Biofunctional Food Research Articles

Utilization of Saccharina japonica as a Solid-Fermented Substrate for the Production of Bioactive Ethanolic Extract

Marine biomass, Saccharina japonica was fermented as a solid-fermented substrate by Monascus spp. for the production of bioactive ethanolic extract. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-Azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS), superoxide anion radical scavenging and DNA protection activities of ethanolic extracts obtained from S. japonica fermented by M. purpureus (SjMp) showed the highest activity followed by M. kaoliang fermented S. japonica (SjMk) and unfermented (SjU) extract at 10 mg/mL concentration. Kinetic analysis revealed that ethanolic extract of fermented S. japonica inhibited the α-amylase competitively but α-glucosidase displayed competitive inhibition at 10 mg/mL concentration and non-competitive inhibition at 1 mg/mL concentration. The Linewaver-Burk kinetics analysis revealed that ethanolic extract of SjMk showed significantly higher Km value (4.55 mg) than SjMP (2.74 mg) followed by SjU (0.35 mg) at 10 mg/mL concentrations in α-amylase inhibition. But incase of α-glucosidase inhibition, the Km value was maximum in ethanolic extract of SjMp (2.30 mg) with Vmax (0.29 mg/min) at 10 mg/mL concentrations. Both of the fermented and unfermented samples did not show toxic effect on Caco-2 cells. The amino acid compositional analysis showed that fermentation process changed free amino acids contents in ethanolic extract. Monascus-fermented ethanolic extract showed antibacterial activity on Aeromonas hydrophila and Staphylococcus aureus. So, Monascus spp. fermented S. japonica extract played an important role in prevention of free radicals formation and hyperglycemia which can be applied in biofunctional food formulation.

Trial for the Development of Bio-Functional Foods to Prevent Diabetes and Dementia Using a High-Pressure Treatment

Type-2 diabetes and Alzheimer’s disease are very serious diseases and the former has been suggested to be one of the causes of the latter. Low glycemic index foods inhibit rapid increases in blood glucose and insulin secretion after meals. In this study, we investigated the palatability of boiled rice and inhibition of an abrupt increase in blood glucose level (BGL) and amyloid β peptide production after eating blend of ordinary brown rice, “Koshihikari” and anthocyanin-rich black-rice, “Okunomurasaki” unpolished rice cooked after a high-pressure treatment (HPT KO). “Okunomurasaki” showed a high antioxidant capacity and high inhibitory activity against β-secretase even after HPT and cooking. A randomized, single-blind, crossover-designed study was conducted using 15 subjects with a normal BGL. BGLs at 90 and 120 min after ingesting the cooked HPT KO were significantly lower than that for cooked Koshihikari polished rice (p < 0.05). Furthermore, the increase in the amyloid β40 peptide in the blood 120 min after eating HPT KO tended to be lower than that of cooked Koshihikari polished rice. It would be necessary to conduct a long-term test using the present HPTKO in terms of inhibitory activity against the abrupt increase of BGL and amyloid β peptide production for the probability to prevent type-2 diabetes and Alzheimer’s disease.

Physical and functional properties of tunicate (Styela clava) hydrolysate obtained from pressurized hydrothermal process

