Effect of glasswort (<Emphasis Type="Italic">Salicornia herbacea</Emphasis> L.) and rice (<Emphasis Type="Italic">oryza sativa</Emphasis> L.) on quality of <Emphasis Type="Italic">Ganjang</Emphasis> (Korean Soy Sauce)

Four types of meju were made from 100%(w/w) defatted soybean (DFS), a mixture of 80%(w/w) defatted soybean, and 20%(w/w) glasswort (DFS-G), a mixture of 80%(w/w) defatted soybean and 20%(w/w) rice (DFS-R), and a mixture of 60%(w/w) defatted soybean, 20%(w/w) glasswort, and 20%(w/w) rice (DFS-GR). Four types of Korean traditional soy sauce were prepared from the 4 types of meju. Mineral and antioxidant contents in the soy sauce made of DFS-G and DFS-GR were significantly higher than others. Citric, malic, succinic, lactic, and pyroglutamic acid contents in soy sauce made of DFS-R and DFS-GR were 1.3–1.5 times higher than others. Total nitrogen and free amino acid contents in soy sauce were correlated with DFS concentration in the meju. The bacterial community in the non-fermented meju-making ingredients was replaced largely by Bacillus sp. in the fermented meju. The use of glasswort and rice in the meju-making process did not alter the bacterial community responsible for the fermentation of meju.     

Optimization of culture medium for yellow pigments production with <Emphasis Type="Italic">Monascus anka</Emphasis> mutant using response surface methodology

In our laboratory, one Monascus anka mutant able to produce high yield of yellow pigments screened by physical and chemical combination mutagenesis was obtained. This study evaluated peptone, NH₄NO₃ and KH₂PO₄ as the most significant variables for Monascus yellow pigment production by this M. anka mutant MYM in submerged fermentation. Response surface methodology (RSM) optimized these nutrient parameters for maximum yellow pigment production (87.24 OD units), which resulted at 10.3 g/L peptone, 11.9 g/L NH₄NO₃ and 4.7 g/L KH₂PO₄ in the medium. According to the fitting equation, through five replication experiments under the optimized conditions, the average yellow pigment production obtained was 88.14 OD units for flask cultivation and 92.45 OD units for 5 L fermenter cultivation. Meanwhile, the citrinin could not be detected by HPLC method.     

Ethanolic fermentation from red ginseng extract using <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> and <Emphasis Type="Italic">Saccharomyces carlsbergensis</Emphasis>

The pH of red ginseng extracts fermented with Saccharomyces cerevisiae and Saccharomyces carlsbergensis decreased rapidly during 3 days of fermentation, with no further significant change thereafter. After 20 days of fermentation, a relatively small difference remained in the acidity of extracts fermented with S. cerevisiae (0.54%) and S. carlsbergensis (0.58%). Reducing sugar in the S. cerevisiae and S. carlsbergensis extracts decreased from 258.6 to 45.4 and 43.2 mg/mL glucose equivalents, respectively; and ethanol contents increased from 1.5% at day 0 to 16.0 and 15.0%, respectively, at day 20. Ginsenosides Rb₁, Rb₂, Rc, Re, Rf, and Rg₁ decreased during the fermentation with S. cerevisiae, but Rd and Rg₃ increased by day 12. Ginsenosides Rb₁, Rb₂, Rc, Re, and Rg₁ decreased gradually in the extract with S. carlsbergensis, but Rd and Rg₃ were increased at day 6 and 9, respectively.     

Effect of different levels of malt extract on antinutrients, <Emphasis Type="Italic">in vitro</Emphasis> digestibilities and viscosity during fermentation of <Emphasis Type="Italic">Jeungpyun</Emphasis>

The effect of different levels of malt extract on the fermentation of jeungpyun (a Korean fermented steamed rice cake) was investigated. Relative to the control batter, the fermentation rate increased with increasing level of malt extract due to its effect in expediting the fermentation. The contents of total phenols and phytic acid in the jeungpyun batter were reduced during fermentation, and even more so after steaming of the batter. The reduced content of antinutritional factors in the batter was accompanied by increases in in vitro protein and starch digestibilities. The effect of different levels of malt extract on the viscosity and hardness was similar. These results indicate that the addition of malt extract during fermentation may produce a healthier and more nutritious jeungpyun. It also facilitated the production of thin fermented batter, thus affecting the textural characteristics of jeungpyun.     

