Quality and staling characteristics of white bread fortified with lysozyme-hydrolyzed mealworm powder (Tenebrio molitor L.).

Edible insects have a low environmental impact but are rich in nutrients and have been promoted as alternative protein sources. However, adding insect flour to bread negatively affects the overall quality, especially loaf volume and textural properties. Furthermore, relevant studies on chitin are limited. Therefore, this study examined chitin hydrolysis using lysozymes to enhance the quality characteristics in defatted mealworm (Tenebrio molitor L.) powder (DF-M)-supplemented bread. The chitin hydrolysis degree by lysozymes was evaluated using the 3,5-dinitrosalicylic acid assay and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. The amount of chitin oligomers increased with time, and no significant difference in the hydrolysis efficiency between water and 400 mM acetate buffer was observed. Enzymatic hydrolysis improved the DF-M water- and oil-binding and antioxidant capacities. In addition, chitin hydrolysis increased the volume and softened the texture of white bread. In particular, bread supplemented with DF-M hydrolyzed for 4 h at 10 % had the highest moisture content among the mealworm-added bread groups during storage for 5 days. Moreover, sensory evaluation showed a positive effect of chitin hydrolysis on acceptability. Our findings indicate that chitin hydrolysis can improve the quality of bread containing insect additives. In conclusion, this study provides novel insights into producing high-quality and functional bakery products from edible insects by the enzymatic hydrolysis of edible insect powders and could expand the applications of edible insects as food ingredients.

Characterization of Lactic Acid Bacteria and Yeast from Grains as Starter Cultures for Gluten-Free Sourdough.

With the increasing number of people affected by gluten consumption-related diseases, adhering to a gluten-free (GF) diet is the most effective preventive measure. Herein, we aimed to isolate and characterize the functional properties of autochthonous lactic acid bacteria (LAB) and yeast from various GF sourdoughs to determine their suitability in starter cultures for sourdough preparation. Three LAB, Weissella confusa BAQ2, Lactobacillus brevis AQ2, Leuconostoc citreum YC2, and Saccharomyces cerevisiae BW1, were identified. The isolated LAB exhibited greater TTA, faster acidification rates, and higher acid tolerance than commercial LAB. W. confusa BAQ2 exhibited the highest EPS production, W. confusa BAQ2 and L. brevis AQ2 showed high maltose utilization, and S. cerevisiae BW1 exhibited the highest CO2 production rate. Accordingly, all four microbial strains were mixed for the starter culture. The sourdough prepared with starter cultures exhibited differences in gas production depending on fermentation time, which influenced the volume of GF bread dough. GF bread prepared with fermented sourdough exhibited a 16% higher specific volume and enhanced crumb firmness and elasticity than that prepared using non-fermented sourdough. Thus, autochthonous LAB strains isolated from various GF sourdoughs can be used together to improve the quality of sourdough bread, demonstrating their potential for use in starter cultures for GF sourdough production.

Changes in physicochemical properties of rice flour by fermentation with koji and its potential use in gluten-free noodles.

To use rice flour as an ingredient in gluten-free noodles, improved texture properties such as increased hardness and reduced adhesiveness are required. We investigated the physicochemical characteristics of rice flour obtained by fermenting japonica rice with koji, determined the pasting and textural properties of the resulting gel, and suggested a method for producing gluten-free noodles. Koji-fermented rice flour was obtained by fermenting rice grains for 24 and 48 h. Koji fermentation reduced the protein and ash content of the rice and lowered the pH. The change in amylose content was not significant, but the short-to-long-chain ratio of amylopectin increased. Changes in the structural and compositional characteristics facilitated swelling of the rice flour and starch leaching. Variations in the gelatinization and hydration properties of the rice flour increased its peak viscosity and gel hardness, and reduced its gel adhesiveness. Noodles made from koji-fermented rice flour have improved physical features, such as modified textural properties resulting from a gel texture and increased whiteness, indicating that koji-fermented rice flour is a desirable noodle ingredient for gluten-free foods.

Analyzing Gluten Content in Various Food Products Using Different Types of ELISA Test Kits.

