Inactivation modeling of human enteric virus surrogates, MS2, Qβ, and ΦX174, in water using UVC-LEDs, a novel disinfecting system

Kim, D.K.,Kim, S.J.,Kang, D.H. Published on behalf of the Canadian Institute of F 2017 Food Research International Vol.91 No.-

<P>In order to assure the microbial safety of drinking water, UVC-LED treatment has emerged as a possible technology to replace the use of conventional low pressure (LP) mercury vapor UV lamps. In this investigation, inactivation of Human Enteric Virus (HuEV) surrogates with UVC-LEDs was investigated in a water disinfection system, and kinetic model equations were applied to depict the surviving infectivities of the viruses. MS2, Q beta, and Phi X 174 bacteriophages were inoculated into sterile distilled water (DW) and irradiated with UVC-LED printed circuit boards (PCBs) (266 nm and 279 nm) or conventional LP lamps. Infectivities of bacteriophages were effectively reduced by up to 7-log after 9 mJ/cm(2) treatment for MS2 and Q beta, and I mJ/cm(2) for Phi X 174. UVC-LEDs showed a superior viral inactivation effect compared to conventional LP lamps at the same dose (1 mJ/cm(2)). Non-log linear plot patterns were observed, so that Weibull, Biphasic, Log linear-tail, and Weibull-tail model equations were used to fit the virus survival curves. For MS2 and Q beta, Weibull and Biphasic models fit well with R-2 values approximately equal to 0.97-0.99, and the Weibull-tail equation accurately described survival of Phi X 174. The level of UV-susceptibility among coliphages measured by the inactivation rate constant, k, was statistically different (Phi X 174 (ssDNA) > MS2, Q beta (ssRNA)), and indicated that sensitivity to UV was attributed to viral genetic material. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Metabolomics reveals the effect of garlic on antioxidant- and protease-activities during Cheonggukjang (fermented soybean paste) fermentation

Oh, D.G.,Jang, Y.K.,Woo, J.E.,Kim, J.S.,Lee, C.H. Published on behalf of the Canadian Institute of F 2016 Food Research International Vol.82 No.-

<P>We performed mass spectrometry (MS)-based metabolite profiling of Cheonggukjang (CGJ) and three types of garlic (normal, sprouted, and fermented) added CGJ (G-CGJ). Metabolite profiling suggested that the major distinguishing factor between the four types of CGJ lay in whether garlic was added, although different metabolic states were observed in G-CGJ. Among the discriminant metabolites between CGJ and G-CGJ, the levels of four amino acids such as L-valine, L-isoleucine, L-leucine, and glycine were decreased in G-CGJ compared to CGJ because garlic inhibited the protease activity of Bacillus subtilis during fermentation. In addition, the relative contents of L-cysteine, s-allyl-cysteine, s-allyl-cysteine sulfoxide, soyasaponin beta g, and soyasaponin gamma g, which showed positive correlation with antioxidant activities, were high in G-CGJ. These results suggest that MS based metabolite profiling could be a useful tool for understanding the metabolic differences of fermented foods according to the additives, and their relationship with antioxidant activity. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Wheat dough syruping in cold storage is related to structural changes of starch and non-starch polysaccharides

Kim, H.J.,Song, Y.,Lee, S.,Lee, K.P.,Lee, B.H.,Yoo, S.H. Published on behalf of the Canadian Institute of F 2017 Food Research International Vol.99 No.1

<P>Even though the refrigerated dough industry is growing quickly due to the convenience and freshness of refrigerated dough over a prolonged storage period, dough syruping, which is a brownish liquid that leaches out from dough during the storage, is a quality-diminishing factor that needs to be resolved. The objectives of this study were to understand dough syruping and how it is related to structural changes in water-soluble arabinoxylan (WS-AX) and starch in wheat flours during refrigeration as well as to prevent syruping by applying exogenous cell wall polysaccharides. Dough syruping increased to 6.5, 6.9, and 17.2% in weak, strong, and jopoom wheat flours, respectively, after a 35-day storage period. The endoxylanase activity of jopoom wheat flour was substantially greater compared to other commercial flours, but the activity of this flour did not change over the whole cold storage period. The molecular size reduction of WS-AX was inversely related to the degree of dough syruping. The addition of beta-glucan, carboxymethylcellulose, and xylan effectively reduced syrup formation in jopoom wheat flour dough.</P>

