• Title/Summary/Keyword: log k-pH profile

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Quality changes of fresh-cut lettuce with different oxygen permeability of films during storage (포장 필름의 산소투과율에 따른 신선편의 양상추의 저장 중 품질변화)

  • Hwang, Tae-Young
    • Journal of Applied Biological Chemistry
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    • v.61 no.1
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    • pp.25-31
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    • 2018
  • This study investigated the effect of different $O_2$ transmission rate (OTR) of films on surface temperature, weight loss, pH, $O_2$, $CO_2$ and sensory characteristics, microbial quality, total phenolic contents and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity of fresh-cut lettuce during storage at $10^{\circ}C$ for 7 days. $80{\pm}5g$ of fresh-cut lettuce were packaged with oriented polypropylene films respectively. The OTR of packaging materials was 5,000, 8,000 and $10,000cc/m^2{\cdot}day{\cdot}atm$. Quality characteristics showed significant differences during storage. The surface temperature was averaged 13 and lower in higher OTR of films. The weight loss of lettuce ranged from 2.8 to 5.4% and the highest loss showed in $5,000cc/m^2{\cdot}day{\cdot}atm$ of film. pH was increased during storage and the highest pH was found in $5,000cc/m^2{\cdot}day{\cdot}atm$. The $O_2$ content in the packaging was decreased with increasing $CO_2$ content during storage. The lowest $CO_2$ was found in $10,000cc/m^2{\cdot}day{\cdot}atm$. As OTR was decreased, antioxidant profile of lettuce was decreased. Total aerobic bacteria showed from 5.48 to 6.59 log CFU/g. From the result of the overall sensory test, the marketability of fresh-cut lettuce stored at $10^{\circ}C$ seemed to be maintained effectively over 5 days.

Quantification of Soil Properties using Visible-NearInfrared Reflectance Spectroscopy (가시·근적외 분광 스펙트럼을 이용한 토양 이화학성 추정)

  • Choe, Eunyoung;Hong, S. Young;Kim, Yi-Hyun;Song, Kwan-Cheol;Zhang, Yong-Seon
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.6
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    • pp.522-528
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    • 2009
  • This study focused on establishing prediction models using visible-near infrared spectrum to simultaneously detect multiple components of soils and enhancing the performance quality by suitably transformed input spectra and classification of soil spectral types for prediction model input. The continuum-removed spectra showed significant result for all cases in terms of soil properties and classified or bulk predictions. The prediction model using classified soil spectra at an absorption peak area around 500nm and 950nm efficiently indicating soil color showed slightly better performance. Especially, Ca and CEC were well estimated by the classified prediction model at $R^{2}$ > 0.8. For organic carbon, both classified and bulk prediction model had a good performance with $R^{2}$ > 0.8 and RPD> 2. This prediction model may be applied in global soil mapping, soil classification, and remote sensing data analysis.

Characterization of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time

  • Nath, Caroline Daiane;Neres, Marcela Abbado;Scheidt, Kacia Carine;Bersot, Luciano dos Santos;Sunahara, Samantha Mariana Monteiro;Sarto, Jaqueline Rocha Wobeto;Stangarlin, Jose Renato;Gomes, Simone Damasceno;Sereno, Mallu Jagnow;Perin, Ana Paula
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.8
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    • pp.1197-1204
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    • 2018
  • Objective: The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. Methods: The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. Results: The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units/g). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with a greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g/kg. Conclusion: Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods.