米糠精制产品的应用

对米糠综合利用的途径进行了详细论述；并总结厂各种米糠精制产品在日用化工、医药工业、食品工业、精细化工领域的具体用途，包括米糠油的浸提技术，米糠油作为营养保健食品的开发利用，米糠油作为油脂化工原材料的深加工；米糠油精炼皂脚中提取游离脂肪酸及脂肪酸衍生物的制备；米糠脱水、脱臭、脱色的小皂化物提取谷甾醇、生育酚、谷维素的方法；米糠脱蜡副产物制备糠蜡和二十烷醇的利用及米糠饼(粕)提取植酸钙、植酸和肌醇的利用途径，最后提出了大力发展我国米糠产业的市场前景。     

Properties of rice bran oil‐derived functional ingredients

Lipid ingredients that demonstrate high stability and positive health profiles without the use of trans‐fats are needed in the food supply. Rice bran oil can be fractionated at low temperatures to create a series of spreads that show promise as functional ingredients. A rice bran oil‐derived spread can extend the fry life of soybean oil and can also be incorporated into baked goods such as bread and granola as a trans‐fat free alternative to butter or shortening.     

Effect of oil unsaturation and wax composition on stability,properties and food applicability of oleogels

Oleogelation is emerging as one of the most exigent oil structuring technique. The main objective of this study was to formulate and characterize rice bran/sunflower wax-based oleogels using eight refined food grade oils such as sunflower oil, mustard oil, soybean oil, sesame oil, groundnut oil, rice bran oil, palm oil, and coconut oil. Stability and properties of these oleogels with respect to oil unsaturation and wax composition were explored. Sunflower wax exhibited excellent gelation ability even at 1%–1.5% (w/v) concentration compared to rice bran wax (8%–10% w/v). As the oleogelator concentration increased, peak melting temperature also increased with increase in strength of oleogels as per rheological studies. X-ray diffraction and morphological studies revealed that oleogel microstructure has major influence of wax composition only. Sunflower wax oleogels unveiled rapid crystal formation with maximum oil binding capacity of 99.46% in highly unsaturated sunflower oil with maximum polyunsaturated fatty acid content. Further, the applicability of this wax based oleogels as solid fat substitute in marketed butter products was also scrutinized. The lowest value of solid fat content (SFC) in oleogel was 0.20% at 25°C, resembling closely with the marketed butter products. With increase in oil unsaturation, oleogels displayed remarkable reduction in SFC. Depending upon prerequisite, oleogel properties can be modulated by tuning wax type and oil unsaturation. In conclusion, this wax-based oleogel can be used as solid fat substitute in food products with extensive applications in other fields too.     

Factors affecting refining losses in rice (Oryza sativa L.) bran oil

Components of rice bran oil have been assessed for their effect on refining losses. Rice bran oil used in the study had the following (percent) analysis: free fatty acids, 6.8; phosphatides, 1.25; wax, 2.85; monoglycerides, 1.67; diglycerides, 4.84, and oryzanol, 1.85; the rest (80.74) was mostly triglycerides. The phosphatides and mono- and diglycerides had no noticeable effect on refining losses at levels of up to 2% in the oil. Waxes and oryzanol increased the refining losses substantially. In model experiments where these were incorporated into peanut oil individually and in combination, the wax at as low a level as 1% increased the refining losses by about 80% more than control and the refining losses increased with concentration of wax. Oryzanol had a similar effect. When wax and oryzanol were present together in the oil, the effect was synergistic—the refining losses were higher than the sum of their individual effects. Phosphatides, mono- and diglycerides tended to reduce the adverse effect of wax and oryzanol. The main components responsible for higher than normal refining losses in rice bran oil have been identified as wax and oryzanol.     