In this study, marine tunicate Styela clava hydrolysate was produced by an environment friendly and green technology, pressurized hot water hydrolysis (PHWH) at different temperatures (125–275 °C) and pressure 50 bar. A wide range of physico-chemical and bio-functional properties such as color, pH, protein content, total carbohydrate content, reducing sugar content, and radical scavenging activities of the produced hydrolysates were evaluated. The appearance (color) of hydrolysates varied depending on the temperature; hydrolysates obtained at 125–150 °C were lighter, whereas at 175 °C gave reddish-yellow, and 225 °C gave dark brown hydrolysates. The L* (lightness), a* (red–green), and b* (yellow–blue) values of the hydrolysates varied between 35.20 and 50.21, −0.28 and 9.59, and 6.45 and 28.82, respectively. The pH values of S. clava hydrolysates varied from 6.45 (125 °C) to 8.96 (275 °C) and the values were found to be increased as the temperature was increased. The hydrolysis efficiency of S. clava hydrolysate was ranged from 46.05 to 88.67% and the highest value was found at 250 °C. The highest protein, total carbohydrate content, and reducing sugar content of the hydrolysates were found 4.52 mg/g bovine, 11.48 mg/g and 2.77 mg/g at 175, and 200 and 200 °C, respectively. Hydrolysates obtained at lower temperature showed poor radical scavenging activity and the highest DPPH, ABTS, and FRAP activities were obtained 10.25, 14.06, and 10.91 mg trolox equivalent/g hydrolysate (dry matter basis), respectively. Therefore, S. clava hydrolysate obtained by PHWH at 225–250 °C and 50 bar is recommended for bio-functional food supplement preparation.

Effects of super-hard rice bread blended with black rice bran on amyloid β peptide production and abrupt increase in postprandial blood glucose levels in mice

Alzheimer's disease and type 2 diabetes are very serious diseases with the latter having been suggested to cause the former. We prepared super-hard rice bread blended with black rice bran (SRBBB), which contained a high amount of resistant starch that showed strong inhibitory activities against β-secretase and acetylcholinesterase even after heating. Black rice bran showed greater β-secretase inhibitory activity (3.6-fold) than Koshihikari rice. The bran contained more oleic acid and anthocyanin, meaning that it is potentially a biofunctional food with a high antioxidant capacity. Furthermore, aged mice, which were fed a SRBBB diet for four weeks, showed lower amyloid β 40 peptide in the blood than mice fed a commercial diet (p<0.01). Additionally, their initial blood glucose levels (BGLs) after 12 weeks of being fed SRBBB were significantly lower than those in the control group. Taken together, our results indicate SRBBB shows promise for inhibiting not only amyloid β production, but also abrupt increases in postprandial BGLs.

Antioxidant Effects of Sheep Whey Protein on Endothelial Cells

Excessive production of reactive oxygen species (ROS) may cause endothelial dysfunction and consequently vascular disease. In the present study, the possible protective effects of sheep whey protein (SWP) from tert-butyl hydroperoxide- (tBHP-) induced oxidative stress in endothelial cells (EA.hy926) were assessed using oxidative stress biomarkers. These oxidative stress biomarkers were glutathione (GSH) and ROS levels determined by flow cytometry. Moreover, thiobarbituric acid-reactive substances (TBARS), protein carbonyls (CARB), and oxidized glutathione (GSSG) were determined spectrophotometrically. The results showed that SWP at 0.78, 1.56, 3.12, and 6.24 mg of protein mL−1 increased GSH up to 141%, while it decreased GSSG to 46.7%, ROS to 58.5%, TBARS to 52.5%, and CARB to 49.0%. In conclusion, the present study demonstrated for the first time that SWP protected endothelial cells from oxidative stress. Thus, SWP may be used for developing food supplements or biofunctional foods to attenuate vascular disturbances associated with oxidative stress.

Chocolate and other cocoa products: effects on human reproduction and pregnancy.

Chocolate and other cocoa products are not all alike. They differ between themselves in term of nutrients, calories, and bioactive constituents. Therefore, some of them are unhealthy foods, whereas others do not affect health and still others are healthy foods. One wonders which chocolate and other cocoa derivatives can be considered as biofunctional food products. This review explores the constituents of cocoa and chocolate and summarizes evidence about the role of cocoa and chocolate components on human health and particularly on reproduction. On the basis of the literature review, it can be asserted that some kinds of cocoa products have favorable effects on human health at different stages of life. Women seem to be particularly favored by consuming of cocoa products, and chocolate with specific features can also be a good supplementary source of energy for pregnant woman. However, many aspects remain to be investigated and others are still to be clarified. Future studies and systematic reviews will shed light on some preventive effects and health benefits of cocoa products.

Polyphenolic composition of grape stem extracts affects antioxidant activity in endothelial and muscle cells.

