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1.
The 1976 and 1977 crops of glanded cottonseed from oil mills located in 7 major U.S. cottonbelt growing areas were evaluated as to their suitability for processing into edible, high-protein flours. Both the physical and chemical characteristics of fuzzy seed samples were studied. Ginned seed samples were hulled, dried, comminuted, slurried with hexane and liquid classified by both a laboratory differential settling test (DST) and pilot plant liquid cyclone process (LCP). Liquid cyclone operating data and extensive analytical data of the kernels, flour and meals produced are shown. A free gossypol level of 1.10% or less in full fat kernels was the determining factor for producing edible flours from glanded seed by the LCP. The Lower Rio Grande Valley area was the only area from which liquid classified cottonseed flour consistently exceeded the current maximal free gossypol standard of 450 ppm. Ca. 94% of the total U.S. cottonseed production is suitable for producing edible, high-protein flours by liquid classification.  相似文献   

2.
A powder flow analyzer attached to a Texture Analyser (Stable Micro Systems, UK) was used to compare the flow behaviour of four cereals systems: maize and wheat (in both starch and flour forms), as functions of particle size and distribution, water content and the addition of different types of oil. It was expected that the smaller the particle size the higher the tendency to stick (because of less free volume between the particles), but that was not the case. The results showed that wheat starch used, with bigger particle size than maize starch, had higher cohesion properties and as water content increases the cohesion increases by the same magnitude. This was attributed to the differences in granular shape as well as protein quantity and quality. Caking strength for both starches was influenced by the water content; in particular at 30% water content (w/w), neither cohesion nor caking indices could be measured for wheat starch because of the high stickiness of the particles.Although the two flours had particles of very similar sizes, with differences in the distributions only, maize showed higher cohesion indices compared to wheat flour. These values decreased with increasing water content. The caking property for maize was not significantly affected by water content with values of approximately 100 ± 5. The caking strength increased for wheat flour from 8 to 500 as moisture increased from 12.5 to 30%. This was ascribed to the differences in hydration properties of the two flours. For wheat flour and as the water content increased, gluten started to form and would require more than 30% to form a homogenous, visco-elastic mass.Generally, cohesivity and cake forming ability were affected by water content as well as the physical state of the oil i.e. by the solid/liquid ratios. As water content increases, wheat starch showed the greatest packing and cohesive behaviour, with and without the oil, while maize flour exhibited the weakest packing and cohesive properties.  相似文献   

3.
In direct screw pressing, kernels must undergo seed preparation steps of size reduction, flaking and steam conditioning prior to mechanical extraction. Mechanical wear and tear, maintenance expenses and electricity are the major costs. The direct solvent extraction process is used in larger plants. Production cost depends mainly on solvent loss and energy used in solvent recovery and pelletizing. However, oil recovery is more complete than in screw pressing. A third processing method uses pre-pressing followed by solvent extraction. The choice of process or machinery depends on capital investment, production cost, oil recovery and its value. Whether the higher investment and production cost incurred in solvent extraction is offset by the higher oil extraction rate needs to be determined. Strict quality control right from fruit processing to kernel extraction is necessary to ensure production of good quality oil and by-products. Malaysian palm kernel oil has proven to be of consistent quality, with narrow ranges in chemical characteristics. The palm kernel cake and pellets are important ingredients for animal feed.  相似文献   

4.
The process of grinding soybeans to a fine flour and extracting the flour with hexane was studied on a pilot plant scale. The crude oil from the pilot plant study had 15 ppm phosphorus and was suitable for physical refining after a light acid pretreatment and bleaching. The refined oil showed a Lovibond color of 1.4 yellow and 0.3 red. The pilot plant study also showed that grinding of the soybeans and the separation of solid from miscella were the most difficult steps in solvent extraction with fine flour. A laboratory study on separation of miscella from meal by aqueous ethanol reduced the hold-up volume, but it did not remove all the miscella. A test with betacarotene showed that only the miscella outside the flour particles was displaced. Aqueous ethanol solutions used as a second solvent extracted additional nontriglyceride materials (primarily phospholipids) from the meal. Also, the free fatty acid content of the oil was increased with aqueous ethanol solution wash. The quality of the extracted crude oil was lowered by using a second solvent, but it had the advantage of needing only one centrifugation to separate miscella from meal.  相似文献   

