Property and quality of japonica rice cake prepared with Polygonatum cyrtonema powder.

Rice cake is a common traditional food in China. In this study, the effect of Polygonatum cyrtonema (PC) on the qualities and characteristics of rice cake was investigated. The incorporation of PC powder in rice cakes endowed a light-yellow color and increased the water content and water absorption of products. Rheological analysis showed that the rice cake containing PC exhibited weak-gel properties. Additionally, PC (40%) inhibited the rice cake aging and lowered the hardness of rice cakes to 13.86 N after 4 h storage. In vitro starch digestion analysis showed that PC (40%) reduced the digestibility of rice cakes by decreasing the starch hydrolysis rate from 88.70 to 58.95%, displaying a low estimated glycemic index (eGI) of 52.14. The findings mentioned above indicated that the inclusion of PC powder in rice cakes enhanced their characteristics and attributes, which also provided an approach for the development of PC products.

Airway obstruction due to mochi (sticky rice cake) retrieved with a cryoprobe.

Cryoprobes represent an option for bronchial foreign body removal in cases of bronchial obstruction due to viscous substances such as mochi at body temperature.

Rice cake ileus.

Japanese rice cake, mochi, is made from glutinous rice, a very sticky food. Mochi is a popular preserved food during the New Year holiday celebration. However, mochi can be hazardous because of lethal choking or ileus.

Cake of Japonica, Indica and glutinous rice: Effect of matcha powder on the volatile profiles, nutritional properties and optimal production parameters.

Matcha addition decreased the relative crystallinity and provided with a refreshing flavor for all types of rice cakes. Matcha also significantly enhanced the phenolic content and the oxidant defense of cakes. Compared with the other two types of rice cakes, the one made of glutinous rice are with the lowest starch digestibility. Adding matcha to rice cakes inhibited the in vitro starch digestion, and a significant decrease in the expected glycemic index (eGI) and an increase in resistant starch (RS) were observed. Besides, according to the results of sensory evaluation, an optimized formulation of matcha rice cake was expected to contain 1.6% matcha, 82% water and steamed for 39 min. These findings suggest that matcha could be a favorable food additive to improve both the flavour and nutritional value of steamed rice cake.

Development of Fermented Rice Water to Improve the Quality of Garaetteok, a Traditional Korean Rice Cake.

In the rice processing industry, wastewater is an inevitable by-product of rice washing. To increase the utilization of washed rice water (WRW), seven types of fermented washed rice water (FWRW) were prepared using lactic acid bacteria (LAB) and carbohydrate hydrolase. The total concentration of small maltooligosaccharides (MOSs) in the amyloglucosidase (AMG) treatment groups was about ten times higher than in the untreated groups. After 6 h of fermentation, six of the seven FWRW samples reached a pH of 4 due to the increased concentration of organic acids and could, therefore, be used as food acidity regulators. To confirm the applicability of FWRW, the traditional Korean rice cake garaetteok was prepared with FWRW and stored at 4 °C for 5 days. A texture profile analysis (TPA) revealed that the hardness of garaetteok treated with FWRW was significantly lower than that of untreated garaetteok following storage. Differential scanning calorimetry (DSC) showed that FWRW retarded the retrogradation of garaetteok during storage. The addition of FWRW using Lactobacillus reuteri with an AMG group was particularly effective for inhibiting microbial activity in garaetteok during storage. These results suggest that FWRW using AMG-added L. reuteri can be used as a novel food additive for improving the quality of traditional Korean starch foods and could also reduce the volume of waste WRW.

Effect of static magnetic field treatment on γ-aminobutyric acid content and sensory characteristics of germinated brown rice cake.

This study aimed to improve γ-aminobutyric acid (GABA) content and sensory characteristics of brown rice (BR) cake by static magnetic field (SMF)-assisted germination. BR was pre-treated by SMF (10 mT, 60 min, 25 °C), germinated for 36 h, and then germinated BR (GBR) was used to prepare rice cake. The optimal formula was: 60 % GBR, 40 % white rice, 1 % yeast, 20 % sugar, and 55 % water. SMF significantly increased the GABA content by stimulating glutamate decarboxylase, with the values increasing from 28.17 to 32.43 mg/100 g and from 2.50 to 6.27 mg/100 g in GBR (36 h) and GBR cake, respectively. SMF also altered the swelling power and water solubility of GBR flour by promoting the hydrolysis of starch, protein, and fiber, thus improving the texture, flavor, and storage stability of GBR cake. Overall, SMF could be a prospective technique for improving the nutritional and sensory qualities of whole-grain food.

New Year's silent killer in Japan: Undigested mochi.