The aim of the present study was the assessment of the antioxidant effects of polyphenolic extracts derived from the stems of three Greek grape varieties (Moshomayro, Mavrotragano and Mandilaria) in endothelial (EA.hy926) and muscle (C2C12) cells. We also investigated the effects of the polyphenolic composition on the antioxidant effects of the grape stem extracts. For this purpose, the endothelial and muscle cells were treated with low non-cytotoxic concentrations of the extracts for 24 h in order to assess the effects of the extracts on cellular redox status using oxidative stress biomarkers. The oxidative stress markers were thiobarbituric acid reactive substances (TBARS), protein carbonyl (CARB) levels, reactive oxygen species (ROS) levels and glutathione (GSH) levels. The results revealed that treatment of the EA.hy926 cells with Mandilaria extract significantly decreased the TBARS levels by 14.8% and the CARB levels by 25.9 %, while it increased the GSH levels by 15.8% compared to the controls. Moreover, treatment of the EA.hy926 cells with Mavrotragano extract significantly increased the GSH levels by 20.2%, while it significantly decreased the TBARS and CARB levels by 12.5% and 16.6%, respectively. Treatment of the C2C12 cells with Mandilaria extract significantly decreased the TBARS levels by 47.3 %, the CARB levels by 39.0 % and the ROS levels by 21.8%, while it increased the GSH levels by 22.6% compared to the controls. Moreover, treatment of the C2C12 cells with Mavrotragano significantly decreased the TBARS, CARB and ROS levels by 36.2%, 35.9% and 16.5%, respectively. In conclusion, to the best of our knowledgel, our results demonstrate for the first time that treatment with grape stem extracts at low concentrations improves the redox status of endothelial and muscle cells. Thus, grape stem extracts may be used for developing antioxidant food supplements or biofunctional foods. However, it was also found that the polyphenolic composition of grape stem extracts affects their antioxidant capacity. For example, the results suggested that trans-resveratrol, gallic acid, (+)-catechin, ferulic acid, caffeic acid, quercetin, coumaric acid and kaempferol may be essential for the antioxidant activity of grape stem extracts.

The proliferative effects of Pyropia yezoensis peptide on IEC-6 cells are mediated through the epidermal growth factor receptor signaling pathway.

For a number of years, seaweed has been used as a functional food in Asian countries, particularly in Korea, Japan and China. Pyropia yezoensis is a marine red alga that has potentially beneficial biological activities. In this study, we examined the mechanisms through which a Pyropia yezoensis peptide [PYP1 (1–20)] induces the proliferation of IEC-6 cells, a rat intestinal epithelial cell line, and the involvement of the epidermal growth factor receptor (EGFR) signaling pathway. First, cell viability assay revealed that PYP1 (1–20) induced cell proliferation in a concentration-dependent manner. Subsequently, we examined the mechanisms responsible for this induction of proliferation induced by PYP1 (1–20). EGFR is widely expressed in mammalian epithelial tissues, and the binding of this ligand affects a variety of cell physiological parameters, such as cell growth and proliferation. PYP1 (1–20) increased the expression of EGFR, Shc, growth factor receptor-bound protein 2 (Grb2) and son of sevenless (SOS). EGFR also induced the activation of the Ras signaling pathway through Raf, MEK and extracellular signal-regulated kinase (ERK) phosphorylation. In addition, cell cycle analysis revealed the expression of cell cycle-related proteins. The results demonstrated an increased number of cells in the G1 phase and an enhanced cell proliferation. In addition, the upregulation of cyclin D, cyclin E, Cdk2, Cdk4 and Cdk6 was observed accompanied by a decreased in p21 and p27 expression. These findings suggest that PYP1 (1–20) stimulates the proliferation of rat IEC-6 cells by activating the EGFR signaling pathway. Therefore, PYP1 (1–20) may be a potential source for the development of bio-functional foods which promotes the proliferation of intestinal epithelial cells.

Biocheese: a food probiotic carrier.

