• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.747-754
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• 1999

Food waste in school foodservices is an important factors in managing expense and in evaluating the acceptance of served meals. This study was undertaken to investigate the management of food waste and the opinion of dietitians in one hundred fourty nine elementary school foodservices, in Pusan, Korea. When serving places were compared, the classroom generated more leftover and plate waste than those of lunchroom(p<0.05). In rank for generating raw waste, the residue from vegetables was the highest in first order. Fruit, eggs, fish, and shell fish also left the most raw waste, respectively, in descending order. The residue that generated the most plate waste in the first and the second order was from soup and pot stew, and vegatables side dishes, respectively. The treatment process of food waste which was the most common in school foodservices was the fertilization by processing machine in order to make recyclable fertilizer(52.1%). Food waste at 30.8% of foodservices was processed for live stock feed. At 92.3% of investigated foodservices, food waste water was drained through a round net basket. Before treating as a waste, food residue was recycled at only 41.9% of foodservices. The main utilization of food residue was the production of soap from used oil. Most dietitians in school foodservices recognized that treating food waste was not so inconvenient, although, the problems of odor and hygiene were not solved. They also thought that the liquid residue(54.1%) and oil(30.4%) among food waste were primarily responsible for resulting environmental pollution.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.5
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• pp.661-673
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• 1994

We have gathered a fatty acid to recycle the waste oil of food manufacturing process, and then made a soap from the waste oil by alkali saponification. Effects of the washing elements such as the concentration of the soap, temperature and time were evaluated to find out the optimum washing conditions, and results are as follows. 1. We could find soaps made from the soybean oil (A), corn oil (B), rape seed salad oil (C), cotton seed oil (D) and a soap consisting of the each oil 25% respectively (I) had the lowest surface tension at the concentration of 0.225% -0.25%. Compared with the single fatty-acid soap, the multi-component soap I showed the lower surface tension at the cmc. 2. All the samples of A-I showed the lowest contact angle for the solid material at the concentration of 0.25%. The multi-component soap of I showed higher contact angle than the single.component soaps of A, B, C and D. 3. The soap G, made from the waste oil, show lower surface tension than 5, made from the complex raw fats of the eatable fatty oil acid and H, commercial soap. 4. The washing efficiency depends on the washing time. Especially the 25-minute was found to be the optimum washing time. 5. The highest washing efficiency was found at the 0.25% cont. reagardless of the washing temperature. At 0.15% concentration level the washing efficiency reduces as washing tem- perature increases. At 0.3% concentration level the highest washing efficiency was found between $50^{\circ}$-$60^{\circ}$. 6. The soap made from the waste oil showed the highest washing efficiency in terms of concentration, temperature, and time. 7. The soap made from the waste oil showed the similiar concentration of hydrogen ion to the synthetic detergent. 8. The hand value of the fabric washed by the soap made from the waste oil was a little lower value than those washed by the synthetic detergent.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.683-693
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• 2017

Transport biofuels have been recognized as a promising means to resolve the following issues like global warming, oil depletion and environmental pollutions. Among various biofuels, biodiesel has several advantages such as less emission of air pollutants and higher cetane values compared to diesel oil. Demand for biodiesel in Korea is increasing that leads to higher dependence on the imported feedstocks. Therefore, it is important to utilize the waste materials collected domestically for biodiesel production. Food waste oil collected in waste treatment facility has not been used for biodiesel production due to high free fatty contents in the oil. In this work, biodiesel conversion of food waste oil by Amberlyst 15 was studied. Synthetic and actual food waste oils have been used in the study. First, the effects of the major operating parameters including reaction temperature, methanol to oil molar ratio and catalyst loading on the conversion rates and yields were determined with synthetic waste oil. Kinetic modelling work was also done to determine the activation energy of the reaction. From the work, optimization reaction conditions were determined to be 383K, 1: 26.1 for methanol molar ratio to oil, 10 wt.% for catalyst loading and 360 min for reaction time. Activation energy of the reaction is determined to be 29.75 kJ/mol, lower than those reported in the previous works. So the solid catalyst, Amberlyst 15, was more efficient for esterification than the solid catalysts employed in the other works. Agitation rates have the negligible effects on the conversion rates and yields. With the identified optimization conditions, conversion of the actual food waste oil was also carried out. The esterification yield of actual food waste oil in 60 min was 13% lower than that of synthetic waste oil but the final yields in 240 min were similar each other, 98.12% for synthetic oil and 97.62% for actual waste oil.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.29-41
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• 2020

