Fermented Rice Product Research Articles

Development of a Rapid LC/DAD/FLD/MSn Method for the Simultaneous Determination of Monacolins and Citrinin in Red Fermented Rice Products

Red fermented rice is used worldwide by many patients as an alternative therapy for hyperlipidemia; however, the discovery of a toxic fermentation byproduct, citrinin, causes much controversy about the safety of red mold rice products. A new and fast high-performance liquid chromatography method was developed and validated for simultaneous determination of cholesterol-lowering compounds monacolin K (lovastatin), monacolin K hydroxy acid, and other monacolins present in red fermented rice as well as nephrotoxic mycotoxin citrinin in a single run using connected diode array and fluorescence and mass spectrometric detectors. The proposed method was successfully applied for the analysis of red fermented rice food samples and various dietary supplements also containing other natural lipid-lowering agents. The deviations between label content and levels of active compounds found in investigated samples as well as high batch-to-batch variation found in one product indicate that the regular quality control of red fermented rice products is of great importance.

富铬灵芝发酵米谷粉之抗氧化和降血糖研究

灵芝是华人重要的药用和食用菇蕈类，灵芝最主要的活性成分为多醣和三萜，具有抗氧化、抗肝炎、降血糖、抗发炎和降胆固醇的活性；三价铬对于糖尿病有血糖控制与葡萄糖耐受性有改善的作用。添加不同三价铬浓度(0, 100 and 200 ppm)于水分含量为50%的糙米基质中，并在30℃下，灵芝发酵14天，进一步分析抗氧化成分和微波萃取物的降血糖效果。添加200 ppm的三价铬会有较佳的多醣和总多酚含量、螯合亚铁能力及还原力。分别以0%、25%、50%、75%、95%酒精以300 W微波萃取富铬灵芝发酵糙米产物10 min，其中25%酒精比例可以获得较多的有效成分，其中粗多醣含量19.75%，粗三萜0.34%，总铬0.0026%。在以小鼠动物模式分别以正常组、糖尿病(STZ)对照组、糖尿病管喂50 ppm灵芝萃取物四周，记录采水量及采食量，并每周测量空腹血糖，在饮食及饮水部分则是在第二周及第三周开始即有显著降低，在四周后可以发现空腹血糖值有显著降低。 Ganoderma lucidum is one of the most important Chinese medicinal and edible mushrooms. The most im- portant active components of G. lucidum were polysaccharides and triterpenoids. They have been proven to possess many pharmacological functions such as antioxidant, anti-hepatitis, hypoglycemic activity, anti-inflammation and hy- pocholesterolemia. Trivalent chromium for diabetes can improve blood sugar control and glucose tolerance. Therefore, the different chromium concentrations (0, 100 and 200 ppm) were added in brown rice medium with 50% moisture content for 14-day solid-state fermentation of Ganoderma lucidum at 30℃. Further the Ganoderma lucidum fermented brown rice products were extracted by microwave to analyze the antioxidant activities and hypoglycemic effects. The 200 ppm chromium addition level in Ganoderma lucidum fermented brown rice product had higher polysaccharides, total phenol, ferrous ions and reducing power. The different ethanol concentrations (0%, 25%, 50%, 75% and 95%) were used for extracting chromium enriched Ganoderma lucidum fermented rice products by 300 W microwave for 10 min, and 25% ethanol obtained more active compounds, such as 19.75% crude polysaccharides, 0.34% crude triterpe- noids, and 0.0026% total chromium. The mice were divided to normal group, Streptozotocin (STZ)-induced mice groups containing control group and 50 ppm Ganoderma lucidum (GL) extracts group. After 4-week feeding, water intake, feed intake and plasma glucose of mice were analyzed. The feed intake and water intake significantly decreased at STZ-induced mice groups with 50 ppm GL extracts by 25% ethanol after 2-week and 3-week, respectively; and the hypoglycemic effects were appeared after 4-week feeding.

Study of antioxidant activity and anti-cholesterol content on red yeast rice with substrates variation (rice, corn and dried cassava)

