Maher M. Al-Dabbas

Antioxidant and α-Amylase Inhibitory Compounds from Aerial Parts of Varthemia iphionoides Boiss

Various extracts of aerial parts of Varthemia (Varthemia iphionoides Boiss) were investigated for radical-scavenging activity, antioxidative activity, and porcine pancreas α-amylase inhibitory activity. The ethanol and water extracts showed a pronounced 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, with inhibition of about 90% at a concentration of 100 μg/ml, and α-amylase inhibitory activity of about 70% at a concentration of 200 μg/ml by the 2-chloro-4-nitrophenyl α-maltotrioside (CNP-G3) degradation method. The ethanol extract was purified by column chromatography to give seven 3-methoxyflavones (1–7) and eudesmane sesquiterpene, selina-4,11(13)-dien-3-on-12-oic acid (8). The structures of these compounds were established by NMR, MS, and UV spectroscopy. Of 3-methoxyflavones, 5,7,4′-trihydroxy-3,6-dimethoxyflavone (1), 5,7,4′-trihydroxy-3,3′-dimethoxyflavone (2), and 5,4′-dihydroxy-3,7,3′-trimethoxyflavone (3,7,3′-tri-O-methyl-quercetin) (7) exhibited pronounced radical-scavenging activity. The antioxidative activity in the linoleic acid system was considerable in compounds 1, 2, and 5,4′-dihydroxy-3,6,7-trimethoxyflavone (4). Compounds 1, 2, 4, 5 (5,7,4′-trihydroxy-3-methoxyflavone), and 6 (5,4′-dihydroxy-3,7-dimethoxyflavone) showed markedly high inhibitory activity against porcine pancreas α-amylase. Eudesmane sesquiterpene did not show any activity.

Survival and growth of Salmonella Typhimurium, Escherichia coli O157:H7 and Staphylococcus aureus in eggplant dip during storage

Eggplant dip is an internationally popular appetizer, prepared in some instances under uncertain hygienic conditions with inconsistent refrigeration. This study examined the effects of citric acid on the survival of pathogenic microorganisms (Salmonella Typhimurium, Escherichia coli O157:H7 and Staphylococcus aureus) and naturally present organisms (lactic acid bacteria, LAB, aerobic bacteria, APC and yeast and mold, YM) in eggplant dip during storage. Eggplant dip with 0, 0.2, 0.4, 0.6 or 0.8% citric acid was inoculated with S. Typhimurium, E. coli O157:H7 or S. aureus and stored at 4, 10 and 21 °C for ≤15 d. Throughout the study, the survival of the inoculated microorganisms was monitored, and LAB, APC, YM numbers and pH were determined. There was no significant (p>0.05) effect of citric acid on inoculated S. Typhimurium and E. coli O157:H7. Salmonella and E. coli O157:H7 survived >7d with little reduction in viability. Reduction of S. aureus viability increased with citric acid concentration and reached>3.0 log10 CFU/g by 15 d at 4 °C. Citric acid had no effect (p>0.05) on the background YM during storage at 4, 10 and 21 °C or LAB stored at 4 and 10 °C, while at 21 °C, 0.6 and 0.8% citric acid significantly reduced LAB. Citric acid had no effect (p>0.05) on the APC in samples stored at 4 °C but it had significant effects on samples stored at 10 and 21 °C. Work reported showed that the use of citric acid at 0.4-0.8% can inhibit the growth of S. aureus in eggplant dip, but adequate refrigeration is essential to minimize risk from this and other pathogens in this product.

Effect of Stabilized Rice Bran Fractions on the Formation of Rice Flour Pasting Properties

ABSTRACT Rice flour composition played a key role in determining the changes in pasting properties of rice flour. The influence of incorporating defatted rice bran (DFRB), rice bran fiber (RBF), rice bran protein (RBP), and stabilized rice bran (SRB) fractions on the mechanism of rice flour pasting viscosities was investigated. Pasting properties of long- and medium-grain rice flour substituted with 5, 10, 15, 20, and 100% bran fractions resulted in a significant decrease (P < 0.05) in rice flour pasting property values. Flour substituted with RBP had the lowest pasting property measurements compared with other fractions, and the greater the percentage substituted, the lower the pasting property values. DFRB and RBF were least affected properties when used as a replacement. Results were attributed to the contribution of rice starch in the mechanism of rice paste formation, in which decreasing starch in a rice flour sample, as a result of substituting with fractions of SRB, may have resulted in faster swel...

