Comparison of germination–parboiling, freeze–thaw cycle, and high pressure processing on the cooking quality of brown rice

2019 ◽  
Vol 42 (5) ◽  
Author(s):  
Yang Du ◽  
Songming Zhu ◽  
Hosahalli S. Ramaswamy ◽  
Hao Wang ◽  
Jian Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
Cooking Quality ◽  
Brown Rice ◽  
High Pressure Processing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

Comparison of Germination-Parboiling, Freeze-Thaw Cycle and High Pressure Processing on Phytochemical Content and Antioxidant Activity in Brown Rice Evaluated after Cooking and In-Vitro Digestion

2018 ◽  
Vol 14 (11-12) ◽  
Author(s):  
Yong Yu ◽  
Yang Du ◽  
Hosahalli S. Ramaswamy ◽  
Hao Wang ◽  
Xiuping Jiang ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
High Pressure ◽  
Brown Rice ◽  
In Vitro Digestion ◽  
High Pressure Processing ◽  
Phytochemical Content ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

Abstract Three treatments, namely germination-parboiling (PG), freeze-thaw cycle (FTC) and high pressure processing (HPP) were compared for phytochemical content and antioxidant activity of brown rice (BR). These were determined in raw (uncooked), cooked, and in-vitro digested BR and compared with those from untreated BR and white rice (WR). PG showed the highest retention of phytochemicals after cooking (87–100%) while it dropped to 59–72% with FTC and 64–76% with HPP. After in-vitro digestion, the highest amount of phenolics was found in PG-24 h and flavonoids in FTC for two cycles. The antioxidant activity, as determined by oxygen radical absorbance capacity and ABTS methods, showed the highest value to be associated with in-vitro digested sample of PG-24 h, and lowest in WR. The results of this study show that these three treatments could improve or retain the phenolic content and antioxidant activity in cooked BR after in-vitro digestion.

Dynamics of Texture Change and in Vitro Starch Digestibility with High-Pressure, Freeze-Thaw Cycle, and Germination-Parboiling Treatments of Brown Rice

2021 ◽  
Vol 64 (1) ◽  
pp. 103-115
Author(s):  
Hao Wang ◽  
Songming Zhu ◽  
Hosahalli S. Ramaswamy ◽  
Yang Du ◽  
Yong Yu ◽  
...  
Keyword(s):  
High Pressure ◽  
Glycemic Index ◽  
Amylose Content ◽  
Brown Rice ◽  
In Vitro Digestibility ◽  
White Rice ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

HighlightsFreeze-thaw cycle (FTC) treated brown rice texture was much closer to white rice texture.Both high-pressure (HP) and FTC treatment helped to moderate the bran layer of brown rice.FTC treatment of brown rice resulted in higher conversion to resistant starch.The glycemic index of treated rice correlated positively with the amylose/amylopectin ratio.Abstract. High-pressure (HP), freeze-thaw cycle (FTC), and germination-parboiling (GP) treatments were used to improve the texture characteristics and in vitro digestibility of starch in brown rice (BR). The texture of FTC-treated BR was the closest to the texture of white rice. Improved water absorption ratio, HP and FTC induced modification of the bran layer, and GP induced partial starch gelatinization were considered to be responsible for improving the texture of BR. All treatments improved the in vitro digestibility of BR starch, and FTC < HP < GP with respect to the order of increase. FTC treatment also resulted in the minimal glycemic index (GI), while GP treatment resulted in higher GI. In general, the amylose content was lower for untreated BR than for treated BR. Further, the HP, GP, and FTC treatments showed improved amylose/amylopectin ratios. HP and GP decreased the gelatinization enthalpy, while FTC increased it. GI had a positive correlation with amylose content and amylose/amylopectin ratio, while gelatinization enthalpy had a negative correlation. Keywords: Brown rice, Freeze-thaw cycle, Germination-parboiling, High pressure, Starch in vitro digestibility, Texture.

Quality Enhancement of Tapioca Starch Gel using Sucrose and Xanthan Gum

2017 ◽  
Vol 13 (8) ◽  
Author(s):  
Duenchay Tunnarut ◽  
Rungnaphar Pongsawatmanit
Keyword(s):  
Xanthan Gum ◽  
Quality Enhancement ◽  
Sucrose Content ◽  
Water Separation ◽  
Tapioca Starch ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Starch Gel

AbstractThe quality of starch gel could be enhanced by sugar and hydrocolloid. Sucrose (0, 10 % and 20 %) and xanthan gum (Xan) (0.3125 %) were added in the tapioca starch (TS) gels (25 %w/w TS and TS/Xan gels) for quality investigation. Sucrose increased gelatinization temperatures of starch mixtures. Moisture content and water activity decreased with increasing sucrose content and Xan addition. Freeze–thaw stability of TS and TS/Xan gels with and without sucrose was evaluated. Sucrose and Xan decreased water separation from repeated freeze–thaw cycles. A regression model for predicting water separation from Xan, sucrose and selected freeze–thaw cycle was developed and showed a good predictability. After keeping the TS and TS/Xan gels at 5 °C for 7 and 14 days, the hardness of TS and TS/Xan gels increased with increasing sucrose content but was retarded by adding Xan (p<0.05), suggesting Xan impeded the structure formation contributed from amylose molecule association during cold storage.

scholarly journals Research on Corrosion Damage and Bearing Characteristics of Bridge Pile Foundation Concrete under a Dry-Wet-Freeze-Thaw Cycle

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zhongju Feng ◽  
Jianwei Huo ◽  
Haibo Hu ◽  
Ruixin Zhao ◽  
Fuchun Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Pile Foundation ◽  
Loss Rate ◽  
Corrosion Damage ◽  
In Situ Test ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