5.
木粉增强木质素/环氧树脂复合材料的制备与力学性能   总被引:2,自引:0,他引:2  
将玉米秸秆酶解木质素和双酚A环氧树脂共混,利用低相对分子质量聚酰胺作为同化剂,采用热压工艺制备了一种木粉增强的交联型木质素,环氧树脂复合材料,研究了热压温度、热压压力以及木粉的加入对复合材料力学性能的影响。研究结果表明,随着热压温度和热压压力的增加,木粉增强木质素,环氧树脂复合材料的弯曲强度和冲击强度均先升高而后降低,在120℃热压温度、8MPa热压压力下复合材料的力学性能达到最佳。随着木粉含量的增加,复合材料的弯曲强度和冲击强度均升高;木粉的粒径也对复合材料的力学性能有较大影响;综合考虑复合材料的力学性能,优选加入40—80目的木粉,木粉的含量为20%。  相似文献   

6.
Navy beans,Phaseolus vulgaris, were dry roasted in a particle-to-particle heat exchanger, dehulled by air aspiration, pin-milled and air-classified to yield a high protein fraction. Proximate analyses, nitrogen solubility indices and oligosaccharide contents of this high protein fraction as influenced by processing parameters which affected final product temperature were determined. Farinograms of wheat/bean protein fraction composite flours were run. A high-protein bean flour fraction was selected from these dry and roasted treatments and used in product development. Quality characteristics and consumer acceptability of high-protein prototype products were evaluated. Results of this research indicate that the dry roasting process influences the characteristics of the air-classified protein fraction. Flour color, nitrogen solubility and dough mixing properties were most greatly influenced by roasting time and temperature. Increased roasting resulted in increased browning and decreased nitrogen solubility and dough mixing stability. Wheat flour bread products, substituted with low levels of high-protein bean flour, were of high quality. Presented at the 73rd AOCS annual meeting, Toronto, 1982.  相似文献   

7.
Defatted pistachio kernel flour (DPKF) is a byproduct of specialty oil industries and a promising product to be further used as a food ingredient. The purpose of this study was to evaluate nutritional value, functional properties, bioactivity, and microstructure of DPKF prepared by cold pressing (partially defatted, ~22 % residue fat d.b.) and pre‐press‐solvent extraction (totally defatted, <1 % residue fat d.b.) methods both using raw and roasted kernels. DPKF was rich in protein (34.36–46.47/100 g flour, d.b.) and carbohydrate (36.61–48.71/100 g flour, d.b.). Also, DPKF showed low Na contents with high concentrations of K, P, Ca, Mg, Zn, and Se. Excluding the sulfur amino acid, all essential amino acids were significantly higher than the reference values recommended by Food and Agriculture Organization/WHO. Totally defatted flours presented better functional properties than the partially defatted ones with exceptions of foaming stability. DPKF also exhibited appreciably higher total phenolic (552–792 mg gallic acid equivalent/100 g flour, d.b.) and flavonoid (124–280 mg RE/100 g flour, d.b.) contents as well as antioxidant capacities. Therefore, DPKF may have potential applications as functional ingredients and supplements in foods.  相似文献   

8.
Soybean flakes extracted with hexane or aqueous isopropyl alcohol (85%, 87.7% and 90.5% IPA by weight) were processed to toasted flours and the miscellas to refined soybean oils. These products were evaluated for sensory characteristics and oxidative stability. Sensory analyses of initial oils and flours indicated good quality products. Initial flavor scores of IPA-extracted oils and flours were not significantly different from those of hexane-extracted oil and flour. Flour samples aged at 49 C for 1 mo and 37 C for 3 mo were rated slightly lower in flavor score than the initial flours. Flavor scores of oils decreased after aging but remained acceptable. Oils extracted with aqueous IPA concentrations of 85% and 90.5% received significantly lower scores than oils extracted with hexane or 87.7% IPA after 8 hr of fluorescent light exposure. Oxidative stability measured by the induction of weight increases of the oils during aging was similar. Residual solvent flavors were slightly detectable in unaged IPA flours and in those aged 3 mo at 37 C.  相似文献   

