Biotransformation of Major Ginsenoside Rb1 to Rd by Dekkera anomala YAE-1 from Mongolian Fermented Milk (Airag).

Dekkera anomala YAE-1 strain separated from "airag" (Mongolian fermented mare's milk) produces ß-glucosidase, which can convert ginsenoside Rb1 from Panax ginseng. Ginseng-derived bioactive components such as ginsenoside Rb1 have various immunological and anticancer activities. Airag was collected from five different mare milk farms located near Ulaanbaatar, Mongolia. YAE-1 strains were isolated from airag to examine the hydrolytic activities of ß-glucosidase on Korean Panax ginseng using an API ZYM kit. Supernatants of selected cultures having ß-glucosidase activity were examined for hydrolysis of the major ginsenoside Rb1 at 40°C, pH 5.0. The YAE-1 strain was found to be nearly identical at 99.9% homology with Dekkera anomala DB-7B, and was thus named Dekkera anomala YAE-1. This strain exerted higher ß-glucosidase activity than other enzymes. Reaction mixtures from Dekkera anomala YAE-1 showed great capacity for converting ginsenoside Rb1 to ginsenoside Rd. The ß-glucosidase produced by Dekkera anomala YAE-1 was able to hydrolyze ginsenoside Rb1 and convert it to Rd during fermentation of the ginseng. The amount of ginsenoside Rd was highly increased from 0 to 1.404 mg/ml in fermented 20% ginseng root at 7 days.

Impact of Different Gums on Textural and Microbial Properties of Goat Milk Yogurts during Refrigerated Storage.

In this study, the impact of seven different gums on textural and microbiological properties of goat milk yogurt during refrigerated storage was investigated. The results showed that yogurt containing xanthan and locust bean gums had enhanced firmness, consistency, cohesiveness, and viscosity during four weeks of storage compared to the control and yogurt fortified with other gums (p < 0.05). The addition of gums also helped to maintain the microbial viability of the yogurt culture and the probiotic Bifidobacterium spp. This study thus demonstrated that these gums could be used in the production of goat milk yogurt with enhanced textural properties.

Effect of iron fortification on microstructural, textural, and sensory characteristics of caprine milk Cheddar cheeses under different storage treatments.

In this study, we manufactured 3 types of caprine milk Cheddar cheese: a control cheese (unfortified) and 2 iron-fortified cheeses, one of which used regular ferrous sulfate (RFS) and the other used large microencapsulated ferrous sulfate (LMFS). We then compared the iron recovery rates and the microstructural, textural, and sensory properties of the 3 cheeses under different storage conditions (temperature and duration). Compositional analysis included fat, protein, ash, and moisture contents. The RFS (FeSO4·7H2O) and LMFS (with 700- to 800-µm large particle ferrous sulfate encapsulated in nonhydrogenated vegetable fat) were added to cheese curds after whey draining and were thoroughly mixed before hooping and pressing the cheese. Three batches of each type of goat cheese were stored at 2 temperatures (4°C and -18°C) for 0, 2, and 4 mo. We analyzed the microstructure of cheese using scanning electron microscopy and image analysis software. A sensory panel (n = 8) evaluated flavors and overall acceptability of cheeses using a 10-point intensity score. Results showed that the control, RFS, and LMFS cheeses contained 0.0162, 0.822, and 0.932 mg of Fe/g of cheese, respectively, with substantially higher iron levels in both fortified cheeses. The iron recovery rates of RFS and LMFS were 71.9 and 73.5%, respectively. Protein, fat, and ash contents (%) of RFS and LMFS cheeses were higher than those of the control. Scanning electron microscopy analyses revealed that LMFS cheese contained smaller and more elongated sharp-edged iron particles, whereas RFS cheese had larger-perimeter rectangular iron crystals. Iron-fortified cheeses generally had higher hardness and gumminess scores than the control cheese. The higher hardness in iron-fortified cheeses compared with the control may be attributed to proteolysis of the protein matrix and its binding with iron crystals during storage. Control cheese had higher sensory scores than the 2 iron-fortified cheeses, and LMFS cheese had the lowest scores for all tested sensory properties.