Effects of different <Emphasis Type="Italic">Lactobacillus</Emphasis> and <Emphasis Type="Italic">Enterococcus</Emphasis> strains and chemical acidification regarding degradation of gluten proteins during sourdough fermentation

Dough quality and baking performance of wheat dough are significantly affected by the qualitative and quantitative composition of the gluten. Therefore, the degradation was studied of specific fractions of gluten proteins in sourdough as affected by starter cultures. Doughs were fermented for 0, 5, and 24 h at 30 °C after addition of Lactobacillus sakei, L. plantarum, L. sanfranciscensis or Enterococcus faecalis. Chemically acidified doughs were used as controls. All doughs were analyzed quantitatively for their content of albumins, globulins, gliadins, glutenins, and glutenin macropolymer by means of a combined extraction/HPLC procedure. Protein degradation during sourdough fermentation was primarily due to acidic proteases present in flour. While L. sakei, L. plantarum and L. sanfranciscensis were mostly non-proteolytic, E. faecalis clearly contributed to gluten proteolysis. Single gluten protein types were clearly different in their resistance to proteolytic activities of the dough system and E. faecalis, and, in contrast to total glutenins, the amounts of gluten macropolymer were significantly reduced already after 5 h of incubation. When longer fermentation times were applied, gluten was substantially degraded. The strongest decrease was found for the glutenin fraction leading to an increase of alcohol soluble oligomeric proteins in the gliadin fraction. The extent of the decrease of monomeric gliadins was strongest for the γ-type followed by the α- and the ω-types. This indicates that dough properties residing in specific types of gluten fractions can be influenced by the duration of fermentation and the application of proteolytic strains.     

Estrogenic effects of various extracts from <Emphasis Type="Italic">Chamdanggui</Emphasis> (<Emphasis Type="Italic">Angelica gigas</Emphasis> Nakai) and <Emphasis Type="Italic">sogdan</Emphasis> (<Emphasis Type="Italic">Phlomis umbrosa</Emphasis> Turcz)

The various extracts from chamdanggui (Angelica gigas Nakai) and sogdan (Phlomis umbrosa Turcz) were evaluated for estrogenic activity and characterized according to HPLC profile. Chamdanggui and sogdan were individually extracted with 4 solvents (hot water, 70% ethanol, n-butanol, and dichloromethane) of differing polarities. Estrogenic activity was determined by E-screen using an estrogen-dependent MCF-7 BUS cell. Although almost all extracts showed estrogenic effects in a concentrationdependent manner, the hot water extract from chamdanggui (250 μg/mL) had the higher effect (138%). Among 90 fractions using HPLC separation of the hot water extract from chamdanggui, fraction 21 and 28 produced the highest estrogenic effects of 178 and 163% at 10 μg/mL, respectively. The results imply that the hot water extract from chamdanggui could be useful as an alternative hormone replacement therapy.     

红曲霉固态发酵产Lovastatin的培养条件

对 1株红色红曲霉固态发酵产Lovastatin的培养条件进行了研究。得出固态基质最佳初始含水量为 40 %,基础基质中加入葡萄糖和有机氮源能显著提高发酵产物中Lovastatin含量 ,多种蔬菜浸出汁都能提高Lovastatin产量 ,红曲米浸泡水对Lovastatin有明显的促进作用。稻米的种类及米的粉碎度对Lovastatin的合成也有一定的影响。在优化的培养条件下 ,干曲中Lovastatin的含量可以达到 2 5～ 3 0mg/g。     

Thermal inactivation kinetics of quality-related enzymes in cauliflower (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">botrytis</Emphasis><Emphasis Type="Bold">)</Emphasis>

Thermal inactivation of quality-related enzymes in both cauliflower crude enzyme extracts and fresh tissue samples was studied in temperature range 50–100 °C. For crude enzyme extracts, several parameters, reaction rate constants (k) and activation energy (E _a) as well as decimal reduction time (D) and (z) values, were used to characterize the thermal stability. The rates of inactivation were found to follow first-order inactivation kinetics. Activation energies varied between 101.18 and 208.42 kJ mol⁻¹ with z values of 10.59–24.09 °C. The examined kinetics indicated that lipoxygenase was the most heat resistant followed by peroxidase, polyphenol oxidase, pectin methyl esterase and ascorbic acid oxidase. Furthermore, the obtained results from the blanched fresh tissues indicated that inactivation of lipoxygenase secured disappearing of any other enzyme activities. Therefore, this study recommends using lipoxygenase as an indicator enzyme to optimize the thermal treatments of cauliflower products.     