Swallowed rice cake (mochi) without chewing retained in the stomach intactly. We successfully treated the hardened mochi without surgery. Eye-catching images showed as many as 10 intact mochi in the stomach and endoscopic crushing procedure.

The particle size of rice flour greatly affects the structural, textural and masticatory properties of steamed rice cake (Baekseolgi).

In this study, steamed rice cakes prepared with different particle sized flour were used to investigate how the structures of rice cakes affected masticatory properties and bolus starch hydrolysis. Decreasing the particle size increased the surface areas requiring hydration, resulting in a loose structure and fluffy starch network during gelatinization. Increasing the particle size led to a tight and firm network, but was easily melted in the oral cavity. The chewing cycle and time differed among the samples. The conditions of inter-individual salivary flow rate and salivary α-amylase were diverse. The oral carbohydrate hydrolysis in the bolus before swallowing showed no significant differences in reducing sugar levels among particle sizes. However, salivary concentration was related to initial starch hydrolysis in the oral cavity, indicating the food structures affected mastication factors and physiological conditions. This study provides food structure and physiological factor information that could help design customized foods in industry.

Effects of packaging parameters on the microbial decontamination of Korean steamed rice cakes using in-package atmospheric cold plasma treatment.

The effects of packaging materials, package shape, and secondary packaging on the inactivation of indigenous mesophilic aerobic bacteria in Korean steamed rice cakes using in-package atmospheric dielectric barrier discharge cold plasma (ADCP) treatment were investigated. Inactivation of indigenous mesophilic aerobic bacteria by ADCP treatment (21 kV, 3 min) was significantly increased by 0.6 and 0.8 log CFU/g (p < 0.05) from 0.7 ± 0.1 and 0.5 ± 0.1 CFU/g, respectively, when polypropylene (PP) and low-density polyethylene (LDPE) were laminated with nylon, respectively. Secondary packaging lowered the inactivation level by 0.7-0.8 log CFU/g from 1.1 to 1.3 log CFU/g. In-package ADCP treatment did not alter the water vapor permeability, oxygen transmission rate, and tensile properties of PP, LDPE, nylon/PP, and nylon/LDPE. Thus, the results demonstrated that lamination of PP or LDPE with nylon and treatment before secondary packaging may be effective strategies for microbial inactivation by in-package ADCP treatment.

Genetic region responsible for the differences of starch properties in two glutinous rice cultivars in Hokkaido, Japan.

Starch properties are major determinants of grain quality and food characteristics in rice (Oryza sativa L.). Control of starch properties will lead to the development of rice cultivars with desirable characteristics. We performed quantitative trait locus analysis and detected a putative region on chromosome 2 associated with phenotypic variation of starch properties in two glutinous rice varieties developed in the Hokkaido region of Japan: 'Kitayukimochi', which has a low pasting temperature and creates soft rice cakes, and 'Shirokumamochi', which has a high pasting temperature and creates hard rice cakes. Starch branching enzyme IIb (SbeIIb) was identified as a candidate gene within the region. Sequence analysis of SbeIIb in parental lines identified two single-nucleotide polymorphisms (SNPs) with non-synonymous mutations in the coding region of the 'Shirokumamochi' genotype (SbeIIbsr ). We genotyped over 100 rice cultivars, including 28 rice varieties in the Honshu region of Japan, using the CAPS marker, which was designed using one of the SNPs. However, SbeIIbsr was not found in rice cultivars in Honshu. Distribution analysis indicated that SbeIIbsr was introduced to the rice breeding population in Hokkaido from the American variety 'Cody' via the Hokkaido cultivar 'Kitaake'. As a result, SbeIIbsr was distributed only in progenies of 'Kitaake'.

Anti-inflammatory activities of the mixture of strawberry and rice powder as materials of fermented rice cake on RAW264.7 macrophage cells and mouse models.

Rice cake is a traditional food in Korea, and is made by rice alone, or with other grain powder. To improve the health benefits of fermented rice cake, the rice powder was supplemented with strawberry powder. Anti-inflammatory activities of the mixture of strawberry and rice powder were evaluated. Treatment with the mixture significantly decreased the production of nitric oxide (NO). The mixture of strawberry and rice powder in the ratio 10: 90 effectively and dose-dependently reduced the immune-associated genes iNOS, IL-1ß, IL-6, COX-2, and TNF-α. Furthermore, carrageenan-injected mice were used to study the anti-inflammatory effect of the mixture. Pre-oral administration of the mixture of strawberry and rice powder at doses of 50 and 100 mg/kg BW significantly reduced paw edema induced by carrageenan. These results suggest that for fermented rice cake production and processing, the strawberry and rice powder mixture may be a potential source of anti-inflammatory activity.

