• New & Renewable Energy
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• v.9 no.1
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• pp.25-32
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• 2013

It is indispensable to increase the conversion rate of a reducing sugars such as pentose and hexose derived from cellulosic wastes for a highly efficient bioethanol fermentation from food wastes. The saccharification liquid from cellulosic substrates such as vegetable food wastes contained lots of hexose like glucose and pentose like xylose. Since Saccharomyces-based yeasts could not convert xylose to bioethanol, Pichia stipitis which could directly ferment xylose to ethanol was chosen. After selecting Saccharomyces coreanus and P. stipitis, fermentation characteristics by mixture of two yeasts were investigated. As a result, it was verified the production of ethanol was enhanced by the co-fermentation, although there were somewhat differences between the fermentation characteristics by the aeration methods. Moreover, the consumption of pentose, hexose and disaccharide was obviously observed, and aeration in the process of fermentation seemed to stimulate the activity of P. stipitis.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.249-252
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• 2008

Flow behaviors of sweet potato starch (SPS) pastes (5% w/w) were studied in the presence of various sugars (xylose, glucose, fructose and sucrose) and sugar alcohols (xylitol and sorbitol). The flow properties of SPS-sugar mixtures were determined from the rheological parameters of power law model. The vane method was also employed for determining yield stresses of SPS-sugar mixtures directly under a controlled low shear rate. At $25^{\circ}C$ all the samples showed shear-thinning behaviors ($n=0.35{\sim}0.44$) with yield stress. The consistency index (K) values of SPS-sugar mixtures increased in the following order: sorbitol> xylitol> control (no sugar)> sucrose> fructose> glucose> xylose, showing that the addition of sugar alcohols enhanced the K values. The yield stress values were reduced in the presence of ugars and sugar alcohols and they also increased with an increase in swelling power of starch granules in the SPS-sugar mixture systems.

• Food Science and Preservation
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• v.15 no.3
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• pp.477-482
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• 2008

The quality characteristics of Goami by-product under the mixed enzyme treatment condition of $\alpha$-amylase and cellulase have been compared, and found the highest amount of soluble solids and reducing sugars at the $\alpha$-amylase treated group (A), and the contents revealed to show gradual decrease with the increase of cellulase content. The amounts of total dietary fiber and total sugars did not show large difference by both of enzyme concentration. The result of sugar analysis revealed the presence of all $G{\sim}G5$ in all treatment groups, and the content of malto-oligosaccharide recorded the highest content of 2,200 mg% at the $\alpha$-amylase treatment group (A). When the quality characteristic of the hydrolyzed powders manufactured by the optimum hydrolysis condition was compared, no significant color difference was found between samples. Among the contents of dietary fibers, insoluble dietary fiber was found to present in the lowest content of 6.95% at the Goami flour (GF) and the Goami by-product powder (GBPP) and Goami by-product hydrolysate powder (GBPHP) resulted the similar content around 14% and the highest soluble dietary fibers content was found in Goami by-product hydrolysate powder (GBPHP), which was followed by in the order of Goami by-product powder (GBPP) and Goami flour (GF), but the content variation was not large. The free amino acid was found to be highest in Goami by-product hydrolysate powder (GBPHP) followed by in the order of Goami by-product powder (GBPP) and Goami flour (GF). In the sugar analysis, the Goami by-product hydrolysate powder (GBPHP) was found with all $G{\sim}G5$ sugars by showing the highest amount of 1,800 mg% At the Goami by-product powder (GBPP), $G{\sim}G2$ sugars were detected with about 66 mg% and malto-oligosaccharides were not detected at the Goami flour (GF). Based upon the results, the functionality of Goami by-product hydrolysate powder (GBPHP) was found to be enforced compared to Goami flour (GF) and Goami by-product powder (GBPP), which allow us to expect it to be used as the various rice processing food source.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.615-620
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• 2006