Xanthan gum production under different operational conditions by <Emphasis Type="Italic">Xanthomonas axonopodis</Emphasis> pv <Emphasis Type="Italic">vesicatoria</Emphasis> isolated from pepper plant

The influence of operational conditions (pH, stirrer speed, and temperature) used in the process of xanthan production by Xanthomonas axonopodis pv vesicatoria (XCVA3-1) isolated from pepper plant were evaluated through yield of xanthan and compared with control strain Xanthomonas campestris NRRL-B 1459. Different conditions used during the fermentation affected the xanthan production. In this study the best combination of yield was obtained, reaching 1.325 g/100 mL with the use of pH 7.0, 30°C, and 250 rpm during fermentation. Increased yield of xanthan production can be obtained at high agitation values, with the maximum at 400 rpm. Higher yields of gum production can be obtained at 30°C and the optimum pH was found 7.0. This results were similar for the X. campestris NRRL-B 1459.     

Studies concerning the use of <Emphasis Type="Italic">Lactobacillus helveticus</Emphasis> and <Emphasis Type="Italic">Kluyveromyces marxianus</Emphasis> for rye sourdough fermentation

The aim of this study was to investigate the fermentation behaviour, antioxidant activity and rheological behaviour of the sourdoughs prepared with Lactobacillus helveticus and Kluyveromyces marxianus. The final acidity of the sourdough after 18 h of fermentation was higher at higher temperatures (40 °C) and for the formulations with whole rye flour. The highest lactic/acetic acid ratios were obtained in case of more fluid sourdoughs fermented at 40 °C. The antioxidant properties of the sourdoughs are correlated with metabolic activity of the microorganisms, the DPPH radical scavenging activity being higher for optimum conditions of Lactobacillus helveticus growth. On the other hand, the rheological properties of the sourdoughs are not significantly influenced by the temperature. Sourdoughs formulations with whole flour are more viscous, as well as the controls fermented by the spontaneous microflora. The results of the bread-making process simulation by means of Mixolab indicate differences between dough formulations mainly depending on flour type.     

Isolation of lactic acid bacteria starters from <Emphasis Type="Italic">Jeung</Emphasis>-<Emphasis Type="Italic">pyun</Emphasis> for sourdough fermentation

Lactic acid bacteria (LAB) are key for the fermentation of sourdoughs to improve the quality and nutritive value of bread. The aim of this study was to isolate the LAB starter for sourdough fermentation from Jeung-pyun, a Korean traditional rice cake. Among the twenty two LAB screened, five isolates were selected based on exo-polysaccharide production. Among them, three isolates showed cell growth greater than 8.5 Log CFU/g, maximum increase in the volume of dough, and dextran concentration up to 0.16%. During the sourdough fermentation, pH and total titratable acidity (TTA) were changed, as the three isolates synthesized lactic acid and acetic acid with fermentation quotients less than 2.0. They were identified as Leuconostoc lactis EFEL005, Lactobacillus brevis EFEL004, and Le. citreum EFEL006. They displayed good fermentation properties (growth, dextran production, pH, and TTA) in dough and they are regarded as potential starters to be used in sourdough fermentation.     

Lactic acid fermentation of<Emphasis Type="Italic"> Brassica rapa</Emphasis>: chemical and microbial evaluation of a typical Italian product (<Emphasis Type="Italic">brovada</Emphasis>)

Brovada is an ancient traditional product from the northeast Italian region, included in any list of typical Italian products, which is obtained by natural fermentation of turnips (Brassica rapa). Turnips are cleaned and put in vats, alternating them with a layer of grape skins. Before covering the vat a mix of water and salt or water only is added. The vegetable fermentation is a spontaneous process caused by the microorganisms present on the various components (turnip and grape skins). A total 225 lactic acid bacteria (LAB) and 63 yeasts were isolated during this natural fermentation process. The main heterofermentative population was identified as Lactobacillus spp. while the major homofermentative LAB were Pediococcus spp., Candida spp. was the main yeast present. During the first 24 h of fermentation, the pH decreased rapidly to 3.7. At different steps of fermentation the headspace aroma compounds of brovada were analyzed by solid-phase-micro-extraction/gas chromatography/flame ionization detection to define the characteristic aroma profile of this particular product.     

