Use of Lactobacillus rossiae DC05 for bioconversion of the major ginsenosides Rb1 and Re into the pharmacologically active ginsenosides C-K and Rg2

Rb1 and Re are the major ginsenosides in protopanaxadiol and protopanaxatriol with contents of 38.89 and 13.34%, respectively. β-Glucosidase-producing food grade Lactobacillus rossiae DC05 was isolated from kimchi using esculin-MRS agar and an enzyme of L. rossiae DC05 was used for bioconversion of the major ginsenosides Rb1 and Re. Strain DC05 showed strong activity in converting ginsenosides Rb1 and Re into the minor ginsenosides compound-K and Rg2, respectively. Within 4 days, 100% of ginsenoside Rb1 was decomposed and converted into C-K, while 85% of Re was decomposed and converted into Rg2 after 6 days of incubation. The biosynthesis rate of ginsenoside C-K was 72.88%, and the biosynthesis rate of Rg2 was 53.94%. Strain DC05 hydrolyzed ginsenosides Rb1 and Re along the pathway Rb1→Rd→F2→CK and the pathway Re→Rg2, respectively. The optimum temperature and pH of the enzyme were 30°C and 7.0, respectively.     

高效液相色谱法同时测定人参制剂中20 种人参皂苷方法的建立

为了更加有效评价人参制剂生产质量,建立了一种同时测定人参制剂中20 种人参皂苷的高效液相色谱方法。结果表明,20 种人参皂苷Rg1、Re、Rg2、Rg3、Rg5、Rf、F1、F2、Rc、Rd、Rb1、Rb2、Rb3、Rh2、compound K、20（R）-Rh1、Rk3、Rh4、原人参二醇及原人参三醇均得到良好分离,线性关系良好（R≥0.999 2）。该方法快捷简便、稳定可靠,能够精确全面检测分析人参皂苷含量,对于人参加工品及其制剂的质量控制更为全面准确可行。     

β-Glycosidase-assisted bioconversion of ginsenosides in purified crude saponin and extracts from red ginseng (Panax ginseng C. A. Meyer)

Major ginsenosides in ginseng (Panax ginseng) and its products are highly glycosylated, hence poorly absorbed in the gastrointestinal tract. β-Glycosidase-assisted deglycosylation of pure ginsenosides was peformed to study bioconversion mechanisms. Ginsenoside standard compounds, crude saponin, and red ginseng extracts were incubated with β-glycosidase (0.05% w/v, 55°C). β-Glycosidase has a broad specificity for β-glycosidic bonds, hydrolyzing the β-(1→6), α-(1→6), and α-(1→2) glycosidic linkages. The final metabolite of protopanaxadiol ginsenosides was Rg3 while the metabolite of protopanaxatriol ginsenosides was Rh1. β-Glycosidase treatment of red ginseng extracts resulted in a decrease in the amounts of Rb1, Rc, Re, and Rg2 after 24 h, whereas levels of the less glycosylated Rd, Rb1, Rg, Rg3, Rg1, and Rh1 forms increased. When crude saponin was incubated with β-glycosidase for 24 h, levels of Rb1, Rc, Re, and Rg1 decreased while levels of Rd, Rg3, and Rh1 increased as deglycosylated ginsenosides.     

Enhancement of low molecular weight ginsenosides from low-quality ginseng through ultra-high-pressure and fermentation processes

