Drying and rehydration behaviors of green bell peppers

İbrahim Doymaz, Osman İsmail

                                                                                  

Abstract

In this study, the drying behaviors of green bell peppers were examined in convection dryer. The study was carried out for 3 drying temperatures (55, 65, and 75°C) and for pre-treated samples with ethyl oleate solution against control samples. The pre-treated samples dried faster than the control ones. Drying time decreased with an increase of drying temperature. Rehydration ratio of the pre-treated samples was higher than control samples. Moisture transfer from green bell peppers was described by applying the Fick’s diffusion model and the effective moisture diffusivity (D _eff ) was calculated. The D _eff values for pre-treated and control samples varied between 0.705 and 2.618×10⁻⁹ m²/sec. Activation energy values for moisture diffusion ranged from 41.67 and 52.99 kJ/mol. Drying data was fitted to 4 thin-layer drying models, namely, Lewis, Henderson and Pabis, logarithmic, and Page. The best model, which best represented the green bell peppers drying, was logarithmic.

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Keywords :activation energy ,drying,effective moisture diffusivity ,green bell pepper ,rehydration ratio.

Parallel analysis of 7 food-borne pathogens using capillary electrophoresis-based single-strand conformation polymorphism

Ae-Rim Kim, Mi-Hwa Oh, Kuk-Hwan Seol, Gi-Won Shin, Gyoo Yeol Jung, Sangsuk Oh

                                                                      

Abstract

Capillary electrophoresis-based single-strand conformation polymorphism (CE-SSCP) coupled with multiplex polymerase chain reaction (PCR) method was used for the detection of 7 pathogens associated with foodborne illness, including Salmonella enterica, Clostridium perfringens, Bacillus cereus, Listeria monocytogenes, Yersinia enterocolitica, Vibrio parahaemolyticus, and Escherichia coli O157:H7. The method was applied to model food systems, both of culture medium and cooked rice. The detection limit of individual microbes was in the range of 10¹–10³ CFU/g, and that of the mixture of 7 microbes was 10³ CFU/g in the cooked rice sample. This method allowed the detection and identification of all 7 food-borne pathogens within 5 hr without the requirement for enrichment steps.

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Keywords :food-borne pathogen ,capillary electrophoresis-based single-strand conformation polymorphism (CESSCP) ,multiplex polymerase chain reaction (PCR).

Determination of polycyclic aromatic hydrocarbons in commercial roasted coffee beans

Kyueun Lee, Han-Seung Shin

                                                                     

Abstract

This study was conducted to investigate the presence of 7 polycyclic aromatic hydrocarbons (PAHs) [benzo[a]anthracene (BaA), chrysene (CRY), benzo[b] fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a] pyrene (BaP), dibenzo[a,h]anthracene (DahA), benzo [g,h,i]perylene (BghiP)] in roasted coffee beans from Korean market. In this study, the method for sample preparation involved liquid-liquid extraction after saponification with potassium hydroxide (KOH), followed by solid-phase extraction (SPE). The external standard method was used for measurement, and regression coefficients ranged from 0.9938 to 0.9995. To determine how much of the analyte remained in the samples after sample preparation, 3-methylcholanthrene was spiked into the samples for a recovery study. The limits of detection and quantification of the 7 PAHs ranged from 0.016 to 0.497 and 0.054 to 1.656 μg/kg, respectively. The concentrations of PAHs in the 10 coffee samples ranged from 0.62±0.08 to 53.25±9.38 μg/kg. According to the results, the critically harmful PAH, BaP, was presented at levels harmless to humans.

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Keywords :polycyclic aromatic hydrocarbon ,roasted coffee ,carcinogen ,fluorescence detection.

Determination of toluene and other residual solvents in various food packaging materials by gas chromatography/mass spectrometry (GC/MS)

Ilwon Seo, Han-Seung Shin

                                                                                       

Abstract

Levels of toluene and other residual solvents were evaluated in food packaging materials as a preventive action against hazard occurrence in foods via migration and to confirm food safety. Automated headspace sampling and gas chromatography/mass spectrometry (HS-GC/MS) were used to determine residual solvent levels in the food packaging materials. Correlation coefficients as calibration factors were over 0.999 and relative standard deviations (RSD) of repeatability were below 3.6%. Limits of quantification (LOQ) ranged from 0.001 to 0.01 mg/m². The levels of 7 residual solvents including toluene for potential migration from food packaging materials to food samples were below Korean regulatory limits

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Keywords :food packaging material ,residual solvent ,toluene ,gas chromatography/mass spectrometry.