9.
Wheat breeding for end-use quality is enhanced by development and application of a selective and sensitive method for ranking early generation cultivars as part of the effort of generating desirable wheat lipids. A desirable wheat lipid, the increased concentration of which in hard wheat flour correlates positively with bread loaf volume, is digalactosyldiglyceride (DGDG). A mass spectrometric test for DGDG was applied to 100-mg samples of flour isolated from the F6 generation of hard winter wheats. The test enables prediction of desirable lipids in early generations so that decisions about the F6 progeny improve wheat breeding efficiency. Previous attempts to screen wheat cultivars for desirable glycolipids were constrained by sample size, lipid extraction and purification, and time. Here, we present flour glycolipid data obtained from individual wheat plants grown in short rows in two nurseries. The endosperm (100 mg) representing several kernels was exhaustively extracted with a total lipid solvent. Following isolation of the lipids and addition of an internal standard, the lipids were subjected to tandem mass spectrometry (MS–MS). The concentration of DGDG in the flour from five to seven kernels was found to vary by a factor of two within single nurseries. Thus, early generation lipid screening enables informed selection for this hard wheat quality indicator.  相似文献   

10.
A brief background is presented on the development of the Liquid Cyclone Process as modified to process glanded cottonseed kernels from the Texas high plains into a gland-free 65+% protein flour. Southern Regional Research Center's pilot plant process is described and related to the commercial process that will become operational in early 1974 at Plains Cooperative Oil Mill, Lubbock, Texas. Some of the functional properties of the flours and results of their evaluation in food application are discussed. One of seven papers presented at the symposium, “Processing Methods for Oilseeds,” AOCS Spring Meeting, New Orleans, April 1973. ARS, USDA.  相似文献   

11.
Hull-free cottonseed flakes were prepared for direct solvent extraction by two passes through a pilot plant size, hot air drier set at 200 F. Moisture content was reduced to 6.5% without evidence of gossypol binding. Improved drainage characteristics resulted in better extraction. Glanded and glandless flakes which had been extracted and partially desolventized at low temperatures were heated indirectly in a batch desolventizer under vacuum to temperatures above the point of steam condensation and solvent stripped with superheated steam. Resulting available lysine and protein solubility values on the meals and flours were desirably high. The desolventization was accomplished without significant color darkening. Operated by the Texas Engineering Experiment Station for the Cotton Research Committee of Texas.  相似文献   

12.
Most seed oils are obtained by pre‐pressing the crushed seeds followed by solvent extraction of oil from the press cake. The prepressed oil will contain no solvent residues, and is moreover expected to contain more nutritionally valuable compounds, which can in turn enhance the oxidative stability of the oil. However, reports on differences between extracted and pressed oils are scarce. Therefore, in this study, for a case study on rapeseed oil, the composition and quality were systematically compared between pre‐pressed and solvent extracted oil. In the extracted oil, solvent residues and a clear sensory difference were detected, which disappeared almost completely during refining. The crude oils had a high content in free fatty acids and in primary and secondary oxidation products, which were higher in the extracted than in the pressed oil. However, surprisingly, also the content of minor compounds was slightly higher in the extracted oil than in the pressed oil. This can be explained by a selective extraction of those compounds into the solvent. During refining, a difference between pressed and extracted oils still existed but was less pronounced. The slight difference in antioxidants content might explain the higher oxidative stability of extracted over pressed oils. Practical applications : Traditionally, high yields of vegetable oils are obtained by pre‐pressing the seeds, followed by solvent extraction of the residual oil from the press cake. The solvent extraction leads to higher oil yields, but is expected to affect the composition and quality of the oil, and has moreover negative environmental impacts. In this study, the solvent extracted oil contained slightly higher levels of tocopherols and phytosterols, and had slightly higher oxidative stability, which are desirable quality aspects. In contrast, the solvent extracted oil contained also higher levels of undesirable phospholipids, as well as solvent residues, which were, however, removed during degumming and deodorization, respectively. These results suggest that the final quality of refined pre‐pressed and solvent extracted oils is comparable from nutritional and safety point of view. A choice for pressing instead of solvent extraction will, therefore, rather be driven by sustainability concerns than by nutritional aspects.  相似文献   