Unspecified duo-trio tests can be as powerful as the specified 2-AFC: Effects of instructions and familiarization procedures on cognitive decision strategies

Shin, H.K.,Hautus, M.J.,Lee, H.S. Published on behalf of the Canadian Institute of F 2016 Food Research International Vol.79 No.-

<P>Using signal detection theory (SDT) and Thurstonian analysis, it has been possible in the food industry to make various business decisions such as reformulations and cost reductions based on the degree of consumer sensory discriminability by applying equivalence/difference testing. To achieve more efficient decision-making, it is important to investigate a theoretically and operationally more powerful consumer discrimination test method. Cognitive decision strategies used in discrimination methods largely determine relative test power and thus are of theoretical and practical significance. The goal of this study was to investigate if test procedures using a constant-ref. duo-trio design enable untrained/naive subjects to use a powerful 2-AFC strategy. Although previously the constant-ref. duo-trio design showed operational superiority to other unspecified test methods, the 'comparison of distance' (COD) strategy which is conventionally assumed for the duo-trio, lacks theorized power. The tested variables included two versions of duo-trio design, different familiarizations, instructions and experimental session designs. Three different iced tea samples were discriminated from a reference by 263 untrained/naive subjects using 5 different duo-trio test procedures. Results showed that untrained/naive subjects were able to perform the duo-trio with the reference presented twice, first and middle (DTFM) as a 2-AFC procedure, even with multiple pairs in a block design, after only two reference tastings with the information of the constant-reference. The duo-trio preceded by specified tetrad tests also showed potential as another efficient two-sequence test design. These results suggest that such constant-ref. duo-trio protocols using a 2-AFC strategy can be an alternative to the unspecified triangle and tetrad test. (C) 2015 Elsevier Ltd. All rights reserved.</P>

Fermentation, a feasible strategy for enhancing bioactivity of herbal medicines

Hussain, A.,Bose, S.,Wang, J.H.,Yadav, M.K.,Mahajan, G.B.,Kim, H. Published on behalf of the Canadian Institute of F 2016 Food Research International Vol.81 No.-

<P>Herbal drugs, which possess immunomodulatory, anti-inflammatory, anti-diabetic, anti-infective, and anti-allergic activities, encompass various therapeutic areas, and have been used as traditional medicines for thousands of years. Fermentation is an indispensable traditional technology for the improving the efficacy or reducing adverse effects of herbal medicines. The fermentation process has been shown to improve biological properties of plants, vegetables, and herbs. More specifically, fermentation causes decomposition and/or biotransformation of complex substrates into compatible components, thereby modulating product properties or changing the quantity of certain bioactive compounds. Accumulating evidence indicates the valuable contribution of probiotics and their fermented food products to health. In recent years, considerable attention has been paid to fermentation technology across the globe for improving herbal drugs through production and enrichment of additional bioactive metabolites of medicinal importance including isoflavones, saponins, phytosterols, and phenols. For example, the phenolic contents of the herbal preparation can be increased as a consequence of fermentation and a positive correlation between polyphenols and the anti-oxidant activities of herbs has been well demonstrated. This is in agreement with evidence showing fermentation-mediated enhancement of the pharmacological properties and therapeutic efficacies of herbal formulations against a number of diseases including obesity and inflammation. The subject of fermentation of herbal preparations has been maturing and gaining considerable attention of scientific and technical communities worldwide. In the current review we have addressed these issues in detail with emphasis on understanding the contribution of fermentation-derived bioactive substances to therapies against a number of diseases. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Bactericidal effect of 266 to 279nm wavelength UVC-LEDs for inactivation of Gram positive and Gram negative foodborne pathogenic bacteria and yeasts

Kim, D.K.,Kim, S.J.,Kang, D.H. Published on behalf of the Canadian Institute of F 2017 Food Research International Vol.97 No.-