Evaluating the Oil‐Gelling Properties of Natural Waxes in Rice Bran Oil: Rheological,Thermal, and Microstructural Study

The main objective of this research was to enhance the understanding of the oil‐structuring properties of natural waxes. A number of natural food‐grade waxes were evaluated for their oil‐gelling properties using a combination of techniques, including rheology, differential scanning calorimetry, and polarized light microscopy. Based on the rheological measurements (oscillatory, flow, and thixotropic behavior), we found that rice bran wax, carnauba Brazilian wax and fruit wax showed weak gelling behavior in rice bran oil (prepared at concentrations as high as 5 % w/w), exhibiting relative low elastic moduli that displayed a high frequency dependency. On the contrary, carnauba wild wax, berry wax, candelilla wax, beeswax, and sunflower wax were efficient oleogelators forming strong gels at concentration of <2 % w/w. We attempt to explain these observed differences in gelling behavior by crystal morphology, network formation, and the final amount of crystalline phase.     

硝基复合肥油性防结块剂的制备

以米糠蜡与矿物油为基础原料,添加十八醇、硬脂酸钾、十八胺3种表面活性剂,开发一种新型油性防结块剂。通过单因素实验优化了米糠蜡与矿物油的配比及3种表面活性剂添加量。当600 g化肥中防结块剂的添加量为1.5 g时,可使22-8-10粒状硝基复合肥的防结块率达到88%,而且,此防结块剂可改善常见的复合肥结块问题。     

Preparation and characterisation of protein hydrolysates from Indian defatted rice bran meal

Rice bran meal is a very good source of protein along with other micronutrients. Rice bran meal has been utilized to produce protein isolates and respective protein hydrolysates for potential application in various food products. De-oiled rice bran meal, available from Indian rice bran oil extraction plants, was initially screened by passing through an 80-mesh sieve (yield about 70%). A fraction (yield-30%) rich in fibre and silica was initially discarded from the meal. The protein content of the through fraction increased from 20.8% to 24.1% whereas silica content reduced from 3.1% to 0.4%. Rice bran protein isolate (RPI) was prepared by alkaline extraction followed by acidic precipitation at isoelectric point. This protein isolate was hydrolysed by papain at pH 8.0 and at 37 degrees C for 10, 20, 30, 45 and 60 minutes. The peptides produced by partial hydrolysis had been evaluated by determining protein solubility, emulsion activity index (EAI), emulsion stability index (ESI), foam capacity and foam stability (FS). All protein hydrolysates showed better functional properties than the original protein isolate. These improved functional properties of rice bran protein hydrolysates would make it useful for various application especially in food, pharmaceutical and related industries.     

Separation and Determination of Wax Content Using 100-Å Phenogel Column

Rice bran wax (RBW) is a by product of rice bran oil refinery. Crude RBW from refineries in Thailand had only 20–40% of the wax ester. The major impurity was triglyceride (TG). Purification of RBW requires a rapid and reliable method of analysis. In this study, a modified size exclusion HPLC column (100-Å Phenogel) was reported. Degree swellings of the gel matrix were controlled by isooctane–toluene mobile phase ratio. With pure toluene as the mobile phase, the gel matrix is fully swollen. Wax and TG could not be separated. With 65:35 (v/v) of isooctane–toluene, wax and TG as well as other lipids were baseline separated. The resolution (Rs) between wax and TG was greater than 1.5. Acetic acid (0.1% or higher) in the mobile phase could suppress peak tailing and improved separation of the lipid containing active hydroxyl groups such as free fatty acid, diglyceride and monoglyceride without affecting retention times of the wax and the TG. Separation of lipids in crude RBW could be completed in a single run on the modified Phenogel column (100 Å) with the total analysis time less than 15 min. The relationship between the amount of wax in the sample and the peak area was linear with the R ² greater than 0.98.     

Rapid equilibrium extraction of rice bran oil at ambient temperature

Rapid equilibrium extraction of soybean flour has been effective in obtaining an oil with reduced phospholipid content. This technique was examined to obtain a low phospholipid and low free fatty acid rice bran oil (RBO). The amount of RBO extracted with hexane from 1 g of rice bran at 22°C was measured over a 10-min period. The amount of oil extracted from variable amounts of bran with a fixed volume of solvent was also studied. Ninety percent of the oil was extracted in one minute, with 93% of the total RBO being extracted after ten minutes. This compares with the 98% yield obtained from soy flour, but increasing the amount of bran used did not reduce the extraction rate. This extraction method produced a good quality RBO with low phospholipid, low free fatty acid and low peroxide values.     