Wiyoto H, Andriani MAM, Parnanto NHR. 2011. Study of antioxidant activity and anti-cholesterol content on red yeast rice with substrates variation (rice, corn and dried cassava). Biofarmasi 9: 38-44. Red yeast rice is one of fermented rice product by Monascus purpureus. Traditionally, the substrate used to produce red yeast rice is rice. Usually, the rice with high amylose content is proper to produce red yeast rice than low amylose. The other substrates that be used to produce red yeast rice are corn and dried cassava. The purposes of this research were to determine the effect of substrates variation (rice, corn and dried cassava) on antioxidant activity and anti-cholesterol content in red yeast rice, and to determine the substrate(s) that produce the highest antioxidant activity and anticholesterol content. The design of this research was a Completely Randomized Design with one factor, i.e. the kind of substrates: rice, corn and dried cassava, with three replications. Then, the data were analyzed with ANOVA at a level of significance α=0.05, and continued with DMRT at the same level. This results showed that the effect of substrates kind to antioxidant activity and anti-cholesterol content on red yeast rice. The rice substrate had higher antioxidant activity and anti-cholesterol content than corn and dried cassava substrates. The antioxidant activity and the anti-cholesterol content on red yeast rice from rice substrate were 45.6100% and 0.026600%, respectively. The antioxidant activity and the anti-cholesterol content on red yeast rice from corn substrate were 44.0500% and 0.022833%, respectively, while the antioxidant activity and the anti-cholesterol content on red yeast rice from dried cassava substrate were 42.8333% and 0.013200%, respectively.

Identification of Acetobacter strains from Thai fermented rice products based on the 16S rRNA gene sequence and 16S-23S rRNA gene internal transcribed spacer restriction analyses

Fermented rice flour (khao-khab, a non-glutinous rice) and related products are Thai traditional products. The types of acetic acid bacteria (AAB) microflora in khao-khab have not been reported. In this study, Acetobacter strains were isolated and identified based on the phenotypic and chemotaxonomic characteristics and molecular aspects. Twenty-five acetic acid bacteria isolated from fermented rice products and a starter for sweetened rice in Thailand by an enrichment culture approach, were assigned to the genus Acetobacter by phenotypic and chemotaxonomic characterisations. On the basis of the 16S rRNA gene sequence and 16S-23S rRNA gene ITS restriction analyses, 25 isolates were divided into six groups and identified at the specific level: (1) Group 1 included five isolates, which were identified as A. indonesiensis; (2) Group 2 included two isolates, which were identified as A. lovaniensis; (3) Group 3 included one isolate, which was identified as A. orientalis; (4) Group 4 included eleven isolates, which were identified as A. pasteurianus; (5) Group 5 included three isolates, which were identified as A. syzygii and (6) Group 6 included three isolates, which were unidentified and considered to constitute a new species. Results revealed that various Acetobacter species were distributed in Thai fermented rice flour and related products. A novel Acetobacter species was isolated from the product.

Hypocholesterolemic Action of Fermented Brown Rice Supplement in Cholesterol‐Fed Rats: Cholesterol‐lowering Action of Fermented Brown Rice

ABSTRACT:Fermented rice products have been implicated in vascular injury and atherosclerosis in recent animal and human studies. In the current study, whether consumption of differently processed brown rice diets may change the cholesterol metabolism was evaluated in male Spraque Dawley (SD) rats after 28 d of treatment with diets containing 1% cholesterol. The experimental diets include corn starch alone as control diet (CO) or a diet containing a 50% substitute of CO; uncooked brown rice (UB), cooked brown rice (CB), lactic acid bacteria (LAB), brown rice mixed with LAB (BLAB), and fermented‐brown rice by LAB (FB), respectively. Among them, FB group elicited significantly lower levels of plasma and hepatic triglycerides, plasma total cholesterol, low‐density lipoprotein cholesterol (LDL‐C), and very low‐density lipoprotein cholesterol (VLDL‐C) by 33% to 50%, whereas higher levels of HDL‐C were elicited by 227% compared with the CO group (P < 0.05). These amelioration action on lipid profile in FB group appeared to correspondent to the higher excretions of fecal weight, triglyceride (TG), total cholesterol (TC), and bile acid (P < 0.05). Furthermore, sensory properties such as flavor liking, taste liking, and overall acceptability of the diet were significantly improved by the addition of fermented brown rice. Conclusively, fermented‐brown rice may have a potent cholesterol‐lowering benefits with sensory quality improvement of the diet.

Studies on Lao-Chao Culture Filtrate for a Flavoring Agent in a Yogurt-Like Product

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and NH3 were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 4 :602-609)

Fermentation of rice using amylolytic Bifidobacterium

Twenty-two amylolytic bifidobacteria grown in BHI-starch media were compared for the amylase activity of the intra- and extra-cellular enzymes. The activity of the cells grown in the liquid medium differed considerably. Among the strains tested B. adolescentis Int57 and B. adolescentis ZS8 exhibited higher activities than others. In rice medium containing 0.05% l-cysteine·HCl and 0.2% yeast extract, the amylolytic Bifidobacterium strains grew considerably better than non-amylolytic Bifidobacterium strains. B. adolescentis Int57, which showed highest growth and amylase activity in the rice medium, was chosen and rice fermentation was investigated. The titratable acidity (TA) reached 2.43 and pH decreased to 4.4 after 24 h fermentation. The relative ratio of acetic acid to lactic acid gradually decreased during fermentation. The concentration of reducing sugar and amylase activity gradually increased and reached 14 mg maltose equivalent/ml and 35 mU/ml min, respectively, in 24 h. The accumulated reducing sugar was mostly maltotriose. The layer-separation of fermented product was stabilized by the addition of 1% gelatin. It was suggested that amylolytic bifidobacteria may be used for the production of fermented rice products.

