玉米黄粉酶解液在黄原胶发酵生产应用的研究

以玉米黄粉酶解液为氮源应用于黄原胶发酵培养基，探讨了蛋白酶种类、玉米黄粉酶解液添加量和酶添加量等因素对其发酵黄原胶粘度和产胶率的影响，并优化了复配氮源的种类及其复配比例。结果表明，碱性蛋白酶水解液作为氮源发酵黄原胶的粘度和产胶率优于其它蛋白酶解液；当酶解液添加量为6%、碱性蛋白酶添加量为8kU时，发酵黄原胶的粘度和产胶率可以达到4235cp和24.4g/L。大豆蛋白与玉米黄粉酶解液复配效果优于与棉籽粉、豆粕粉、花生粉的复配；玉米黄粉酶解液与大豆蛋白复配比为3:7时，发酵黄原胶的粘度和产胶率可以达到5833cp和32.4g/L，与单独以大豆蛋白为氮源无明显差异。本研究为提高玉米黄粉资源利用率、降低黄原胶的发酵生产成本提供了新思路。     

Conditioning of oil-bearing materials for solvent extraction by extrusion

A new procedure, based on extrusion, was developed to prepare soybeans for direct solvent extraction. The procedure eliminates the need of controlled cracking, partial shell remotion, heating and flaking, requiring only an adequate communition to particles passing Sieve USS 14 followed by extrusion in a specially developed extruder. Extruded soybeans were obtained in the form of hard and porous agglomerates, without any dusting tendency, higher extraction, draining and percolation rates, lower solvent hold up and higher apparent density than the best possible flakes. Extruded soybeans were processed by solvent extraction in batch and continuous industrial installations, enabling substantial increases in capacity (up to 100%) and reduction in overall steam consumption (up to 30%) when compared with flakes processing. Extracted oil from extruded soybeans seems to show lower levels of gums and toasted meal at higher soluble protein levels for the same urease activity. Peanut press-cakes were preconditioned by extrusion before solvent extraction in batch-type installations, enabling a substantial reduction in residual oil for similar conditions with nonextruded press-cake. For existing plants, the new procedure allows a substantial increase in plant capacity and lower steam consumption. For new plants, the new procedure allows substantial capital savings in equipment and space. The new procedure enables soybean processing by direct solvent extraction in small batch-type installation, which may be very convenient for some underdeveloped areas.     

Effect of enzyme inactivation on the extracted soybean meal and oil

The objective was prevention of lipoxygenase activity prior to oil extraction in order to obtain a meal of superior flavor quality and a crude oil of superior oxidative stability. Accordingly, experiments were performed in which soybeans were heated at various moisture contents and times to inactivate the enzyme system. Once the optimal conditions were determined, heat treated and raw beans were extracted in a laboratory system designed to simulate conditions in commercial solvent extraction and the component oil and meal were evaluated. Oxidative stability of the oil from heat-treated beans was increased as determined by the Swift stability test and an organoleptic evaluation. Similarly, organoleptic blandness ratings of the heat-treated meal were also superior to the meal produced from raw beans. It was concluded that steam heat treatment of soybeans prior to extraction was beneficial to quality of both oil and flake.     

A new method of detoxification of cottonseed by means of mixed solvent extraction

For several decades, scientists in the field of vegetable oils tried unsuccessfully to detoxify cottonseed by a practical method. By using 20-30% (by wt) of ethyl alcohol (90% in vol) with commercial hexane as a mixed solvent, we were able to extract effectively both gossypol and oil from cottonseed prepressed cake or flakes. Free gossypol in meal was reduced to ca. 0.013-0.04%; total gossypol was reduced to 0.32-0.55%; residual oil was reduced to ca. 0.5% or less. Any aflatoxin present also can be eliminated by this process. The detoxified cottonseed meal can be used as animal feed. Cottonseed protein can be used to substitute for soy protein. The extracted oil is of better quality than that obtained by the usual hexane extraction method, and gossypol is a valuable byproduct.     