Biodiesel is a clean energy resource that can replace diesel as fuel, which can be used without any structural changes to the engine. Vegetable oil accounts for 95 percent of the raw materials used to produce biodiesel. Thus, many problems can arise, such as rising prices of food resources and an imbalance between supply and demand. Most of the previous studies using waste cooking oil used waste cooking oil from a single material. However, the waste cooking oil that is actually collected is a mixture of various types of waste cooking oil. Therefore, in this study, biodiesel produced with mixed waste cooking oil was supplied to an agricultural single-cylinder diesel engine to assess its potential as an alternative fuel. Based on the results, the brake specific fuel consumption (BSFC) increased compared to diesel, and the axis power decreased to between 70 and 99% compared to the diesel. For emissions, NO_x and CO₂ were increased, but CO and HC were decreased by up to 1 to 7% and 16 to 48%, respectively, compared to diesel. The emission characteristics of the mixed waste cooking oil biodiesel used in this study were shown to be similar to those of conventional vegetable biodiesel, confirming its potential as a fuel for mixed waste cooking oil biodiesel.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.437-444
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• 2010

Dry Process(natural drying, hot-air drying, oil fry drying), optimized mixture ratio and the condition of carbonization was carried out in order to improve the product durability develop eco-friendly solid fuel mixing food waste and paper sludge. As a result of the experiment, oil fry drying process was the fastest method for drying food waste and paper sludge mixture that contains 80% water inside, and the optimized mixture ratio to minimize the generating concentration of chlorine gas against caloric value of mixture ratio was 7:3. Additionally proper temperature of product carbonization was about $200^{\circ}C$ and shown increasing product durability through the carbonization. Therefore, the pelletized solid fuel be shaped diameter around 0.5cm, length 2cm under which was pulverized and molded using 7:3 mixture of food waste, and paper sludge was the eco-friendly solid fuel possible to be industrialized which is consist of chlorine concentration of below 2.0wt% and the lowest caloric value of over 5,000kcal/kg. In conclusion, this developing manufacturing process of the solid fuel can be interpreted to contribute alternative energy development in accordance with low carbon and green growth era.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.397-405
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• 2022

Castor oil cake is widely used as a raw material for organic fertilizers (OF) in Korea. Compared to other fertilizer raw materials, it is highly dependent on imports. In terms of replacing raw materials, dehydrated food waste powder (FDP) and castor oil cake have similar nutritional content, and if 30% is replaced, about 20% of the raw material cost can be saved. However, few studies on the effects on crop growth and soil properties when organic fertilizer and dry food waste powder are mixed and applied to the soil have been reported. The effects of an organic fertilizer made by mixing the commercial available organic fertilizer with dehydrated food waste (OF + FDP) on soil properties and the growth of two types of leafy vegetables (lettuce and young radish) were evaluated and compared with the performance of OF. The fresh weights of lettuce and young radish were the highest with OF amendment and stood at 114.3 and 119.0 g·plant^-1, respectively. These were followed by OF + FDP amendment, which produced 103.1 and 109.6 g·plant^-1, respectively. Compared to the control, OF and OF + FDP increased the lettuce fresh weights by about 69% and 52%, respectively, while the fresh weights of the radish were increased by about 223% and 207%, respectively. The soil pH, EC, total carbon content, and organic matter content in OF and OF + FDP increased. The mixture of dehydrated food waste powder and organic fertilizers is expected to improve soil quality and facilitate stable production of crops and contribute to the substitution of imported organic fertilizer raw materials.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.27-32
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• 1988