Gluten is an insoluble protein produced when glutelins and prolamins, which are found in grains such as wheat, barley, and oats, combine to form an elastic thin film. This dietary gluten can cause severe contraction of the intestinal mucous membrane in some people, preventing nutrient absorption. This condition, called celiac disease (CD), affects approximately 1% of the world's population. The only current treatment for patients with CD and similar diseases is lifelong avoidance of gluten. To analyze the gluten content in food, various enzyme-linked immunosorbent assay (ELISA) tests are currently used. In this study, the gluten content in various food products was analyzed using different kinds of ELISA test kits. For gluten-free food, three different ELISA test kits mostly yielded values below the limit of detection. However, gluten was detected at 24.0-40.2 g/kg in bread, 6.5-72.6 g/kg in noodles, and 23.0-86.9 g/kg in different powder food samples. A significant difference (p < 0.05) in gluten content was observed for these gluten-containing food products. Reproducibility issues suggest that it is necessary to use several ELISA kits for the accurate detection and quantification of gluten in various food products rather than using one ELISA kit.

Korean ginseng extract ameliorates abnormal immune response through the regulation of inflammatory constituents in Sprague Dawley rat subjected to environmental heat stress.

BACKGROUND: Increases in the average global temperature cause heat stress-induced disorders by disrupting homeostasis. Excessive heat stress triggers an imbalance in the immune system; thus protection against heat stress is important to maintain immune homeostasis. Korean ginseng (Panax ginseng Meyer) has been used as a herbal medicine and displays beneficial biological properties. METHODS: We investigated the protective effects of Korean ginseng extracts (KGEs) against heat stress in a rat model. Following acclimatization for 1 week, rats were housed at room temperature for 2 weeks and then exposed to heat stress (40°C/2 h/day) for 4 weeks. Rats were treated with three KGEs from the beginning of the second week to the end of the experiment. RESULTS: Heat stress dramatically increased secretion of inflammatory factors, and this was significantly reduced in the KGE-treated groups. Levels of inflammatory factors such as heat shock protein 70, interleukin 6, inducible nitric oxide synthase, and tumor necrosis factor-alpha were increased in the spleen and muscle upon heat stress. KGEs inhibited these increases by down-regulating heat shock protein 70 and the associated nuclear factor-κB and mitogen-activated protein kinase signaling pathways. Consequently, KGEs suppressed activation of T-cells and B-cells. CONCLUSION: KGEs suppress the immune response upon heat stress and decrease the production of inflammatory cytokines in muscle and spleen. We suggest that KGEs protect against heat stress by inhibiting inflammation and maintaining immune homeostasis.

A study of the quality characteristics of frozen Korean rice cake by using different thawing methods.

The characteristics of frozen rice cakes after thawing them using different methods, such as standing at room temperature (NT), running water (RWT), pan-grill (PT), steam (ST), microwave (MWT), and superheated steam thawing (SHST), were compared. Frozen rice cakes treated by MWT or SHST showed the shortest thawing time of 3 min. The MWT treatment showed the largest thawing loss, while the ST treatment showed the highest moisture content. The ST, RWT, and MWT treatments showed the highest water activity values. The NT treatment exhibited the highest hardness values, whereas the ST treatment showed the lowest values, possibly due to the adverse effects of high temperature on them. Sensory evaluation showed differences in appearance, moistness, and tenderness according to the thawing method, but there was no significant difference in overall acceptability. This study suggests that the qualities of frozen rice cakes varied depending on the different thawing methods.

Distribution of Microorganisms in Cheongyang Red Pepper Sausage and Effect of Central Temperature on Quality Characteristics of Sausage.

The objective of this study was to provide preliminary data for food industry by investigating the distribution of microorganisms in raw materials and sausage examining the effect of heating temperature on sausage quality. Total microbes in sausage ranged 2.21-3.11 Log CFU/g. Bacillus pumilus, B. licheniformis, Staphylococcus saprophyticus, and Enterococcus faecalis were detected on sausage. Total microbes in raw materials was 1.59-7.16 Log CFU/g. Different types of microorganisms were found depending on raw materials, with B. pumilus and B. subtilis were being detected in both raw materials and sausage. Total microbes in sausage after heating was in the range of 1.10-2.22 Log CFU/g, showing the trend of decrease in total microbe with increasing heating temperature, although the decrease was not significant. With increasing heating temperature, pH and hardness were also increased. The yield of sausage manufactured at 85°C was 95.42% while that manufactured at 65°C was 96.67%. Therefore, decreasing heating temperature during sausage production might increase yield and save energy without microbiological effect.

Optimization of Replacing Pork Meat with Yellow Worm (Tenebrio molitor L.) for Frankfurters.