Dry extrusion as an aid to mechanical expelling of oil from soybeans

A new concept is described for mechanical extraction of oil from soybeans, using dry extrusion as a pretreatment. It was found that coarsely ground whole soybeans at 10 to 14% moisture could be extrusion cooked so that the extrudate emerges from the die in a semi-fluid state. The dwell time within the extruder was less than 30 seconds, and the temperature was raised to about 135 C. The semi-fluid extrudate was immediately pressed in a continuous screw press to obtain high quality oil and press cake. Extrusion prior to expelling greatly increased the throughput of the expeller over the rated capacity. An oil recovery of 70% was obtained in single pass expelling using pilot model expellers. Higher recovery rates can be expected with commercial scale expellers. The high temperature-short time extrusion cooking process eliminates the prolonged heating and holding of raw material in conventional expelling. Under the experimental conditions, press cake with 50% protein, 6% residual oil and 90% inactivation of trypsin inhibitors was obtained. The low fat cake was easily ground in a hammer mill without the usual problems associated with milling of whole beans. The expelled oil was remarkably stable with an AOM stability of 15 hr, which is comparable to refined deodorized oil according to NSPA specifications. The new procedure offers potential for producing natural soybean oil and food grade low fat soy flour by a relatively low cost operation. It may be adopted as an improvement to existing conventional expelling operations in less developed countries or as a commercial or on-farm operation for producing value added products from soybeans within the U.S.     

Solvent effects on the products of soybean oil extraction

Summary Ethanol, isopropanol, isobutanol, ethylene dichloride, trichloroethylene, carbon tetrachloride, and hexane (b.p. range 30° to 60°C.) were used as solvents for the extraction of soybean oil and the comparative effect of the solvent on the color and other properties of the oil, meal, and isolated protein was measured. Ethanol extraction gave the best results with respect to the color of oil, meal, and protein, and it also served as a debittering agent for the soybean meal. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

The nutritive value of soybean oil meal prepared by the different methods of oil extraction

This article is primarily a review of the literature pertaining to the subject. Solvent extracted, hydraulic, and expeller soybean oil meals all contain, if properly cooked, protein of high biological value, similar to that of milk protein. Solvent extracted meal has a higher percentage of protein. Since expeller and hydraulic meals contain more oil than solvent extracted soybean oil meal, they naturally have a slightly higher vitamin A and D potency, but the amounts of these vitamins contained in any type of soybean meal or even in the whole soybean are not significant. Levine’s assays reveal that solvent process soybean oil meal contains roughly 2.8 I.U. of vitamin B per gram of solids compared to 1.0 I.U. for hydraulic meal. According to results of Cornell experiments, the vitamin G content of soybeans is not materially affected by any of the common methods of processing. Kraybill reports that expeller and hydraulic pressed soybean oils contain more “lecithin” (total phospholipins) than hexane extracted soybean oil. Therefore his results indicate that our domestic solvent extracted meal contains slightly more “lecithin” than expeller meal. “Lecithin” in soybean oil meal may be valuable as an antioxidant to stabilize the vitamin A contained in mixed feeds.     

水酶法提取大豆油

The procedure of enzymatic aqueous extraction of soybean oil was assessed when two-step controlled enzymatic hydrolysis was applied. With aqueous extraction of soybean oil-containing protein, the highest yield of oil was 96.1% at the optimized conditions studied. Soybean oil-containing protein was hydrolyzed and resulted in releasing part of oil. The separated protein that contained 40% oil was enriched due to its adsorption capacity of released oil, the average oil extraction yeild reached 93.5%. Then the high oil content protein was hydrolyzed again to release oil by enzyme, the oil extraction yeild was 80.4%. As a result, high quality of soybean oil was obtained and the content of total oil vield was 74.4%.     

Estimating the processed value of soybeans

Interest in marketing soybeans on the basis of protein and oil content is increasing. Producers, breeders, handlers and buyers of soybeans need a method of evaluating soybean lots of different composition. A model is presented that predicts, given soybean composition and processing conditions, the yield of crude soybean oil and soybean meal from the processing of soybeans in a solvent extraction plant. From these yields, an estimated processed value (EPV) was calculated. For one set of price conditions, the EPV of typical soybeans had a range of $0.93 per bushel if premiums were paid for meal protein in excess of specifications and a range of $0.53 per bushel if meal protein premiums were not paid. Trading rules established by the National Oilseed Processors Association for domestic meal markets have a significant effect on the value and composition of soybean meal.     