This review describes some aspects related to the technological barriers encountered in the development and stability of probiotic cheeses. Aspects concerning the viability of probiotic cultures in this matrix are discussed and the potential of cheese as a biofunctional food carrier is analyzed, outlying some points related to health and safety. In general, the manufacture of probiotic cheese should have little change when compared with the elaboration of cheese in the traditional way. The physicochemical and technological parameters influencing the quality of these products have also to be measured so as to obtain a process optimization.

Biochemical and biological assessment of the inhibitory potency of extracts from vinification byproducts of Vitis vinifera extracts against glycogen phosphorylase

The inhibitory potency of thirteen polyphenolic extracts obtained from vinification byproducts of Greek varieties of Vitis vinifera against glycogen phosphorylase (GP) has been studied by kinetic experiments. GP is an enzyme involved in glucose homeostasis and a molecular target for the discovery of new hypoglycemic agents. Studies have shown that all extracts display significant inhibitory potency for GP in vitro with IC50 values in the range of low μg/mL. X-ray crystallographic analysis of GP crystals soaked with two of these extracts revealed that the most active ingredient is quercetin which binds at novel binding site, distinct from the other known sites of the enzyme. One of the most potent of the studied extracts had also a moderate effect on glycogenolysis in the cellular lever with an IC50 value of 17.35μg/mL. These results highlight the importance of natural resources in the quest for the discovery of new hypoglycemic agents, while at the same time they can serve as the starting point for their exploitation for antidiabetic usage and the development of novel biofunctional foods.

Bio-accessibility of bioactive compounds (ACE inhibitors and antioxidants) from extruded maize products added with a red seaweed Porphyra columbina

An expanded maize product added with red seaweeds Porphyra columbina (3.5 g 100 g−1) was developed and bio-accessibility of minerals and bioactive compounds such as ACE inhibitors and antioxidants provide by algae were evaluated using a pepsin/pancreatin digestion and equilibrium dialysis method. Extruded maize added with red seaweed showed higher dialyzability of ACE inhibitor compounds (41.0% ACE inhibition), total phenolic content (0.83 mg gallic acid/g dialysate) and antioxidant capacity (36.6% DPPH inhibition, 2.4 mM TEAC, power reduction and 99.4% copper-chelating activity) than extruded maize. Results about bio-accessibility of bioactive compounds provided by red edible seaweeds may help food technologists to tailor new bio-functional foods, such as functional snacks.

Induction of apoptosis and the regulation of ErbB signaling by laminarin in HT-29 human colon cancer cells

Laminarin, found in marine brown algae, is used as a carbohydrate reserve for phytoplankton; however, it is also used in traditional Chinese medicine, and has been shown to have several biological activities, including anticancer activities. In this study, we examined the mechanisms through which laminarin from Laminaria digitata induces apoptosis in HT-29 colon cancer cells, as well as the involvement of the ErbB signaling pathway. Cell viability assay revealed that laminarin induced cell death in a dose-dependent manner. Cell cycle analysis revealed that laminarin increased the percentage of cells in the sub-G1 and G2-M phase. Western blot analysis demonstrated that laminarin inhibited the heregulin-stimulated phosphorylation of ErbB2. A decrease in cellular proliferation was also observed; this was found to be dependent on ErbB, which activates c-Jun N-terminal kinase. These findings demonstrate the important role of the epidermal growth factor receptor in colon cancer tumorigenesis, and suggest the potential of laminarin as a bio-functional food with anticancer effects on human colon cancer.

