• Advances in Energy Research
• /
• v.8 no.4
• /
• pp.233-241
• /
• 2022

Biodiesel is a non-polluting and non-toxic energy source that can replace conventional diesel. However, the higher production cost and raw material scarcity became challenges that obstruct the commercialization of biodiesel production. In the current investigation, fried cooking oil is used for biodiesel production in a hydrodynamic cavitation reactor, thus enhancing raw material availability and helping better waste oil disposal. However, due to the cavitation effect inside the reactor, the hydrodynamic cavitation reactor can give biodiesel yield above 98%. Thus, the use of orifice plates (having a different number of holes for cavitation) in the reactor shows more than 90% biodiesel yield within 10 mins of a time interval. The effects of rising temperature at different molar ratios are also investigated. The five-hole plate achieves the highest yield for a 4.5:1 molar ratio at 65℃. And the similar result is predicted by the response surface methodology model; however, the optimized yield is obtained at 60℃. The investigation will help understand the effect of hydrodynamic cavitation on biodiesel yield at different molar ratios and elevated temperatures.

• Journal of Forest and Environmental Science
• /
• v.9 no.1
• /
• pp.67-80
• /
• 1993

There are a lot of serious problums associated with conventional pulping processes, such as kraft and sulfite. In order to tackle these difficulties, organic acid pulping of Populus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. have been investigated as on alternative method. The acetic acid cooking of Populus tomentiglandulosa T. Lee achieved good delignification with pulp yields of 55-65% under almost all cooking conditions. In the acetic acid cooking of Pinus densiflora S. et Z., it was not cooked at a low temperature. The strength properties of the acetic acid pulps from Pinus tomentiglandulosa T. Lee showed the optimum with 95% acetic acid concentration at $185^{\circ}C$ maximum cooking temperature for 0.5hr cooking time. The strength properties of the acetic acid pulps from Pinus densiflora S. et Z. displayed excellent tear strength in comparison with those of the other softwoods. In the process of acetic acid cooking, glucose has been removed a little, but other sugars have been eliminated. The elemental compositions and $C_9$ formulas of acetosolv lignins from Populus tomentiglandulosa T. Lee were 63.88% carbon, 5.45% hydrogen and 30.67% oxygen and $C_9H_{9.15}O_{3.24}$ The elemental compositions and $C_9$ formulas of acetosolv lignins from Pinus densiflora S. et Z. were 61.85% carbon, 6.14% hydrogen and 32.01% oxygen and $C_9H_{9.15}O_{3.50}$ The Wt. av. MWT's of the acetosolv lignins from Pinus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. were 731 and 725.

• Microbiology and Biotechnology Letters
• /
• v.14 no.5
• /
• pp.415-420
• /
• 1986

Alcohol fermentation of uncooked naked barley was carried out by the combined action of the maceration enzyme from black Aspergillus niger and the glucoamylase from Rhizopus sp. The combined enzyme preparation was found to be effective in maceration and saccharification of the raw naked barley starch. The Hydrolysis rate measured by the amount of glucose liberated reached more than 70% at pH 4.5 and 3$0^{\circ}C$ after 76 hrs. For alcohol fermentation without cooking, the naked barley mash of 18% initial total sugar was pretreated with concentrated sulfuric acid (0.15 weight % of the mash volume) at 55$^{\circ}C$ for 2hr, and used for alcohol fermentation. A simultaneous saccharification and fermentation was carried out at pH 4.8 and 3$0^{\circ}C$ for 96 hrs. Under this fermentation condition, 3.5% increase in alcohol yield together with 2.0% increase in alcohol concentration were obtained when compared with the conventional cooking fermentation.