Salt substitute effect of flavorings and intensity rating of beef soup in different test settings

Nam-E. Kang, Kyung-Won Lee, Mi-Sook Cho

                                                                           

Abstract

A high salt concentration in soup has been one of the hot health issues of Koreans. The purpose of this study is to reduce salt concentration of soup by different levels of flavorings addition, and to figure out the variation of acceptability and consumers’ attribute recognition levels on attribute by testing locations. The results of consumer acceptability and attribute intensity test showed a significant difference (p<0.05) by the addition of different amount of salt, black pepper, and red pepper in beef soup at laboratory and restaurant settings. In restaurant settings, the substitution of ground red pepper for salt was found to be effective. Based on the fact that ground red pepper was used as one of the additional ingredients to reduce salt used in Korea, the effect of salt substitution of the ground red pepper could be considered as a major element to look into.

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Keywords :salt substitution ,testing location ,consumer’s acceptability.

Free phenolic contents and their antioxidant activities of fresh and fermented rice spent water

Keun-Sung Kim, Kyung-Shik Park, Min-Joo Kim, So-Yeong Kim

                                                                    

Abstract

A new rice milling produces large quantities of a wet byproduct, rice spent water (RSW) containing rice polishings. However, RSW is wasted or destined to undervalued uses. Therefore, the objective of this study was to improve the bioaccessibility of phytochemical phenolics in RSW by means of value-added fermentation process. This study was designed accordingly to compare the methanol-extractable free phenolic contents and their antioxidant activity in fresh and fermented RSW. The results showed that methanol extraction yielded 7 fold higher phenolic contents from the fermented RSW than from the fresh. In addition, the DPPH radical scavenging activity and the reducing power of each RSW equivalent were positively correlated with the methanol-extractable phenolic contents of each equivalent before and after the fermentation, respectively. These data suggest that more insoluble bound phenolic compounds may be freely released in RSW during the fermentation and the bioaccessibility of phytochemical phenolics in RSW may be improved.

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Keywords :rice spent water ,fermentation ,methanol extract ,phenolic acid ,antioxidant activity.

Effects of fermented milk peptides supplement on blood pressure and vascular function in spontaneously hypertensive rats

Sung Min Kim, Soojin Park, Ryowon Choue

                                                                                                    

Abstract

This study investigated the effects of fermented milk peptides (FMP) in spontaneously hypertensive rats (SHR). Systolic blood pressure (SBP) and the angiotensin-converting enzyme (ACE) activity were significantly ameliorated in FMP (10 mg/kg BW/day) group compared to those of the skimmed milk or captopril (CAP, 50 mg/kg BW/day) groups, respectively. The higher plasma nitric oxide (NO) level and the reduced aortic thickness were found in the FMP and CAP groups versus those in the control group, respectively. In conclusion, fermented milk products containing tripeptides have been shown to be a well-tolerated dietary option against mild hypertension.

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Keywords :fermented milk peptide ,hypertension ,blood pressure,angiotensin-converting enzyme ,aortic thickness.

Potent aroma-active compounds of cooked Korean non-aromatic rice

Jae Sung Park, Kwang-Yup Kim, Hyung Hee Baek

                                                                            

Abstract

To characterize the aroma of cooked Korean non-aromatic rice, volatiles were extracted by simultaneous steam distillation and solvent extraction (SDE) and dynamic headspace sampling (DHS). The potent aroma-active compounds were then evaluated using gas chromatography-olfactometry. A total of 16 aroma-active compounds with log3 flavor dilution >1 were detected by SDE. On the other hand, 10 aroma-active compounds were detected by DHS. 2-Methyl-3-furanthiol (2-MF) and 2-acetyl-1-pyrroline were considered the most potent aroma-active compounds in cooked Korean non-aromatic rice. Especially, 2-MF was identified for the first time as a potential aroma-active compound of cooked Korean non-aromatic rice.

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Keywords:rice aroma,gas chromatography-olfactometry,aroma-active compound,2-acetyl-1-pyrroline
2-methyl-3-furanthiol.

