• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.883-895
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• 2014

This study investigated quality characteristics of pan breads prepared with 0, 10, 20, 30 and 40% purple rice flour and naturally fermented blueberry-rice starters. RVA (Rapid Visco Analyzer) analysis showed that wheat flour retrogradation was not retarded by addition of purple rice flour. Using amylography, gelatinization tem. perature of purple rice flour samples was higher than that of the control, whereas maximum viscosity temperature. and maximum viscosity of purple rice flour samples were lower than those of the control. Weights of pan breads containing purple rice flour were lower than that of the control, whereas volume, specific volume and baking loss rate were higher than those of the control. The anthocyanin contents and antioxidative activites as measured by DPPH radical scavenging activity of breads increased as the concentration of purple rice flour increased. The moisture content of pan breads containing purple rice flour decreased as storage time increased. The pH of breads containing purple rice flour was higher than that of the control. Color L value decreased, whereas a and b values increased significantly, as storage time increased. In texture analyzer measurement, hardness of breads containing purple rice flour significantly increased as storage time increased. Breads containing 10~20% purple rice flour showed acceptable sensory properties, such as mouth feel, appearance, flavor, texture, taste and overall acceptability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.1-9
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• 1996

The edible natural pigments extracted from plant organs become steadly popular to consumer because of those physiological functions desirable for food preservation and human health in recent years. There are a number of colored rice genotypes from light brown to blackish purple via reddish brown and purple. Some researchers reported their results on extraction recipes and identification of chemical structure of the pigments from the colored rice. The pigments extracted from colored rices can be largely divided into two types of anthocyanin and tannin pigments. Anthocyanin pigments are mainly contained in purple or blackish purple rice while tannin pigments are mainly contained in brown or reddish brown rice. Some brownish purple rices showed two peaks of tannin and anthocyanin pigments simultaneously. Purple rices showed better extraction of pigments in $0.1\%$ HCl-contained $80\%$ methanol or $0.5\%$ malic-acid-contained $80\%$ ethanol, while red rices revealed better extraction of pigments in $0.01\%$ citric-acid-contained $80\%$ ethanol. The anthocyanin pigments are generally unstable to heat, light and acidity of solution. The pigments extracted from colored rice can be preserved stably under the dark and cool(<$5^{\circ}C$) condition and at pH $2.0\~4.0$. The anthocyanin pigments of purple rice are mainly composed by cyanidin-3-glucoside (chrysanthemin). The other pigment fractions in purple rice were identified to peonidin-3-gluco-side, malvidin-3-galactoside(uliginosin) and cyanidin-3-ramnoglucoside(keracyanin). The pericarp coloration of purple rices is controlled by three complimentary genes C (anthocyanin), A(activator) and $Pl^{w}$(purple leaf) genes, while the red rices are expressed by complimentary interaction between Rc(basic substance of pigment) and Rd(distribution of pigment) genes or C and $Pl^{w}$ genes. Recently, the antioxidation and antimutagenic activity in main component of anthocyanin pigments extracted from colored rice were identified. The natural pigments from colored rice can be useful for beverages, cakes, ice scream, cosmetic and so on.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.555-563
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• 2016

Purple rice is a strain of glutaneous rice rich in anthocyanins and ${\gamma}$-oryzanol. Both types of compounds are involved in antioxidant and lipid metabolism of mammals. Three experimental diet types were used which consisted approximately by half either of purple rice, white rice or corn. Diets were fed to $3{\times}10$ pigs growing from about 30 to 100 kg. Meat samples were investigated either as raw or cured loin chops or as smoked bacon produced from the belly. Various physicochemical traits were assessed and data were evaluated by analysis of variance. Traits describing water-holding capacity (drip, thaw, and cooking losses) and tenderness (sensory grading, shear force) of the meat were mostly not significantly affected by the diet type. However, purple rice feeding of pigs resulted in lower fat and cholesterol contents of loin and smoked bacon compared to white rice, but not compared to corn feeding except of the fat content of the loin. The shelf life of the raw loin chops was improved by purple rice as well. In detail, the occurrence of thiobarbituric acid reactive substances after 9 days of chilled storage was three to four times higher in the white rice and corn diets than with purple rice. The n-6:n-3 ratio in the raw loin chops was 9:1 with purple rice and clearly higher with 12:1 with the other diets, meat lipids. Level and kind of effect of purple rice found in raw meat was not always recovered in the cured loin chops and the smoked bacon. Still the impression of flavor and color, as well as overall acceptability were best in the smoked bacon from the purple-rice fed pigs, whereas this effect did not occur in the cured loin chops. These findings suggest that purple rice has a certain, useful, bioactivity in pigs concerning meat quality, but some of these effects are of low practical relevance. Further studies have to show ways how transiency and low recovery in meat products of some of the effects can be counteracted.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9517-9522
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• 2014

