties of starch extrudates. In addition, the extrudates structure was observed using scanning electron microscopy (SEM) and confocal laser microscopy (CSLM). Wheat, corn and potato starch were extrusion-cooked with different process parameters (moisture content, screw speed, process temperature) in a single screw extruder. Results showed influence of the process parameters on extruded starches pasting properties. Viscosity measurements indicated that water content during starch extrusion is more important than process temperature. The extrudates structure observed with scanning electron and confocal laser microscopes showed that the main effect of extrusion-cooking was loss of the crystalline structure of the starch and the formation of a cellular structure of the extrudates. In extrudates processed at higher starch moisture content reduced the quantity and diameters of created cells was observed.


Author(s):  
Yaoyao Li ◽  
Shaowei Liu ◽  
Xue Liu ◽  
Xiaozhi Tang ◽  
Jian Zhang

Abstract Starch isolated from sweet potato was subjected to different levels of HMT at 15, 20, 25, 30, and 35 %. HMT showed negligible effect on the swelling power of starch. The swelling power was decreased with the increasing of the initial moisture content of the starch. The apparent amylose contents of HMT starches decreased from 24.11 % to 20.56 % with the initial moisture content increasing from 15 % to 35 %. The pasting temperatures enhanced from 73.1 to 81°C (p < 0.05) with the rapidly digestible starch (RDS) contents decreasing from 86.97 to 70.24 % (p < 0.05). Avrami equation analysis showed that HMT reduced the rate of starch retrogradation. The Avrami exponents of native and HMT-35 starches were 0.70 and 0.98 with the recrystallization rates 0.22 and 0.10, respectively. HMT could restrain the starch retrogradation and these results could provide theoretical guidance on sweet potato starch modification.


1990 ◽  
Vol 53 (1) ◽  
pp. 72-74 ◽  
Author(s):  
REGINALD H. WALTER ◽  
SHIRLEY C. SEEGER

Refrigeration and the use of certain food additives were studied as optional means of influencing the water activity (aw) of a selection of ethnic foods in Hawaiian commerce. The aw was measured at 27.6 and 6.7°C. The former temperature did not result in any of the aw &lt;0.97, a value conducive to spoilage and the growth of Clostridium botulinum, whereas the latter temperature did not result in aw &gt;0.89, a value more in the vicinity of a biologically safe food environment. The foodstuff (Manapua) with the lowest gravimetric moisture content (35.9%) gave among the highest aw (0.88) at the lower temperature, thereby showing no relationship, necessarily, between total moisture content and aw. The lower temperature was recommended as the storage and holding temperature for the ethnic foods in the tropical environment. The additives (acetic, propionic and butyric acids, glycerol, propyleneglycol, potato starch, and Guar gum) did not have any appreciable impact on aw (at 26.7°C).


2013 ◽  
Vol 31 (No. 4) ◽  
pp. 347-354 ◽  
Author(s):  
M. Stasiak ◽  
M. Molenda ◽  
I. Opaliński ◽  
W. Błaszczak

The interrelations between moisture content and mechanical properties of dry and wet native starches of wheat, maize, and potato were investigated. Strength parameters of powders were tested using direct shear and ring shear tester. Carr indices and associated parameters were determined using a Hosokawa Powder Tester. Particle size distribution of powder was analysed using an Infrared Particle Sizer. Uniaxial compression test was conducted to determine the reaction of powder in a cylindrical probe to vertical load. Mechanical behaviour of the material was found to be changing with increasing moisture content. Mechanical behaviour of potato starch was found to be different from that of cereal starches, which may require different utilisation in some processes. &nbsp;


2016 ◽  
Vol 55 (7) ◽  
pp. 597-611 ◽  
Author(s):  
Magdalena Kristiawan ◽  
Laurent Chaunier ◽  
Guy Della Valle ◽  
Denis Lourdin ◽  
Sofiane Guessasma

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