Margarine from Organogels of Plant Wax and Soybean Oil

Organogels obtained from plant wax and soybean oil were tested for their suitability for incorporation into margarine. Sunflower wax, rice bran wax and candelilla wax were evaluated. Candelilla wax showed phase separation after making the emulsion with the formulation used in this study. Rice bran wax showed relatively good firmness with the organogel, but dramatically lowered firmness for a margarine sample. Sunflower wax showed the greatest firmness for organogel and the margarine samples among the three plant waxes tested in this study. Firmness of the margarine containing 2–6 % sunflower wax in soybean oil was similar to that of margarine containing 18–30 % hydrogenated soybean oil in soybean oil. The firmness of commercial spread could be achieved with about 2 % sunflower wax and that of commercial margarine could be achieved with about 10 % of sunflower wax in the margarine formulation. Dropping point, DSC and solid fat content of the new margarine containing 2–6 % sunflower wax showed a higher melting point than commercial margarine and spreads.     

Quantitation of steryl ferulate andp-coumarate esters from corn and rice

The principal steryl ferulate andp-coumarate esters of different fractions from processed corn brans and corn oils, unrefined and refined, and from rice bran and rice bran oil were quantified by high-performance liquid chromatography. The results show that hexane-extracted corn oils yield more than five times the amount of esters compared to expeller processed oils. The yields of esters from bran and related products ranged from 0.07 to 0.54 mg/g of bran. Unrefined corn oils had levels from 0.18 to 8.6 mg/g for oil from hexane-extracted bran. By comparison, rice bran had ester levels of 3.4 mg/g of bran, and rice bran oil had levels of 15.7 mg/g of oil. The predominant esters from corn were sitostanyl and campestanyl ferulate, and sitostanyl and campestanylp-coumarate. The principal esters from rice bran were cycloartenyl, 24-methylenecy-cloartanyl, and campesteryl ferulate. Rice bran oils had low levels of 24-methylenecycloartanyl but high levels of cyclobranol esters. The data presented provide a direct comparison of steryl ferulate andp-coumarate levels in the two cereals, and will aid in selecting the most suitable sources for the isolation of these compounds from corn products. Based on a paper presented at the Symposium on the “Regulation of Biosynthesis and Function of Isopentenoids,” Atlanta, Georgia, May 1994.     

Lipase catalyzed synthesis of neutral glycerides rich in micronutrients from rice bran oil fatty acid distillate

Neutral glycerides with micronutrients like sterols, tocopherols and squalene may be prepared from cheap raw material like rice bran oil fatty acid distillate (RBO FAD). RBO FAD is an important byproduct of vegetable oil refining industries in the physical refining process. Glycerides like triacylglycerols (TAG), diacylglycerols (DAG) and monoacylglycerols (MAG) containing significant amounts of unsaponifiable matter like sterols, tocopherols and hydrocarbons (mainly squalene) may certainly be considered as novel functional food ingredients. Fatty acids present in RBO FAD were esterified with glycerol of varying amount (1:0.33, 1:0.5, 1:1 and 1:1.5 of FAD : glycerol ratio) for 8 h using non-specific enzyme NS 40013 (Candida antartica). After esterification the product mixture containing mono, di- and triglycerides was purified by molecular distillation to remove excess free fatty acids and also other volatile undesirable components. The purified product containing sterols, tocopherols and squalene can be utilized in various food formulations.     