Effects of Epigallocatechin gallate glucoside on antitumor activities in human laryngeal epidermoid carcinoma Hep2

Jin Ha Lee, Doman Kim, Young-Hwan Moon, Yeon-Jin Jeong, Kyung-Joo Seong, Hoi-Soon Lim, Sun-Hun Kim, Won-Jae Kim, Ji-Yeon Jung

 

                                                                           

Abstract

(−)-Epigallocatechin-3-gallate (EGCG) has been reported to inhibit cellular proliferation and induce apoptosis in a range of cancer cells. This study examined the cytotoxicity of EGCG glucoside on human laryngeal epidermoid carcinoma Hep2 cells. The EGCG glucoside treatment decreased the cell viability in Hep2 cells. Furthermore, EGCG glucoside caused apoptotic morphological changes with chromatin condensation and nuclear fragmentation, as observed by a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and activated caspase-3 immunohistochemisty. However, the EGCG glucoside did not induce the production of reactive oxygen species (ROS), suggesting that oxidative stress is not involved in the apoptotic response. EGCG glucoside induces apoptosis in Hep2 cells through not the generation of ROS, but the activation of caspase-3.

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Keywords :human laryngeal epidermoid carcinoma Hep2 ,epigallocatechin-3-gallate glucoside ,reactive oxygen species ,caspase-3.

Effect of licorice (Glycyrrhiza uralensisfisch) on amyloid-β-induced neurotoxicity in PC12 cells

Ji Yun Ahn, Suna Kim, Sung Eun Jung, Tae Youl Ha

                                                                                 

Abstract

Alzheimer’s disease is characterized by neuronal loss and the presence of extracellular senile plaques whose major constituent is amyloid-β peptide (Aβ). In this study, we investigated the effects of a water extract of licorice (Glycyrrhiza uralensis F.) (GWE) on Aβ25-35-induced apoptosis in PC12 cells. Exposure to Aβ25-35-induced apoptosis, such as decreased mitochondrial transmembrane potential, increased lipid peroxide formation, decreased antiapoptotic bcl-2 and poly(ADP-ribose) polymerase, and elevated proapoptotic bax, and caspase-3. However, treatment of GWE effectively decreased cell deaths evoked by Aβ25-35. This result suggests that GWE exerts protective effect against apoptotic neuronal cell death induced by Aβ fragments.

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Keywords :licorice (Glycyrrhiza uralensis Fisch) ,neuroprotective effect ,apoptosis ,Alzheimer’s disease.

Juice extraction from mango pulp using an enzymatic complex of Trichoderma sp. produced by solid-state fermentation

Juan Buenrostro-Figueroa, Heliodoro de la Garza-Toledo, Vrani Ibarra-Junquera, Cristóbal Noe Aguilar

                                                                                       

Abstracts

In this study, 2 Trichoderma strains (T-I and T-II) were evaluated for the production, by submerged (SmF) and solid state fermentation (SSF) of an enzymatic complex with the capacity to degrade the cell components of mango peels, using these as support (in SSF) and source of nutrients. Highest enzymatic activity (7,552.5 units of endo-glucanase/L) was found in T-II by SSF. Efficiency of this crude enzymatic extract in the extraction of mango juice was evaluated, improving the yield up to 79%, representing an alternative to give an added value of mango peels improving the yields of production of mango juice.

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Keywords :Trichoderma ,solid-state fermentation ,enzymatic complex ,mango ,juice extraction.

Fractionation and quantification of phenolic antioxidants from Saeunamu(Ostrya japonica)

Jae-Sung Park, Mi-Bo Kim, Young-Hwan Ko, Sang-Bin Lim

                                                                               

Abstract

Saeunamu (Ostrya japonica), a natural plant in Jeju, was extracted and fractionated on a Sephadex LH-20 column, and their phenolic compounds and integral antioxidative capacity (IAC) were evaluated. Eight fractions were obtained, and the relative contents of ethanol fractions (F1-F6) and methanol fractions (F7, F8) were 64.0 and 33.1%, respectively. Total phenolics in the methanol fractions were high as 672.8 and 613.3 mg catechin equivalents (CE)/g in F8 and F7, compared with those in the ethanol fractions as 438.4 and 411.1 mg CE/g in F4 and F5, respectively. Only 4 phenolics such as protocatechuic acid, caffeic acid, catechin, and quercetin were identified. Catechin was concentrated as 4.6 and 4.4 times in F7 and F8, and quercetin was 2.9 and 2.6 times in F5 and F6, respectively, compared with the unfractionated. IAC of water-soluble substances were high as 6.41 and 7.71 mmol ascorbic acid equivalents/g, and those of lipid-soluble substances were high as 2.50 and 2.41 mmol Trolox equivalents/g in F4 and F5, respectively. It was concluded that ethanol fractions (F4-F6) possessing strong IAC may be used as a natural source of antioxidants in functional food ingredients.

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Keywords :saeunamu (Ostrya japonica) ,fractionation ,phenolic compound ,integral antioxidant capacity.