The effects of replacing pork meat with yellow mealworms on the physicochemical properties and sensory characteristics of frankfurters were investigated in this study. The control (50% pork ham), T1 (45% pork ham + 5% yellow mealworm), T2 (40% pork ham + 10% yellow mealworm), T3 (35% pork ham + 15% yellow mealworm), T4 (30% pork ham + 20% yellow mealworm), T5 (25% pork ham + 25% yellow mealworm), and T6 (20% pork ham + 30% yellow mealworm) were prepared, replacing lean pork meat with yellow mealworm. The moisture content, lightness, sarcoplasmic protein solubility, hardness, gumminess, chewiness, and apparent viscosity of frankfurters with yellow mealworm were lower than those of the control (p<0.05), whereas the content of protein and ash, pH, and yellowness of frankfurters with yellow mealworm were higher than those of the control (p<0.05). The fat content of frankfurters in T1 (p<0.05) was the highest, and the fat content of treatments decreased with increasing yellow mealworm concentrations (p<0.05). Frankfurters with increasing yellow mealworm concentrations had lower color, flavor, off-flavor, and juiciness scores. The overall acceptability was not significantly different in the control, T1, and T2 (p>0.05). Thus, the results of this study showed that replacing lean pork meat with up to 10% yellow mealworm successfully maintained the quality of frankfurters at a level similar to that of the regular control frankfurters.

Quality Characteristics of Tteokgalbi with Black Rice Bran and Organic Acid to Substitute Synthetic Caramel Colorant.

This study aimed to evaluate the quality characteristics of Tteokgalbi with 1% (w/w) black rice bran only (T1), or with black rice bran and one of the following four types of organic acid: ascorbic acid (T2), citric acid (T3), tartaric acid (T4), or maleic acid (T5) as a substitute for caramel colorant. Tteokgalbi with only black rice bran showed the highest (p<0.05) values of moisture content and water holding capacity (WHC), while there were no significant differences in protein content, fat content, ash content, and thiobarbituric acid reactive substance (TBARS) values in treatments and controls (p>0.05). All the treated samples with any one of the four organic acids showed lower pH than controls (p<0.05). The lightness and redness of Tteokgalbi treated with any one of the four organic acids and black rice bran were higher than those of T1. The volatile basic nitrogen (VBN) values of T4 and T5 were higher than those of the other treatments (p<0.05). With regards to sensory characteristics, T1 and T2 showed overall acceptability similar to that of the controls (p>0.05). The results reported in this study show that Tteokgalbi with black rice bran and any one of the four organic acids listed above not only improved quality characteristics in cooking loss, WHC, lipid oxidation but also could successfully replace the synthetic caramel colorant. Overall, the most satisfactory results were obtained by adding black rice bran and ascorbic acid.

Effects of Pre-Converted Nitrite from Red Beet and Ascorbic Acid on Quality Characteristics in Meat Emulsions.

We investigated the effects of fermented red beet extract and ascorbic acid on color development in meat emulsions. The pH of meat emulsions containing red beet extract decreased with an increase in the amount of extract added. The redness of the treated meat emulsions was higher than that of the control with no added nitrite or fermented red beet extract (p<0.05), though the redness of the meat emulsions treated with fermented red beet extract only was lower than in that treated with both fermented red beet extract and ascorbic acid (p<0.05). The highest VBN, TBARS, and total viable count values were observed in the control, and these values in the meat emulsions treated with fermented red beet extract were higher than in that treated with both fermented red beet extract and ascorbic acid (p<0.05). E. coli and coliform bacteria were not found in any of the meat emulsions tested. Treatment T2, containing nitrite and ascorbic acid, had the highest overall acceptability score (p<0.05); however, there was no significant difference between the T2 treatment and the T6 treatment, which contained 10% pre-converted nitrite from red beet extract and 0.05% ascorbic acid (p>0.05). The residual nitrite content of the meat emulsions treated with ascorbic acid was lower than in those treated without ascorbic acid (p<0.05). Thus, the combination of fermented red beet extract and ascorbic acid could be a viable alternative to synthetic nitrite for the stability of color development in meat emulsions.

Effect of Fermented Spinach as Sources of Pre-Converted Nitrite on Color Development of Cured Pork Loin.