Culture Filtrates from a Fermented Rice Product (Lao‐Chao) and Their Effects on Milk Curd Firmness

ABSTRACTTo develop a new Oriental‐style dairy product, the characteristics of culture filtrate from lao‐chao with Rhizopus oryzae, used as a milk‐clotting agent, and factors (heat‐treatments, calcium, sucrose, and curdling temperature) affecting curd firmness were determined. The optimal conditions for proteolytic activity were around 40°C and pH 3. No activity was detected over the range of pH 8 to 11. After high‐heat treatment (121°C, 15 min) on skim milk, no clotting was observed. Sucrose resulted in the retardation of milk‐clotting. Ca++ could be used to increase curd firmness which also increased from 29. 2–2.8g to 80. 3–4.7g when the curdling temperature was increased from 25°C to 45°C.

Screening and characterization of fungal cultures for a milk-clotting enzyme for use in an oriental style dairy product

SummaryThe aim of this work was to develop new oriental style dairy products coagulated with culture filtrates from lao-chao, a traditional fermented rice product. The fermenting fungal cultures screened wereRhizopus javanicus, Rhiz. oryzae, Rhiz. chinensis, Rhiz. oligosporus, Aspergillus oryzae, Mucor racemosusand chiu-yao, a commercial starter. All the inocula liquefied a steamed glutinous rice base and produced culture filtrates with both milk-clotting and proteolytic activities. Of the fungal products tested,Rhiz. javanicuswas the most successful, producing a good yield of culture filtrate with the desired milk-clotting activity, and the resultant yogurt-like product was more acceptable to consumers than any except that from chiu-yao. The firmness was less acceptable, but this could be improved by using mixed pure cultures ofRhiz. javanicusandM. racemosus.

Lactic acid bacteria in fermented fishery product, “burong bangus”

Abstract Analyses of the microflora of “burong bangus”, a traditional fermented fish and rice product of the Philippines, revealed that a sequential type of fermentation with overlapping growth takes place. Streptococcus initiated the fermentation process and generally persisted up to the latter part of the fermentation. Pediococcus appeared next, but comprised only a small percentage of the microflora. Both Leuconostoc and Lactobacillus appeared on the 3rd day and were generally present up to the end of the fermentation, with Lactobacillus predominating among the microflora in the final days. In the course of characterizing the lactic acid bacteria involved in the fermenting rice-fish mixture, some isolates were found to be capable of hydrolyzing starch. These were revealed to be Gram positive, rod-shaped and catalase negative. Tentative identification of one of the isolates, L137, showed that this strain possesses very similar characteristics to those of Lactobacillus plantarum and Lactobacillus coryniformis subsp. coryniformis . The % G+C of L137 was 45.2 while those of L. plantarum and L. coryniformis subsp. coryniformis are 45.1 and 45.0 respectively. However, L137 differs from the other two in its ability to utilize starch.

The analysis of the quality of red fermented rice (RFR) product with Monascus purpureus 3090

Analysis of red fermented rice product with Monascus purpureus 3090 was conducted on monascus floor product (MFP- 264), MFP-244 and rice monascus product (RMP). Evaluation of microbiological, pigment intensity and lovastatine contentanalysis result was aimed to see quality differences on each production of 5 kg rice raw material. Of both product types(MFP-264, RMP) which only oven dried compare to MFP-244 which is sterilized in autoclave showed a significantly difference of population level on total microorganism colonies, that is mould 26x106 propagule/ml, bacteria 13x106 cell/ml(MFP-264), mould 85x106 propagule/ml, bacteria 265x106 cell/ml (RMP). The MFP-244 produced highest absorptionspectra 0.3513-0.4050 compare to MFP-264 0.3110-0.3324, rice monascus product (RMP) 0.3343-0.3663. Pigment biosynthesis seems occurred at sexual developmental stage or conidia formation of M. purpureus 3090, which is produced color changes of yellow pigment, orange pigment, and red pigment. Lovastatine content of MFP-264 has Rf value 0.84 MFP-244 Rf 0.83 and RMP Rf 0.82 showed higher value compare to Rf 0.81 of the lovastatine standard solution. 2004 Jurusan Biologi FMIPA UNS SurakartaKey words: quality analysis, rice fermented product, Monascus purpureus 3090