Raw Material Moisture Research Articles

Special features of SCF solid extraction of natural products: deoiling of wheat gluten and extraction of rose hip oil

Supercritical CO2 extraction has shown great potential in separating vegetable oils as well as removing undesirable oil residuals from natural products. The influence of process parameters, such as pressure, temperature, mass flow and particle size, on the mass transfer kinetics of different natural products has been studied by many authors. However, few publications have focused on specific features of the raw material (moisture, mechanical pretreatment, bed compressibility, etc.), which could play an important role, particularly in the scale-up of extraction processes. A review of the influence of both process parameters and specific features of the material on oilseed extraction is given in Eggers (1996). Mechanical pretreatment has been commonly used in order to facilitate mass transfer from the material into the supercritical fluid. However, small particle sizes, especially when combined with high moisture contents, may lead to inefficient extraction results. This paper focuses on the problems that appear during scale-up in processes on a lab to pilot or industrial plant scale related to the pretreatment of material, the control of initial water content and vessel shape. Two applications were studied: deoiling of wheat gluten with supercritical carbon dioxide to produce a totally oil-free (< 0.1 % oil) powder (wheat gluten) and the extraction of oil from rose hip seeds. Different ways of pretreating the feed material were successfully tested in order to develop an industrial-scale gluten deoiling process. The influence of shape and size of the fixed bed on the extraction results was also studied. In the case of rose hip seeds, the present work discusses the influence of pretreatment of the seeds prior to the extraction process on extraction kinetics.

Supercritical fluid extraction of oil from millet bran

AbstractProso millet bran [Panicum miliaceum (L.)], variety Dakota White, was extracted with supercritical carbon dioxide (SC‐CO2) to yield crude oil. The effects of operating parameters (pressure, temperature, and specific solvent flow) and of features of the raw material (moisture content and particle size) on oil extraction were investigated. Complete de‐oiling of ground millet bran pellets was achieved under 300 bar at 40°C with a specific solvent flow of 2–10 h−1 within 200 to 500 min. Solvent requirements were 20–30 kg CO2/kg raw material. Composition of crude SC‐CO2 oil extracted under optimal conditions, i.e., fatty acid profile, amount of unsaponifiables, tocopherols, free fatty acids, sterols, sterol esters, waxes, hydrocarbons, and phospholipids, was compared to that of crude oil obtained by petroleum ether extraction. These two oils were similar in terms of fatty acid profile and amount of free fatty acids, unsaponifiables, peroxides, and tocopherols. They differed in respect to phospholipids (present in petroleum etherextracted oil and absent in SC‐CO2 extracted oil), metals, and waxes (lower levels in SC‐CO2 extracted oil). The effects of extraction procedures on oxidative stability of crude SC‐CO2 oil were studied. Ensuring that all pieces of the extractor in contact with the oil were in stainless steel; cleaning the separator, i.e., washing with KOH, rinsing, purging with N2 and CO2, and heating; performing a couple of extractions before the main extraction; and achieving the extraction without interruption all positively influenced the oxidative stability of the oil. Conversely, increasing CO2 purity above 99.5% had no effect. Oxidative stability of the SC‐CO2 oil extracted under these conditions was only slightly lower than that of the oil extracted with petroleum ether.

Effect of extrusion process variables on physical and chemical properties of extruded oat products.

The purpose of this research was to study the effects of initial moisture levels and extrusion temperatures on bulk density, water absorption and water solubility indexes, viscosity, and color of extruded oat products. The dehulled grains were ground in a Brabender Quadrumat Senior mill and the coarse fraction, with higher amounts of crude protein, lipids, and dietary fiber content, were conditioned to moisture levels of 15.5-25.5% and extruded in a Brabender single-screw laboratory extruder. The water absorption index of extrudates were relatively low (4.16-6.35 g gel/g sample) but increased as the initial moisture of the raw material as well as the extrusion temperature was elevated. The water solubility index was inversely proportional to the extrusion temperature. Initial viscosity of the paste increased with the increase of raw material moisture and extrusion temperature, while the maximum viscosity (at a constant temperature) diminished with the increase of temperature. Products with lower values of L* (luminosity) and greater values of a* (red) and b* (yellow) were obtained at high moisture rates and at a 120 degrees C extrusion temperature.

ULTRASTRUCTURAL CHANGES IN DEFATTED SOY FLOUR INDUCED BY NONEXTRUSION TEXTURIZATION

ABSTRACTA Korean “textured” snack food press (Hand Press) was used to produce nonextrusion soy products. Constant processing conditions were plate temperature, top and bottom (190°C); pressure (21.1 kg/cm2); raw material moisture (30%) and premoistened sample mass (25g). The varying condition was retention time (2, 4, 6, 8 and 10 sec). The present study was initiated to investigate the sequence of cellular and sub‐cellular changes taking place during the development of texture in defatted soy flour. Ultrastructural changes produced during nonextrusion texturization occurred in the following well‐defined stages: two (2) set stage, fusion of flour components; 2–8 sec stage, protein bodies deformed, ruptured and fused with carbohydrates forming a protein carbohydrate matrix and final, 10 sec stage, fibrillation of the protein‐carbohydrate matrix.

實驗結果から得た焼結機構に關する一考察

After Sintering experiments using the Greenawalt sintering pan, we can obtain some conclusions about sintering practice, that is;(1) It is possible to regulate the sintering conditions such as moisture of raw materials, mixing ratio, sintering time etc, by examinig the microstructure of sinter in the proceed of production.(2) Decreasing the lower limit of the size of sinter from 15 mm to 10 mm, we can expect the increase of yield of sinter by 13.6%, and the strength by 10.5%. But in this case, not the latter buf the former contains bedding materials in it.(3) Comparing the shatter strength of each size of sinter (5-10mm, 11-15mm, 16-50mm over 50mm), we can find that the smaller the size of sinter the more the percentage of sinter keeping its own size before sbatter test becomes.

On the pulverizing of cement raw materials

5th report Relation of revolving speed and pulverizing efficiency Conditions of test are as follows.dimention of mill φ0.265m×l0.270assortment of flint ball.φmm 50 40 30 25 ∠25kg 1.275 2.125 1.275 1.275 2.550ball volume% 39.5%feed limestone 5-2.5mm 3.600kgrevolving speed 55.3 69.5 87.4author reached to such following conclusions.1. When RPM is 69.5 the dry pulverizing capacity is the greatest but in the wet milling RPM in the greater the capacity the more.2. The pulverizing efficiency showed with KWh/kg is the best when RPM is 69.5 and specific surface area about 2100-2050.3. Revolving speed which gives the best pulverizing efficiency is calculated from such formula given by Oyama.N=C/(D0.47X0.14)N……RPMC……Constant 62D……innerdiameter of mill (m)X……charged volume (%)4. Capacity of wet milling is almost 2 times as the dry.5. At the wet milling the pulverizing efficiency is less influenced than the dry by the revolving speed.6. th report Moisture of raw materials and mill Capacity. When moisture Content of ground material becomes greater than 1.0% starts the lining Coating and decrease of mill Capacity.when grind lime stone Capacity decreases abaut 30% per 0.5% moisture increase.We see that porcelain mill lining coats similarly to a cast iron lining.At the plant the moisture Content of ground material from mill must be kept less than 1% when we wish no lining Coating.