<P>Recently, UVC-LED technology has been validated as an alternative to eradiation with conventional mercury UV lamps. In this study, we sought to determine primary factors affecting reduction trends shown in several microorganisms. Four major foodborne pathogens (Escherichia coil 0157:H7, Salmonella spp. Listeria monocytogenes, Staphylococcus aureus) and spoilage yeasts (Saccharomyces pastorianus, Pichia membranaefaciens), important to the brewing industry, were inoculated onto selective and non-selective media in order to investigate reduction tendencies at 4 different peak wavelengths (266 to 279 nm). As irradiation dose increased, inactivation levels for every microorganism were enhanced, but there were different UV-sensitivities in Gram positive bacteria (GP), Gram negative bacteria (GN), and yeasts (Y). Loss of membrane integrity measured by propidium iodide (PI) increased as peak wavelength increased for every microorganism studied. Similar results were observed in membrane potential measured by DiBAC4(3). However, there were contrasting results which showed that greater DNA damage occurred at a lower peak wavelength as measured by Hoechst 33,258. The level of DNA damage was strongly related to trends of microbial inactivation. This study showed that even though membrane damage was present in every microorganism studied, DNA damage was the primary factor for inactivating microorganisms through UVC-LED treatment.</P>

Consumer perception of balsamic vinegar: A cross-cultural study between Korea and Italy

Torri, L.,Jeon, S.Y.,Piochi, M.,Morini, G.,Kim, K.O. Published on behalf of the Canadian Institute of F 2017 Food Research International Vol.91 No.-

<P>Understanding cross-cultural differences in food perception is a key issue of food research in order to understand consumer behaviour in different countries. The objective of this study was to explore potential cultural differences of balsamic vinegar perception between Korean and Italian consumers using the sorted napping method. Nine balsamic vinegars different in terms of ingredients, aging time, and origin were evaluated by Korean (n = 50) and Italian (n = 49) consumers using sorted napping. Familiarity and food matching were also examined. Descriptive analysis was performed to verify the attitude of the consumers in product description. The results obtained from two groups of consumers in Korea and Italy revealed a higher description attitude of the Italians (higher number of total elicited attributes, of attributes in common with the trained panel, of attributes shared with the vocabulary reported in literature, of significant specific positive product-attribute associations). Italian subjects generated various descriptors associated with the European gastronomic culture (aromatic herbs, fortified wine, dried figs, Indian fig, Parmigiano-Reggiano cheese), whereas Korean consumers used more terms related to the Asian food culture (red ginseng, Chinese medicine, Japanese apricot teriyaki sauce, persimmon vinegar, balloon flower roots). Moreover, cultural differences of food matching were also observed: the Italians would pair the balsamic vinegars mainly with vegetables, fruits and cheese, while Koreans would combine the balsamic vinegars preferably with bread, vegetables and meat. In conclusion, familiarity resulted the main factors for cross-cultural differentiation. (C) 2016 Published by Elsevier Ltd.</P>

Idiographic duo-trio tests using a constant-reference based on preference of each consumer: Sample presentation sequence in difference test can be customized for individual consumers to reduce error

Kim, M.A.,Sim, H.M.,Lee, H.S. Published on behalf of the Canadian Institute of F 2016 Food Research International Vol.89 No.1

As reformulations and processing changes are increasingly needed in the food industry to produce healthier, more sustainable, and cost effective products while maintaining superior quality, reliable measurements of consumers' sensory perception and discrimination are becoming more critical. Consumer discrimination methods using a preferred-reference duo-trio test design have been shown to be effective in improving the discrimination performance by customizing sample presentation sequences. However, this design can add complexity to the discrimination task for some consumers, resulting in more errors in sensory discrimination. The objective of the present study was to investigate the effects of different types of test instructions using the preference-reference duo-trio test design where a paired-preference test is followed by 6 repeated preferred-reference duo-trio tests, in comparison to the analytical method using the balanced-reference duo-trio. Analyses of d' estimates (product-related measure) and probabilistic sensory discriminators in momentary numbers of subjects showing statistical significance (subject-related measure) revealed that only preferred-reference duo-trio test using affective reference-framing, either by providing no information about the reference or information on a previously preferred sample, improved the sensory discrimination more than the analytical method. No decrease in discrimination performance was observed with any type of instruction, confirming that consumers could handle the test methods. These results suggest that when repeated tests are feasible, using the affective discrimination method would be operationally more efficient as well as ecologically more reliable for measuring consumers' sensory discrimination ability.