Tyramine production of technological important strains of <Emphasis Type="Italic">Lactobacillus</Emphasis>, <Emphasis Type="Italic">Lactococcus</Emphasis> and <Emphasis Type="Italic">Streptococcus</Emphasis>

The aim of this paper was to study the biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermine and spermidine) production of selected technological important lactic acid bacteria (strains of the genera Lactococcus, Lactobacillus and Streptococcus). Three methods (ion-exchange chromatography (IEC), PCR and cultivation method with pH indicator) were used. Within the 39 strains of lactic acid bacteria tested, the production of tyramine (formed by tyrosine decarboxylase) was detected in eight strains (3 strains of Lactococcus lactis subsp. lactis, three strains of Lactococcus lactis subsp. cremoris, 1 strain of Streptococcus thermophilus and 1 strain of Lactobacillus delbrueckii subsp. bulgaricus). The other tested biogenic amines were not detected. Cultivation in decarboxylation broth seems to be the least accurate method for the detection of biogenic amines due to enhanced risk of false-positive reactions. Therefore, in order to detect bacteria producing biogenic amines, the combination of PCR and chromatographic methods (e.g. IEC) can be recommended.     

Cell surface properties of <Emphasis Type="Italic">Lactobacillus salivarius</Emphasis> under osmotic stress

The modifications of cell morphology and surface properties of Lactobacillus salivarius under osmotic stress were investigated. When deMan–Rogosa–Sharpe (MRS) medium was supplemented with NaCl (0.8 mol l⁻¹), changes in cell size and shape of L. salivarius cells occurred. A higher autoaggregation percentage and a lower hydrophobicity of L. salivarius determined by microbial adhesion to hydrocarbons were observed under osmotic stress. Moreover, coaggregation was strain specific and depended on incubation time as well as growth medium. On the other hand, fatty acid analysis by gas chromatograph–mass spectrometer revealed increases in the ratio of saturated/unsaturated fatty acids and cyclopropaneoctanoic acid, which is a useful way to enhance their osmotic resistance for maintaining the structural and functional integrity of cell membranes.     

Modeling high pressure inactivation of <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Listeria innocua</Emphasis> in whole milk

The survival curves of Escherichia coli and Listeria innocua inactivated by high hydrostatic pressure (HHP) were obtained at room temperature (∼22 °C) and at five pressure levels (400, 450, 500, 550 and 600 MPa) in whole milk. These curves were described by the Weibull model and parameters of this model were reduced from two to one with slight loss of goodness-of-fit. The logarithm of the time constant parameter (δ) of the reduced Weibull model was described with respect to high pressure (P). This approach can be used to define a z _p value analogous to the modeling of the classical D value (increase in pressure that results in one log unit decrease of δ values). The development of accurate survival models under high pressure, as presented here, can be very beneficial to food industry for designing, evaluating and optimizing HHP processes as a new preservation technology.     

Novel anticoagulant compound from fermented red alga <Emphasis Type="Italic">Pachymeniopsis elliptica</Emphasis>

Natural fermentation was tested as a method of releasing active compounds during screening for potential anticoagulant activity in three types of algae (Pachymeniopsis elliptica, Sargassum horneri, and Ulva pertusa). Freeze dried algae samples (2.5 g) were fermented by adding 75 g of sugar and 500 mL of water and thereafter kept at room temperature (25 °C) for 3 months. Activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) were measured every 2 weeks for 3 months to determine the optimum time for the highest activity. Fermented P. elliptica, (which had the highest activity) was subjected to anion exchange chromatography (DEAE-cellulose) and sepharose 4B gel permeation chromatography. The purified sample was analyzed by agarose-gel electrophoresis and polyacrylamide gel electrophoresis (PAGE) to confirm the purification and to determine the molecular mass, respectively. The 360 μg/mL of purified compound (Mwt > 500,000 Da) had both APTT and PT activities (>1,000 s). However, at the concentrations of 180 μg/mL, purified compound and heparin showed 540 and >1,000 s APTT activity, respectively. Though, the purified compound of P. elliptica considered as a weaker anticoagulant than heparin, this purified anticoagulant polysaccharide could be considered as a good alternative source as an anticoagulant. Moreover, the technique of fermentation is an inexpensive and feasible, this purified anticoagulant polysaccharide compound could be used in pharmaceutical and biomedical industry. Further investigations need to be performed to determine the mechanism of this novel anticoagulant compound. The authors Prashani Mudika Ekanayake and Chamilani Nikapitiya contributed equally to this work.     