Purple rice (Oryza sativa L. var. indica) cv. Kum Doisaket is cultivated in northern Thailand. This study evaluated the mutagenic and antimutagenic properties of hydrophilic and lipophilic components of purple rice using the Ames test. The seed and hull of purple rice were extracted with hexane, methanol, ethanol, and water. The methanol extracts had the highest amounts of phenolic acids and flavonoids, while the hexane extracts contained large amount of tocols and ${\gamma}$-oryzanol. None of the extracts were mutagenic in Salmonella typhimurium strains TA98 and TA100. The hexane extract of rice hull and the methanol extract of rice seed were strongly effective against aflatoxin B1- and 2-amino-3, 4 dimethylimidazo (4, 5-f) quinoline-induced mutagenesis, while aqueous extracts showed weakly antimutagenic properties. All extracts with the exception of aqueous extracts enhanced the number of revertant colonies from benzo (a) pyrene induced-mutagenesis. None of the extracts inhibited mutagenesis induced by the direct mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and sodium azide. The hull extracts showed more potent antimutagenicity than the seed extracts. Based on a chemical analysis, ${\gamma}$-oryzanol and ${\gamma}$-tocotrienol in the hull and cyanidin-3-glucoside and peonidin-3-glucoside in the seed are candidate antimutagens in purple rice. The antimutagenic mechanisms of purple rice might be related to either modulation of mutagen metabolizing enzymes or direct attack on electrophiles. These findings supported the use of Thai purple rice as a cancer chemopreventive agent.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.173-178
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• 2006

Anthocyanin in blackish purple rice is composed of cyanidin, peonidin, malvidin, pelargonidin and delphinidin flavylium ion and their glucosides, which shows antioxidant activity similar to a-tocoperol. It has been demonstrated that cyanidin-3-glucoside(C3G) of anthocyanin has a high-potency antioxidant activity, and is a prominent in anticancer and antithrombotic activity. In analysis of content of anthocyanin from the genetic source of blackish purple rice, the level of C3G was approximately 80% of total contents of anthocyanins, and showed the highest content in Heugjinjubyeo, of which contains an amount of 500 mg by weight of 100g brown rice in comparison that most of varieties has less than 50mg by weight of 100g brown rice. We found that C3G pigment in blackish purple rice was considerably affected by cultural season, cultivation area, ripening temperature, and weather condition, etc. as well as genetic properties. In cross combination between Heugjinjubyeo and Suwon425, intermediate parent $F_9$ generation which was three times higher or more in C3G content than that of Heugjinjubyeo was bred, of which it contained an amount of 1678 mg by weight of 100g brown rice, and we called it 'C3GHi' Rice. And, we found that the C3GHi rice was more excellent than that of the existing Heugjinjubyeo in anticancer and antithrombotic activity. Methanol extract from Heugjinjubyeo was fractionated by organic solvents in order of n-hexane, $CH_{2}Cl_2$ and n-BuOH, and then oryzafuran, quercetin, vanillic acid and protocatechuic acid and their structures from the n-BuOH fraction were ascertained. Oryzafuran of these compounds was a natural compound found firstly in nature. Quercetin and protocatechuic acid besides new compound oryzafuran showed excellent antioxidant ability to vitamin C. These results suggest that blackish purple rice has very high value as a source of various functional food as well as staple food.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.2
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• pp.250-256
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• 2013

We investigated noodles supplemented with turmeric, purple sweet potato, or seaweed (Hizikia fusiforme) for their functional properties, including total phenol, flavonoid contents, electron donating abilities, and nitrite scavenging abilities. The percentage of total phenolic compounds in turmeric, purple sweet potato, and seaweed noodles were 2.40, 2.47, and 1.27%, respectively, whereas the percentage of total flavonoid contents were 0.55, 0.92, 0.74%, respectively. Results showed that purple sweet potato noodles had the highest amount of phenolic compounds and flavonoids compared to the other types of noodles. The electron donating abilities of the turmeric, purple sweet potato, and seaweed noodles were 4.72, 4.11, and 3.11 at 1,000 ppm respectively. The nitrite scavenging abilities of the turmeric, purple sweet potato, and seaweed noodles were 75.93, 79.81, and 73.51% at pH 1.2, respectively. Purple sweet potato noodles had the highest nitrite scavenging abilities, with an effect better than BHT and ascorbic acid. The ferrous ion chelating effect of turmeric, purple sweet potato, and seaweed noodles were 12.17, 13.63, and 42.12%. All of the experimental results showed good anti-oxidative activity; thus rice noodles supplemented with turmeric, purple sweet potato, or seaweed, have good functional effects for human beings.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.2
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• pp.211-217
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• 2013

We investigated the quality characteristics of rice noodles supplemented with turmeric, purple sweet potato, or seaweed (Hizikia fusiforme). RVA (Rapid Visco Analyser), color, water activity, texture, and cooking properties were tested. Initial gelatinization temperature of noodles containing turmeric were the highest. Peak viscosity, holding strength, break down, final viscosity, and set back of noodles containing purple sweet potato were highest, indicating that the gelatinization state was more unstable and retrogradation would occur faster. The L value of the seaweed noodle was the lowest, while the a and b value of the turmeric noodles were $7.3{\pm}0.3$ and $40.2{\pm}1.3$ respectively, higher values than turmeric and seaweed noodles. Water activity of the seaweed noodle was 0.665, higher than turmeric and purple sweet potato noodles. Cooking properties (including weight, volume, and water absorption) and turbidity of seaweed noodles showed the highest growth rate. In terms of texture, the hardness was highest in purple sweet potato noodles, and the cohesiveness and gumminess was highest in seaweed noodles. The quality characteristics of rice noodles supplemented with turmeric, purple sweet potato, or seaweed showed that seaweed noodles were stable in gelatinization and cooking properties.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3371-3376
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• 2015