The effect of fermented spinach extracts on color development in cured meats was investigated in this study. The pH values of raw cured meats without addition of fermented spinach extract or nitrite (negative control) were higher (p<0.05) than those added with fermented spinach extract. The pH values of raw and cooked cured meats in treatment groups were decreased with increasing addition levels of fermented spinach extract. The lightness and yellowness values of raw cured meats formulated with fermented spinach extract were higher (p<0.05) than those of the control groups (both positive and negative controls). The redness values of cooked cured meats were increased with increasing fermented spinach extract levels, whereas the yellowness values of cooked cured meats were decreased with increasing levels of fermented spinach extract. The lowest volatile basic nitrogen (VBN) and thiobarbituric acid reactive substances (TBARS) values were observed in the positive control group with addition of nitrite. TBARS values of cured meats added with fermented spinach extract were decreased with increasing levels of fermented spinach extract and VBN values of curing meat with 30% fermented spinach extract was lower than the other treatments. Total viable bacterial counts in cured meats added with fermented spinach extract ranged from 0.34-1.01 Log CFU/g. E. coli and coliform bacteria were not observed in any of the cured meats treated with fermented spinach extracts or nitrite. Residual nitrite contents in treatment groups were increased with increasing levels of fermented spinach extract added. These results demonstrated that fermented spinach could be added to meat products to improve own curing characteristics.

Dynamic prediction of patient outcomes during ongoing cardiopulmonary resuscitation.

PURPOSE: The probability of the return of spontaneous circulation (ROSC) and subsequent favourable outcomes changes dynamically during advanced cardiac life support (ACLS). We sought to model these changes using time-to-event analysis in out-of-hospital cardiac arrest (OHCA) patients. METHODS: Adult (≥18 years old), non-traumatic OHCA patients without prehospital ROSC were included. Utstein variables and initial arterial blood gas measurements were used as predictors. The incidence rate of ROSC during the first 30min of ACLS in the emergency department (ED) was modelled using spline-based parametric survival analysis. Conditional probabilities of subsequent outcomes after ROSC (1-week and 1-month survival and 6-month neurologic recovery) were modelled using multivariable logistic regression. The ROSC and conditional probability models were then combined to estimate the likelihood of achieving ROSC and subsequent outcomes by providing k additional minutes of effort. RESULTS: A total of 727 patients were analyzed. The incidence rate of ROSC increased rapidly until the 10th minute of ED ACLS, and it subsequently decreased. The conditional probabilities of subsequent outcomes after ROSC were also dependent on the duration of resuscitation with odds ratios for 1-week and 1-month survival and neurologic recovery of 0.93 (95% CI: 0.90-0.96, p<0.001), 0.93 (0.88-0.97, p=0.001) and 0.93 (0.87-0.99, p=0.031) per 1-min increase, respectively. Calibration testing of the combined models showed good correlation between mean predicted probability and actual prevalence. CONCLUSIONS: The probability of ROSC and favourable subsequent outcomes changed according to a multiphasic pattern over the first 30min of ACLS, and modelling of the dynamic changes was feasible.

Antihypertensive effect of Korean Red Ginseng by enrichment of ginsenoside Rg3 and arginine-fructose.

BACKGROUND: Ginsenoside Rg3 and arginine-fructose (Arg-Fru) are known as the hypotensive compounds of Panax ginseng; however, their efficacy on antihypertension has not been reported yet to our best knowledge. Thus, hypotensive components-enriched fraction of red ginseng (HCEF-RG) was prepared from fine root concentrate (FR) and their antihypertensive effects were investigated in spontaneously hypertensive rats (SHR). METHODS: Male SHRs were divided into six groups: control (Wistar Kyoto, SHR); FR 500; FR 1,000; HCEF-RG 500; and HCEF-RG 1,000; samples (mg/kg body weight) were orally administered every day for 8 wk. Blood pressure was monitored at 1 wk, 2 wk, 3 wk, 4 wk, 6 wk, and 8 wk by tail cuff method. At 8 wk after samples administration, mice were killed for the measurement of renin activity (RA), angiotensin-I converting enzyme inhibition, angiotensin II, and nitric oxide (NO) levels in plasma. RESULTS: HCEF-RG with four-fold more Rg3 and 24-fold more Arg-Fru contents was successfully prepared from reacted mixtures of FR and persimmon vinegar (12 times against FR, v/v) at 80°C for 18 h. Both FR 1,000 and HCEF-RG 1,000 showed lowered systolic blood pressure than SHR control group and HCEF-RG 1,000 group exhibited a significant decrease in diastolic blood pressure. RA was significantly lowered in all treated groups, while angiotensin II did not affect by FR and HCEF-RG treatment. However, angiotensin-I converting enzyme inhibition and NO in FR 1,000 and HCEF-RG 1,000 were significantly increased compared with SHR control group. CONCLUSION: HCEF-RG is more effective and useful for alleviating hypertension than FR, implying the health benefit of Rg3 and Arg-Fru.

