• Journal of environmental and Sanitary engineering
• /
• v.16 no.1
• /
• pp.108-116
• /
• 2001

It is difficult to task to achieve high biological nutrient removal from municipal wastewater because of low organic content. Volatile fatty acids(VFAs) produced from acid fermentation of food wastes can be utilized as external carbon sources for the biological nutrient process. Significant reduction and stabilization of the food wastes can also be obtained from the acid fermentation. The objective of this study is to evaluate characteristics of acid fermentation of the food wastes. Results obtained from the batch experiment of various organic wastes showed that the food wastes had high potential to be used as an external carbon source because of the largest production of the VFAs with low nitrogen and phosphorus content. The fish waste was found to be the next possible organic waste, while the others such as radish cabbage and molasses waste showed high VFAs consumption potential as a results of high nitrogen and phosphorus content. alkaline hydrolysis of the food waste was carried out using NaOH prior to the acid fermentation. As the alkali addition increased, solubilization of the organics as well as TSS reduction increased. However, fraction of soluble COD to total COD became stable after a sharp increase. Alkali addition greater than 0.5g NaOH per g TS resulted in significant increase in pH.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.1
• /
• pp.16-23
• /
• 1998

Effect of Fermentation temperature on the changes of chemical components in Kakudgi during fermentation was investigated by measuring free sugar, organic acid and volatile compounds up to 57 days at several temperatures. The mannitol was increased in palatable period in contrast with those of other free sugars. The higher the initial fermentation temperature was and the longer the initial fermentation time at 2$0^{\circ}C$ was, the faster the second increasing period was and the less the initial contents was. Lactic acid was increased 6~31 times from a little amount at the initial period. The higher the initial fermentation temperature was and the more the increasing content was. But malic acid which was abundant(55.1% of total nonvolatile organic acid) in the initial fermentation period was remarkably decreased in the palatable period. The change of the sulfides among the volatile compounds was remarkable. Methyl allyl sulfide which was a little in the initial fermentation period was remarkably increased in the final fermentation period, and the correlation coefficients between the content of methyl allyl sulfide and aroma in sensory evaluation were high. It could be suggested that the fermentation temperature should be set to 4$^{\circ}C$ after fermentating at 2$0^{\circ}C$ for 36 hours in the view point of keeping the Kakdugi taste and quality well because of high content of free sugar and nonvolatile organic acids.

• Korean Journal of Food Science and Technology
• /
• v.24 no.3
• /
• pp.272-278
• /
• 1992

Takju, a Korean traditional wine, was prepared by using nuruk and Koji which were inoculated with Aspergillus kawachii and Aspergillus shirousamii. Those chemical composition such as alcohols and organic acids were determined with gas chromatography to investigate the variation of its content by the fermentation. Alcohol such as methyl, ethyl, n-propyl, i-butyl, i-amyl alcohol were detected in the most takju mash samples. Alcohol contents in the groups fermented with KNR and SNR were slightly higher than KKR, SKR groups. Lactic acid were concentrated and organic acids such as pyruvic, oxalic, malonic, succinic, maleic, malic, ${\alpha}-keto$ glutaric acid were also detected in the most samples. The pH was lowest in the KKR group. The total acid content was slightly decreased at the later fermentation and was highest in KKR. The content of minerals were highest in the WNR and BNR groups. Throughout fermentation the content of potassium and magnesium varied greatly with the tested groups.

• Korean Journal of Food Science and Technology
• /
• v.28 no.4
• /
• pp.638-643
• /
• 1996

The efficiency of dewatering of soybean milk residue was improved by hydraulic pressing after pH adjustment to 4.5 with organic acids such as acetic and lactic acids. Water content of raw soybean milk residue was reduced from 80% to 72% by pressing after pH adjustment, while only to 78% by the conventional hydraulic press. The water content of the residue after pH adjustment was further reduced to 63% by hydraulic pressing with ohmic heating. The pH adjustment facilitated separation of cake from the filter cloth and reduced the solid content of the expressed liquid from 10 to 3%.

• Journal of the East Asian Society of Dietary Life
• /
• v.4 no.2
• /
• pp.39-44
• /
• 1994

To prepare the basic information for the fermentation of high quality persimmon vinegar in the farm. the quality of the complex fermented persimmon vinegar(CFPV) was compared to that of naturally fermented persimmon vinegar (NFPV). The titratable acidity of the CFPV was 3% which was the half concentration of the NFPV. The content of total free sugar by HPLC was 6% in CFPV and NFPV was 5%. Organic acid compositions in persimmon vinegar were oxalic acid, malic acid, lactic acid, citric acid, succinic acid and glutaric acid in addition to acetic acid. Total content of the organic acids in NFPV was higer than in CFPV. Especially, the content of latic acid in NFPV was very higher than that of CFPV. the flavour, color and taste of persimmon fruit itself in CFPV were stronger than those in NFPV.