汽爆秸秆膜循环酶解耦合丙酮丁醇发酵

利用新型的汽爆玉米秸秆膜循环酶解耦合发酵系统进行了丙酮丁醇发酵的研究,并对使用该系统所导致的丙酮丁醇梭菌(Clostridium acetobutylicum AS1.132)代谢的变化进行了讨论. 在稀释率为0.075 h-1的条件下,丁醇的产量为0.14 g/g (纤维素+半纤维素),最大丁醇产率达到0.31 g/(L×h),溶剂组成为丁醇:丙酮:乙醇65.3:24.3:10.4(体积比),纤维素和半纤维素的转化率分别为72%和80%,使用单位纤维素酶所产生的丁醇量为3.9 mg/IU,是分步水解批次发酵的1.5倍. 利用该系统使酶解和发酵分别在各自最适的条件下同时连续进行,减少了纤维素酶的用量,有效地解除了酶解产物对纤维素酶的抑制作用,并减轻了溶剂产物尤其是丁醇对微生物活性的影响,延长了发酵周期.     

Cottonseed oil

Research on the effects of genetics and growing location on cottonseed has shown that oil and fatty acid composition could be improved if geneticists and agronomists would strive for improved seed quality as vigorously as they do for improved fiber quality. Breeding of glandless or gossypol-free cottonseed was a genetic breakthrough. Glandless varieties are now available that produce yields having the quality of fiber and seed equivalent to those of glanded cultivars. Oil, food-grade lecithin and meal byproducts are readily processed from glandless cottonseeds because of the absence of gossypol. Major research programs on cottonseed processing include: (a) testing alternative screw-press and extrusion operations for efficient direct solvent oil extraction; (b) developing alternative solvent extraction systems with ethanol, isopropanol and supercritical fluids; (c) using gas chromatographic/mass spectrophotometric techniques to characterize enzymatic and nonenzymatic mechanisms that produce secondary oxidation off-flavor products; and (d) controlling hexane losses in solvent extraction systems.     

Enzymatic treatment of rice bran to improve processing

A modification of the process of oil extraction from rice bran is proposed, introducing one or two enzymatic reactions previous to solvent extraction. Although a total aqueous enzymatic extraction process did not result in reasonable oil extraction yields, an interesting alternative results from enzymatic reactions previous to solvent extraction or pressing. A thermal treatment of rice bran is first applied to deactivate lipase, but also to gelatinize starch previous to reaction with α-amylase. This is followed by a saccharifying step with glucoamylase to produce glucose (28 g/100 g of rice bran treated), while the residual paste, 66.7% of the original bran, may be subjected to a proteolytic process for protein extraction or directly treated with the solvent to obtain bran oil. Finally, under the defined extraction conditions using hexane, yields of oil are 5% higher when rice bran has been previously treated with α-amylase.     

Total and polar lipids in soybean protein meals

Soybean protein meals obtained by various oil extraction methods have different neutral oil content, and they may contain differnet amounts of polar lipids. Three soy protein meals obtained by different processing methods were extracted by two solvents consecutively, chloroform/methanol (2:1, vol/vol) and water-saturated butanol, for total lipid analysis. The organic flour (i.e., ground soybean) containted 15.52% total lipids; the high protein dispersibility index flour from extrusion-expelling processing and the white flour from conventional solvent extraction contained 11.20 and 1.84% total lipids, respectively. Organic flour contained more polar lipids than the other two protein meals on a dry-weight meal basis. Chloroform/methanol extracted most of the lipid from the meals, whereas water-saturated butanol resulted in an extract with more polar lipids than that from chloroform/methanol extraction.     

Performance of Green Solvents in the Extraction of Sunflower Oil from Enzyme-Treated Collets

The main goal of this work is to evaluate the extraction of sunflower oil from enzyme-treated collets using ethanol and isopropanol (IPA) as solvents. The sunflower collets are pretreated with the multienzyme complex Viscozyme L prior to solvent extraction by the Soxhlet method. The influence of the moisture content of the collets, pretreatment, processing time, and solvent type on the amount of total extracted material and the oil extraction efficiency is studied. Some quality parameters such as phospholipid content of the oil and chlorogenic acid content of the residual meal are also analyzed. At low moisture content (7%) the solvents exhibit similar oil extraction ability (98–99%), but with increasing moisture the extraction efficiency of ethanol decreases to about 85%, while no significant differences are observed for IPA. The enzymatic treatment increases the extraction efficiency for all times, especially for ethanol. It is observed that IPA is more efficient in the extraction compared to ethanol, and the amount of nonlipid material is reduced by ≈70%. In addition, the oil extracted with IPA have lower phospholipid content and the residual meal presents a higher chlorogenic acid content. Practical Applications:This work would contribute toward the use of green solvents in the extraction of sunflower oil from collets. Ethanol and isopropanol, used as solvents, present attractive advantages, including low toxicity, good operational security, as well as being obtained from a renewable source. The obtained data provide up-to-date information on the use of these alcohols in the extraction of sunflower oil from collets and the influence of operating conditions, such as moisture content, enzymatic pretreatment of the collets, and the extraction time. Information about oil and meal quality is also reported.     