This study investigated the corrosion damage and bearing characteristics of bridge pile foundations under a dry-wet-freeze-thaw cycle of composite salt in an alpine salt marsh area using an in situ test, laboratory test, and numerical simulations. The in situ test showed that the dry-wet-freeze-thaw cycle has little effect on the quality of the concrete specimens and rebar. The area of the rebar at a depth of 0.25 m had the highest corrosion rate of 91%. The application of epoxy resin on the surface improved erosion resistance. After one year of outdoor dry-wet-freeze-thaw cycle test, due to the interaction of compound salts, the quality of specimens is reduced under the denudation of chloride ions, while the mass of specimens is increased by the corrosion products formed under the joint action of carbonate and sulfate, resulting in less obvious change of specimen quality, the antierosion coefficient of the specimens decreased, the maximum loss rate of compressive strength was 38.2%, and the pile foundation began to deteriorate. The laboratory test showed that expansive substances, such as Friedel salt, appeared in the concrete specimens of pile foundation during 225 cycles of dry-wet-freeze-thaw cycles, the relative dynamic elastic modulus was reduced by 60.9%, the antierosion coefficient was reduced to 0.51, and the compressive strength loss rate was 65.9%. As such, the pile foundation was seriously damaged. The numerical simulation shows that, with an increase of the peeling thickness and the corrosion depth, the bearing capacity of the pile foundation will gradually decrease after 8 years. Without maintenance, the bearing capacity of a pile foundation will decrease by 34.45% in the 20th year.

scholarly journals Effect of freeze–thaw cycle on physical and mechanical properties and damage characteristics of sandstone

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Longxiao Chen ◽  
Kesheng Li ◽  
Guilei Song ◽  
Deng Zhang ◽  
Chuanxiao Liu
Keyword(s):  
Mechanical Properties ◽  
Shear Failure ◽  
Triaxial Compression ◽  
Physical And Mechanical Properties ◽  
Freeze Thaw ◽  
Damage Characteristics ◽  
Large Pore ◽  
Natural Rock ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

AbstractRock deterioration under freeze–thaw cycles is a concern for in-service tunnel in cold regions. Previous studies focused on the change of rock mechanical properties under unidirectional stress, but the natural rock mass is under three dimensional stresses. This paper investigates influences of the number of freeze–thaw cycle on sandstone under low confining pressure. Twelve sandstone samples were tested subjected to triaxial compression. Additionally, the damage characteristics of sandstone internal microstructure were obtained by using acoustic emission (AE) and mercury intrusion porosimetry. Results indicated that the mechanical properties of sandstone were significantly reduced by freeze–thaw effect. Sandstone’ peak strength and elastic modulus were 7.28–37.96% and 6.38–40.87% less than for the control, respectively. The proportion of super-large pore and large pore in sandstone increased by 19.53–81.19%. We attributed the reduced sandstone’ mechanical properties to the degenerated sandstone microstructure, which, in turn, was associated with increased sandstone macropores. The macroscopic failure pattern of sandstone changed from splitting failure to shear failure with an increasing of freeze–thaw cycles. Moreover, the activity of AE signal increased at each stage, and the cumulative ringing count also showed upward trend with the increase of freeze–thaw number.

Non-linear creep damage model of sandstone under freeze-thaw cycle

2021 ◽  
Vol 28 (3) ◽  
pp. 954-967
Author(s):  
Jie-lin Li ◽  
Long-yin Zhu ◽  
Ke-ping Zhou ◽  
Hui Chen ◽  
Le Gao ◽  
...  
Keyword(s):  
Damage Model ◽  
Creep Damage ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Linear Creep ◽  
Non Linear ◽  
Freeze Thaw Cycle ◽  
Creep Damage Model

scholarly journals Strength and Microscopic Damage Mechanism of Yellow Sandstone with Holes under Freezing and Thawing

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Huren Rong ◽  
Jingyu Gu ◽  
Miren Rong ◽  
Hong Liu ◽  
Jiayao Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pore Size ◽  
Power Function ◽  
Damage Mechanism ◽  
Uniaxial Compression Test ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Microscopic Damage

In order to study the damage characteristics of the yellow sandstone containing pores under the freeze-thaw cycle, the uniaxial compression test of saturated water-stained yellow sandstones with different freeze-thaw cycles was carried out by rock servo press, the microstructure was qualitatively analyzed by Zeiss 508 stereo microscope, and the microdamage mechanism was quantitatively studied by using specific surface area and pore size analyzer. The mechanism of weakening mechanical properties of single-hole yellow sandstone was expounded from the perspective of microstructure. The results show the following. (1) The number of freeze-thaw cycles and single-pore diameter have significant effects on the strength and elastic modulus of the yellow sandstone; the more the freeze-thaw cycles and the larger the pore size, the lower the strength of the yellow sandstone. (2) The damage modes of the yellow sandstone containing pores under the freeze-thaw cycle are divided into five types, and the yellow sandstone with pores is divided into two areas: the periphery of the hole and the distance from the hole; as the number of freeze-thaw cycles increases, different regions show different microscopic damage patterns. (3) The damage degree of yellow sandstone is different with freeze-thaw cycle and pore size. Freeze-thaw not only affects the mechanical properties of yellow sandstone but also accelerates the damage process of pores. (4) The damage of the yellow sandstone by freeze-thaw is logarithmic function, and the damage of the yellow sandstone is a power function. The damage equation of the yellow sandstone with pores under the freezing and thawing is a log-power function nonlinear change law and presents a good correlation.

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