Soy processing: From beans to ingredients

Soybean processing does not end with the products oil and meal. To the food ingredient business, this is only the beginning. This presentation is a simplified general scheme to show the processing of soybeans from the whole bean to each of its end protein ingredients and to show where they might fit into the food business. It portrays bean preparation and oil extraction, meal handling, and conversion of the meal into food ingredients. Soy flour, soy concentrates, soy isolates, and modified protein products, such as spun fibers and textured vegetable protein products, are covered. Some values and applications of the ingredients also are discussed. One of 13 papers presented in the symposium, “Soy Protein,” at the AOCS Spring Meeting, Mexico City, April 1974.     

Phytosterols in cereal by-products

Phytosterols are hypocholesterolemic. Like corn fiber oil, the lipid extracts of certain cereal by-products may be rich sources of these health-promoting compounds. The objective of this research was to examine the phytosterol content and composition of various cereal by-products. Total lipids in rice bran, wheat bran, wheat germ, durum wheat (bran and germ mixture), oat bran, oat hull, and corn fine fiber were extracted, and the sterol profiles of the extracted lipids were analyzed by GC. Rice bran contained the most lipids (22.2%), followed by wheat germ, durum wheat, oat bran, wheat bran, and oat hull; corn fine fiber contained the least amount of lipids (1.7%). Sitosterol, campesterol, and stigmasterol were the major phytosterols in these lipid extracts, whereas brassicasterol was detected only in wheat samples. Rice bran oil contained considerable amounts of cycloartenol and 24-methylenecycloartanol, which were unique to these samples. Total sterol concentrations in extracted lipids were similar for rice bran, wheat bran, wheat germ, and durum wheat (21.3–15.1 mg/g), but they were very low in oat bran lipids and oat hull lipids (3.4 and 8.2 mg/g, respectively). Corn fine fiber lipids contained the highest amount of sterols (48.3 mg/g). Rice bran appears to be the best source of phytosterols, with the highest oil content and high concentration of sterols.     

Simultaneous recovery of wax and oil from rice bran by filtration-extraction

Summary Hard rice waxes of high melting points have been obtained directly from rice bran while simultaneously producing oil. These waxes were produced by the following two methods. 1. selective cold hexane-extraction of cooked rice bran to remove the oil, hot hexane-extraction to remove the wax, chilling of the hot miscella and separation of the precipitated wax by centrifugation; 2. single hot hexane-extraction of raw or cooked rice bran, hot water washing and chilling of the miscella, separation of the wax precipitate by settling or centrifugation, and multiple cold hexane-washings of the wax. Wax can also be processed from rice oil settlings by the latter method after a miscella has been prepared. The cold extraction-hot extraction method should be preferable as a process when conducted on a single continuous filtration-extraction unit without reslurrying. Indications are that oil refining losses may be decreased by this method. Yields of rice wax varied from 0.22 to 0.31% of the original rice bran, or 1.29 to 1.82% of the extracted oil. Presented at the annual fall meeting, American Oil Chemists’ Society, Nov. 2–4, 1953, Chicago, Ill. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, United States Department of Agriculture.     

Oxidative stability and characterization of oleogels obtained from safflower oil-based beeswax and rice bran wax and their effect on the quality of cake samples

Safflower oil-based oleogels were produced from beeswax and rice bran wax. Oleogels demonstrated higher oxidative stability than shortening at the cooking temperature. Peroxide values in shortening, rice bran wax oleogels, and beeswax oleogels samples were found in the range of 4.8–27.76, 13.21–20.45 and 4.30–7.72 meqO₂kg⁻¹ oil. Following oleogelation, there was no significant change in fatty acid composition of safflower oil. In addition, after baking process, the changes in the major fatty acids were not determined to be significant. Solid fat content ratios (carried out at 35°C) of rice bran wax oleogels, in beeswax oleogels and in shortening samples were defined in the range of 4.10%–7.70%, 0.80%–5.00%, and 9.61%, respectively. The highest oil binding capacity was revealed in beeswax oleogels with 99.93%–99.98%. The shortest crystallization time was determined as 3 min in oleogel containing 10% rice bran wax. Cakes consisted of oleogel were acceptable in terms of texture and sensory properties compared to cake produced with shortening. Sensory results revealed that some cakes produced with oleogels were found to be more acceptable as compared with control group samples. In this respect, oleogels produced with safflower oil-based beeswax and rice bran wax could be used instead of commercial solid fat widely used in the cake industry.     