Characterization of Paenibacillus sp. MBT213 Isolated from Raw Milk and Its Ability to Convert Ginsenoside Rb1 into Ginsenoside Rd from Panax ginseng.

This study was conducted to isolate and characterize Paenibacillus sp. MBT213 possessing ß-glucosidase activity from raw milk, and examine the enzymatic capacity on the hydrolysis of a major ginsenoside (Rb1). Strain MBT213 was found to have a high hydrolytic ability on ginsenoside Rb1 by Esculin Iron Agar test. 16S rDNA analysis revealed that MBT213 was Paenibacillu sp. Crude enzyme of MBT213 strain exhibited high conversion capacity on ginsenoside Rb1 into ginsenoside Rd proven by TLC and HPLC analyses. The API ZYM kit confirmed that Paenibacillu sp. MBT213 exerted higher ß-glucosidase and ß-galactosidase activity than other strains. Optimum pH and temperature for crude enzyme were found at 7.0 and 35°C in hydrolysis of ginsenoside Rb1. After 10 d of optimal reaction conditions for the crude enzyme, ginsenoside Rb1 fully converted to ginsenoside Rd. Ginseng roots (20%) were fermented for 14 d, and analyzed by HPLC showed that amount of ginsenoside Rb1 significantly decreased, while that of ginsenoside Rd was significantly increased. The study confirmed that the ß-glucosidase produced by Paenibacillus sp. MBT213 can hydrolyze the major ginsenoside Rb1 and convert to Rd during fermentation of the ginseng. The ß-glucosidase activity of this novel Paenibacillus sp. MBT213 strain may be utilized in development of variety of health foods, dairy foods and pharmaceutical products.

Thymic Stromal Lymphopoietin Induction Is Mediated by the Major Whey Proteins α-Lactalbumin and ß-Lactoglobulin through the NF-κB Pathway in Immune Cells.

α-Lactalbumin and ß-lactoglobulin are two major whey proteins that specifically bind immunoglobulin E and are suspected as major allergens causing cow's milk allergy (CMA). Recent studies have shown that thymic stromal lymphopoietin is a critical factor linking at the interface of the body and environment to the T-helper 2 response. However, it is not known whether thymic stromal lymphopoietin expression is changed by α-lactalbumin and ß-lactoglobulin in immune cells. Using RT-PCR and ELISA, the present study was conducted to examine if intravenous injection of α-lactalbumin and ß-lactoglobulin increased pro-inflammatory cytokines, T-helper 2 cytokines, and thymic stromal lymphopoietin expression in several immune cells, including macrophages, mast cells, and keratinocytes. Results showed that α-lactalbumin and ß-lactoglobulin induced thymic stromal lymphopoietin, interleukin-6, and tumor necrosis factor-α expression. It was concluded that the allergenicity of α-lactalbumin and ß-lactoglobulin may be attributed to thymic stromal lymphopoietin induction, T-helper 2 cytokines, and pro-inflammatory cytokines.

Purification, characterization, and properties of an alkaline protease produced by Serratia marcescens S3-R1 inhabiting Korean ginseng rhizosphere.

BACKGROUND: An alkaline protease produced by the Serratia marcescens S3-R1 which inhabits in the Korean ginseng rhizosphere was investigated. The purposes of this study were to characterize and purify the bacterial enzyme by four different purification steps: precipitation of enzyme fraction by ammonium sulfate, loading the enzyme pellets on a DEAE-Sepharose anion-exchange chromatograph, separation of the fraction containing enzyme activity by fast protein liquid Mono Q chromatography and identification of the single-band fraction by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and then quantification of the single-band fraction by reverse-phase high-performance liquid chromatography. RESULTS: The molecular weight of the purified protease was estimated as 50 308 Da by matrix-assisted laser desorption ionization time-of-flight analysis. The N-terminal amino acid sequence of the protease was identified as Ala-Val-Thr-Ile-Glu-Asp-Ala-Val-Asp-Asp, and the enzyme belongs to the metalloprotease family. The optimal activities of the protease occurred at pH 7-9 and a temperature 40 °C. The ranges of pH and thermal stability of the enzyme were at 7-10 and 30-40 °C, respectively. CONCLUSION: The alkaline protease was successfully purified and characterized from the bacterium Serratia marcescens S3-R1, which has potential for industrial application, including milk protein hydrolysates.