Changes in chemical components caused by the degree of ripening and harvesting factors in Korean single-harvested peppers (SR211 vs. SR213 varieties) were analyzed. The ASTA color values of SR211 and SR213 were 104.23 and 189.66, respectively. Capsaicinoids contents of red, mixed, and green peppers of SR211 were 174.89, 157.00, and 192.01 mg/100 g, respectively. However, those in SR213 contanined <5 mg/100 g. Free sugar contents of red, mixed, and green fruits were 15.99%, 14.85%, and 8.03% in SR211 and 21.44%, 19.43%, and 8.10% in SR213, respectively, and those in SR211 and SR213 increased positively with the degree of ripening. L-ascorbic acids contents of red, mixed and green fruits were 11.41, 11.04, and 6.71 mg/g in SR211, respectively and 7.47, 7.16, and 3.66 mg/g in SR213, respectively and those in SR211 and SR213 increased positively with the degree of ripening. Changes in ASTA color values, capsaicinoids and free sugars in two varieties were monitored for 3 years. The characteristics of pungency and high redness were maintained in two varieties. Most notably, capsaicinoid contents of SR211 harvested in 2004 were above 250 mg/100 g in both red and green fruits.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.739-745
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• 1999

This study was carried out to investigate the oligosaccharide and amino acid utilization by mixed cultures during soy yogurt fermentation. Three types soy yogurt were prepared by fermenting with Lactobacillus acidophilus and Streptococcus thermophilus, Streptococcus thermophilus and Saccharomyces uvarum, Lactobacillus acidophilus and Saccharomyces uvarum. The utilized amount of oligosaccharide and amino acid was determined by HPLC during the fermentation period. The oligosaccharide and amino acid utilization efficiency of S. thermophilus and Sac. uvarum was greater than the other mixed cultures. It was found that Sac. uvarum produced enzymes which can convert oligosaccharide and common sugars in soy milk into glucose, galactose and fructose which can be fermented by L. acidophilus and S. thermophilus, and in turn stimulated acid production and amino acid utilization of the latter.

• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.42-50
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• 2002

This experiment was carried out to investigate the effect of Maesil extract on the acid production and growth of yoghurt starter in the skim milk medium. The Maesil extract was added to skim milk medium fur 1% to 9% and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria(Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus, bulgaricus, Lactobacillus casei). The chemical composition of Maesil, the changes in acid production (titratable acidity, pH) and number of viable cells of the medium during lactic fermentation in skim milk added with Maesil extract, and the keeping quality of curd yoghurts containing Maesil extract have determined. The composition of Maesil were 0.4% crude ash, 4.1% dietary fiber, 4.66%l citric acid, 0.264% total sugars and 405.34mg% vitamin C. The addition of Maesil extract stimulated the acid production and propagation of the lactic acid bacteria. Among the treatments tested, the addition of 3% Maesil extract with the mixed culture of Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus casei produced the highest amount of acid(1.23%) and showed the highest number of viable cell counts(3.6$\times$10$^{11}$ cfu/mL). When the curd yoghurts containing 3% Maesil extract with the mixed culture of the lactic acid bacteria were kept at 4$^{\circ}C$ and 2$0^{\circ}C$ for 30 days, it was showed that the changes of titratable acidity, pH and number of viable cell counts of the lactic acid bacteria were not significantly different during storage. Therefore the keeping quality of the curd yoghurts adding 3% Maesil extract showed relatively good at the shelf-life.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.303-310
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• 2002

An optimization for fermentation processes to make lactic acid juice with extracts from apples, carrots, celery, watercress, jujube and lycii (3 : 3 : 1 : 1/2 : 1 : 1/2) using co-cultures of Leuconostoc mesenteroides, Lactococcus lactis and Lactobacillus cellobiosus isolated from Dongchimi had been investigated on the emphasis of composition of sugars and sodium chloride at various temperatures. The concentration of sugars less than 25% and salt less than 0.8% did not affect remarkably the cell growth of lactic acid bacteria and acid formation during fermentation. The fermenting juice showed increases in the population of lactic acid bacteria and acidity, and decreases in population of coliform bacteria and sugar concentration with high cultural temperature. At $25^{\circ}C$ viscous substance was not formed as it had at $15^{\circ}C$. The optimum composition, based on the sensory evaluation, was determined to be oligosaccharide and 0.2% for sodium chloride. It took 3 days to produce the most preferable juice of pH 3.62 at $25^{\circ}C$. At the optimal state the fermented juice showed viable cell counts (cfu/mL) of exponential numbers 8 for lactic acid bacteria and 4 for yeast. Coliform bacteria which had been $5.6{\times}10^2\;cfu/mL$ at the beginning of fermentation were not detected.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.296-302
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• 2002