The almost similar degumming effect was obtained by using oxalic acid instead of phosphoric acid, which also improves waste-water treatment. At this point, solution of Phosphoric, Acetic, Citric, Oxalic, and Nitric acid were used for degumming of rapeseed and soybean oil. Compared with Phosphoric(PA) and Oxalic acid(OA) were showed a simillar degumming effect in these vegetable oils. In rapeseed oil of 85% PA treating group and 5,10% OA fretting group, residual soap and phosphorus content in neutralized oil, color in bleached oil, and peroxide value and fatty acid content in deodrized oil were showed to simillar result. Soybean oil as well as rapeseed oil were showed to similar result. As a result, we could comfirmed substitutive possibility, which change PA into OA as a degumming agent. In the other hand, waste waters were obtained from 55% PA treating group and 10% OA treating group. Analytical result for this waste waters has showed a wide difference, especially in the BOD and COD. The amount of treating agents and time required in the precipitation seperation and chemical treatment each 3 and 1.7 times, which is PA treating group than OA treating group. We have investigated both the simillar degumming effect by OA solution and an alternative the pollution program means of a chemical treatment process is not possible.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.584-590
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• 2023

In this study, we focus on the recycling of cardboard waste and sugarcane bagasse (SCB) for the preparation of carboxymethyl cellulose (CMC) and its conversion into a biodegradable film. Sodium alginate (SA) was added to form a biodegradable composite film. SA was used to increase film permeability. Glycerol, which is a plasticizer, was used to increase the tensile strength (TS) and film expansion. To characterize the CMC, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were used. The addition of olive oil to the CMC-SA matrix highlighted its antimicrobial property against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). A slight decrease in tensile strength was observed with the addition of olive oil (OO), which improved the functional properties of the control films as well as lowered moisture content and water solubility. But considering all other factors, the composite films obtained from sugarcane bagasse and cardboard waste incorporated with olive oil are suitable for applications in the field of food packaging.

• Food Science and Preservation
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• v.30 no.4
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• pp.549-561
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• 2023

Recently, consumers have gained an interest in natural and minimally processed foods, inciting the food industry to consider using of natural products as preservatives. Strawberries are a widely consumed fruit but are also highly perishable. Therefore, in this study, the physicochemical properties of strawberries (Fragaria×ananassa) were evaluated after a 12-h treatment with lemon essential oil (Citrus×limon) or cinnamon essential oil (Cinnamomum cassia) vapor during storage at 22℃ for 4 days in an accelerated shelf-life study and 4℃ for 18 days in a validation study. Weight loss was blunted in fruit treated with oil vapor during the first days of storage (p<0.05). Lemon essential oil delayed fruit darkening (p<0.05) but reduced the firmness of strawberries (p<0.05). Strawberries treated with cinnamon essential oil had a higher concentration of reducing sugars (p<0.05), and a decrease of 16.7% visible decay, although the difference was insignificant. Oil vapor treatment did not alter the pH, organic acid content, or soluble solid content during storage compared to the control. Since lemon and cinnamon essential oils have well-documented antimicrobial properties, they may be suitable for the natural preservation of fruit. This study provides new information on using essential oil vapor treatment to preserve fruits, and potentially decrease fruit loss and waste.

• New & Renewable Energy
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• v.4 no.4
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• pp.37-43
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• 2008

Three properties of food waste are water 80%, ash 3%, volatile matter 17%. When food waste goes through treatment process such as removal of foreign substances, removal of water as well as sodium, dryness, and pulverization, it transforms into 4,000 Kcal/kg purverized fuel if moisture content is below 13%. Fuel ratio (fixed carbon/volatile matter) of purverized fuel is low compared with bituminuous coal. Ignition temperature measured by thermogravimetry analyzer is about $460^{\circ}C$. Combustion test of purverized fuel have been performed using energy recovery facility which include storage tank of dewatered cake, dryer, hammer mill, combuster including burner, boiler, flue gas treatment equipment. When 160-180 kg/hr of fuel is steadily supplied to burner for 3 hours, combustor temperature reaches about $1000^{\circ}C$ and CO is 77-103 ppm at 1.55 excess air ratio and SOx and Cl are under 2 ppm and 1ppm, respectively. This experiment demonstrate that purverized fuel made from food waste could be an alternative clean energy at the age of high oil price.