Plasma LDL cholesterol lowering by plant phytosterols in a hamster model

Stabilization of Rice Bran: A Review

One of the major problems in food science is meeting the demand of the world's growing population, despite environmental limitations such as climate change, water scarcity, land degradation, marine pollution, and desertification. Preventing food from going to waste and utilizing nutritive by-products as food rather than feed are easy and powerful strategies for overcoming this problem. Rice is an important staple food crop for more than half of the world's population and substantial quantities of rice bran emerge as the main by-product of rice grain milling. Usually, rice bran is used as animal feed or discarded as waste. Although it is highly nutritious and comprises many bioactive compounds with considerable health benefits, the rapid deterioration of bran limits the exploitation of the full potential of rice bran. Hydrolytic rancidity is the main obstacle to using rice bran as food, and the enzyme inactivation process, which is termed stabilization, is the only way to prevent it. This study reviews the methods of stabilizing rice bran and other rice-milling by-products comprising rice bran in the context of the efficiency of the process upon storage. The effect of the process on the components of rice bran is also discussed.

Effect of rice bran oil spread on the physical, sensory and fatty acid profile of cake

Studies were carried out to replace hydrogenated fat (HF) with rice bran oil (RBO) and two varieties of rice bran oil spread RBOS1 and RBOS2 in the preparation of cake. Physico-chemical properties, sensory properties, scanning electronic microscopic (SEM) study and fatty acid estimation with reference to trans fatty acids of cake made with control and experimental samples were studied. The best acceptable cake among the four i.e., RBOS2 cake was selected for consumer evaluation along with control (HF) cake. Results revealed that there was no significant difference in overall acceptability of cake made with HF and RBOS2. The internal structure and pore structure of RBOS2 cake was finer and smoother than the control cake as per SEM imaging. The pores within the core varied in diameter between 13.9 and 29.6 µm in control cake and between 16.9 and 58.6 µm in RBOS2 cake at 500 × magnification indicating good textural properties compared to HF cake. The fatty acids analysis results showed that the amount of total trans fatty acids (TFA) was 15.46% in HF cake, 3.56% in RBO cake, 4.54% in RBOS1 cake, and 3.78% in RBOS2 cake. The major trans fatty acids observed in all samples were elaidic acid (C18:1 trans-9) and Linolelidic acid (C18:2, trans-6). Elaidic acid was the highest in HF cake (6.64%) and the least in RBO cake (2.62%). Linolelidic acid was the highest in HF cake (8.48%) and the least in RBOS2 cake (0.91%). Trans Vaccenic acid was detected only in HF cake (0.34%). TFA content assumes significance in terms of its ill effects on the health of consumers, only if fat content is also high. Hence, consumption of the HF products might prove to be harmful, if consumed in large amounts and at higher frequencies. Therefore RBOS can be promoted as healthy fat for production of baked products.

Rheological and physical properties of yogurt enriched with phytosterol during storage

Phytosterols enriched products are innovative types of functional foods, in which dairy products, like low fat yogurt are ideal vehicles for this functional component. In this study, phytosterol dispersions were prepared using an oil/water (O/W) emulsion. The emulsion was added to yogurt milk. pH, titratable acidity (TA), syneresis, firmness and apparent viscosity of enriched yogurt were determined during storage. Moreover, phytosterols distribution in different parts of enriched yogurt was studied. Results indicated that in enriched yogurt, apparent viscosity and syneresis were lower and firmness was higher compared to the control. Addition of phytosterol to the yogurt had significant effect on acidity. Distribution of phytosterols in different parts of one sample was not uniform. Sensory results showed that there was no significant difference between enriched and control on texture, appearance, flavor and overall acceptance.

Structure and antioxidant activity of phenolic compounds isolated from the edible fruits and stem bark of Harpephyllum caffrum

Antioxidant activity in edible fruits is an important characteristic in the choice of fruits for human consumption, and has profound influence on nutrition and health. Two pharmacologically active triterpenoids, β-sitosterol and lupeol, and the powerful flavan-3-ol antioxidant, (+)-catechin, were isolated from the edible fruits of Harpephyllum caffrum while a mixture of cardanols, an alkyl p-coumaric acid ester, and (+)-catechin were isolated from the stem bark. This is the first report of these compounds being isolated from this plant. The antioxidant capacity of (+)-catechin was higher than the other isolated compounds as well as the known antioxidant, ascorbic acid.

Evaluation of γ-oryzanol content and composition from the grains of pigmented rice-germplasms by LC-DAD-ESI/MS

Background

Rice is the staple food and one of the world’s three major grain crops. Rice contains more than 100 bioactive substances including phytic acid, isovitexin, γ-oryzanol, phytosterols, octacosanol, squalene, γ-aminobutyric acid (GABA), tocopherol, tocotrienol derivatives, etc. Out of them, γ-oryzanol is known to have important biological profile such as anti-oxidants, inhibitor of cholesterol oxidation, reduce serum cholesterol levels in animals, effective in the treatment of inflammatory diseases, inhibit tumor growth, reduce blood pressure and promotes food storage stability when used as a food additive, etc. Hence in the present investigation, we aimed to evaluate the content and composition of γ-oryzanol from pigmented rice germplasms using a liquid chromatography with diode array detection and electrospray ionization-mass spectrometry (LC-DAD-ESI/MS).