Effect of PrA encoding gene-<Emphasis Type="Italic">PEP4</Emphasis> deletion in industrial <Emphasis Type="Italic">S</Emphasis>. <Emphasis Type="Italic">cerevisiae</Emphasis> WZ65 on key enzymes in relation to the glycolytic pathway

S. cerevisiae proteinase A (PrA) is a member of the aspartic proteinase superfamily. The roles of PrA in S. cerevisiae physiology and cell metabolism are controversial. The objective of the current study was to elucidate the effects of the absence of PrA on key enzymes with regard to the glycolytic flux in industrial S. cerevisiae. The observed activities of hexokinase (HK), phosphofructokinase (Pfk) and pyruvate kinase (PYKi) in PrA-modified S. cerevisiae strains (SC2 and SC3) were lower than that of the wild-type strain (p < 0.01). Compared to other strains, SC3 revealed the lowest activity of three key glycolytic enzymes. Current results imply that PrA in industrial S. cerevisiae may control the glycolytic enzymes expression (HK, Pfk and PYKi) in the direct or indirect manner and thus lead to the delay of cell metabolism. The observed intracellular ATP levels between the wild-type strain and PrA-modified strains (SC1 and SC2) were significantly different (p < 0.01). The pronounced differences of key glycolytic enzymes between the wild-type and PEP4-modified strains were as well characterized by SDS–PAGE. The intracellular protein concentration in the presence of PrA is higher than those of the PrA-modified strains. As a result, the interaction mode of PrA and the glycolytic enzymes was postulated in this work. The findings herein suggest that the glycolytic flux direction and rate may be regulated by vacuolar PrA in industrial S. cerevisiae. The present data obtained provide insights into understanding the roles of PrA in industrial S. cerevisiae.     

A New Multiplexed Real-Time PCR Assay to Detect <Emphasis Type="Italic">Campylobacter jejuni</Emphasis>, <Emphasis Type="Italic">C. coli</Emphasis>, <Emphasis Type="Italic">C. lari</Emphasis>, and <Emphasis Type="Italic">C. upsaliensis</Emphasis>

A new rapid method based on real-time PCR was developed to detect four thermophilic Campylobacter species (Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis) in food samples. The assay targeted the bipA gene for C. upsaliensis and C. lari, whereas the gene encoding the ATP-binding protein CJE0832 was used to detect C. coli and C. jejuni. These genes were chosen for this assay due to their low variability and mutation rate at a species level. The multiplex PCR showed 100% inclusivity for all 25 thermophilic Campylobacter strains tested and 100% exclusivity for 38 non-targeted strains belonging to closely related species. The newly developed real-time PCR could detect down to 10² genomes/reaction and displayed efficiency above 97% for all species except for C. upsaliensis (90.1%). The method proved to be a reliable tool for food analysis, showing 100% sensitivity, 96% efficiency, and 92.45% specificity when validated against the gold standard method UNE-EN ISO 10272:2006 using 200 diverse food samples (meat, fish, fruits and vegetables, and raw milk). In artificially spiked samples, the detection limit of the method was 10 cfu/g in salad, 5 cfu/g in turkey meat, and 1 cfu/g in the rest of meat samples tested. Consequently, the newly designed molecular tool represents a quick and safe alternative to obtain reliable results concerning the presence/absence of the main thermophilic Campylobacter in any food sample.     

Characteristics of Monascus sp. isolated from Monascus fermentation products

To screen for the strains suitable for industrial applications, 15 Monacus sp. were isolated from various Monascus fermentation products. The isolated strains were belonging to Monascus pilosus, Monascus purpureus, Monascus albidulus, and Monascus femeus based on the ITS sequence and morphological characteristics. They produced globular and hyaline conidia, and red, orange, or hyaline ascomata except for M. fumeus, in which ascomata was not observed in malt extract media. Each strain produced monacolin K and citrinin at different levels on different media: 15.79–20.05 mg/L of monacolin K and 0–255 μg/L of citrinin in submerged culture of monacolin K producing media, 1.27–2.69 mg/L and about 507.4 μg/L in YES medium, 0–0.78 g/kg and 0–9.7 mg/kg in Monascus red rice products, suggesting that it is necessary to adopt the similar conditions to a specific application for screening as well. These various isolated strains would be great resources for industrial application to develop Monascus fermented functional products.