• Journal of Life Science
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• v.18 no.4
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• pp.447-453
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• 2008

Zinc is an essential trace element in Human Being. Highly zinc containing yeast strain isolated from the tropical fruit, rambutan and the zinc concentration in this yeast strain was 306 ppm (30.6 mg%)per dry matter basis. This strain was found to be a rounded type, normal size, and multi-polar budding. Phylogenetic analysis using the ITS1-5.85 rDNA sequences from isolated strain is most similar to yeast Saccharomyces cerevisiae at the level of nucleotide sequence identity at 99%. This strain was produced alcohol by about 12% using fully colonized koji-rice with Aspergillus oryzae. In conclusion, the isolated strain was found to be closely related to the S. cerevisiae based on its morphological and physiological properties, and alcohol fermentation. The phylogenetic analysis of strain FF-10 using ITS 5.8S rDNA sequence data also supported the closely related to the S. cerevisiae. Accordingly, the isolated yeast was named as S. cerevisiae FF-10. Further studies on the best culture conditions for zinc production from zinc-enriched S. cerevisiae FF-10 are under investigation.

• Food Science and Preservation
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• v.15 no.2
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• pp.174-184
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• 2008

The quality and storage characteristics of low salted onion and five cereals-doenjang (DFO) were investigated. At the DFO, soybean koji ($57{\sim}62%$), onion (3%) and salt (8%) were mixed with equal amount of rice, barley, glutinous millet and glutinous indian millet ($10{\sim}30%$), and water ($7{\sim}12%$). The storage of DFO was done by vacuum packing in polypropylene tube, and sterilized at $121^{\circ}C$. The fermentation and storage was conducted for 60 days at $25^{\circ}C$ at each condition. Control doenjang (GD) was the salinity of 16% soybean doenjang that was not sterilized and packed in plastic containers for storage. During the fermentation, pH of DFO was lower than GD. The pH maintained stability during the storage, and revealed to be lowered, as the proportion of mixed cereals was higher. During the fermentation of DFO, the brix degree revealed to be higher than GD and maintained s1ability during the storage. During the fermentation and storage, the amino nitrogen content of DFO was ranged $400{\sim}470mg%$ by showing higher content than GD and maintained stable content during the storage. During the fermentation, the activities of protease and ${\beta}$-amylase were maintained to be high at DFO, but the activities during the storage were high at GD. The color $L^*$ value of DFO during fermentation and storage maintained higher values than GD, but $a^*$ value revealed lower pattern. Total free amino acids of DFO was ranged $1,918{\sim}2,290mg%$ which was higher than GD that recorded 1,291 mg%. When the sensory evaluation was conducted for DFO that was fermented and stored for 60 days, the DFO mixed with $20{\sim}30%$ of cereals resulted to have more savory taste, flavor, and sweeter than GD, and overall acceptability for color and overall taste was high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.76-82
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• 2009

Wheat is the most widely cultivated cereal and an important source of dietary protein worldwide. Wheat allergy, defined as an adverse immunologic reaction to wheat, encompasses a broad spectrum of disorders with different pathomechanisms and clinical manifestation. The Nuruk, a traditional Korean Koji for brewing, was made with wheat flour and fermenting microbes such as bacteria, yeast and mold. The strains grown on Nuruk secrete various enzymes as amylase and protease. By the activation of such enzymes, starch and proteins in Nuruk are hydrolyzed to sugar and amino acid. Therefore, it is supposed to reduce allergic proteins in wheat. To study quality properties and degradation degree of allergenicity in Nuruk by fermentation, we investigated the changes of general ingredients and allergenicity in Nuruk during fermentation. Moisture contents was decreased from 24.2% to 13.6% during fermentation. Crude lipid and protein contents were gradually increased during fermentation. After 15 days of fermentation, reducing sugar and total sugar contents were reached its maximum level, and they were 27.45% and 39.00%, respectively. Acid and neutral protease activity were significantly increased during fermentation, but alkaline protease activity was not detected. ${\alpha}$-amylase activity was gradually increased and showed maximum level about 2,833.00 U/g after 15 days of fermentation. Glucoamylase activity was the highest level about 497.9 U/g after 10 days of fermentation. The increase of these proteolytic and saccharogenic enzyme activities will provide efficient condition for production of rice wine. Also, protein fractions were isolated from Nuruk, and degradation of these proteins during fermentation were confirmed by SDS-PAGE. IgE immunoblotting using patient's sera with wheat allergy was performed to confirm allergenic protein in Nuruk. These results as fermentation of Nuruk will provide a useful tool for developing safer wheat products to prevent wheat allergy.

• Food Science and Preservation
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• v.17 no.5
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• pp.741-751
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• 2010

We evaluated the nutritional value of a Monascus pilosus mycelial ethanolic extract (MEM) and culture filtrate (CFM) by determining the contents of monacolin K and citrinin, and by measuring antioxidant and antimicrobial activities. The yields of freeze-dried MEM and CFM powder were 4.02% and 3.35% of wet weight, respectively. Pigment content ($OD_{500}$ value) of MEM (0.79) and CFM (0.63) were lower than those of commercial rice beni-koji ethanolic extracts (EERB) (0.87), but were in good agreement with the L*, a*, and b* values and the hue angles of the products. The total monacolin K content of MEM (24.91 mg%) was higher than those of CFM (1.27 mg%) and EERB (14.65 mg%). However, the active monacolin K content of EERB (5.48 mg%) was higher than those of MEM (3.35 mg%) and CFM (0.4 mg%). Citrinin was not detected in any sample. The total polyphenol content of MEM (4.68%, w/w) was similar to that of CFM (4.29%, w/w), thus 13.75.20.94% higher than that of EERB. The total flavonoid content of EERB was 6.8.7.0-fold higher than those of MEM (0.64%, w/w) and CFM (0.66%, w/w). The total antioxidant capacity of CFM (3.51%, w/w) was 1.62.2.08-fold higher than those of MEM (2.74%, w/w) and EERB (1.69%, w/w). The electron-donating capacities of 1% (w/v) solutions of CFM, MEM, BHT, and EERB were 86.20%, 77.25%, 77.25%, and 44.82%, respectively, and the corresponding reducing powers ($OD_{700}$ values) were 2.1, 2.4, 1.1, and 1.6, respectively. SOD(superoxide dismutase)-like activities were in the order MEM (39.85%) > BHT (37.68%) > EERB (26.70%) > CFM (21.5%). Although the TBARS (% value) of MEM was a little lower than that of BHT, it was higher than those of CFM and EERB. The antibacterial activities of CFM acting on Bacillus brevis and Escherichia coli were somewhat higher than those of MEM, whereas the activities of MEM on Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus epidermidis, and Salmonella enteritidis were higher than those of CFM. However, the antibacterial activities of MEM and CFM were less than those of EERB and BHT. In conclusion, although further studies are needed, we offer experimental evidence that the by-products of M. pilosus MEM and CFM contain significant antioxidant and antimicrobial activities that may be useful in the development of healthy foods.