Jau-Tien Lin

Effects of roasting temperature and duration on fatty acid composition, phenolic composition, Maillard reaction degree and antioxidant attribute of almond (Prunus dulcis) kernel

Roasting treatment increased levels of unsaturated fatty acids (linoleic, oleic and elaidic acids) as well as saturated fatty acids (palmitic and stearic acids) in almond (Prunus dulcis) kernel oils with temperature (150 or 180 °C) and duration (5, 10 or 20 min). Nonetheless, higher temperature (200 °C) and longer duration (10 or 20 min) roasting might result in breakdown of fatty acids especially for unsaturated fatty acids. Phenolic components (total phenols, flavonoids, condensed tannins and phenolic acids) of almond kernels substantially lost in the initial phase; afterward these components gradually increased with roasting temperature and duration. Similar results also observed for their antioxidant activities (scavenging DPPH and ABTS(+) radicals and ferric reducing power). The changes of phenolic acid and flavonoid compositions were also determined by HPLC. Maillard reaction products (estimated with non-enzymatic browning index) also increased with roasting temperature and duration; they might also contribute to enhancing the antioxidant attributes.

Composition of flavonoids and phenolic acids in lychee (Litchi Chinensis Sonn.) Flower extracts and their antioxidant capacities estimated with human LDL, erythrocyte, and blood models.

Lychee (Litchi chinensis Sonn.) flower is a major nectar source in Taiwan. Antioxidant activities of acetone, ethanol, and hot-water extracts of the flower were estimated through three biochemical models: inhibition of Cu(2+) -induced oxidation of human low-density lipoprotein, scavenging ability of oxygen radicals in human blood, and inhibition of human erythrocyte hemolysis induced by peroxyl radicals. Composition and content of flavonoids and phenolic acids in these extracts were also determined by high-performance liquid chromatography. Results showed that antioxidant effects of all test models as well as contents of flavonoids and phenolic acids for the lychee flower extracts were in the order: acetone extract > ethanol extract > hot-water extract. Gentistic acid and epicatechin were the major phenolic acid and flavonoid in the extracts, respectively.

Determination of steroidal saponins in different organs of yam (Dioscorea pseudojaponica Yamamoto)

Yams (Dioscorea spp.) are perennial trailing rhizome plants. Steroidal saponins, furostanol and spirostanol glycosides are the marked functional compounds in yams. In this investigation, a C18 solid phase extraction method was developed for yam saponins purification. The contents of saponins in various organs of yam (Dioscorea pseudojaponica Yamamoto) were also determined. Results showed that the recoveries of yam saponins extracted by the developed method were about 99.48-100.08% when the saponins (each saponin weighed 0.20, 0.50 and 1.00mg) passing through the C18 cartridge. The extractive method could efficiently reduce the interferences from impurities in yam saponin extracts prior to HPLC analysis. The recoveries of added saponins in different yam organs were 98.34-99.92% for tuber flesh, 95.98-98.89% for tuber cortex, 97.89-99.44% for rhizophor, 93.82-98.01% for leaf and 93.87-97.65% for vine, respectively. The yam tuber cortex had the highest amount of saponins (582.53μg/gdw), which was higher than that existed in the tuber flesh (227.86μg/gdw) about 2.55 times. The contents of saponins in the rhizophor, leaf and vine of yam were 29.39, 24.41 and 23.96μg/gdw, respectively.

Inhibitory effect of litchi (Litchi chinensis Sonn.) flower on lipopolysaccharide-induced expression of proinflammatory mediators in RAW264.7 cells through NF-κB, ERK, and JAK2/STAT3 inactivation.

Litchi (Litchi chinensis Sonn.) flower ethanolic extract (LFEE) was found to contain five flavanoids [total amount, 102.73 ± 5.50 mg/g of dried extract (gDE)], nine phenolic acids (total amount, 60.31 ± 4.52 mg/gDE), and proanthocyanidin A2 (79.31 ± 2.95 mg/gDE). LFEE was used to evaluate the inhibitory effects on lipopolysaccharide- (LPS-) induced pro-inflammatory mediators in RAW264.7 cells. The results showed that LFEE treatment could suppress the expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), the productions of nitric oxide (NO) and prostaglandin E2 (PGE2), and the secretions of pro-inflammatory cytokines [interleukin-1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)] in the LPS-mediated RAW264.7 cells. The attenuation of LPS-induced inflammatory responses by LFEE was found to be closely related to the inhibition of the translocation of nuclear factor κB (NF-κB) p50/p65 subunits correlated with suppression of the activation of the inhibitor of κB kinase (IKK) α/β and downregulation of activation of extracellular signal-regulated kinase (ERK) and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3).

Antioxidant effect and active components of litchi (Litchi chinensis Sonn.) flower.