13.
In order to utilize hardened beans, we proposed to find the method most indicated for the preparation of bean flour to determine their nutritional value, and to make bread of high industrial, nutritional quality, and good sensory characteristics, using blends of bean and wheat flours. Two types of flour were prepared, testing four soaking temperatures (22, 30, 40 and 50 degrees C) and two methods to remove the testa (under moist and dry conditions). At laboratory level, the dry testa removal method gave the best flour yields (mean = 85.8%) and the highest protein content (mean = 23.7%). Comparison between soaking temperature at 30 and 50 degrees C was not significant (alpha = 0.05). At pilot plant level, with soaking at 50 degrees C the flour yields were 58.0% for moist testa removal (H1) and 74.0% for dry removal (H2), with a protein content of 22.6% for H1 and 23.0% for H2. The H1 and H2 flours were added to wheat flour at 5, 10 and 15% for bread making. The addition of 5.0% gave breads with similar protein content and sensory characteristics to those of the control, wheat. A diet based on bean-flour bread resulted in greater weight gains than that with casein for gold hamsters. The study also demonstrated the importance of heat-treating of the bean flours, because when flour without previous heat treatment was administered, the animals lost weight and died. This effect was overcome by the process of baking the flours at 140 degrees C for four hours.  相似文献   

14.
Ultraviolet weathering performance of polyvinyl chloride (PVC) filled with different concentrations of wood flour was studied. Extruded PVC/wood‐flour composite samples were subjected to cyclic ultraviolet lamps/condensation exposures and assessed over a total of 400 and 2600 hours. Each assessment consisted of DRIFTFTIR and XPS collections, contact angle measurement, color measurement, and tensile property testing. The experimental results indicated that wood flours are effective chromophore materials since their incorporation into a rigid PVC matrix accelerated the degradation of the polymeric matrix. Photodegradation converted unfilled PVC samples to a colored material of lower extensibility. Although composite samples exhibited greater discoloration than unfilled PVC samples, they retained all their original strength and stiffness properties even after 2600 hours of cyclic UV irradiation/condensation exposures.  相似文献   

15.
The objective of this work was to develop three foodstuffs based on mixes of wheat and fermented and non-fermented legumes, for the purpose of contributing with a healthy alternative for school snacks. To this aim, refined wheat flour was partially substituted with whole legume flours for the preparation of cakes, brownies and cookies, foodstuffs traditionally consumed by school age children. Cakes were formulated substituting 20% of wheat flour with Phaseolus vulgaris flour, brownies with 30% of Cajanus cajan flour and cookies with 30% of Vigna sinensis flour, using fermented and non-fermented legumes in the three products. When these products were subjected to sensorial evaluation through a test of degree of acceptability and using a hedonic scale of 7 points, values higher than 5 in the attributes taste, color and overall appraisal were found for all the products. In addition, the preference was measured with a group of 90 school children, corroborating the results obtained at laboratory level. Chemical characterization showed protein contents between 12 and 13% for the cake, 10 and 11% for the brownies and 10% for the cookies and protein digestibilities in vitro of 91%, 87% and 93%, respectively. The calorie supply, calculated per portion was of 199 kcal, 246 kcal and 237 kcal, for cakes, brownies and cookies, respectively. It was concluded that it is technically possible to incorporate fermented and non-fermented Phaseolus vulgaris, Vigna sinensis and Cajanus cajan, to highly consumed products such as cakes, brownies and cookies with a higher nutritional content and well-accepted by school-age children.  相似文献   

16.
A bioassay in broilers was carried out during a six-week period, to evaluate, as a protein source, the quality of fish silage produced by microbiological means and to compare it with that of fish flour and soybean flour. A total of 28 broilers of the Cross by Cross strain were used, sexed and assigned at random. Additionally, the fish silage was subjected to moisture (8.1%), ash (18.4%), protein (59.5%), fat (7.55%), carbohydrates (6.47%), and pH (4.2) determinations for its inclusion in the diets formulation. The results obtained did not permit establishment of significant differences between the weight increments presented by chicks fed with fish flour, and those fed with fish silage. Nevertheless, the food conversion index of the chicks consuming the diet prepared with fish silage proved to be better that the conversion index of the diet prepared with fish and soy flours. No lesions in the organs of the animals studied were observed, and the sensory trials indicated that chicks fed with the fish silage did not present differences with those commercially acquired.  相似文献   