Xanthoangelol and 4-Hydroxyderricin Are the Major Active Principles of the Inhibitory Activities against Monoamine Oxidases on Angelica keiskei K

Monoamine oxidase inhibitors (MAOI) have been widely used as antidepressants. Recently, there has been renewed interest in MAO inhibitors. The activity-guided fractionation of extracts from Angelica keiskei Koidzumi (A. keiskei K.) led to the isolation of two prenylated chalcones, xanthoangelol and 4-hydroxyderricin and a flavonoid, cynaroside. These three isolated compounds are the major active ingredients of A. keiskei K. to inhibit the MAOs and DBH activities. Xanthoangelol is a nonselective MAO inhibitor, and a potent dopamine β-hydroxylase (DBH) inhibitor. IC50 values of xanthoangelol to MAO-A and MAO-B were calculated to be 43.4 μM, and 43.9 μM. These values were very similar to iproniazid, which is a nonselective MAO inhibitor used as a drug against depression. The IC50 values of iproniazid were 37 μM, and 42.5 μM in our parallel examination. Moreover, IC50 value of xanthoangelol to DBH was calculated 0.52 μM. 4-Hydroxyderricin is a potent selective MAO-B inhibitor and also mildly inhibits DBH activity. The IC50 value of 4-hydroxyderricin to MAO-B was calculated to be 3.43 μM and this value was higher than that of deprenyl (0.046 μM) used as a positive control for selective MAO-B inhibitor in our test. Cynaroside is a most potent DBH inhibitor. The IC50 value of cynaroside to DBH was calculated at 0.0410 μM. Results of this study suggest that the two prenylated chalcones, xanthoangelol and 4-hydroxyderricin isolated from A. keiskei K., are expected for potent candidates for development of combined antidepressant drug. A. keiskei K. will be an excellent new bio-functional food material that has the combined antidepressant effect.

야생버섯 메탄올추출물의 생리활성 검색

In this study, the biological activities of 33 kinds of wild mushroom methanol extracts were investigated. Boletellus elatus showed the greatest fibrinolytic activity (1.08 plasmin units/mL) in a fibrin plate assay, and the activity of Heterobasidion insulasis was 0.89 plasmin units. The thrombin inhibitory activities of Boletellus elatus and Heterobasidion insulasis were 93.32% and 93.69%, respectively. In a -glucosidase inhibitory activity test, Laccaria amethystina showed the greatest inhibitory activity at 81.25%. The antioxidative activities of Gomphus sp. and Geastrum lageniforme were 91.37% and 90.42%, respectively. Since Boletellus elatus and Heterobasidion insulasis have strong fibrinolytic and thrombin inhibitory and antioxidative activities, the two mushrooms can be used as material for the development of biofunctional foods for cardiovascular diseases.

Monoamine Oxidase and Dopamine β-Hydroxylase Inhibitors from the Fruits of Gardenia jasminoides

This research was designed to determine what components of Gardenia jasminoides play a major role in inhibiting the enzymes related antidepressant activity of this plant. In our previous research, the ethyl acetate fraction of G. jasminosides fruits inhibited the activities of both monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B), and oral administration of the ethanolic extract slightly increased serotonin concentrations in the brain tissues of rats and decreased MAO-B activity. In addition, we found through in vitro screening test that the ethyl acetate fraction showed modest inhibitory activity on dopamine-β hydroxylase (DBH). The bioassay-guided fractionation led to the isolation of five bio-active compounds, protocatechuic acid (1), geniposide (2), 6'-O-trans-p-coumaroylgeniposide (3), 3,5-d-ihydroxy-1,7-bis (4-hydroxyphenyl) heptanes (4), and ursolic acid (5), from the ethyl acetate fraction of G. jasminoides fruits. The isolated compounds showed different inhibitory potentials against MAO-A, -B, and DBH. Protocatechuic acid showed potent inhibition against MAO-B (IC50 300 μmol/L) and DBH (334 μmol/L), exhibiting weak MAO-A inhibition (2.41 mmol/L). Two iridoid glycosides, geniposide (223 μmol/L) and 6'-O-trans-p-coumaroylgeniposide (127μmol/L), were selective MAO-B inhibitor. Especially, 6'-O-trans-p-coumaroylgeniposide exhibited more selective MAO-B inhibition than deprenyl, well-known MAO-B inhibitor for the treatment of early-stage Parkinson’s disease. The inhibitory activity of 3,5-di-hydroxy-1,7-bis (4-hydroxyphenyl) heptane was strong for MAO-B (196 μmol/L), modest for MAO-A (400 μmol/L), and weak for DBH (941 μmol/L). Ursolic acid exhibited significant inhibition of DBH (214 μmol/L), weak inhibition of MAO-B (780 μmol/L), and no inhibition against MAO-A. Consequently, G. jasminoides fruits are considerable for development of biofunctional food materials for the combination treatment of depression and neurodegenerative disorders.