The effects of scavenging 2, 2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radicals and inhibiting low-density lipoprotein (LDL) oxidation, and phenolic quantities were used for the activity-guided separation to identify the effective components of litchi flower. The acetone extract of the flower with notable antioxidant capacities was suspended in water and sequentially partitioned with n-hexane, ethyl acetate (EA) and n-butanol. The EA partition with the highest phenolic levels and antioxidant capacities was subjected to silica gel column chromatography. Thirteen fractions (Fr. 1-13) were collected; Fr. 10-12 with higher phenolic levels and antioxidant effects were applied to Sephadex LH-20 column chromatography. Each fraction was further separated into three sub-fractions and the second ones (Fr. 10-II, 11-II, and 12-II) were the best, which two major compounds could be isolated by semi-preparative high performance liquid chromatography (HPLC). Through Mass (MS) and Nuclear Magnetic Resonance (NMR) measurements, they could be identified as (-)-epicatechin and proanthocyanidin A2. Their contents in the litchi flower were 5.52 and 11.12 mg/g of dry weight, respectively. The study was the first time to reveal the effective antioxidant components of litchi flower.

Simultaneous Determination of Furostanol, Pennogenyl, and Diosgenyl Glycosides in Taiwanese Rhizoma Paridis ( Paris formosana Hayata) by high-performance liquid chromatography with evaporative light scattering detection.

A high-performance liquid chromatographic method with an evaporative light scattering detector (HPLC-ELSD) was developed to simultaneously determine 10 steroidal saponins, including 3 furostanol glycosides, 3 pennogenyl glycosides, and 4 diosgenyl glycosides in Taiwanese rhizoma paridis ( Paris formosana Hayata). The condition was a Cosmosil C18 column kept at 35 °C and a step-gradient solvent system consisting of acetonitrile and water (25:75, v/v) in the first 30 min, 45:55 (v/v) from 31 to 45 min, and 50:50 (v/v) from 45 to 65 min, at a flow rate of 1 mL/min. The separation factors (α) and resolutions (Rs) were better than 1, and the limits of detection (LODs) and limits of quantification (LOQs) were 0.01-0.27 and 0.04-0.90 μg, respectively, for these saponins. Moreover, 203 nm UV detection was also used for comparison. The saponins in P. formosana Hayata gathered from various areas of Taiwan were determined by applying the established method.

Phenolic compositions and antioxidant attributes of leaves and stems from three inbred varieties of Lycium chinense Miller harvested at various times

Antioxidant components and properties (assayed by scavenging DPPH radicals, TEAC, reducing power, and inhibiting Cu(2+)-induced human LDL oxidation) of leaves and stems from three inbred varieties of Lycium chinense Miller, namely ML01, ML02 and ML02-TY, harvested from January to April were studied. Their flavonoid and phenolic acid compositions were also analyzed by HPLC. For each variety, the leaves and stems collected in higher temperature month had higher contents of total phenol, total flavonoid and condensed tannin. Contents of these components in the samples collected in different months were in the order: April (22.3°C)>March (18.0°C)>January (15.6°C)>February (15.4°C). Antioxidant activities of the leaves and stems for all assays also showed similar trends. The samples from different varieties collected in the same month also possessed different phenolic compositions and contents and antioxidant activities. Their antioxidant activities were significantly correlated with flavonoid and phenolic contents.

Isolation and Identification of Steroidal Saponins in Taiwanese Rhizoma Paridis Cultivar (Paris formosana Hayata)

台灣蚤休(Paris formosana Hayata)具有九個類固醇皂苷，其化學結構是利用液－液萃取配合高效能液相層析儀進行分離純化，再經液相層析質譜儀與核磁共振儀進行結構鑑定得知。此九個類固醇皂苷包括三個furostanol glycosides: 26-O-β-D-glucopyranosyl-22α-methoxyl-(25R)-furost-5-en-3β, 26-diol 3-O-α-L-rhamnopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→4)-O-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside, 26-O-β-D-glucopyranosyl-22α-methoxyl-(25R)-furost-5-en-3β, 26-diol 3-O-α-L-rhamnopyranosyl-(1→2)-O-[α-L-arabinofuranosyl-(1→4)]-β-Dglucopyranoside和26-O-β-D-glucopyranosyl-22α-methoxyl-(25R)-furost-5-en-3β, 26-diol 3-O-α-L-rhamnopyranosy-(1→2)-O-[β-D-glucopyranosyl (1→3)]-β-D-glucopyranoside，二個pennogenyl glycosides (spirostanol glycosides): 25 (R)-spirost-5-en-3β, 17-diol 3-O-α-L-rhamnopyranosy-(1→4)-O-α-L-rhamnopyranosyl-(1→4)-O-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside和(25R)-spirost-5-en-3β, 17-diol 3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-arabinofuranosyl-(1→4)]-β-D-glucopyranoside以及四個diosgenyl glycosides (spirostanol glycosides): (25R)-spirost-5-en-3β-ol 3-O-α-L-rhamnopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→4)-O-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside, 3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranoside-(1→3)]-β-D-glucopyranoside, (25R)-spirost-5-en-3β-ol 3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-arabinofuranosyl-(1→4)]-β-D-glucopyranoside (25R)-spirost-5-en-3β-ol和(25R)-spirost-5-en-3β-ol 3-O-α-Lrhamnopyranosyl-(1→2)-O-β-D-glucopyranoside.