Influence of lactate and acetate salt adaptation on <i>Salmonella</i> Typhimurium acid and heat resistance

Yuan, Wenqian,Á,goston, Ré,ka,Lee, Dongwon,Lee, Seung-Cheol,Yuk, Hyun-Gyun Elsevier 2012 FOOD MICROBIOLOGY Vol.30 No.2

<P><B>Abstract</B></P><P>The aim of the present study was to determine the survival of <I>Salmonella</I> Typhimurium adapted with sodium lactate (NaL), potassium lactate/sodium acetate mixture (KL/NaA) or sodium acetate (NaA) in simulated gastric fluid (SGF) and during heat treatment. NaL-, KL/NaA- and NaA-adapted cells were prepared by incubating in tryptic soy broth (TSB) containing these salts at 5, 5 and 3% (w/v) concentration levels, respectively, for 24 h at 37 °C. The Baranyi model was used to compare the growth kinetic parameters of adapted cells. The acid and heat resistance of adapted cells were determined by incubating in SGF (pH 2.04) at 37 °C and in TSB at 55.8, 57.8 and 59.8 °C, respectively. Adapted cells had significantly (<I>P</I> < 0.05) longer lag phase duration (LPD) and slower maximum growth rate (MGR) than non-adapted cells. The acid resistance of KL/NaA-adapted cells was not significantly (<I>P</I> > 0.05) different from that of non-adapted cells. NaL-adapted cells were more susceptible to the low pH environment, whereas NaA-adapted cells showed enhanced acid resistance compared to non-adapted and other adapted cells. Unlike acid resistance, both NaL- and NaA-adapted cells showed enhanced heat resistance with increased <I>D</I>-values, regardless of treatment temperatures. Thus, this study indicates that adaptation of <I>S.</I> Typhimurium to 5% NaL or 3% NaA could enhance their ability to survive thermal processes or in the human stomach, possibly increasing the risk of <I>Salmonella</I> outbreaks.</P> <P><B>Highlights</B></P><P>► Sodium lactate-adapted <I>S</I>. Typhimurium showed enhanced heat resistance. ► Adaptation to sodium acetate increased heat and acid resistance of <I>S.</I> Typhimurium. ► Adaptation to KL/NaA did not affect their resistance to heat and acid. ► A mixture of KL/NaA may be effective technique in controlling <I>Salmonella</I> spp.</P>

Phase Behavior and Characterization of W/O Microemulsion Systems Containing Sodium Dodecyl Sulfate/Butyl Lactate/Isopropyl Myristate/Water

Park, Sang Joon,Won, Jong Hoon,Lim, Jong-Choo,Kim, Ji Hyeon,Park, Sangkwon 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.1

An investigation on a microemulsion system consisting of sodium dodecyl sulfate (SDS), butyl lactate (BL), water, and isopropyl myristate (IPM) was performed to evaluate butyl lactate as a cosurfactant. The pseudo-ternary phase diagrams revealed that the so-called U-type microemulsions consisting of single isotropic region could be obtained. In addition, an increased weight ratio of BL to SDS induced wider regions of microemulsion. For characterizing the W/O microemulsions with BL, electrical conductivity and dynamic light scattering (DLS) measurements were performed. In the DLS work, a new method was proposed for accurate evaluation of the inherent viscosity of continuous oil phase by utilizing the ratio r = [cosurfactant]/[SDS] at the interface of W/O microemulsions from the conductivity study and the viscosity data for the blended solution of BL and IPM. The conductivity study shows that the ratio r was near 2 and decreased to 0.4 upon increasing the weight ratio of (SDS+BL) to IPM. The size of the W/O microemulsions was relatively small, ca. 4~16 nm, and the size was a function of the volume fractions of water and the total concentrations of SDS and BL. The present work shows that a wide microemulsion region can be attained when using BL as an cosurfactant. These microemusion systems, owing to the skin compatibility of BL, should be very effective when they are employed for dermal drug delivery and cosmetic applications.

Use of Antimicrobial Food Additives as Potential Dipping Solutions to Control Pseudomonas spp. Contamination in the Frankfurters and Ham