Histopathological Effect of Probiotics after Intra-Peritoneal Injection of Ehrlith Ascites Tumor Cells

Background: Some functional foods such as probiotics play a beneficial role functions in the treatment of some health problems and ameliorate the oxidative stress mechanisms and other risks which improving the quality of life. Cancer is one of the most important health problems. Methods: For this study forty four female Swiss albino mice were used. These mice were subdivided into four groups (negative control, positive control and two induced carcinogenic groups fed on probiotics). Yoghurt and fermented kidney beans used as probiotics. Cancer induced by intra-peritoneal injection of 2×106 Ehrlich ascites tumor cells. The tumer will examine histopathologically. Results: of degeneration and necrosis. Feeding on fermented kidney beans was more effective than yogurt in which the neoplastic cells became smaller in size, degenerated and lost their nuclei. Conclusion: In this study the two tested probiotics (yoghurt and fermented kidney beans) used as biofunctional foods to reduce the high risk of these disease.

Protective effect of a polysaccharide from Hizikia fusiformis against ethanol-induced cytotoxicity in IEC-6 cells

In the present study, we examined the signaling pathways related to the ethanol-protective effect of Hf-PS-1 in IEC-6 cells. Ethanol induced the death of IEC-6 cells in a dose-dependent manner, and pretreatment with Hf-PS-1 abrogated the ethanol toxicity. When we examined whether the effect of Hf-PS-1 on ethanol cytotoxicity was associated with insulin growth factor-I receptor signaling pathways, involving mitogen-activated protein kinase (MAPK), we found that ethanol treatment decreased the phosphorylation of Shc and the binding of Grb2 to Shc, and Hf-PS-1 pretreatment increased them. Ethanol treatment also induced the phosphorylation of JNK and ERK, whereas Hf-PS-1 pretreatment decreased JNK activation but not ERK activation. Using a JNK inhibitor (SP600125), we examined GSH levels to determine whether Hf-PS-1 pretreatment mi20 ght protect against ethanol-induced gastric intestinal damage by down-regulating JNK. Co-treatment with SP600125 and ethanol decreased GSH levels, indicating that JNK phosphorylation is a critical factor during ethanol-induced injury and that the effect of Hf-PS-1 occurs via JNK down-regulation. We have thus demonstrated the protective effect of Hf-PS-1 against ethanol-induced cellular damage. Therefore, Hf-PS-1 may be useful as a bio-functional food source to protect against ethanol-induced gastrointestinal injury.