This study aimed to analyze the conversion pattern of high to low molecular weight ginsenosides in low-quality ginseng during lactic acid fermentation associated with an ultra-high-pressure process. It was found that the relative quantities of various low molecular weight ginsenosides were increased by 20 min of pressure treatment at 500 MPa following fermentation with Bifidobacterium longum. Specifically, after ultra-high-pressure extraction, the triol-type, low molecular weight Rg2 was the most abundant ginsenoside, at 1.213 mg/g. However, when low-quality ginseng was fermented, the concentrations of diol-type, low molecular weight ginsenosides (e.g., Compound-K (CK), Rh2, and Rg3) largely increased to 1.52, 1.241, and 0.947 mg/g, respectively. These data indicate that high molecular weight ginsenosides in ginseng could be broken down by two different hydrolysis mechanisms. In the fermentation process, the β-1,2 and β-1,4 glycosidic bonds in high molecular weight ginsenosides such as Re, Rc, and Rb1 were hydrolyzed to diol-type, low molecular weight ginsenosides by the β-glucosidase enzyme of the lactic acid bacterium. Meanwhile, the physical energy of the ultra-high-pressure process specifically hydrolyzed relatively weak bonds of the sugars in high molecular weight ginsenosides such as Re to form the low molecular weight ginsenoside Rg2. Rg2, Rg3, Rh2, and CK increased to 2.043, 1.742, 1.834, and 2.415 mg/g, respectively, possibly due to a synergistic effect of combining both processes. Therefore, low molecular weight ginsenosides with higher biological activities than high molecular weight ginsenosides can be selectively obtained from low-quality ginseng using both fermentation and ultra-high-pressure processes.     

Mutations in gyrase and topoisomerase genes associated with fluoroquinolone resistance in Salmonella serovars from retail meats

Mutations in gyrase and topoisomerase genes (gyrA, gyrB, parC and parE) were examined among 30 multidrug-resistant (MDR) Salmonella isolates recovered from retail meats using PCR and DNA sequencing analysis. Six isolates had a single gyrA mutation (Ser83 → Phe or Ser83 → Tyr or Asp87 → Asn) with ciprofloxacin (Cip) minimum inhibitory concentrations (MICs) ranging from 0.125 to 0.5 μg/ml except 1 with 16 μg/ml. Three isolates had both a gyrA mutation (Ser83 → Tyr or Ser83 → Phe) and a parC mutation (Ser80 → Arg) (Cip MICs, 8 to 16 μg/ml). Fifteen isolates had both double mutations in gyrA (Ser83 → Phe and Asp87 → Gly or Asp87 → Asn) and a single mutation (Ser80 → Arg) in parC (Cip MICs, 8 to ≥ 16 μg/ml). Three had double gyrA mutations (Ser83 → Phe, Asp87 → Gly or Asp87 → Asn), one parC mutation (Ser80 → Arg), and 1 parE mutation (Lys428 → Gln or Gly442 → Ser) (Cip MICs, 8 to ≥ 16 μg/ml). One had double gyrA mutations (Ser83 → Phe, Asp87 → Gly or Asp87 → Asn), one parC mutation (Ser80 → Arg), and 2 parE mutations (Lys441 → Ile and Asp494 → Asn) (Cip MICs, 8 to ≥ 16 μg/ml). Isolates with single gyrA mutations were less resistant to quinolone and fluoroquinolones than those together with additional parC and/or parE mutations in Salmonella. Our findings confirmed the importance of point mutations in gyrase and topoisomerase in reduced susceptibility to quinolone and fluoroquinolones. Mutations in gyrA confer low-level quinolone and fluoroquinolone resistance, while additional gyrA mutation(s) together with parC and/or parE mutations increase the resistance to a high level.     

In vitro and in vivo protective effects of gingenosides on acute renal injury induced by cantharidin

Ginsenosides are major active constituent of Panax ginseng which is a popularly used functional food or drug in several Asian countries. The effects of ginsenosides on the renal dysfunction and injury caused by cantharidin were investigated in vitro and in vivo. Ginsenosides inhibited the cytotoxicity in rat normal kidney NRK cell induced by cantharidin. Cantharidin caused NRK cell apoptosis accompanied with decreasing bcl-2 expression. Pretreatment of ginsenosides reduced apoptosis rate and increased bcl-2 expression. In experimental rats, administration of cantharidin (0.14 mg/kg) for 15 days induced renal damage, which was evident from significantly increased levels of serum creatinine, urine protein and urea nitrogen. Pretreatment of ginsenosides reduced the increases of serum creatinine, urine protein, urea nitrogen and histological change in rats. These findings provide the evidence that ginsenosides might be useful in enhancing the tolerance of the kidney against renal injury associated with cantharidin.     

Detection of pyrrolizidine alkaloids in commercial honey using liquid chromatography–ion trap mass spectrometry

Pyrrolizidine alkaloids (PAs) are known secondary plant metabolites which can cause hepatotoxicity in both humans and livestock. PAs can be consumed through the use of plants for food, medicinal purposes and as contaminants of agricultural crops and food. PA contaminated grain has posed the largest health risk, although any PA contamination in our food chain should be recognised as a potential health threat. For this purpose, retail honeys were tested by LC–MS/MS. The method allows for specific identification of toxic retronecine and otonecine-type PAs by comparison to reference compounds via a spectral library. In total, 50 honey samples were matched to the reference spectra within a set of tolerance parameters. Accurate data analysis and quick detection of positive samples was possible. Positive samples contained an average PA concentration of 1260 μg kg^?1 of honey. Good linear calibrations were obtained (R² > 0.991). LOD and LOQ ranged from 0.0134 to 0.0305 and 0.0446 to 0.1018 μg mL^?1, respectively.     

Furostanol saponins in Allium caepa L. Var. tropeana seeds

An analysis of the polar extracts from seeds of Allium caepa L. var. tropeana led to the isolation of eight furostanol saponins, one of which was previously reported in the literature. On the basis of 1D, 2D NMR and mass spectrometry data, the structures of the compounds were elucidated as 1-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-1β,3β,22α,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 2″)-O-α-L-arabinopyranoside (1a), its epimer at position 22, 1-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-1β,3β,22β,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 2″)-O-α-L-arabinopyranoside (1b), 1-O-β-D-glucopyranosyl-22-O-methyl-(25R)-furost-5(6)-en-1β,3β,22ξ,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 2″)-O-α-L-arabinopyranoside (probably artefact) (2), 1-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-1β,3β,22β,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 6″)-O-β-D-galactopyranoside (3), 1-O-β-D-glucopyranosyl-22-O-methyl-(25R)-furost-5(6)-en-1β,3β,22ξ,26-tetraol-26-O-α-L-rhamnopyranosyl-(1‴ → 6″)-O-β-D-galactopyranoside (probably artefact) (4), 26-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-3β,22α,26-triol-3-O-α-L-rhamnopyranosyl-(1″ → 2′)-O-[β-D-glucopyranosyl-(1‴ → 6′)-O]-β-D-glucopyranoside (5a) and its epimer at position 22,26-O-β-D-glucopyranosyl-(25R)-furost-5(6)-en-3β,22β,26-triol-3-O-α-L-rhamnopyranosyl-(1″ → 2′)-O-[β-D-glucopyranosyl-(1‴ → 6′)-O]-β-D-glucopyranoside (5b) and the known compound 26-O-β-D-glucopyranosyl-22-O-methyl-(25R)-furost-5(6)-en-3β,22ξ,26-triol-3-O-α-L-rhamnopyranosyl-(1″ → 2′)-O-[β-D-glucopyranosyl-(1‴ → 6′)-O]-β-D-glucopyranoside (6) [Mimaki, Y., Satou, T., Kuroda, M., Sashida, Y., & Hatakeyama, Y. (1999). Steroidal saponins from the bulbs of Lilium candidum. Phytochemistry, 51, 567–573]. This is the first report on furostanol saponins in the seeds of Allium caepa L. var. tropeana.     