오미화,박범영,조현지,이수민,이희영,최경희,윤요한 한국축산식품학회 2014 한국축산식품학회지 Vol.34 No.5

This study evaluated the effect of sodium diacetate and sodium lactate solutions for reducing the cell count of Pseudomo-nas spp. in frankfurters and hams. A mixture of Pseudomonas aeruginosa (NCCP10338, NCCP10250, and NCCP11229),and Pseudomonas fluorescens (KACC10323 and KACC10326) was inoculated on cooked frankfurters and ham. The inoc-ulated samples were immersed into control (sterile distilled water), sodium diacetate (5 and 10%), sodium lactate (5 and10%), 5% sodium diacetate + 5% sodium lactate, and 10% sodium diacetate + 10% sodium lactate for 0-10 min. Inoculatedfrankfurters and ham were also immersed into acidified (pH 3.0) solutions such as acidified sodium diacetate (5 and 10%),and acidified sodium lactate (5 and 10%) in addition to control (acidified distilled water) for 0-10 min. Total aerobic platecounts for Pseudomonas spp. were enumerated on Cetrimide agar. Significant reductions (ca. 2 Log CFU/g) in Pseudomo-nas spp. cells on frankfurters and ham were observed only for a combination treatment of 10% sodium lactate + 10% sodiumdiacetate. When the solutions were acidified to pH 3.0, the total reductions of Pseudomonas spp. were 1.5-4.0 Log CFU/g. The order of reduction amounts of Pseudomonas spp. cell counts was 10% sodium lactate > 5% sodium lactate ≥ 10%sodium diacetate > 5% sodium diacetate > control for frankfurters, and 10% sodium lactate > 5% sodium lactate > 10%sodium diacetate > 5% sodium diacetate > control for ham. The results suggest that using acidified food additive antimicro-bials, as dipping solutions, should be useful in reducing Pseudomonas spp. on frankfurters and ham.

Use of Antimicrobial Food Additives as Potential Dipping Solutions to Control Pseudomonas spp. Contamination in the Frankfurters and Ham

Oh, Mi-Hwa,Park, Beom-Young,Jo, Hyunji,Lee, Soomin,Lee, Heeyoung,Choi, Kyoung-Hee,Yoon, Yohan Korean Society for Food Science of Animal Resource 2014 한국축산식품학회지 Vol.34 No.5

This study evaluated the effect of sodium diacetate and sodium lactate solutions for reducing the cell count of Pseudomonas spp. in frankfurters and hams. A mixture of Pseudomonas aeruginosa (NCCP10338, NCCP10250, and NCCP11229), and Pseudomonas fluorescens (KACC10323 and KACC10326) was inoculated on cooked frankfurters and ham. The inoculated samples were immersed into control (sterile distilled water), sodium diacetate (5 and 10%), sodium lactate (5 and 10%), 5% sodium diacetate + 5% sodium lactate, and 10% sodium diacetate + 10% sodium lactate for 0-10 min. Inoculated frankfurters and ham were also immersed into acidified (pH 3.0) solutions such as acidified sodium diacetate (5 and 10%), and acidified sodium lactate (5 and 10%) in addition to control (acidified distilled water) for 0-10 min. Total aerobic plate counts for Pseudomonas spp. were enumerated on Cetrimide agar. Significant reductions (ca. 2 Log CFU/g) in Pseudomonas spp. cells on frankfurters and ham were observed only for a combination treatment of 10% sodium lactate + 10% sodium diacetate. When the solutions were acidified to pH 3.0, the total reductions of Pseudomonas spp. were 1.5-4.0 Log CFU/g. The order of reduction amounts of Pseudomonas spp. cell counts was 10% sodium lactate > 5% sodium lactate ${\geq}$ 10% sodium diacetate > 5% sodium diacetate > control for frankfurters, and 10% sodium lactate > 5% sodium lactate > 10% sodium diacetate > 5% sodium diacetate > control for ham. The results suggest that using acidified food additive antimicrobials, as dipping solutions, should be useful in reducing Pseudomonas spp. on frankfurters and ham.

Use of Antimicrobial Food Additives as Potential Dipping Solutions to Control Pseudomonas spp. Contamination in the Frankfurters and Ham

Mi Hwa Oh,Beom Young Park,Hyun Ji Jo,Soo Min Lee,Hee Young Lee,Kyoung Hee Choi,Yo Han Yoon 한국축산식품학회 2014 한국축산식품학회지 Vol.34 No.5

This study evaluated the effect of sodium diacetate and sodium lactate solutions for reducing the cell count of Pseudomo-nas spp. in frankfurters and hams. A mixture of Pseudomonas aeruginosa (NCCP10338, NCCP10250, and NCCP11229),and Pseudomonas fluorescens (KACC10323 and KACC10326) was inoculated on cooked frankfurters and ham. The inoc-ulated samples were immersed into control (sterile distilled water), sodium diacetate (5 and 10%), sodium lactate (5 and10%), 5% sodium diacetate + 5% sodium lactate, and 10% sodium diacetate + 10% sodium lactate for 0-10 min. Inoculatedfrankfurters and ham were also immersed into acidified (pH 3.0) solutions such as acidified sodium diacetate (5 and 10%),and acidified sodium lactate (5 and 10%) in addition to control (acidified distilled water) for 0-10 min. Total aerobic platecounts for Pseudomonas spp. were enumerated on Cetrimide agar. Significant reductions (ca. 2 Log CFU/g) in Pseudomo-nas spp. cells on frankfurters and ham were observed only for a combination treatment of 10% sodium lactate + 10% sodiumdiacetate. When the solutions were acidified to pH 3.0, the total reductions of Pseudomonas spp. were 1.5-4.0 Log CFU/g. The order of reduction amounts of Pseudomonas spp. cell counts was 10% sodium lactate > 5% sodium lactate ≥ 10%sodium diacetate > 5% sodium diacetate > control for frankfurters, and 10% sodium lactate > 5% sodium lactate > 10%sodium diacetate > 5% sodium diacetate > control for ham. The results suggest that using acidified food additive antimicro-bials, as dipping solutions, should be useful in reducing Pseudomonas spp. on frankfurters and ham.