다발구멍장이버섯으로부터 분리한 혈전용해 세린분해효소의 특성 연구

3단계를 거처 식용 가능한 다발구멍장이버섯으로부터 분리한 혈전용해효소의 비활성은 30.49 U/mg이었으며, MALDI-TOF/MS로부터 분자량이 30086.41 Da이었다. 일차 아미노산 구조는 Glu-Thr-Val-Thr-Glu-Thr-Thr-Ala-Pro-Trp-Gly-Leu-Ser-Arg-Ile으로 밝혀졌으며, pH 8.0에서 pH 10.0의 넓은 범위에서 큰 활성을 나타내는 alkaline protease로, 최적온도는 <TEX>$50^{\circ}C$</TEX>이며, <TEX>$30^{\circ}C$</TEX>까지는 대체로 열에 안정한 효소였다. 이 효소는 합성 기질 N-Suc-Ala-Ala-Pro-Phe pNA을 강하게 분해하였으며, <TEX>$Hg^{2+}$</TEX> 금속이온의 첨가로 효소 활성이 완전히 사라졌다. 효소저해제인 PMSF의 첨가로 혈전용해활성이 사라지는 결과로부터 serine 분해효소임을 알 수 있었다. A fibrinolytic serine protease was purified from the fruiting bodies of an edible mushroom, Albatrellus confluens. The enzyme had a molecular mass of 30086.41 Da, as measured by MALDI-TOF mass spectrometry. The N-terminal amino acid sequence of the enzyme was Glu-Thr-Val-Thr-Glu-Thr-Thr-Ala -Pro-Trp-Gly-Leu-Ser-Arg-Ile. It displayed optimal activity at <TEX>$50^{\circ}C$</TEX> and within a pH range of <TEX>$8.0{\sim}10.0$</TEX>, suggesting that the enzyme is an alkaline protease. The enzyme was stable up to <TEX>$30^{\circ}C$</TEX>. The enzyme displayed a strong substrate specificity for the synthetic peptide, N-Suc-Ala-Ala-Pro-Phe pNA. The enzyme activity was completely inhibited by addition of PMSF, indicating that the enzyme is a serine protease. No inhibition was observed following addition of E-64, pepstatin, or EDTA. The activity of the purified enzyme was decreased in the presence <TEX>$Fe^{2+}$</TEX> or <TEX>$Co^{2+}$</TEX>, and the enzyme was completely inhibited by addition of <TEX>$Hg^{2+}$</TEX>. From these results, we propose that Albatrellus confluens could be used for biofunctional foods development and has potential therapeutic value for the treatment of vascular diseases.

Oleuropein as a bioactive constituent of functional milk and yogurt

In recent years, interest in antioxidants isolated from plants has arisen due to their vital role in the protection of cell damage caused by the excess of free radicals (oxidative stress) [1]. Moreover, antioxidants are also used by food industries, as additives for the improvement of several properties of foods (biofunctional foods). One of the most important and developing category in this area is the dairy products, which are natural sources of high nutritional value [2]. Oleuropein is an important constituent of olive fruits. According to in vivo and in vitro studies, oleuropein exhibits anti-ischemic, antioxidative, and hypolipidemic effects [2]. In the present study, two functional dairy products were prepared by addition of oleuropein. An analytical method for the measurement of oleuropein in milk and yogurt was developed and validated. The new products were examined about the stability of oleuropein during their treatment. The results showed that oleuropein was resistant during heating of milk at 90oC for 5min. Furthermore, during coagulation of milk, oleuropein was not hydrolysed by the produced acids, it was not metabolized by lactic acid bacteria and it did not stop their growth. Also its stability during the maintenance of milk and yogurt for 35 days at 4 oC was proven. The functional milk and yogurt production was performed in laboratory and semi-industrial scale. Oleuropein was completely soluble in the selected concentration (0.1mg/ml) and it did not give any peculiar taste, as the products had the same taste and flavor with the conventional ones [4]. The selection of the concentration was based on the oleuropein quantity corresponding to consumption of 15 olive drupes per day. All the above results show that oleuropein can be added as active ingredient in milk and yogurt and two new biofunctional products can be produced, whose properties remain constant, during the overall process.

야생버섯 메탄올추출물의 혈전용해 활성과 α-Glucosidase 저해 활성

The aim of this study was to investigate the physiological functionalities of 60 wild mushroom methanol extracts. We determined their fibrinolytic and inhibitory activities. Among them, 11 mushrooms showed fibrinolytic activity. In particular, Armillaria sp. showed the greatest enzyme activity (4.2 plasmin units/ml) in a fibrin plate assay. The fibrinolytic activities of Amanita virosa. Gymnophilus sp. and Lepista nuda were 2.3, and the activities of Amanita citrina and Cortinarius alboviolaceus were 2.1 and 2.0 plasmin units, respectively. In a inhibitory activity test, Naematoloma fasciculare showed the greatest inhibitory activity at 98.5%. The inhibitory activities of Suillus luteus and Gomphidius maculatus were 66.6% and 61.5%, respectively. This study suggests that both Armillaria sp. and N. fasciculare can be used as candidates for the development of new medicine effective to cardiovascular diseases and biofunctional food.