Findings

In the present study, 33 exotic pigmented rice accessions (red, white and purple) have been evaluated. Among them, the contents of γ-oryzanol varied from 3.5 to 21.0Âmg/100Âg with a mean of 11.2Âmg/100Âg. A total of ten components of γ-oryzanol including ∆⁷-stigmastenyl ferulate were identified of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components. The mean proportions of steryl ferulates were in the descending order of 24-methylenecycloartanyl ferulate > cycloartenyl ferulate > campesteryl ferulate > sitosteryl ferulate > ∆⁷-campestenyl ferulate > campestanyl ferulate > sitostanyl ferulate > ∆⁷-stigmastenyl ferulate > stigamsteryl ferulate > ∆⁷-sitostenyl ferulate. Almost 11 accessions (33%) showed higher content than the control rice Chucheongbyeo and higher proportions ranged from 10 to 15Âmg/100Âg. Interestingly, the red rice accession Liberian Coll. B11/B-11 (21.0Âmg/100Âg) showed higher content γ-oryzanol than control rice Jeokjinjubyeo (19.1Âmg/100Âg) and the purple rice accession Padi Adong Dumarat, Mardi No.4376 (20.3Âmg/100Âg) showed a similar content with control rice Heugjinjubyeo (21.4Âmg/100Âg).

Conclusions

Most of analyzed rice accessions were found to possess higher contents of γ-oryzanol than the control rice, Chucheongbyeo. In particular, the red accessions showed highest content than the white and purple accessions. The content and composition of γ-oryzanol in 33 exotic pigmented rice accessions have been evaluated and compared significantly by the present investigation.

Concentration-dependent displacement of cholesterol in micelles by hydrophobic rice bran protein hydrolysates

BACKGROUND

Rice bran, containing about 100-150 g kg(-1) protein, is a by-product of rice milling that has only become an available ingredient in recent years owing to the centralisation of rice milling. Rice bran, but not its protein fraction or hydrolysates, has been shown to have a hypocholesterolaemic effect. Peptides from soy, milk and other foods have been proposed to have hypocholesterolaemic effects based on their ability to lower cholesterol solubility in bile acid/phosphotidyl choline micelles.

RESULTS

Rice bran protein hydrolysates (RBPHs) were prepared and investigated for their potential to lower cholesterol concentration in micelles. The RBPHs were produced by digestion using four different peptidases, alcalase 2.4L(®), neutrase 0.8L(®), papaya latex papain and porcine pancreas trypsin, and then fractionated by hydrophobicity using styrene/divinylbeneze resins. Alcalase 2.4L(®) produced the highest degree of hydrolysis, and the resulting hydrolysates had the highest micellar cholesterol inhibition ability in an in vitro hypocholesterolaemic test. The adsorption dynamics of four different macroporous resins, DA201-C, Sepabeads SP207 and SP825 and Diaion HP20, were determined using the Langmuir isotherm model. DA201-C had the highest adsorption capacity with an equilibrium concentration of 220 mg g(-1). The hydrolysates eluted with 25, 50, 75 and 95% (v/v) ethanol lowered the micellar cholesterol concentration by 11.88, 14.76, 19.37 and 7.56% respectively.

CONCLUSION

A hydrophobic fraction of RBPH had the highest inhibitory activity on micellar cholesterol, which suggests that it may have hypocholesterolaemic properties.

Content of gamma-oryzanol and composition of steryl ferulates in brown rice (Oryza sativa L.) of European origin

The content of gamma-oryzanol and the composition of steryl ferulates were determined in brown rice of European origin using on-line coupled liquid chromatography-gas chromatography (LC-GC). Analysis of 30 brown rice samples of various cultivars, grown at different sites and in different seasons, revealed the gamma-oryzanol content to range from 26 to 63 mg/100 g. Cycloartenyl ferulate and 24-methylenecycloartanyl ferulate were the major components of gamma-oryzanol followed by campesteryl ferulate, campestanyl ferulate, and beta-sitosteryl ferulate. The proportions of individual steryl ferulates exhibited enormous variability. However, irrespectively of the great variations observed for single steryl ferulates, the proportions of the sum of 4,4'-dimethylsteryl ferulates (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate) and the sum of 4-desmethylsteryl ferulates (campesteryl ferulate, campestanyl ferulate, and beta-sitosteryl ferulate) were rather constant. The significant natural variability observed for gamma-oryzanol content and composition of steryl ferulates were shown to be influenced by environmental conditions but not by the degree of maturity of rice grains.

Design, synthesis, and evaluation of pharmacological properties of cinnamic derivatives as antiatherogenic agents

A series of cinnamic and phosphonocinnamic derivatives have been synthesized and their ability to inhibit cell-mediated LDL oxidation and oxidized LDL-induced cytotoxicity was investigated. Electron-donating substituents surrounding the necessary 4-OH group of the aromatic ring showed the best results. Among the different series tested, amide 1, thioester 5c, phosphonoester 7c, and the fluorophosphonocinnamic analogue 12c exhibited a potent inhibitory effect against LDL oxidation (and subsequent toxicity) mediated by cultured human microvascular endothelial cells (HMEC-1), with an efficacy comparable to that observed with probucol. Beside this indirect protective effect, these compounds exhibited a direct protective effect against the toxicity of previously oxidized LDL in HMEC-1. These data suggest that the newly synthesized cinnamic compounds should protect against early events (cell-mediated LDL oxidation) occurring within the vascular wall in atherosclerosis.