Synthesis of potentially-bioactive lactosyl-oligofructosides by a novel bi-enzymatic system using bacterial fructansucrases

Efficient enzymatic synthesis of lactosyl-oligofructosides (LFOS) with a degree of polymerization from 4 to 8 was achieved in the presence of sucrose:lactosucrose and sucrose:lactose mixtures by transfructosylation reaction. The main synthesized LFOS which consist of β-2,1-linked fructose to lactosucrose: β-d-galactopyranosyl-(1 → 4)-α-d-glucopyranosyl-[(1 → 2)-β-d-fructofuranosyl]n-(1 → 2)-β-d-fructofuranoside (where n refers to the number of transferred fructose moieties) was structurally characterized by nuclear magnetic resonance (NMR). The maximum formation of LFOS was 81% (in weight with respect to the initial amount of lactosucrose) and was obtained after 24 h of transfructosylation reaction based on sucrose:lactosucrose (250 g L^− 1 each) catalyzed by an inulosucrase from Lactobacillus gasseri DSM 20604 (IS). The production of LFOS in the presence of sucrose:lactose mixtures required a previous high-yield lactosucrose synthesis step catalyzed by using a levansucrase from Bacillus subtilis CECT 39 (LS) before the inulosucrase-catalyzed reaction. This novel one-pot bi-enzymatic system led to the synthesis of about 22% LFOS in weight, with respect to the initial amount of lactose (250 g L^− 1). The results revealed a high specificity for the substrate involved in the inulosucrase-catalyzed reaction given that, although lactosucrose (O-β-d-galactopyranosyl-(1 → 4)-O-α-d-glucopyranosyl-(1 → 2)-β-d-fructofuranoside) acted as a strong acceptor of β-2,1-linked fructose, lactose (β-d-galactopyranosyl-(1 → 4)-α-d-glucose) was found to be an extremely weak acceptor.     

Changes in ginsenosides and antioxidant activity of Korean ginseng (Panax ginseng C.A. Meyer) with Heating Temperature and Pressure

This study was carried out to investigate the changes of ginsenoside compositions and antioxidant activity of fresh ginseng induced by thermal processing at different temperatures (25, 100, 121, and 150°C), pressure (0.1, 10, 20, and 30 MPa), and soaking solvents (water and ethanol). The levels of ginsenosides were similar trend with the pressure of 0.1–30 MPa, while there were significantly differences in heated ginseng with heating temperature and soaking solvent. When water and ethanol was used, the ginsenoside compositions significantly changed at 100 and 121°C, respectively, and it was rapidly decreased at 150°C. After heating, the level of 3 ginsenosides (Re, Rf, and Rg1) decreased and that of 5 other ginsenosides [Rb1, Rb2, Rb3, Rc, and Rg2(S)] increased up to 121°C compare to raw ginseng. Ginsenoside F2, F4, Rg2(R), Rk3, Rh4, Rg3(S), Rg3(R), Rk1, and Rg5, which was absent in raw ginseng, was detected in heated ginseng. Especially, ginsenoside Rg3(S), Rg3(R), Rk1, and Rg5 were remarkably produced after thermal processing. After heating, the phenolic compounds (1.43–11.62 mg/g), 50% inhibition concentration (IC₅₀) value (1.48–3.11 mg/g), and ABTS radical scavenging activity (0.66–9.09 mg AA eq/g) of heated ginseng were increased.     

Learning to associate compatible and incompatible pictures with food and non-food odours,within a stimulus equivalence paradigm

Within consumer research, it is acknowledged that influential and perhaps unconscious associations to products exist, which require indirect as well as direct methods of investigation. We examine the potential usefulness of one such indirect method, an application of the stimulus equivalence matching-to-sample paradigm [Sidman, M. (1971). Reading and auditory–visual equivalences. Journal of Speech and Hearing Research, 14, 5–13].Two experiments are reported (n = 15, n = 20). Both used three, 3-membered stimulus sets: A (food and non-food odours); B (nonsense syllables); and C (pictures), two of which were either ‘compatible’ or ‘incompatible’ with the corresponding items in the A set. Each participant took part in both ‘compatible’ and ‘incompatible’ conditions. First, (A → B), participants were trained to choose one of the three nonsense syllables when presented with one of the odours. Second, (B → C), those who had learned the first task (n = 10, n = 14) were trained to choose one of the three pictures when presented with one of the nonsense syllables, and finally, in a test phase (C → A), to choose one of the three odours when presented with one of the pictures. In both experiments, B → C trials to criterion and response times were significantly greater in the ‘incompatible’ condition, and the error structure differed between conditions. In other phases, no consistent inter-condition differences were found. We discuss the use of this paradigm in consumer research on odours and tastes as a very indirect way of measuring pre-existing associations.     