17.
Olfactory responses of 72- to 96-hr-old, 24-hr starved adult male, female, or mixed-sex groups of the red flour beetle,Tribolium castaneum (Herbst), to volatiles from wheat and millet kernels, certain milled fractions, and solvent extracts were recorded by using a lightsensitive apparatus. Wheat-germ volatiles from intact germ or solvent extracts were generally more attractive than volatiles of wheat endosperm or wheat bran. Volatiles of whole wheat kernels were the least attractive among test materials of wheat origin, whereas there were no significant differences among whole wheat flour, germ, and endosperm. Wheat-germ extracts, however, were more attractive than were extracts of the other fractions. Whole millet flour or fermented millet flour volatiles were more attractive than those from whole millet kernels or millet starch. Beetles reached maximum responsiveness to grain volatiles by 72–96 hr after adult ecdysis. Groups of virgin female beetles generally were more responsive than male or mixed-sex groups to volatiles of substances tested.Contribution 82–137-j, Department of Entomology, Kansas Agricultural Experiment Station (Project Hatch 322), Kansas State University, Manhattan, Kansas.  相似文献   

18.
Peanut flour has been evaluated for use in a variety of food products as a replacement for animal source proteins. In breakfast cereals and snack foods, peanut flour blends well with cereal flours to yield products with excellent flavor, texture, and color. Peanut flour can be used to produce textured vegetable protein or can be used directly in ground meats to provide good moisture and fat binding characteristics. In bakery products, peanut flour can be used at levels up to 20% to provide protein supplementation without the astringent flavor of other oilseed flours.  相似文献   

19.
The incorporation of air into a high ratio cake batter by planetary mixing was studied using two bench mixers, a Kenwood KM250 and a Hobart-N50. Power draw (expressed as specific mechanical power input) and air volume fraction, ?, were monitored over time for batters prepared in each mixer for heat-treated and un-treated cake flours. The two flour types gave very similar results, indicating that the benefit of heat treatment for cake manufacture is manifested during the baking step. Both mixers gave a rapid initial increase in ? up to ~0.50 followed by a gradual decay. Bubble size distributions of batters prepared in the Hobart showed the initial aeration stage to be accompanied by the formation of a large number of small bubbles, with diameters around 5 μm: the average bubble size increased and number of bubbles decreased with extended mixing. Batters prepared without emulsifier exhibited a steady increase in ? to a plateau at ~0.2 and contained larger bubbles which did not change in average size significantly over time. All batters exhibited power-law shear-thinning behaviour with power law indices and consistency strongly dependent on ?. At low shear rates, the apparent viscosity showed the non-linear dependency on ? expected for dense suspensions. At higher shear rates, elastic forces generated by the bubble phase became significant. The non-Newtonian nature of the liquid phase and the elasticity generated by the bubbles meant that shear-thinning and bubble break-up could not be predicted by analyses based on the capillary number. The results support a qualitative model of bubble formation and break-up caused by extensional deformation generated by shearing these bubbly liquids: the bubbles cream out slowly owing to the high viscosity of the continuous phase at rest.  相似文献   

20.
With the purpose of diversifying the use of green plantain flour, a functional evaluation was performed by substituting 7% of chocolate cookie wheat flour by dehydrated green plantain flour; thus allowing to obtain a product with good physical and organoleptic qualities, as well as a better nutritional quality, as for dietary fibre and resistant starch. As a result of the use of this dehydrated green plantain flour (G-HT/HPV), the values of some chemical components increased significantly (P 0.05 Pound) in comparison to the standard cookies (GP): ash (2.46 to 2.69%), proteins (8.93 to 9.69%), dietary fiber (4.97 to 5.40%), resistant starch (0.19 to 0.23%) and total sugar (25.26 to 30.55). The G-HT/HPV complies with the industrial requirements as for moisture (2.7300%), ph (8.43), aw (0.205) and color (L = 31.78; a = 7.95 and b = 10.51). Besides, thanks to the use of G-HT/HPV the flours scattering during the kneaded process was diminished, thus reducing the cookie diameter and increasing the resistance to breaking (1.48 to 2.06 Kgf), in comparison to the GP. While evaluating the shelf life for G-HT/HPV, it was demonstrated that was affected by moisture, pH, aw and acidity after the first month of storage. In the preference comparison test between the G-HT/HPV and a trademark cookie (GC), no significant differences were founded. Both were accepted and qualified between good and very good, as for sensorial features like colour, fragrance and taste. However, significant differences were detected in relation to texture, and they were corroborated in the texture profile analysis. In this test the panel staff, while evaluating both types of cookies demonstrated that there are 8 features that can be used to describe them: firm, crumble, crisp, mealy, soft, lumpy, particle size and chewy.  相似文献   

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