The immune-enhancing activity of Cervus nippon mantchuricus extract (NGE) in RAW264.7 macrophage cells and immunosuppressed mice

Hong, S.H.,Ku, J.M.,In Kim, H.,Ahn, C.W.,Park, S.H.,Seo, H.S.,Shin, Y.C.,Ko, S.G. Published on behalf of the Canadian Institute of F 2017 Food Research International Vol.99 No.1

<P>Chemotherapeutics are often used to inhibit the proliferation of cancer cells. However, they can also harm healthy cells and cause side effects such as immunosuppression. Especially traditional oriental medicines long used in Asia, may be beneficial candidates for the alleviation of immune diseases. Cervus nippon mantchuricus extract (NGE) is currently sold in the market as coffee and health drinks. However, NGE was not widely investigated and efficacy remain unclear and essentially nothing is known about their potential immune -regulatory properties. As a result, NGE induced the differentiation of RAW264.7 macrophage cells. NGE-stimulated RAW264.7 macrophage cells elevated cytokines levels and NO production. NGE-stimulated RAW264.7 macrophage cells activated MAPKs and NF-kappa B signaling pathways. NGE encouraged the immuno-enhancing effects in immunosuppressed short-term treated with NGE mice model. NGE or Red ginseng encouraged the immunoenhancing effects in immunosuppressed long-term treated with NGE mice model. Our data clearly show that NGE contains immune-enhancing activity and can be used to treat immunodeficiency.</P>

Comparison of the murine norovirus-1 inactivation in cabbage Kimchi with two different salinities during storage

Kang, S.,Kim, S.j.,Kim, S.H.,Lee, J.H.,Park, S.Y.,Ha, S.D. Published on behalf of the Canadian Institute of F 2016 Food Research International Vol.84 No.-

<P>Enteric noroviruses are occasionally detected in Kimchi, which is a traditional dish made of fermented vegetables. This study was aimed at examining the effects of two levels of salt concentrations on the survival of murine norovirus-1 (MNV-1), a human norovirus surrogate, in experimentally contaminated cabbage Kimchi stored at 5 degrees C for 10 weeks. The number of total aerobic bacteria (TAB) and lactic acid bacteria (LAB), MNV-1 titer pH, and acidity were measured every week The titers of MNV-1 in both low (1.17%) and normal (222%) salinity cabbage Kimchi were significantly (P < 0.05) decreased with increase in storage time. The overall reduction was 1.75 log(10) plaque-forming unit (PFU)/mL in normal salinity cabbage Kimchi and 1.24 log(10) PFU/mL in low salinity cabbage Kimchi. The time required to reduce the titer by >1 log(10) PFU/mL in normal and low salinity cabbage Kimchi were 4 and 8 weeks, respectively. The pH value under both salinities significantly (P < 0.05) decreased until 4 weeks. The maximum acidity was 0.83% and 0.79% in normal and low salinity cabbage Kimchi, respectively, during the 10 weeks. The population of TAB and LAB reached up to 733 log(10) colony-forming unit (CFU)/g as a maximum population during the storage period of 3 weeks in normal salinity cabbage Kimchi. However, the population of TAB and LAB in low salinity cabbage Kimchi reached to 6.99 and 7.04 log(10) CFU/g at 5 and 4 weeks, respectively. Through these findings, fermentation factors such as TAB, LAB, pH, and acidity of cabbage Kimchi were influenced by salt concentration. The inactivation of MNV-1 in normal salinity cabbage Kimchi was much faster than that in low salinity cabbage Kimchi because the fermentation in normal salinity cabbage Kimchi progressed more quickly than that in low salinity cabbage Kimchi. However, both salinity cabbage Kimchi were able to infect cells for 70 days even though the MNV-1 was reduced over 1 log(10) during fermentation. Therefore, the way to protect cabbage Kimchi from norovirus must be considered. (C) 2016 Elsevier Ltd. All rights reserved.</P>