Diversity of urinary excretion patterns of main ellagitannins' colonic metabolites after ingestion of tropical highland blackberry (Rubus adenotrichus) juice

Tropical highland blackberries are a rich source of ellagitannins (ETs), which are metabolized by gut microbiota to yield urolithin, a potentially bioactive compound excreted in urine up to 7 days after ingestion. Following the ingestion of 250 mL of tropical highland blackberry juice, a spot of urine from 26 volunteers collected at 51 ± 4 h was analyzed for urolithin A and B main derivatives (aglycones and glucuronated forms). Three main groups, “no or low urolithin excreters,” “predominantly UA derivatives excreters” and “predominantly UB derivatives excreters,” were observed. These categories were also unambiguously observed from 9 individuals following the total excretion of ETs' main metabolites over a 4-day period after ingesting one shot of blackberry juice. Although relatively high inter- and intra-individual variabilities were observed, individuals preserved their status during different intervention periods with different amounts of ETs ingested. Accurate UPLC-DAD/ESI-Q-TOF/MS2 allowed the tentative assignment of an identity to 15 other ET metabolites in urine, but profiling did not allow the discrimination of any other compounds aside from UA or UB derivatives. The results highlight the importance of the interaction of gut microbiota composition and the host endogenous excretery system, which may play a major role in the observed inter-individual variability.     

Effects of steaming the root of Panax notoginseng on chemical composition and anticancer activities

The root of Panax notoginseng has been shown to change its saponin composition upon steaming. This study examines the effects of different steaming times and temperature on notoginseng root for saponin composition and anticancer activities. Steaming decreased the content of notoginsenoside R1, ginsenosides Rg1, Re, Rb1, Rc, R2, Rb3 and Rd, but increased the content of Rh1, Rg2, 20R-Rg2, Rg3 and Rh2. Steaming significantly influenced the transformation of Rg3. The amount of ginsenoside Rg3, an anticancer compound, was 5.23-fold greater in root steamed for 2 h at 120 °C than at 100 °C, and 3.22-fold greater when steamed for 4 h than for 1 h at 120 °C. For anticancer effects, the extract of steamed root significantly inhibited proliferation of SW-480 human colorectal cancer cells. The IC₅₀ of the steamed extract for 1, 2, 4 and 6 h at 120 °C was 259.2, 131.4, 123.7 and 127.1 μg/mL, respectively; the effect of unsteamed extract was low. Flow cytometric analysis demonstrated that the apoptotic cell induction rates of SW-480 cells were 56.3% and 64.4% with 150.0 and 200.0 μg/mL extract steamed for 6 h. Compared with Rg1 and Rb1, only Rg3 had a significant antiproliferative effect.     

Isolation of antioxidative and ACE inhibitory peptides from protein hydrolysate of skipjack (Katsuwana pelamis) roe

Bioactive peptides from protein hydrolysate of defatted skipjack (Katsuwonus pelamis) roe with 5% degree of hydrolysis (DH) prepared by Alcalase digestion were isolated and characterised. Two active fractions with ABTS radical scavenging activity (973.01–1497.53 μmol TE/mg sample) and chelating activity (0.05–0.07 μmol EE/mg sample) from consecutive purification steps including ultrafiltration, cation exchange column chromatography and reverse phase high performance liquid chromatography (RP-HPLC), were subjected to analysis of amino acid sequence by LC–MS/MS. Seven dominant peptides with 6–11 amino acid residues were identified as DWMKGQ, MLVFAV, MCYPAST, FVSACSVAG, LADGVAAPA, YVNDAATLLPR and DLDLRKDLYAN. These peptides were synthesised and analysed for ACE-inhibitory activity and antioxidative activities. MLVFAV exhibited the highest ACE inhibitory activity (IC₅₀ = 3.07 μM) (p < 0.05) with no antioxidative property, whilst DLDLRKDLYAN showed the highest metal chelating activity, ABTS radical and singlet oxygen scavenging activities. Therefore, peptides prepared from skipjack roe could be further employed as a functional food ingredient.     