• Korean journal of food and cookery science
• /
• v.33 no.2
• /
• pp.121-126
• /
• 2017

Purpose: This study measured the ethyl carbamate (EC) content in commercial and home-made soy sauce and examined the effects of cooking methods, such as boiling and pan-frying, on the EC content. Methods: A total of 20 soy sauce samples including 14 home-made and 6 commercial products were analyzed according to the AOAC official method with some modifications. To simulate conventional boiling, soy sauce containing EC ($14.59{\mu}g/kg$) was heated to $100^{\circ}C$ for four different times: 10, 20, 30, or 40 min. Pan-frying was conducted for 4 min at $170^{\circ}C$. Results: EC was not detected in any of the homemade samples, whereas it was found in the commercial samples, ranging from 2.51 to $14.59{\mu}g/kg$. The concentrations of EC increased gradually with increasing boiling from 14.59 to $26.54{\mu}g/kg$, whereas pan-frying did not affect the EC level in soy sauce. Conclusion: These results indicate that EC is formed by a reaction between the EC precursors during boiling, suggesting that the cooking method of each food should be considered when estimating the dietary exposure to EC.

• Korean Journal of Food Science and Technology
• /
• v.43 no.6
• /
• pp.683-688
• /
• 2011

This study was conducted to investigate the effects of different cooking methods on the nutrient composition of genetically modified (GM) provitamin A(PA)-biofortified rice. PA-biofortified rice was subjected to different cooking methods, namely boiling and a soaking, steaming and roasting process. The proximate components (starch, protein, lipid and ash) of raw PA-biofortified rice were similar to those found in the parental non-GM rice, and were not significantly affected by a conventional boiling treatment. When compared with raw rice, boiled PA-biofortified rice showed a similar nutrient composition, despite a slight reduction in a majority of its amino acid contents. However, the PA-biofortified rice that underwent the soaking/steaming/roasting process exhibited a significant reduction in a majority of its amino acids and mineral contents. This procedure also led to a significant reduction in carotenoid contents. The overall results of this study demonstrate that using a conventional boiling method for PA-biofortified rice retains nutrients better than a soaking/steaming/roasting method.

• Korean journal of food and cookery science
• /
• v.29 no.5
• /
• pp.453-462
• /
• 2013

Recently, two formulas of sulgidduk added to pine needle juice (PNJ) with various physiological activities were developed for metabolic syndrome patients in our lab. According to previous studies, cooking may alter antioxidant properties by initiating destruction, release or transformation of antioxidant compounds contained in food. Therefore, the aim of this study was to compare the antioxidant activities and antigenotixic effects of sulgidduk with/without PNJ and to note changes in these activities after cooking. The ingredients of sulgidduk was added on the basis of 100% rice flour as follows: conventional sulgidduk (S): 1.5% salt, 30.0% sugar; PNJ added to sulgidduk A (PS-A): 1.4% salt, 30.0% sugar, and 1.0% PNJ; PNJ added to sulgidduk B (PS-B): 1.5% salt, 21.4% sugar, and 1.4% PNJ. Ethanol and water extracts of sulgidduk were analyzed for the total phenolic content (TPC), DPPH radical scavenging activity (DPPH RSA), total radical-trapping antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and antigenotoxic effect by comet assay. The ethanol extracts PS-A and PS-B showed higher TPC and antioxidant activities (DPPH RSA, TRAP, and ORAC) than did the S ethanol extract before cooking. The more PNJ was added, the higher TPC and anitoxidant activities were observed in sulgidduk (PS-A$200{\mu}M$ of $H_2O_2$. Taken together, this study suggests that sulgidduk added to 1.44% of pine needle juice may be a good option antioxidant and antigenotoxic source.

• Food Science and Preservation
• /
• v.24 no.5
• /
• pp.593-599
• /
• 2017

The objective of this study was to investigate the effect of superheated steam (SHS) and high hydrostatic pressure (HHP) techniques on the improvement of the quality of Bulgogi product during manufacturing process. Bulgogi product was treated with four different cooking/treatment process: conventional cooking (CC), SHS cooking (SHS), CC and then HHP cooking (CC-HHP), and SHS and HHP cooking (SHS-HHP) samples. SHS treated product increased moisture content, and decreased crude protein. Additionally, hardness, gumminess and shear force values were significantly different among the samples (p<0.05). In safety experiment after 14 days of storage at refrigeration temperature indicated that the bacterial population was lower in the case of SHS-HHP as compared to CC-HHP. Changes in texture during the storage periods at $10^{\circ}C$ for SHS-HHP was lowest values with compared to the initial, while shear force values for both tended to decrease with increasing storage period. The TBA and VBN values for SHS-HHP increased to 0.48 ($5^{\circ}C$)-1.68 ($10^{\circ}C$) mg MD/kg and 25.14 ($5^{\circ}C$)-45.14 ($10^{\circ}C$) mg%, respectively after 15 days of storage. Overall, it was found that the combination of SHS and HHP reduced microbial growth, thus leading to improved product quality and sanitation.

