In this study, the physicochemical and sensory characteristics of low-salt Myungran jeotkal (Alaskan pollock roe) were evaluated after fermentation at 4℃ and 20℃ with or without the addition of deep sea water, salt from deep sea water, and vegetable-origin lactic acid bacteria (Lactobacillus fermentum JS, LBF). When fermented at 20℃, the addition of LBF to Myungran jeotkal resulted in a slow increase in lactic acid content, followed by an abrupt increase after five days of fermentation. However, when fermented at 4℃, the lactic acid content did not change significantly. Further, when Myungran jeotkal fermented at 4℃, the pH decreased as lactic acid production increased. The salinity of Myungran jeotkal fermented at 4℃ and 20℃ was 7% and was not affected by fermentation period. When fermented at 20℃, volatile basic nitrogen and amino nitrogen contents increased with increasing duration of fermentation. Further, volatile acid content decreased, however, the content of amino nitrogen increased after 11 days of fermentation with LBF and no salt effects were observed. When fermented at 20℃ for 13 days, preference (sensory evaluation) was the highest in all experimental groups after 9 days of fermentation, and then decreased as the fermentation period increased. The free amino acid content was highest (1,648.8 mg/100 g) in Myungran jeotkal when sun-dried salt and LBF were added, 2.3 times higher than in the control.

Nanoparticles are widely used in various fields such as electronics, medicines and getting focus on the application in food industry for developing intelligent delivery system with bioactive ingredients or functional nutrients. Basic study on possible toxicological effect of food applicable nanoparticles is required for a practical application in food industry. In this study, size-controlled bovine serum albumin (BSA) nanoparticles were prepared by a desolvation method and their cytotoxicity was investigated. BSA nanoparticles were prepared with mean diameters as 115, 137, 159, and 299 nm, then cytotoxicity was evaluated with RAW 264.7 macrophages as in vitro model. Cell viabilities were significantly affected as increasing nanoparticle concentration. Smaller the sizes of nanoparticles, LD50 values were significantly reduced. LD50 values of BSA nanoparticles were 50, 65, 126, and 170 μg/ml, respectively. Nanoparticle was supposed to induce the apoptosis of RAW 264.7 marcrophages and underlying mechanism will be investigated in future. These findings will be used as valuable basement for nanofood development with BSA nanoparticles.

Non-thermal techniques for microbial decontamination in foods are becoming more promising. This work aims to evaluate suitability and effectiveness of corona discharge plasma jet (CDPJ) for the inactivation of microbial contaminants of dried squid shreds. CDPJ was generated at 20 kV DC and at 58 kHz frequency. Upon the CDPJ treatment for 3 min of the shreds, bacterial contaminants namely aerobic, marine and Staphylococcus aureus were inactivated by 2.0, 1.6, and 0.9 log units, respectively. Also, a 0.9 log reduction of yeasts and molds contaminants was observed. The inactivation pattern fitted well to the pseudo-first-order model rather than first-order kinetic model. The CDPJ treatment did not exert statistically significant (P>0.05) changes in color characteristics and volatile basic nitrogen content of the shreds, as compared to untreated controls. In contrast, the moisture and thiobarbituric acid reactive substances levels were significantly (P<0.05) altered by the plasma exposure. However, the treatment exerted no significant (P>0.05) impact on the sensory characteristics of the shreds. The CDPJ was found effective for bio-decontamination of real-world samples of dried squid. This technology can readily be applied to commercial dried squid processing.

Different pathogenic microorganisms have been reported to cause sprouts-associated outbreaks. This work aimed to evaluate the effect of corona discharge plasma jet (CDPJ) on disinfection of the natural bio-contaminants of broccoli seed and also studied the plasma effect on sprout seed germination rate and physico-chemical properties of sprouts. Aerobic bacteria, molds and yeasts, B. cereus, E. coli, Salmonella spp. were detected on the broccoli seed surface. After 0-3 min treatment using CDPJ, the detected microorganisms were reduced in the range of 1.2-2.3 log units. Inactivation patterns were better explained using pseudo-first-order kinetics. The plasma treatment of seeds up to 2 min exhibited positive effects on the germination rate and the seedling growth. The physico-chemical and sensory characteristics of sprouts were unaffected due to the CDPJ treatment of their respective seeds. The CDPJ can potentially be used for microbial decontamination of broccoli seeds.

In the present study, the effects of non-thermal plasma, corona discharge plasma jet (CDPJ) against foodborne disease bacteria (Escherichia coli O157:H7 ATCC 43894, Salmonella typhimurium ATCC 13311, Staphylococcus aureus ATCC 25923) were determined, and the inactivation patterns were modeled using GinaFiT software in Microsoft Excel. Among inactivation models studied, Weibull-tail model was chosen as the best fit model based on SSE, RMSE, and r 2 values. The initial decimal reduction times (δ) of E. coli O157:H7, S. aureus, and Sal. typhimurium were 6.36, 8.31, and 12.11 s respectively. The inactivation effect increased with the current strength and was highest at span length of 25 mm. After 120 s treatment of the CDPJ at 1.50 A with span length of 25 mm, E. coli O157:H7 was reduced by 5.26 log, S. aureus by 4.21 log, Sal. typhimurium by 2.89 log.

The spotted-wing drosophila Drosophila suzukii (Diptera: Drosophilidae) is an Asian species introduced into North America and Europe. It damages a wide variety of thin-skinned fruits. We sequenced the complete mitochondrial genome (mitogenome) of D. suzukii to better understand the mitogenomic characteristics of this species and understand phylogentic relationships of Drosophila. The 16,230-bp complete mitogenome of the species consists of a typical set of genes, including 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes, and one major non-coding A+T-rich region, with an arrangement typical of insects. Twelve PCGs began with the typical ATN codon, whereas the COI began with TCG, which has been designated as the start codon for other Drosophila species. The 1,525-bp A+T-rich region is the second longest in Drosophila species for which the whole mitogenome has been sequenced, after D. melanogaster. Phylogenetic analysis with the 13 PCGs of the Drosophila species using Bayesian Inference and Maximum likelihood methods both placed D. suzukii at the basal lineage of the previously defined Melanogaster group, with a strong support.

Both Nilaparvata lugens Stål and Laodelphax striatellus Fallén has been known as the major rice pests which were irregularly migrated into Korea by wind current from China. We re-arranged and compared the resistance profiles to detect the existence convergent adaptation by using the previously published dataset (N. lugens at 2014, 17:711-716 and L. Striatellus at 2016, 19:247-252 in J. Asia Pac. Entomol., respectively). Both species commonly exhibited the high level of resistance to imidacloprids. Especially, the immigrant populations of L. Striatellus exhibited higher resistance level to indigenous populations, suggesting that they would settle down in Korea with insecticide resistance traits being predisposed. To detect the convergent adaptation to insecticide, pearson correlation analysis were employed by comparing mean dosage of LD50 and resistance ratio to nine insecticides. Strikingly, high and similar dosage responses were observed between the two species with high correlation coefficients of 0.928 (df=7, P <0.001) and 0.950 (df=7, P <0.001), respectively, in the comparison of LD50 vs. resistance ratio. This finding indicates that convergent adaption has occurred in both species through consistent selection by insecticides with similar usage patterns.