Rice brain oil. I. Oil obtained by solvent extraction

1. Freshly milled rice bran has been extracted with commercial hexane and the recovered oil and extracted meal examined for their respective content of wax. The oils were refined and bleached by standards as well as several special methods. The crude, caustic soda refined, and several refined and bleached oils were examined spectrophotometrically.
2. When freshly milled rice bran of good quality is extracted with commercial hexane, an oil of relatively low free fatty acid content is obtained. This oil possesses good color and is as stable as other similar types of crude oils.
3. If the oils is extracted from the brain at a temperature below about 10°C. and the extraction is discontinued at the right time, the extracted oil represents 90–95% of the total lipids in the brain and contains very little wax. This wax, which is readily extracted with hot commercial hexane as well as other types of solvents, amounts to about 3–9% of the total extractable lipids.
4. When subjected to ordinary caustic soda refining methods, good rice brain oils behave much like cottonseed oils of comparable free fatty acid content. Both caustic soda refining in a hydrocarbon solvent and refining with sodium carbonate result in refining losses approximating the absolute or Wesson loss.
5. Some of the refined oils when bleached according to usual practice produce products acceptable for use in the edible trade. However, refined rice bran oil has a definitely greenish cast resulting from the presence of chlorophyll, but this color can be removed by bleaching with a small amount of activated acidic clay.

     

Effect of method of stabilization on aqueous extraction of rice bran oil

Rice bran oil is widely used in pharmaceutical, food and chemical industries due to its unique properties and high medicinal value. In this study aqueous extraction of rice bran oil from rice bran available in Sri Lanka, was studied. Key factors controlling the extraction and optimal operating conditions were identified. Several methods of bran stabilization were tested and the results were analyzed. The yield and quality of aqueous extracted oil was compared with hexane extracted oil.Aqueous extraction experiments were conducted in laboratory scale mixer–settler unit. Steaming, hot air drying, chemical stabilization and refrigeration better controls the lipase activity compared to solar drying. Steaming is the most effective stabilization technique. The extraction capacity was highest at solution pH range 10–12. Higher oil yield was observed at higher operating temperatures (60–80 °C). Kinetic studies revealed that extraction was fast with 95% or more of the extraction occurring within first 10–15 min of contact time. Parboiling of paddy increases the oil yield. Highest oil yield of 161 and 131 mg/g were observed for aqueous extraction of parboiled bran and raw rice bran respectively. The aqueous extracted oil was low in free fatty acid content and color compared to hexane extracted rice bran oil and other commonly used oils. Major lipid species in rice bran oil were oleic, linoleic and palmitic.     

Effects of flour sources on acrylamide formation and oil uptake in fried batters

Food batters were formulated using flours of long-grain rice, waxy rice, wheat, or corn. Acrylamide and oil analyses were conducted for the flour and the corresponding fried batter. During frying, the formation of acrylamide ranged from 82 ng/g for the long-grain rice batter to 263 ng/g for the corn batter. Oil uptake ranged from 21.4% for the long-grain rice batter to 47.3% for the wheat batter. The incorporation of 5% pregelatinized rice flour and 1.5–3.0% milk as functional additives into the long-grain rice batter only slightly increased the acrylamide and oil contents.     

Effect of dewaxing pretreatment on composition and stability of rice bran oil: Potential antioxidant activity of wax fraction

The effect of dewaxing pretreatment on rice bran oil composition and stability was investigated, as well as the possibility to use rice bran oil waxes as natural antioxidants at high temperatures. A correlation between wax content and dewaxing time was noticed. The pre‐dewaxing process led to a loss of minor compounds, which negatively affected the oxidative stability index (OSI) of the dewaxed oil. The addition of rice bran oil waxes improved the oil stability index and heat stability of sunflower oil. An increase of 60% of the OSI and a significant decrease in polymer formation (59.2%) were observed.