Pigmented rice bran has been suggested to be a valuable source of beneficial phytochemicals. We investigated genotoxic and anti-genotoxic effects of purple rice bran extract (PRBE) in rats using a liver micronucleus assay. Purple rice bran was extracted with methanol, obtaining large amounts of phenolic compounds, including anthocyanins and small amounts of gamma-oryzanol. The experimental protocols were divided into two sets. Male rats were divided into three groups. Group 1 was a negative control, while Groups 2 and 3 were fed with 100 and 500 mg/kg bw of PRBE, respectively, for 28 days. PRBE had no effect on micronucleus formation or xenobiotic metabolizing enzymes in rat liver. Experiments concerning the effect of PRBE on $AFB_1$ showed that PRBE significantly lessened the amount of micronucleated hepatocytes in $AFB_1$ treated rats. Furthermore, it modulated metabolic activation of $AFB_1$ metabolism in the liver by suppressing activity and protein expression of CYP1A2, CYP3A and CYP 450 reductase, and enhancing phase II enzymes including GST and UGT. Overall, purple rice bran extract was not genotoxic in rats. It exhibited anti-genotoxicity by modulation some xenobiotic enzymes active in $AFB_1$ metabolism.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6541-6548
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• 2013

Pigmented rice is mainly black, red, and dark purple, and contains a variety of flavones, tannin, polyphenols, sterols, tocopherols, ${\gamma}$-oryzanols, amino acids, and essential oils. The present study evaluated the cytotoxic effects of purple rice extracts (PREs) combined with chemotherapeutic drugs on human cancer cells and mechanisms of cell death. Methanolic (MeOH) and dichloromethane (DCM) extracts of three cultivars of purple rice in Thailand: Doisaket (DSK), Nan and Payao (PYO), were tested and compared with white rice (KK6). Cytotoxicity was determined by 3-(4, 5-dimethyl)-2, 5-diphenyltetrazolium bromide (MTT) assay in human hepatocellular carcinoma HepG2, prostate cancer LNCaP and murine normal fibroblast NIH3T3 cells. MeOH-PYO-PRE was the most cytotoxic and inhibited HepG2 cell growth more than that of LNCaP cells but was not toxic to NIH3T3 cells. When PREs were combined with paclitaxel or vinblastine, they showed additive cytotoxic effects on HepG2 and LNCaP cells, except for MeOH-PYO-PRE which showed synergistic effects on HepG2 cells when combined with vinblastine. MeOH-PYO-PRE plus vinblastine induced HepG2 cell apoptosis with loss of mitochondrial transmembrane potential (MTP) but no ROS production. MeOH-PYO-PRE-treated HepG2 cells underwent apoptosis via caspase-9 and-3 activation. The level of ${\gamma}$-oryzanol was highest in DCM-PYO-PRE (44.17 mg/g) whereas anthocyanin content was high in MeOH-PYO-PRE (5.80 mg/g). In conclusion, methanolic Payao purple rice extract was mostly toxic to human HepG2 cells and synergistically enhanced the cytotoxicity of vinblastine. Human HepG2 cell apoptosis induced by MeOH-PYO-PRE and vinblastine was mediated through a mitochondrial pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.749-755
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• 2014

Background: Purple rice has become a natural product of interest which is widely used for health promotion. This study investigated the preventive effect of purple rice extract (PRE) mixed diet on DMH initiation of colon carcinogenesis. Materials and Methods: Rats were fed with PRE mixed diet one week before injection of DMH (40 mg/kg of body weight once a week for 2 weeks). They were killed 12 hrs after a second DMH injection to measure the level of $O^6$-methylguanine and xenobiotic metabolizing enzyme activities. Results: In rats that received PRE, guanine methylation was reduced in the colonic mucosa, but not in the liver, whereas PRE did not affect xenobiotic conjugation, with reference to glutathione-S-transferase or UDP-glucuronyl transferase. After 5 weeks, rats that received PRE with DMH injection had fewer ACF in the colon than those treated with DMH alone. Interestingly, a PRE mixed diet inhibited the activity of bacterial ${\beta}$-glucuronidase in rat feces, a critical enzyme for free methylazoxymethanol (MAM) release in the rat colon. These results indicated that purple rice extract inhibited ${\beta}$-glucuronidase activity in the colonic lumen, causing a reduction of MAM-induced colonic mucosa DNA methylation, leaded to decelerated formation of aberrant crypt foci in the rat colon. Conclusions: The supplemented purple rice extract might thus prevent colon carcinogenesis by the alteration of the colonic environment, and thus could be further developed for neutraceutical products for colon cancer prevention.