Flavonoids and antioxidant activity of Santolina rosmarinifolia from Algeria

Santolina is a small genus of the large subfamily Asteraceae of the family Compositae. Species of this genus are used in folk medicine as anthelmintic, antispasmodic, and antifectious agent [1]. Sesquiterpene lactones and volatile terpenes have been isolated from the Spanish subspecies S. rosmarinifolia subsp. canescens, S. rosmarinifolia subsp. rosmarinifolia, and S. chamaecyparissus [2–5]. Terpenes and acetylene derivatives were reported from the roots of S. corsica [6], but no flavonoids have been reported from these two subspecies. The Algerian species S. rosmarinifolia L. [7] has not been the subject of any phytochemical study. It will be interesting to investigate the presence of 6-methoxyflavones previously reported from S. chamaecyparissus [8, 9]. The aerial parts of S. rosmarinifolia were collected on may 2008 in the region of Batna (North Eastern Algerian) [7]. The voucher specimen was identified by Prof. Gerard De Belair (University Badji-Mokhtar, Annaba) and was deposited at the Herbarium of the Laboratory LOST, Mentouri-University (LOST Sr/05/08). Air dried aerial parts of Santolina rosmarinifolia (1000 g) were macerated three times with 70% MeOH solution. The residue was dissolved in water and extracted with petroleum ether, dichloromethane, ethyl acetate, and n-BuOH, successively. The dichloromethane extract was subjected to column chromatography on silica gel (35–70 mm) eluting with cyclohexane and then with a gradient of dichloromethane–ethyl acetate with increasing polarity. The fraction eluted with dichloromethane–ethyl acetate (1:1) was further chromatographed on silica gel (35–70 mm) eluted with dichloromethane–methanol with increasing polarity, leading to compounds 1, 2. The ethyl acetate extract was column chromatographed on silica gel (35–70 mm) eluting with dichloromethane, then with a gradient of dichloromethane–ethyl acetate with increasing polarity, and then with methanol. The fraction eluted with dichloromethane–ethyl acetate (1:9) was further subjected to TLC eluting with dichloromethane–methanol (9:1) to afford compound 3. The fraction eluting with ethyl acetate–methanol (1:8) was separated on silica gel TLC eluting with ethyl acetate–methanol (1:1), leading to compounds 3, 4. The butanolic extract was column chromatographed on silica gel (35–70 mm) eluting with an isochratic system of ethyl acetate–methanol–water (10:1:1), leading to compounds 5–7. Compounds 1–7 were identified by using UV, 1H NMR, 13C NMR, and MS analysis [10–16]. Antioxidant Activity. The DPPH radical-scavenging activity of the ethyl acetate (EESR) and butanolic (BESR) extracts of S. rosmarinifolia was assayed using the slightly modified method of Blois [17]. After 30 min, the absorbance of the solution was measured at 660 nm and the antioxidant activity calculated using the following equation: DPPH radical-scavenging activity % = [(Absorbance of the control – Absorbance of the sample)/Absorbance of the control] 100. 5,7-Dihydroxy-6,3 ,4 -trimethoxyflavone (Eupatilin) (1). C18H16O7, yellow cristals (EtOAc), mp 234–236 C. UV (MeOH, max, nm): 275, 340; + AlCl3/HCl: 259, 288, 362; + NaOH: 275, 320, 379; + NaOAc : 276, 349. 1H NMR (500 MHz, CDCl3, , ppm, J/Hz): 7.57 (1H, dd, J = 2 and 8, H-6 ), 7.47 (1H, d, J = 2, H-2 ), 7.02 (1H, d, J = 8, H-5 ), 6.87 (1H, s, H-3), 6.57 (1H, s, H-8), 3.85 (3H, s, OCH3), 3.82 (3H, s, OCH3), 3.75 (3H, s, OCH3); Mass spectrum (EI, 70 eV), m/z 344 [M]+. 5,7,4 -Trihydroxy-6,3 -dimethoxyflavone (Jaceosidin) (2). C17H14O7, yellow needles (EtOAc), mp 227–229 C. UV (MeOH, max, nm): 274, 346; + AlCl3/HCl: 259, 287, 364; +NaOH: 269, 320, 397; + NaOAc: 275, 370. 1H NMR (300 MHz, CDCl3, , ppm, J/Hz): 7.45 (1H, dd, J = 2.0, 8.0, H-6 ), 7.29 (1H, d, J = 2.0, H-2 ), 7.05 (1H, d, J = 8.0, H-5 ), 6.60 (1H, s, H-3), 6.55 (1H, s, H-8), 3.92 (6H, s, OCH3), 3.80 (6H, s, OCH3). Mass spectrum (EI, 70 eV), m/z 330 [M]+.

Chemistry and antiproliferative activities of 3-methoxyflavones isolated from Varthemia iphionoides

A new isolated flavone, 4′-hydroxy-3,5,6,7-tetramethoxyflavone (6), together with seven known 3-O-methylated flavones isolated from the ethanol extract of the aerial parts of Varthemia iphionoides, were studied for DPPH free radical-scavenging and cytotoxic activities. Flavones 2, 3, 4, and 8 were the most active DPPH free-radical scavengers with inhibition percentage of 63.5, 42.9, 47.9, and 55.6, respectively, at a concentration of 100 μg/mL. Flavones 2 and 8 were the most active as inhibitor for human leukemia HL-60 cells; the IC50 values after 48 h incubation were 20.5 and 23.9 μg/mL, respectively.

Effect of microencapsulation of cardamom’s essential oil in gum Arabic and whey protein isolate using spray drying on its stability during storage

Cardamom essential oil (CEO) was microencapsulated in different materials; gum Arabic (GA), whey protein isolate (WPI) or their combinations (WPI+GA) at different mixing proportions; 1:1 and 3:1, respectively by using spray drying procedure. The stability of the encapsulated oil was evaluated by determining the concentration of encapsulated oil during storage at two temperatures (7 and 25 °C). Results showed that regardless of the storage temperature, GA microcapsules had the highest microencapsulation efficiency and retention of CEO throughout the storage period. However WPI microcapsules had the lowest microencapsulation efficiency and retention of CEO. Both WPI+GA combinations showed intermediate microencapsulation efficiency and CEO retention compared to the single component matrices. Micrographs revealed that both WPI and GA microcapsules were spherical in shape. However, WPI microcapsules had broken surfaces, whereas the GA microcapsules had dented and wrinkled surfaces. In conclusion, GA microcapsu...

Evaluation of Some Chemical and Sensory Properties of Processed Cheese Analogue with Selected Vegetable Oils

Cheese analogues are cheese-like products with varied compositions and functional properties which produced by partial or whole replacement of milk components, in particular milk fat, by non milk-based components. The purpose of this research was to evaluate the effect of replacement of milk fat in processed cheese with different formulations from olive, corn and sesame oils on some chemical and sensory properties. The results indicated that the peroxide values were not affected by the replacement of milk fat with vegetable oils significantly (P