Quality characteristics of mash of takju prepared by wheat flour nuruks (conventional and improved style) were investigated during fermentation. Those were cultured with wild microorganism on whole and crushed wheat (wheat nuruk), wheat flour and mixture of rice and wheat flour, and nuruk cultured with Aspergillus oryzae on wheat flour. Ethanol content reached maximum of 10.6-17.4% after 14 days of fermentation. And the ethanol contents of takju were high in order of wheat nuruk, wheat flour nuruk, Aspergillus oryzae nuruk and mixture of wheat flour and rice nuruk. No difference of pH was among the treatments while the wheat flour nuruk cultured with wild microorganisms contained higher amounts of acids than the others. The amount of total sugars ranged from 16.22-17.74% on the starting day of fermentation, and decreased to 4.28-6.10% after 14 days. The amount of total sugars in mashes brewed with wheat flour nuruk cultured with Aspergillus oryzae was measured to be highest at the beginning stage of fermentation. Afterwards no difference was found among the types of nuruks. Glucose was in the range of 2,735-7,842 mg% at initial period of fermentation, afterwards it was rapidly decreased. The total amounts of free sugar for control and the wheat flour nuruk was higher than other treatments. The total amounts of organic acids were the highest in wheat nuruk to 690-2,241 mg% and the contents of lactic acid and succinic acid were high in mixed rice nuruk to 183-1,293 mg%. The contents of lactic acid and succinic acid were higher than those of the other kinds of organic acids in takju.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.827-838
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• 1997

Optimal substrates and reaction conditions were studied to develop boiled or roasted meat flavor by Maillard reaction under a model system. Sugars for the reactions were xylose, ribose, glucose, lactose, maltose, and sucrose. Amino acids were cystine, cysteine, methionine, lysine, and glycine as the reaction substrates. The reacted solutions were measured their absorbances at 278 nm and 420 nm and were evaluated their sensory properties. Except cysteine, the pentose mixtures with all of the four amino acids showed a faster reaction rate than those mixtures with hexose or disaccharides. pH was decreased rapidly until 8 hours and then changed a little thereafter. Sensory evaluation showed that cystine-lactose or cystine-xylose from single substrate and cystine-lactose-maltose, and cystine-lactose-xylose from mixed substrates reacted at $100^{\circ}C$ for 16 or 20 hours were found to be close to boiled or roasted meat flavor. The volatile compounds from the four selected sugar-amino acid solutions by GC/MS were 8 hydrocarbons, 10 aldehydes, 6 ketones, 7 alcohols, 2 aromatics (benzene), 1 ester, 4 furans, 1 base and 5 sulfur compounds.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.464-471
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• 2016

The purpose of this study was to provide information on the labeling of nutritional components on beverages to aid in nutrition education and oral health promotion. The study was conducted to evaluate nutritional effects and risk factors associated with the consumption of different beverages with respect to oral health. A total of 52 products from seven different types of beverages were analyzed for their nutrient content, sugar content, and pH. The sugar content per serving size, based on the nutrition labeling of beverages, was highest for the milk beverages, at 26.6 g, and lowest for the teas, at 13.0 g. According to the recommendation of the World Health Organization (WHO), beverages should contain less than 10% (50 g) total sugars. Our assessment revealed that total sugars in and carbonated beverages were 53.2% and 50.0% of daily value, respectively. Therefore, the milk and carbonated beverages contained more than 50% sugars per serving size, exceeding the recommendation of WHO. The pH of the beverages, from the most acidic to the least acidic were: carbonated beverages, pH 3.0; fruit and vegetable beverages, pH 3.1; mixed beverages, pH 3.6; fruit and vegetable juices, pH 3.7; teas, pH 4.7; coffees, pH 6.6; and milk beverages, pH 6.8. The intake of acidic and sweetened beverages could potentially cause dental caries and erosion. Therefore, the results of this study could be used by oral health care professionals to counsel their patients by providing relevant information on the possibility of oral disease caused by consumption of commercial beverages.