Biotransformation of ginsenoside Rd in the ginseng extraction residue by fermentation with lingzhi (Ganoderma lucidum)

Ginseng and lingzhi (Ganoderma lucidum) both are valuable traditional Chinese medicines and have been extensively utilised in functional foods and traditional medicines in many Asian countries. However, massive quantity of ginseng residue is produced after extraction of ginseng which still contains a lot of bioactive compounds such as ginsenosides. The goal of this study was to reuse the American ginseng extraction residue as the fermentation medium of G. lucidum to produce bioactive ginsenoside enriched biotransformation products. The changes of ginsenosides in the fermentation products were analysed during fermentation. Our results showed that after 30 days of fermentation, ginsenoside Rg1, Rd, and compound K (CK) significantly increased, especially Rd, while other ginsenosides (Re, Rb1 and Rc) decreased during fermentation. Ginsenoside Rd is the major ginsenoside in the final fermentation product. Furthermore, the biotransformation of ginsenosides was the major reaction in this fermentation process.     

Phenolic and aroma compositions of pitomba fruit (Talisia esculenta Radlk.) assessed by LC–MS/MS and HS-SPME/GC–MS

Pitomba (Talisia esculenta Radlk.) is a Brazilian exotic fruit consumed specially in the Amazonian region. Because of its large consumption and also due to the lack of knowledge regarding its chemical composition, pitomba fruit was studied in relation to its phenolic and aroma constitution. Using liquid chromatography tandem mass spectrometry (LC–MS/MS), 13 phenolic compounds (catechins, flavonoids and organic acids) were tentatively identified by comparison with standards and by fragmentation patterns. A validated method was applied to quantify common phenolic compounds of the pitomba pulp, for which quinic acid was the main compound (507.8 ± 7.4 μg g^− 1 DWP). Gas chromatography mass spectrometry (GC–MS) was employed along with headspace solid-phase microextraction (HS-SPME) to assess the aroma composition of pitomba fruit. A total of 27 volatile organic compounds (VOCs) were tentatively identified for pitomba fruit, for which 2-phenethyl acetate (17.89%) and isopentyl acetate (13.43%) esters were the main VOCs, contributing to the characteristic aroma of pitomba. The antioxidant capacity of the extract of pitomba fruit was evaluated by ABTS, DPPH and ORAC assays. We observed that pitomba has a moderate antioxidant activity.     

Antioxidant activity and characterization of constituents in copao fruits (Eulychnia acida Phil., Cactaceae) by HPLC–DAD–MS/MSn

Copao (Eulychnia acida Phil., Cactaceae) is an endemic species occurring in arid areas of northern Chile. The fruits are commercialized by peasants within the Elqui and Limari valleys and are appreciated for its acidic and refreshing taste. We now report the total phenolic (TP) and total flavonoid (TF) content, antioxidant activity, phenolic composition and main phenolic distribution in pulp and epicarp of copao fruits from different harvesting places from both valleys. The ascorbic acid content was determined in fresh fruit pulp, epicarp and juice. The phenolic-enriched extract was analyzed for antioxidant effect and composition. Ferulic acid, 9,10-dihydroxy-4,7-megastigmadien-3-one hexoside, isorhamnetin and quercetin glycosides were identified by HPLC–DAD–MS/MS analysis. The main compounds were isolated and fully characterized by NMR techniques. The main phenolic in the samples was isorhamnetin-3-O-[α-rhamnopyranosyl-(1 → 6)-β-glucopyranoside]. The HPLC pattern of the phenolic-enriched extracts of the fruits allows a differentiation of samples from the Elqui and Limari valleys. All fruit extracts and Amberlite-retained fraction from the methanolic extract were devoid of toxicity against human gastric AGS cells and human lung fibroblasts, with IC₅₀ values > 400 μg/mL for AGS and 344 to > 400 μg/mL for fibroblasts, respectively. The compound identification, associated with the antioxidant activity and insignificant cell toxicity, adds relevant information for the possible development of this native fruit into a new crop.     