Replacement of Pork Meat with Pork Head Meat for Frankfurters.

The effect of reducing pork meat concentrations from 50% to 30% and replacing it with up to 20% pork head meat on chemical composition, cooking characteristics, physicochemical and textural properties, apparent viscosity, and sensory characteristics of frankfurters was determined. The highest moisture content in frankfurters was found in the control and T1 (frankfurter with 45% pork meat + 5% pork head). Protein and fat contents in frankfurters with pork head meat added were significantly (p<0.05) higher than those in the control. When the concentration of pork head meat was increased from 0% to 20%, cooking loss, total expressible fluid separation, fat separation, and pH of frankfurters were increased, while the lightness, redness, yellowness, and apparent viscosity of frankfurters were decreased. Ash contents, cohesiveness, color, and tenderness of sensory characteristics of frankfurters added with different amounts of pork meat or pork head meat were not significantly (p>0.05) different from those of the control or there treatments. Frankfurters in T4 (frankfurter with 30% pork meat + 20% pork head) had the lowest (p<0.05) hardness and gumminess. The hardness and gumminess of frankfurters in other treatments were not significantly different (p>0.05) from that in the control. Frankfurters with higher pork head meat concentrations had lower flavor, juiciness, and overall acceptability scores. Therefore, replacing pork meat with pork head meat in the formulation could successfully produce results similar to those of control frankfurters. The best results were obtained when 10% pork head meat was used to replace pork meat.

Limiting scan range of cardiac CT and the chance of missed acute aortic syndrome.

PURPOSE: Recently, dedicated cardiac computed tomography (CT) has been performed to rule out acute coronary syndrome in patients with chest pain equivalents. However, acute aortic syndrome (AAS) could mimic acute coronary syndrome. We investigated the reliability of CT with a limited scan range for the detection of AAS. METHODS: Patients older than 18 years with a diagnosis of AAS were included for a 10-year period. We reviewed all patients' electronic medical record and cardiac CT scan images. The AAS lesions outside of the upper or lower margin of the cardiac CT scan range were measured. Other abnormalities defined as indirect evidence of AAS such as pericardial effusion were also collected. RESULTS: Of a total of 309 cases, 6 (1.9%; 95% confidence interval, 0.71-4.17) patients had aortic lesions outside of the cardiac CT scan range. One patient had an aortic lesion above the cardiac CT scan range, and 5 patients had aortic lesions below the cardiac CT scan range. CONCLUSIONS: Aortic lesions outside of the cardiac CT scan range were not rare. Therefore, using a cardiac CT might not guarantee ruling out AAS completely.

External validation of the STONE score and derivation of the modified STONE score.

OBJECTIVE: The STONE score is a clinical prediction rule for the presence of uncomplicated ureter stones with a low probability of acutely important alternative findings. This study performed an external validation of the STONE score, focusing on the Korean population, and a derivation of the modified STONE score for better specificity and sensitivity. METHODS: We retrospectively reviewed medical records of patients complaining of flank pain at a single emergency department from January 2013 to December 2014. Patients were categorized into 3 groups according to their STONE score. The prevalence of ureter stones and other alternative findings were calculated in each group. We derived a modified STONE score based on a multivariable analysis and performed an interval validation. RESULTS: From the 700 patients included in the analysis, 555 patients (79%) had a ureter stone. The area under the receiver operating characteristic curve of the STONE score was 0.92. The sensitivity of the high stone score was 0.56. In the modified STONE score, nausea, vomiting, and racial predictors were substituted by C-reactive protein and previous stone history. The area under the receiver operating characteristic curve and sensitivity of the modified STONE score in the internal validation group significantly increased to 0.94 and 0.80, respectively. CONCLUSION: The STONE score can be used to predict a ureter stone with a low probability of other alternative findings. The modified STONE score might increase the diagnostic performance in suspicious urinary stone cases. KEY POINTS: We performed external validation of the STONE score and derivation of the modified STONE score. This scoring system could help the clinicians with radiation reducing decision making.

Quality and Sensory Characteristics of Reduced-fat Chicken Patties with Pork Back Fat Replaced by Dietary Fiber from Wheat Sprout.