• Journal of Nutrition and Health
• /
• v.35 no.2
• /
• pp.263-271
• /
• 2002

The purpose of this study was to determine the standard work time of dietetic staff through work sampling methodology in school flood service systems. Work measurement through work sampling methodology was conducted in five conventional, five commissary and five joint management flood service systems over two consecutive weeks in October 1999. Statistical analysis was performed on the SAS/Win 6.12 package program for Kruskal-Wallis test and multiple comparison. Observed data were satisfied with a confidence level of 95% and a confidence interval of $\pm$ 0.05. The results of this study can be summarized as follows. The actual time spent by dietetic staff members in conventional, commissary, joint-management flood servile systems was 2,394, 2,521 and 2,110 minutes per week, respectively. Transportation time of each flood service systeml and ILO allowance rate (11%) was applied. Thus, the standard work time per week of dietetic staff members in conventional, commissary, joint-management flood service systems was 2,746.14, 2,861.58 and 2,520.81 minutes, respectively. The standardized index was 1.04, 1.08 and 0.95 men in conventional, commissary, and joint-management flood service systems, respectively. Regardless of the school flood service system, those with "the duty of cooking and distribution management" had the longest labor time, while those with "duty of nutritional education" had the shortest labor time.

• Food Science of Animal Resources
• /
• v.29 no.4
• /
• pp.409-414
• /
• 2009

In this study, the quality of chicken breasts from organically reared chickens was compared with that of chicken breasts from conventionally reared chickens. Broilers were raised in an indoor pen with conventional and organic production system, respectively. The diet formulation for the organically reared chickens and the production density were in accordance with the guidelines for organic chicken products. Twenty birds from each group were slaughtered and their breasts were obtained for analysis. The organic chicken breasts had a higher cooking loss, and waterholding capacity, and a lower shear force (p<0.05) compared to the conventional chicken breasts. The organic chicken breasts also showed higher $a^{\ast}$ and $b^{\ast}$ values and myoglobin contents compared with the conventional chicken breasts (p<0.05). In the fatty-acid analysis, the organic chicken breasts resulted in higher polyunsaturated fatty acid (PUFA) and unsaturated fatty acid contents, and a higher PUFA-saturated fatty acid ratio.

• Korean journal of food and cookery science
• /
• v.8 no.3
• /
• pp.233-239
• /
• 1992

The characteristics of Packsulgi were investigated with different cooking methods of conventional and pressure cookers and variation in panicle size of rice flour. The water contents of rice f1ours and Packsulgis were greater as the particle became coarser. The water contents of Packsulgis cooked with pressure cooker (P) were greater than those of conventional cooker (C). Degree of gelatinization in P was higher than that of C. There were no significant differences among the samples of P, whereas coarser f1ours tended to show higher degree of gelatinization than finer ones in C. The results of textural properties measured by rheometer showed that hardness, cohesiveness and gumminess of P was higher than that of C. The textural parameter of P increased as the particle became finer, whereas mat of C increased as the particle became coarser. L value of C was higher than that of P in me same particle size, whereas a and b value of P was higher than that of C. L and a value of both P and C increased as the particle became finer. b value in P increased as the particle became coarser, whereas mat in C increased as the particle became finer. According to me sensory evaluation, the appearance of C was more acceptable man that of P, whereas the texture of P was more acceptable than mat of C. There were no significant differences in overall quality among P and c and Packsulgis made by 60, 100 mesh rice f1our had higher acceptability than others.