Fate of jimsonweed seed alkaloids in soybean processing

The fate of Jimsonweed seed alkaloids (atropine and scopolamine) during solvent extraction of contaminated soybeans and alkali refining of crude oil was investigated. Extraction of a 50:50 mixture of soybeans and Jimsonweed seeds with petroleum ether yielded meal and crude oil fractions, in which chemical analyses showed that vitrually all the atropine and scopolamine remained in the meal. Alkali refining effectively removed atropine added to crude soybean oil.     

Soybean preparation

Techniques and equipment for a typical soybean preparation plant prior to solvent oil extraction are described. The bean flow is described from incoming beans, to the inlet, to the extractor.     

Protein concentrate of African oil palm (Elaesis guineensis, Jacquin), extraction process and functional properties

A study was carried out for the purpose of obtaining and characterizing a protein concentrate obtained from defatted oil palm cake using alkaline extraction, and compare it with a commercial soy meal. The oil palm cake came from a national industry as a subproduct of the oil extraction of the palm kernels. The moisture, protein, fat, crude fiber and ash content of the oil palm was then determined. The optimum conditions for extraction and precipitation of the proteins were selected. These were the following: extraction at pH, 11.4; adding NaOH 0.06 M solvent; a meal/solvent relation of 1:20 g/ml and extraction time, 20 minutes with magnetic agitation, and precipitation at pH 5.3. The protein concentrate obtained contained: 66.50% protein; 0.07% fat, 0.90% crude fiber, and 3.20% ashes. Then the following functional properties were analyzed: solubility, according to the pH; water absorption (250); oil absorption (175); emulsion activity (27.2), and stability (13.6). The author concludes that the protein concentrate has good water and oil absorption when compared to soymeal; the emulsion, however, was found to be unstable to heat.     

Enzymatic hydrolysis in conjunction with conventional pretreatments to soybean for enhanced oil availability and recovery

Enzymatic hydrolysis of oilseeds prior to extraction has recently been shown to enhance the extractable oil in oilseeds and its recovery. This paper presents the results of optimizing the combination of enzymatic hydrolysis with one or more conventional pretreatments to soybean and of optimizing the hydrolysis parameters as they determine the mechanical extractability as well as the solvent extractability. Enzymatic hydrolysis in conjunction with flaking (dehulling inherent) and steam conditioning offered statistically the best pretreament combination for soybean at a 5% level of significance, enhancing the extractable oil content by about 4.8% of moisture-free sample. The optimal hydrolysis parameter values based on response surface analysis were: hydrolysis moisture content 23.22% wet basis, enzyme concentration 11.99 vol/wt, and incubation period 13.79 h. Over 99% of the total extractable oil released after hydrolysis was extractable within 16 h on a Soxhlet extractor. Presently with Britannia Biscuits Ltd., New Delhi, India.     

乙醇抽提大豆油之研究

<正> 大豆产于我国已有长久历史,产量向居世界第一位.据1949年统计,全世界大豆产量为501,700,000英斛(bushel)(1 bushel=8加侖),中国产量为245,200,000英斛,约占全世界产量二分之一弱;1935—1939年世界平均产量为464,300,000英斛,中国为369,111,000英斛,约佔四分之三强,故大豆为我国国宝之一.大豆不但含有丰富之蛋白质等,为极佳之食品,且平均含油量达18%左右,为吾国同胞食油之主要来源.     

Fractionation of rapeseed meal into hour and hull components

Fine-ground rapeseed meal can be fractionated by liquid cyclone processes into flour and hull fractions. The process can be applied to expeller meal or to the marc after solvent extraction. A nonpolar solvent such as hexane is particularly effective because residual oil in the products is also substantially reduced. The flour, obtained in yield of about66% of the meal, contained over 45% protein and 5-8% of crude fiber. Rapeseed meal is relatively low in digestible energy and the flour fraction would have greater application as a protein supplement in pig and poultry feeds.