The effects of reducing pork fat levels from 20% to 15% or 10% by partially substituting pork back fat with wheat sprout fiber in reduced-fat chicken patties were investigated. Approximate composition, energy value, pH, color, cooking loss, reduction in diameter, reduction in thickness, shear force, and sensory properties were determined. Moisture content, ash contents, yellowness of uncooked and cooked reduced-fat chicken patties with wheat sprout were higher than those in the control, while displaying fat content, calorie content, and pH of uncooked and cooked lower in reduced-fat chicken patties than in the control. Cooking loss, reduction in diameter, and reduction in thickness were the highest in the reduced-fat chicken patties with 10% fat level. Cooking loss, reduction in diameter, and reduction in thickness were decreased when fat levels and wheat sprout levels were increased. Control samples without wheat sprout dietary fiber had significantly (p<0.05) higher color and flavor scores compared to reduced-fat chicken patties containing wheat sprout dietary fiber. The overall acceptability of the control and treatment with 15% fat and 2% wheat sprout dietary fiber (T3) was the highest. Therefore, 15% fat level in reduced-fat chicken patties with the addition of 2% wheat sprout dietary fiber can be used to improve the quality and sensory characteristics of regular-fat chicken patties containing 20% fat level.

Sodium bicarbonate administration during ongoing resuscitation is associated with increased return of spontaneous circulation.

PURPOSE: Sodium bicarbonate is frequently used for patients unresponsive to cardiopulmonary resuscitation (CPR). Its use may be associated with longer resuscitation duration as well as more severe metabolic acidosis. We applied a new analytical method based on a matched case-control study design to control for the potential confounders. BASIC PROCEDURES: Out-of-hospital cardiac arrest patients resuscitated in an emergency department for at least 20 minutes, unless there was any return of spontaneous circulation (ROSC) within the time frame, were analyzed. Patients without ROSC for 20 minutes of CPR were matched to those with ROSC based on initial bicarbonate level categorized using cutoff points of 10, 15, 20, 25, and 30 mEq/L, and their observation durations were trimmed to match their pairs. The association between sodium bicarbonate and ROSC was examined using conditional logistic regression analysis. MAIN FINDINGS: Two matched groups, one with ROSC and the other without (both n = 258), were generated. Sodium bicarbonate administration and its total cumulative dose were significantly associated with an increased ROSC, with odds ratios for ROSC of 1.86 (95% confidence interval [CI], 1.09-3.16; P = .022) and 1.18 (per 20 mEq; 95% CI, 1.04-1.33; P = .008), respectively. The positive associations remained unchanged after multivariable adjustment, with odds ratios for ROSC of 2.49 (95% CI, 1.33-4.65; P = .004) and 1.27 (95% CI, 1.11-1.47; P = .001), respectively. PRINCIPAL CONCLUSION: Sodium bicarbonate administration during CPR in emergency department was associated with increased ROSC.

Effects of millimeter wave treatment on the germination rate and antioxidant potentials and gamma-aminobutyric acid of the germinated brown rice.

Many studies have been conducted to promote germination in brown rice in order to improve its nutritional value in terms of enzymes, protein quality, and micronutrient content. The purpose of this study was to investigate the effect of millimeter wave on germination. Millimeter wave is a form of electromagnetic radiation with frequency between 30 and 300 GHz, and is also called 'biomicrowave'. Millimeter wave significantly stimulated germination. Total polyphenol content and DPPH radical scavenging activity also increased, especially at high frequency and prolonged dose. However, γ-aminobutyric acid content was diminished.

Effect of millimeter waves on the microbiological and physicochemical properties of Korean rice wine Makgeolli.

Millimeter waves are electric waves between 30 and 300 GHz. They are known to affect microbial growth. Here, the effects of millimeter waves on the microbiological and physicochemical properties of Makgeolli irradiated during fermentation were investigated. Millimeter waves at 60 and 70 GHz were used, and the fermentation was carried out at 30°C. The numbers of both lactic acid bacteria and yeasts have changed with similar pattern each then during the fermentation, but the effect of milimeter wave treatment was not critical as growth patterns were independent of both irradiation period and wave frequency. Furthermore, pH and total acidity did not change during fermentation. Although irradiation drastically increased sugar production during the initial stage of fermentation, the change was not frequency dependent. At the end of fermentation, the alcohol content in irradiated Makgeolli was definitely higher than that in un-irradiated Makgeolli, and the difference was frequency dependent.