Effect of Alternative Preservatives on the Quality of Rice Cakes as Halal Food.

The halal food market is steadily increasing. The use of alcohol for any reason is strictly prohibited in halal foods; however, ethanol is widely used as a preservative for commercial rice cakes (tteok). The purpose of this study was to investigate the use of natural substances as alternative preservatives for rice cakes. Four different solutions were tested: distilled water (control), ethanol, grapefruit seed extract (GSE), and a mixture of citric extracts and organic acids (MCO). We investigated the total plate count (TPC), yeast and mold counts, color, texture profile assays (TPA), and sensory evaluation. Significant reductions of 3.65 log CFU were observed in TPC in rice cake treated with MCO solution after 28 days of storage. However, mold and yeast counts were only reduced by ethanol treatment. Among the physical texture properties analysis, hardness was maintained for the 28 days in all samples. The total color difference values (ΔE) revealed no significant color changes in any rice cake compared to the controls. The ethanol-treated rice cake scored the lowest for overall preference and desired hardness.

Hardening Properties of Cheeses by Latilactobacillus curvatus PD1 Isolated from Hardened Cheese-Ddukbokki Rice Cake.

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacilluscurvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.

Inactivation of Indigenous Microorganisms and Salmonella in Korean Rice Cakes by In-Package Cold Plasma Treatment.

The antimicrobial effects of in-package cold plasma (CP) treatment on Korean rice cakes (KRC) were evaluated. The CP treatment (25 kV) inactivated indigenous mesophilic aerobic bacteria by 0.8-1.0 log CFU/g, irrespective of the position of KRC in the package. The addition of a shaking step during CP treatment increased the reduction in microbes by ~1 log CFU/g. The microbial inactivation efficiency increased significantly when the treatment time increased from 1 to 3 min. Microbial inactivation activity was highest for packages containing eight rice cakes. The optimized CP treatment achieved a 2.0 ± 0.1 log CFU/g reduction in indigenous bacteria. In addition, the optimum CP treatment inactivated indigenous yeast and molds and Salmonella in KRC by 1.7 ± 0.1 log CFU/g and 3.9 ± 0.3 log CFU/g, respectively. No significant changes in color and firmness were observed, and the surface temperature of KRC did not exceed 22 °C after CP treatment. Moreover, CP treatment damaged the cellular membrane of Salmonella, mainly by inducing lipid peroxidation. This study demonstrates the potential use of in-package CP treatment for the non-thermal microbial inactivation of KRC.

Small Bowel Obstruction Due to Rice Cake Consumption / 日本プライマリ・ケア連合学会誌

Introduction: There is an increasing number of reports demonstrating that dietary small bowel obstruction caused by rice cake consumption can be treated conservatively. However, the course of conservative treatment and the characteristics of the cases that require surgery remain unclear. The purpose of this study was to clarify the clinical features of small bowel obstruction caused by rice cake consumption and the characteristics of cases that require surgery.Methods: We retrospectively assessed all cases of intestinal obstruction caused by rice cake consumption treated at a single institution over a period of 7 years. We also assessed similar previously reported cases.Results: We assessed nine cases in our study and reviewed 67 previously reported cases. Conservative treatment was employed in 56 cases (73.7%). Dietary small bowel obstruction caused by rice cake consumption occurred 1.7 ± 0.3 days after intake. The computed tomography (CT) value of rice cake in the intestine was 160.0 ± 8.9 Hounsfield Units. Pieces of rice cake (length ≥ 4 cm) were observed in five of six cases in which rice cake consumption caused intestinal perforation.Conclusion: In most cases, patients with dietary small bowel obstruction caused by rice cake consumption will recover after conservative treatment. However, there is a high risk of intestinal perforation if intestinal CT reveals the length of rice cake pieces to be 4 cm or longer.

Starch Retrogradation in Rice Cake: Influences of Sucrose Stearate and Glycerol.

Retrogradation properties and kinetics of rice cakes with the addition of glycerol (GLY) and sucrose fatty acid ester (SE) were investigated. In hardness, both rice cakes with glycerol (RGLY) and rice cakes with sucrose fatty acid ester (RSE) showed lower initial hardening compared with the control for up to 5 days. X-ray diffraction (XRD) pattern of RSE showed a B+V-type pattern, and the relative crystallinity showed that GLY and SE lowered the initial and final crystallization of rice cake. Both GLY and SE affected the retrogradation enthalpy, glass transition temperature, and ice melting enthalpy in differential scanning calorimeter (DSC). However, 1H NMR relaxation time (T2) of rice cake decreased regardless of additives. From these results, the addition of glycerol and sucrose stearate inhibits the retrogradation process of rice cakes, which will solve industrial problems. Applying the Avrami equation for retrogradation kinetics of rice cake was suitable in XRD and DSC with high coefficient of determination (0.9 < R2). Meanwhile, the other retrogradation index improved the R2 when the exponential rise to maximum equation was used. This suggests that there is an alternative of Avrami equation to predict the retrogradation.

