scholarly journals Free fatty acids in rice bran during its storage after a treatment by twin-screw extrusion to prevent possible rapid hydrolytic rancidity of lipids

DYNA ◽  
2019 ◽  
Vol 86 (208) ◽  
pp. 177-181
Author(s):  
Beatriz Guevara Guerrero ◽  
Alejandro Fernández-Quintero ◽  
Juan Carlos Montero-Montero

This research studied the prevention of hydrolytic rancidity during the storage of rice bran stabilized by an extrusion process. A double screw extruder was used, set at 130° C in the barrel and a rotational speed of the screws programmed at 200 RPM. The moisture content of the bran was adjusted at 20%. The treated bran was stored, using two packing methods (with and without vacuum), at two ambient conditions (18° C – 70 % RH and 30° C - 78% RH) for a period of 8 weeks. The content of free fatty acids (FFA) in the rice bran was observed during the storage time period. The extruded treated rice bran stored at 18° C - 70% RH resulted in lower values of FFA in comparison with the values in the bran kept at 30° C - 78% RH. Vacuum packaging showed a significant disadvantage as compared to packaging without vacuum.

2013 ◽  
Vol 80 (3) ◽  
Author(s):  
Thelma G. Manning ◽  
Joseph Leone ◽  
Martijn Zebregs ◽  
Dinesh R. Ramlal ◽  
Chris A. van Driel

In order to eliminate residual solvents in ammunition and to reduce the emissions of volatile organic compounds to the atmosphere, the U.S. Army ARDEC has teamed with TNO in developing a new process for the production of solventless propellant for tank ammunition. To reduce the costs of solventless propellants production, shear roll mill and continuous extrusion processing was investigated. As described in this paper JA-2 a double base propellant cannot be processed without solvent by the extrusion process. An alternative JA-2 equivalent propellant was defined. The aim of this work is to demonstrate the manufacturing of this propellant by solventless continuous twin screw extrusion processing while maintaining gun performance characteristics of conventional JA-2 propellant. This is elucidated by explicitly researching the relationship between interior ballistic properties of the gun propellant and utilizing a continuous manufacturing process. Processing conditions were established, and the propellant was manufactured accordingly. The extruded propellant has the desired properties, which resulted in a comparable gun performance as the conventional JA-2 propellant.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Emil Sasimowski ◽  
Łukasz Majewski

The aim of this study was to investigate the effect of a new intensive plasticizing and mixing screw zone design on the effectiveness of the corotating twin-screw extrusion process for talc-filled polypropylene. The study determined the effect of the angle between the trilobe kneading elements forming the intensive plasticizing and mixing zone of the screws, the screw rotational speed, and the polypropylene/talc filling ratio on the characteristics of the extrusion process in a corotating twin-screw extruder EHP-2x20. The paper describes the experimental design and obtained results as well as the developed empirical models for selected variables of the extrusion process.


DYNA ◽  
2019 ◽  
Vol 86 (209) ◽  
pp. 298-303 ◽  
Author(s):  
Beatriz Guevara Guerrero ◽  
Juan Carlos Montero-Montero ◽  
Alejandro Fernández-Quintero ◽  
Yenny Jovana Rivera-Agredo ◽  
Bernardo Ospina-Patiño ◽  
...  

A ready-to-eat cereal processed by a twin-screw extrusion was formulated, using flour and bran from a quality protein maize (QPM) variety and a zinc biofortified rice. The effect of variation of the content of bran in the formulation on the physical quality of the extruded product was studied. The maize-rice meal mixtures contained rice and maize bran formulated at two levels, 25 and 30 % of the total; within the bran mixture the rice bran content was formulated at levels ranging from 0 to 10 %. Physical characteristics of the extrudates such as expansion ratio (ER) and crispness work indicator (WC), were determined. The treatments with lower content of rice bran showed a better behavior, in terms of the physical variables. The products with higher ER and lower WC had desirable sensorial characteristics. Analysis of the extrudates confirmed an increased content of Zn, lysine, tryptophan in relation to raw materials.


Extrusion ◽  
2014 ◽  
pp. 111-120 ◽  
Author(s):  
John R. Wagner ◽  
Eldridge M. Mount ◽  
Harold F. Giles

2012 ◽  
Vol 204-208 ◽  
pp. 4088-4092
Author(s):  
Ming Ming Zhang ◽  
Xiao Huan Liu ◽  
Chun Peng Wang ◽  
Li Wei Jin

The blend composite materials of bio-ethanol byproduct-Poly(lactic acid) (PLA) were produced by a twin-screw extrusion process. Effects of bio-ethanol byproduct (BEB) contents and different compatibilizers on properties of composite materials were investigated. The research showed that with the increase of contents of bio-ethanol byproduct, the mechanical properties decreased. The mechanical properties of composites were improved by adding the compatibilizers, especially the polypropylene grafted maleic anhydride (PP-MAH). When the PP-MAH content was 2.5%, the mechanical properties of the composite materials were superior to others.


1988 ◽  
Author(s):  
Dilhan M. Kalyon ◽  
Alexandros D. Gotsis ◽  
Costas G. Gogos ◽  
Christos Tsenoglou

2011 ◽  
Vol 393-395 ◽  
pp. 1203-1211
Author(s):  
Bing Du ◽  
Yan Li Jiao ◽  
Zhi Qiang Huang ◽  
Lian Kai Mao ◽  
Yuan Yuan Fan ◽  
...  

In order to increase the extraction rate of flavonoids from mungbean skin, twin-screw extrusion process was used as a pretreatment method. After optimizing conditions of twin-screw extrusion process, effects on ethanol extracting flavonoids were studied. Results revealed that the best extrusion conditions were: screw speed at 268r/min, extrusion temperature at 115~120°C, feed moisture at 17% and feeding rate at 726g/min. Under these conditions, the optimum condition for ethanol extraction of flavonoids was: using 38% ethanol solution at a material-liquid ratio of 1:20 at 77.5 °C with 2.5 h. The average extraction rate of flavonoids from mungbean skin was 3.14%, comparing to rate of un-extruded material 2.07%, extraction rate raised by 51.5%. This pretreatment can destroy the density structure of mungbean skin which has great effect on the increase of extraction rate of flavonoids.


1993 ◽  
Vol 115 (1) ◽  
pp. 118-123
Author(s):  
J. H. Conner ◽  
D. I. Bigio

In the field of plastic extrusion, the accurate feeding of materials to the extrusion process is an important issue. The end product quality is partially dependent upon the extruder receiving feed materials in the correct proportions. Therefore, the understanding of the relationship between the feeder and the extruder is very important. This paper presents and analyzes this relationship. The feeder is usually a separate and distinct item from the extruder. The feed materials and the environmental conditions may affect the flow rate of the reaction or blending process of the extrusion process. The variation of this feed material may cause the quality of the overall product to be beyond an acceptable quality. This paper shows that two feeder parameters, the period and amplitude of the feeder error, affect the composition of the materials throughout the extrusion process. Understanding the effect of these parameters will allow for the overall improvement in product quality. This paper also shows that the extrusion process is able to dampen the error of the feeder. In other words, by mixing a fluid element the average fluid composition will tend towards a nominal value. The fluid composition error associated with the fluid element will decay exponentially. This paper presents two models to describe phenomena described above. The first model is a theoretical description of an idealized mixing process with a time varying feeder error. The second model is an iterative mass transfer model representing a nonintermeshing twin screw extrusion process. An analysis of each of these models will demonstrate how the error of fluid composition reduces as a function of the amount of mixing.


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