Development and validation of a LC-ESI-MS/MS method for the determination of phenolic compounds in honeydew honeys with the diluted-and-shoot approach

A simple, reproducible and sensitive method has been optimized and validated for simultaneous determination of 32 phenolic compounds in bracatinga (Mimosa scabrella Benth.) with the diluted-and-shoot approach, without the need of any additional clean-up steps. It has been based on high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry and electrospray ionization (HPLC-ESI-MS/MS). The chromatography conditions were optimized, and due to the selectivity provided by MRM monitoring, LC separation required only 9 min. The developed method was validated on the basis of Eurachem and European Commission Decision 2002/657/EC guidelines. Mean recoveries ranged from 70.4 to 110%. Intra-day and inter-day precision with RSD (relative standard deviations) from 0.14 to 18.9% and 0.34 to 20.0%, respectively were achieved. Limits of detection (LOD) and quantification (LOQ) ranged from 0.03 to 3.20 μg L^− 1 and 0.20–12.8 μg L^− 1. Finally, the method was applied to samples and 20 phenolic compounds were quantified in all the samples analyzed, representing a contribution to the characterization and quantification of phenolic compounds from bracatinga (M. scabrella Bentham) honeydew honey.     

UV-C treatment of soymilk in coiled tube UV reactors for inactivation of Escherichia coli W1485 and Bacillus cereus endospores

Coiled tube UV reactors were used to investigate the influence of tube diameter (1.6 mm ID, and 3.2 mm ID) and Reynolds number (Re) to inactivate Escherichia coli W1485 and Bacillus cereus spores in raw soymilk (RSM). Four levels of Re (343, 686, 1029 and 1372) were tested in RSM inoculated separately with each bacterium and treated in the UV reactors at a constant residence time of 11.3 s with UV-C dose of 11.187 mJ/cm² at 253.7 nm. Inactivation efficiency of both microorganisms increased with Re. Maximum reductions of 5.6 log₁₀ CFU/ml of E. coli and 3.29 log₁₀ CFU/ml of B. cereus spores were achieved in the 1.6 mm ID UV reactor. Inactivation efficiency was higher in the 1.6 mm ID UV reactor than the 3.2 mm ID UV reactor for both the organisms. Effect of UV-C light on lipid oxidation of untreated RSM, measured as malondialdehyde and other reactive substances (MORS) content, was much higher (95 nmol/ml) than the UV-treated (58 nmol/ml) and thermally pasteurized (55 nmol/ml) RSM during the storage period of 7 days. The UV-C treatment can be effectively used for reducing E. coli cells and B. cereus spores in soymilk without compromising its quality.     

Phenolic profile and antioxidant activity of the Algerian ripe date palm fruit (Phoenix dactylifera)

The aim of this study was to determine the phenolic profile of seven different varieties of ripe date palm fruit (Phoenix dactylifera) from Algeria by LC–DAD–MS (ESI+), to investigate their respective antioxidant activities by the DPPH^· method and to estimate their phenolic content using the Folin–Ciocalteu method. The total phenolic content was in the range of 2.49 ± 0.01 to 8.36 ± 0.60 mg gallic acid equivalents (GAE) per 100 g fresh fruit. This fruit was shown to possess an antioxidant activity, giving values of antiradical efficient (AE) from 0.08 ± 0.00 to 0.22 ± 0.00. The phenolic contents and the antiradical efficiencies of the different varieties were highly correlated (R²=0.975). All the varieties were found to contain mainly p-coumaric, ferulic and sinapic acids and some cinnamic acid derivatives. Three different isomers of 5-o-caffeoylshikimic acid were detected. Different types of flavonoids were identified, mainly flavones, flavanones and flavonol glycosides.