Profiles of non-essential trace elements in ewe and goat milk and their yoghurt, Torba yoghurt and whey.

The objectives of this study were to determine the profiles of non-essential trace elements in ewes' and goats' milk and manufactured products, such as yoghurt, torba yoghurt and whey, as well as changes in trace element content during Torba yoghurt-making processes. Concentrations of non-essential trace elements in ewe (Awassi) and goat (Damascus) milk and their yoghurt, torba yoghurt and whey were quantitatively determined by simultaneous inductively coupled plasma optical emission spectrometer (ICP-OES), after microwave digestion. Aluminium, antimony, arsenic, boron, beryllium, cadmium, nickel, lead, silver, titanium, thallium and vanadium were determined for both types of milk and their products. Barium was not detected in goats' milk or their products. Among all trace elements, boron was the most abundant and beryllium was least present in milk and the manufactured products. The results showed that goats' and ewes' milk and their manufactured products may be a source of 13 non-essential trace elements.

Health information system based on EHR for workplace health promotion.

The multifactoral origins of occupational health, must take into consideration of all factors simultaneously, including the working environment,lifestyle habits and medical examinations. We defined the concepts and requirements of the 'workplace electronic health records' (WEHR). Hereby, we present the architecture and function of health information system (HIS) based on WEHR for workplace health promotion (WHP).

Effects of oxidative compounds on thermotolerance in escherichia coli O157:H7 strains EO139 and 380-94.

An oxidative complex composed of ferric iron chloride hexahydrate, ADP, and ascorbic acid can generate hydrogen peroxide and hydroxyl radicals in fibroblasts. These compounds are naturally found in meat and meat-based products and may elicit oxidative stress on Escherichia coli O157:H7, thus conferring thermotolerance to the bacterium due to the phenomenon of the global stress response. The effect of the levels of the oxidative complex on the thermotolerance of E. coli O157:H7 was investigated. Cultures of E. coli O157:H7 strains EO139 and 380-94 were mixed in three different concentrations (10:10: 40, 15:15:60, and 20:20:80 microM) of the oxidative complex (iron III chloride, ADP, and ascorbic acid, respectively). The samples were inserted into capillary tubes and heated in a circulating water bath at 59 and 60 degrees C for EO139 and 380-94, respectively. Tubes were removed at intervals of 5 min for up to 1 h and contents spirally plated on plate count agar that was incubated for 48 h at 37 degrees C. The thermotolerance of both E. coli O157:H7 strains EO139 and 380-94 was influenced by the concentrations of the oxidative complex. The ratio of 10:10:40 microM enhanced thermotolerance of EO139 and 390-94 at 59 and 60 degrees C, respectively. However, exposure to the ratios of 15:15:60 and 20:20:80 microM rendered the pathogen more sensitive to the lethal effect and did not enhance the thermotolerance of the cells. The significance of this study is twofold. This experiment proves that oxidative stress can enhance thermotolerance of bacterial cells induced by an oxidative complex if only in a specific ratio and concentration. It is possible to speculate that if the chemical compounds are present in this ratio in meats, they may enhance the thermal resistance of E. coli O157:H7 and make the bacteria more difficult to eliminate, thus increasing the risk of foodborne illness in consumers.

Rheological and proteolytic properties of Monterey Jack goat's milk cheese during aging.

To enhance the understanding of the quality traits of goat's milk cheeses, rheological and proteolytic properties of Monterey Jack goat's milk cheese were evaluated during 26 weeks of 4 degrees C storage. As expected with aging, beta-casein levels decreased with concomitant increases in peptide levels and were correlated with changes in rheological properties of the cheese. Hydrolysis of the protein matrix resulted in more flexible (increased viscoelastic properties) and softer (decreased hardness, shear stress, and shear rigidity) cheeses. During the first 4-8 weeks of storage, cheese texture changed significantly (P < 0.05) and then stabilized. Characterization of rheological and proteolytic properties of the goat's milk semihard cheese during aging provided insight into the changes occurring in the protein matrix, the relationship to structure, and a shift in cheese quality.