• Food Science and Biotechnology
• /
• v.16 no.3
• /
• pp.386-391
• /
• 2007

This study was conducted to observe quality characteristics of whole soybean meju fermented with germinated soybean (Glycine max: Hwanggeumkong). The germination rate after 24 hr was $23.0{\pm}1.2%$, then increased rapidly to $90.2{\pm}1.3%$ at 36 hr of germination, and finally reached a level of $99.4{\pm}0.3%$ at 60 hr of germination. It was confirmed that the total isoflavone content immediately after soaking was 100.1 mg%, increasing during the beginning of the germination process; it continued to increase to 114.0 mg% by 24 hr of germination, but decreased thereafter. The isoflavone content at 60 hr of germination was 101.6 mg%. A total of 6 organic acids were detected, and total organic acid content ranged from 963.1-1,145.3 mg%. Differences based on the degree of germination in the raw material were insignificant. The free amino acid levels of the whole soybean meju made from non-germinated soybeans and from soybeans that had germinated 48 hr were 2,580.9 and 2,519.7 mg%, respectively. The content of glutamic acid was highest followed by aspartic acid, lysine, leucine, and proline.

• Journal of the East Asian Society of Dietary Life
• /
• v.6 no.3
• /
• pp.355-363
• /
• 1996

Physicochemical properties of marketing and intensive persimmon vinegar were investigated, the results are as following; Total acidity in D, H, S, J, sweet persimmon(SP) and persimmon vinegar were 4.20, 3.03, 2.58, 3.30, 5.92 and 5.81%, respectively, and the value of intensive persimmon(IP) vinegars wre higher than that of others. SP sample was lower than any other vinegar as compared to L value in colors, no sample was lower than H and S vinegar inturbidity and browning. Brix of IP samples were lower than that of other vinegars, there was a little fructose in the all samples. Among the organic acids, galacturonic acid content except acetic acid was the highest, and ascorbic and malic acid were detected a little, Calium content was the highest of minerals in persimmon vinegars, phosphorus was detected a little. Alcohols of 5~6 types were analyzed in each samples, free amino acids of 17~24 dypes were analyzed, D and IP vinegars have more acohols and amino acids, and their contents were higher than the others. Volatile components of 6~9 types were analyzed in each samples, these have more ethanols except acetic acids than other volatile components, and the contents of IP samples were higher than that of marketing persimmon vinegars.

• The Korean Journal of Community Living Science
• /
• v.26 no.3
• /
• pp.541-549
• /
• 2015

This study compares the major nutritional components of the leaf, flesh, and seed of dry loquat (Eriobotrya japonicaLindl.). Among proximate compositions, the crude fat, crude ash, and dietary fiber of the leaf exceeded those of the seed and flesh, whereas the carbohydrate content of the leaf was lower than that of the seed and flesh. The main component of free sugars in the leaf, flesh, and seed was fructose. Total amino acids of the leaf, flesh, and seed were 552.43, 63.00, and 260.29 mg%, respectively. Although the amino acid composition of the leaf, flesh, and seed varied, glutamic acid and ${\gamma}$-aminobutyric acid were the major amino acids in the leaf, flesh, and seed. Major fatty acids of total lipid were oleic acid and stearic acid in the leaf and seed, and the major acid was linoleic acid in the flesh. Major organic acids were oxalic acid in the leaf, maleic acid in the flesh, and citric acid in the seed. Vitamin C content was higher in the seed than in the leaf and flesh.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.1-14
• /
• 2023

In this study, the nutritional compounds present in various parts of Hovenia dulcis Thunbergii (H. dulcis) were compared. Regarding the free sugar content, fruits exhibited the highest fructose concentration (9.42 g/100 g), whereas branches (2.46 g/100 g) and leaves (5.82 g/100 g) contained the highest glucose levels. The most common types of organic acids were citric and tartaric acids in the fruits, citric and malic acids in the branches, and malic and succinic acids in the leaves. The leaves exhibited the highest total amino acid content of 12,102.91 mg/100 g, whereas vitamin C is predominantly found in branches and leaves at 367.85 mg/100 g and 336.21 mg/100 g, respectively. In H. dulcis, β-carotene was present in high concentration in leaves (2.41 mg/100 g), whereas the branches (0.15 mg/100 g) and fruits (0.09 mg/100 g) contain smaller amounts of it. Vitamin E, α-tocopherol, was present in high concentrations in the fruit (11.01 mg/100 g), branches (6.61 mg/100 g), and leaves (11.01 mg/100 g).

• Journal of Environmental Health Sciences
• /
• v.27 no.1
• /
• pp.14-19
• /
• 2001

The physical and chemical transformation and reduction degree of food waste were investigated in a food waste reduction machine using thermophilic bacteria. The first operation of the reduction machine for grain, vegetables, fishes and flesh wastes proceeded during three weeks. The first and second reduction percentages of the wastes were 98.3% and 93.2%, respectively. The residue of food waste was composed of fruits, fish, and vegetables. The temperature distribution of the reduction machine ranged between 30 and 6$0^{\circ}C$ appropriate for growth of thermophilic bacteria. At initial stage the pH in the reduction machine decreased with organic acids produced, but increased as the organic acids decomposed by different thermophilic bacteria. In the reduction machine, the moisture content of the food waste was reduced from 80-90% to 10-20% after 24 hours, and the salinity of residue was 0.29% after the second operation. The degree of odor was most high between 2 and 4 hours.