Rice bran, obtainment

The sterols and sterolins in rice bran are potent immunomodulators. The best response was obtained with a 100 1 sterol/sterolin mixture that demonstrated T-cell proliferation from 20% to 920% and active cell antigens after four weeks in human subjects (Bouic et al, 1996). Another in vitro experimental study with sterol/sterolins, demonstrated a significant increase in cytokinines, interleukin-2 and y-interferon between 17% and 41 % in addition to an increase in natural killer cell activity. These experiments (Bouic et al, 1996) prove that sterol/sterolins are potent immunomodulators with important implications for the treatment of immune dysfunction. Rice bran products are excellent dietary supplements for the improvement of immune function. It is probable that the effects of rice bran on diabetes, CVD and cancer all result from improved immune function. 

REDDY SASTRY c V, RUKMINI c, IKE LYNCH, MCPEAK D (1999) Process for obtaining micronutrient enriched rice bran oil. US Patent 5,985,344 RiceX Company, Proprietary Technology. 

Different ratios of the solid substrates, wheat bran, rice bran and rice husk, were done and the activity of the pectinases was compared in Figure 5. The mixture of wheat bran, rice bran and rice husk in the ratios of 9 9 2 or 6 12 2 appeared to be two of the best composition ratios for growth of the fungus and the pectinase production.The ratio of 6 12 2 was selected for the enzyme production since rice bran was cheaper than wheat bran and locally obtained. 

Figure 6,7 and 8 showed the results of the pectinase activity when produced in the solid substrates containing wheat bran, rice bran and rice husk in the ratio of 6 12 2. The highest activity obtained when the strain was grown on the solid substrates with 58 % initial moisture content, pH adjusted to 5.7 and incubation temperature was at 32°C. Under these conditions, the highest activity of the enzyme that could be obtained from Rhizopus sp. 26R was ca. 700 units of enzyme activity per gram of solid substrates. 

Mavicyanin (Mj = 18,000) is obtained from green squash (Cucurbito pepo medullosa), where it occurs alongside ascorbate oxidase [64]. It has a peak at 600 nm (e 5000 M cm and reduction potential of 285 mV. Further studies on this and the mung bean and rice bran proteins [65, 66] would be of interest. All the above type 1 Cu proteins have an intense blue color and characteristic narrow hyperfine EPR spectrum for the Cu(II) state. Table 3 summarizes the properties of those most studied. There is some variation in reduction potential and position of the main visible absorbance peak. In the case of azurin, for example, the latter is shifted from 597 to 625 nm. Stellacyanin has no methionine and the identity of the fourth ligand is therefore different [75]. The possibility that this is the 0(amide) of Gln97 has been suggested [63b]. It now seems unlikely that the disulfide is involved in coordination. Stellacyanin has 107 amino acids, with carbohydrate attached at three points giving a 40% contribution to the M, of 20,000 [75]. 

While the hemicelluloses obtained from the germ, aleuron, and caryopsis coat cell walls all showed a similar monosaccharide composition, this was not the case for the endosperm tissue. Thus, a major difference in the structure of hemicellulosic polysaccharides exists between the preparations obtained from the endosperm cell walls and those from the cell walls of the other parts of the grain, i.e., rice bran. (Rice bran consists of the caryopsis coat, aleuron layer and germ.) Comparison of the detailed structural features of the hemicellulosic polysaccharides of endosperm and bran cell walls will be discussed in the following sections. 

Figure 3. Structure of hemicellulosic polysaccharides obtained from rice bran, (a) Deduced from the results of methylation analysis described in ref. 13.

Table III. Possible Structure of Oligosaccharides Obtained by the Partial Acid Hydrolysis of Rice Bran Arabinogalactoglucuronoxylan...

Rice bran oil appears to give similar results to those obtained with tallow when added as an energy source to broiler diets at levels up to 40g/kg (Purushothaman et al, 2005). 

In the present study, we evaluated a two-step process for succinic acid production. The first process was fumaric acid production by Rhizopus sp. using rice bran, and the second process was succinic acid production by Enterococcus faecalis RKY1 (5-7) using fungal culture broth obtained in the first process. We investigated the effects of rice bran on fumaric acid production and optimized the culture medium for fumaric acid fermentation. Furthermore, we optimized the culture conditions for succinic acid conversion from fumaric acid produced by the first process. 

Rice Bran Wax occurs as a hard, slightly crystalline substance that ranges in color from tan to light brown. It is a refined wax obtained from rice bran. It is soluble in chloroform, but is insoluble in water. 

Most of the studies on the antioxidant activity of SF have been performed using y-oryzanol or the addition of rice bran oil (containing also other components with antioxidant activity), and from those studies it is not possible to evaluate the activities of single compounds. Further, the information obtained on the relative antioxidant activities of the different FSs varies from one study to another (Table 10.2). One reason for this may be that the range of antioxidant tests used in these studies is wide and the results, therefore, are not necessarily comparable. More studies are definitely needed to fully understand the possible differences in the antioxidant activity of different SFs in different oxidation systems. 

Limonene has recently been used in rice bran oil extraction as an alternative to hexane, which is commonly used in such processes.The yield and quality of crude rice bran oil obtained from the limonene extraction were almost equivalent to those obtained using hexane. Interestingly, although antioxidants were not present in the limonene, only a very small amount (<1 wt%) of oxidation product was found in the recovered limonene, and therefore the solvent is potentially recyclable in such a process. This also suggests that... 

Attempts have been made to recover the wax using cold and hot extraction (2). Wax yields of 1.29-1.82% of the crade oU are obtained. Continuous dewaxing of rice bran oil by chilling the oil or miscella to less than 20°C followed by filtration through plate and frame filters is practiced. Kinsey and Hummell (44) reported on the use of sodium silicate as an aid for dewaxing. The characteristics and physical properties of a purified rice bran wax are similar to carnauba wax (45). 

A major problem with rice bran oU extraction is the high lipase activity, which results in FFA formation within a few days of milling particularly at high temperature and humidity. Free fatty acid content in rice bran increases during storage, i.e., 2-A% in a fresh crop, 5-8% in 1-year grain, and >10% in a 2-year-old crop (105). Thus, lipase is inactivated to stabihze rice bran prior to oil extraction (88). Heat-stabilized bran may be stored up to three months. However, oil extraction should be carried out within the first month to obtain better efficiency and higher quality oil. 

Rice bran was obtained from a local rice processor in Bangkok, Thailand. It was defatted with hexane to produce DRB using the procedure described by Wang et al. (75), then air dried, ground in a san jle mill and sieved through 80 mesh screen. DRB was packed in polyethylene bags and stored at 5°C. 

We concluded that SC-CO2 can be used to efficiently and rapidly extract oil from all by-products of rice processing. The initial analyses indicated that the quality of the SC-CO2 extracted oil is as suitable for human consumption as the traditionally extracted one. The exhausted cake is still rich in high quality proteins and phosphatides (22). The possibility of obtaining a SC-C02-extracted rice oil rich in y-otyzanol and other antioxidants (e.g. vitamin E) indicates that this rice oil can be considered a nutraceutical product Saito et al. (23) and Dunford and King (24, 25) used SC-CO2 to fractionate rice bran oil by SFF. Their results are extended by the present study to take advantage of the effect of SC-CO2 extraction eventually combined wilh SC-CO2 fractionation to over again increase the value of rice by-products. 

However, ferulic acid is also obtainable from eugenol in an aerobic process, in the presence of Pseudomonas strains. In Asia, ferulic acid is obtained form rice bran. 

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