Preparation of functional rice cake by using ß-carotene-loaded emulsion powder.

The purpose of this study was to apply a powdered ß-carotene-loaded emulsion to a real food product, Korean traditional rice cakes (Garaedduk). ß-Carotene was incorporated into the oil phase of a sodium caseinate-stabilized emulsion. Emulsion powder containing ß-carotene was prepared using freeze-drying, and maltodextrin and gum arabic were used as wall materials. Oil/protein/maltodextrin weight ratios of 3:1:2 and 3:1:5 (core-to-wall ratios of 1:1 and 1:2) were used, and gum arabic was added by replacing the amount of maltodextrin for 0.1%, 0.2%, and 0.5% w/w. Manufactured emulsion powders prepared with wall material at a core-to-wall ratio of 1:2 remained stable after reconstitution in terms of particle diameter and ζ-potential. The encapsulation efficiency of the emulsion powder increased by 90% in the presence of maltodextrin at a core-to-wall ratio of 1:2. Garaedduk containing the emulsion powder was then manufactured and it was confirmed that ß-carotene was not degraded during the manufacturing process of Garaedduk by using HPLC. The results from this study may be useful for rational designing of functional foods with lipophilic bioactive materials.

Effects of different starter cultures on the quality characteristics and shelf-life of fermented rice cake.

The effects of Makgeolli, dry yeast (DY), sourdough with dry yeast (SDDY) and sourdough with Makgeolli (SDMG) on the quality of fermented rice cakes (FRCs) stored at 23 °C for 3 days were determined. The acidity of SDDY and SDMG significantly increased with increasing fermentation time. The FRCs supplemented with sourdough had slightly higher moisture contents than others. The addition of DY and SDDY increased the specific volume of the FRC, in which its texture was softer. The addition of DY and sourdoughs significantly decreased the firming rate of crumb and improved the sensory qualities. The sourdoughs retarded amylopectin retrogradation, indicating their anti-staling effect on the FRC. Compared to the control, the shelf-lives of FRCs made with DY and SDDY were extended by 0.7 and 0.5 days based on the instrumental hardness, respectively. DY and SDDY effectively improved the appearance and texture of FRC and extended its shelf-life.

Ohmic cooking of instant rice cake soup: energy efficiency and textural qualities.

The potential of ohmic heating was investigated to cook instant rice cakes according to electric field strengths (9, 12, 15, 18 V/cm) and cooking times (60, 80, 100, 120 s). Customized ohmic heating system was equipped with ohmic cell, electrodes, thermocouple, proportional-integral-differential controller and data acquisition system. Heating rate significantly increased when electric field strengths increased. Heating rate was 12.1 °C/min at 9 V/cm, and was increased to 38.8 °C/min at 18 V/cm. The energy efficiency was evaluated in terms of system performance coefficient (SPC) energy efficiency. The best SPC energy efficiency was 0.65 at an electrical field strength of 18 V/cm. An electric field strength of 15 V/cm and an 80 s cooking time resulted in the most preferable hardness (7.73 N). Ohmic heating would be applicable to cook instant rice cakes, resulting in good energy efficiency and textural qualities.

Effects of different carbohydrases on the physicochemical properties of rice flour, and the quality characteristics of fermented rice cake.

The rice flours were hydrolyzed using α-amylase (A), α-amylase and xylanase (AX), and α-amylase, xylanase and ß-amylase (AXB). The effects of different enzymatic rice flour hydrolysates (ERH) on the quality of the fermented rice cake (FRC) were determined at 25 °C for 4 days. ERH had higher porosity, water absorption index, water solubility index and lower viscosity than the control. Moisture content of FRC center decreased significantly after 4 days. Specific volumes of fresh A-, AX- and AXB-FRC were higher than the control. Color of fresh A-FRC was closer to that of the control. AXB-FRC had lower hardness and firming rate than other samples during storage. After 4 days of storage, FRC with ERH had lower endotherm enthalpy and more uniform and clearer pore structure than the control. Therefore, the ERH with single or mixed enzymes could improve the structure of FRC, and extend its shelf-life.