젖산나트륨과 젖산칼륨의 첨가가 냉동저장 중 저지방 소시지의 품질특성 및 저장성에 미치는 영향

진구복,안은하,Chin Koo Bok,Ahn Eun Ha 한국축산식품학회 2005 한국축산식품학회지 Vol.25 No.1

본 실험은 저지방 소시지인 대조구와 젖산나트륨 및 젖산칼륨의 첨가 수준에 따라 처리구를 대조구(CTL, Low-fat sausages control), TRT1(Sodium lactate, SL 3.3%), TRT2(SL 2.2% + Potassium lactate, PL 1.1%), TRT3(SL 1.1% + PL 2.2%), TRT4(PL 3.3%)로 나누어 제조하여 냉장저장기간 동안 품질 및 저장성을 조사하기 위하여 실시하였다. 저지방 소시지의 일반성분에서 수분은 73.9∼75.4%, 지방 l∼2%, 단백질은 15.5∼15.9%이였고, pH는 5.8∼6.5범위였으며 젖산나트륨이나 젖산칼륨의 첨가에 따른 냉장 저장 중의 뚜렷한 변화는 보이지 않았다(p>0.05). 냉장 저장 중 유리수분은 전체적으로 22.9∼33.0%범위였으며 저장기간이 증가할수록 증가하는 경향을 보였다(p<0.05). 그러나 진공감량은 2.7∼5.3 범위였고 냉장 저장 중에 차이를 보이지 않았다. 색도는 젖산나트륨이나 젖산칼륨의 첨가에 따른 냉장저장 중의 차이가 거의 나타나지 않음으로써 소시지의 색도에 거의 영향을 끼치지 않는 것으로 나타났다(p<0.05). 조직감의 경우, 대조구는 모든 항목에서, TRT1은 부서짐성과 경도에서, TRT3은 응집력에서 저장기간이 경과할수록 증가하는 경향을 나타내었다. 하지만 젖산나트륨과 젖산칼륨의 첨가는 조직감에 뚜렷한 영향을 미치지 않았다. 미생물의 변화의 경우 저장 4주후부터 10주까지 대조구보다 처리구가 크게 낮아져 유의차가 있었다(p<0.05). 이상의 결과를 종합하면 저지방 소시지에 젖산나트륨 및 젖산칼륨의 첨가는 Listeria monocytogenes에 대하여 저장 중에 품질에 영향을 주지 않으며 우수한 항균효과를 가지고 있었다. This study was performed to investigate physicochemical and textural characteristics, and antimicrobial effect for Listeria monocytogenes (LM) in low-fat functional sausages (LFFS) containing sodium lactate (SL) and potassium lactate (PL) during storage at 4℃ for 10 weeks. The LFFS treatments included CTL (Low-fat sausage control), TRT1 (SL 3.3%), TRT2 (SL 2.2% + PL 1.1%), TRT3 (SL 1.1% + PL 2.2%), TRT4 (PL 3.3%). Proximate composition for LFFS were 73.9∼75.2% moisture, 1∼2% fat and 15.5∼15.9% protein, and pH values ranged from 5.8 to 6.5. Expressible moisture (EM, %) and vacuum purge (VP, %) ranged from 22.9 to 33.0 and from 2.7 to 5.3, respectively. EM of CTL, TRT1 and TRT2 increased with increased storage time, however, no differences in VP were observed during storage time. Hunter color values (L, a, b) were not affected by the addition of SL and PL, and storage time (p>0.05). Most textural properties of LFFS were not affected by the addition of SL and PL, except for few cases, but those of CTL tended to increase with increased storage time. The addition of SL and PL into LFFS, alone or in combination, inhibited the microbial growth of inoculated LM during refrigerated storage, resulting in longer shelf-life than the control.

Influences of partial replacement of sodium chloride with potassium chloride, potassium lactate and calcium ascorbate on quality characteristics of cooked pork ham during cold storage

진상근,김일석,정진연,강석남,신대근,김갑돈 경상대학교 농업생명과학연구원 2013 농업생명과학연구 Vol.47 No.2

This study was conducted to determine the effects of partial replacement (40.0%) of sodium chloride by potassium chloride, potassium lactate and calcium ascorbate on quality characteristics of cooked pork ham during cold storage. The cooked pork hams with partial replacement of sodium chloride by potassium chloride and potassium lactate had lower lightness (L*) and higher bitterness than others (p< 0.05). However, redness (a*), yellowness (b*) and overall acceptability of sensory properties were not different among the treatments (p>0.05). The partial replacement of sodium chloride by all substitutes leads to increase tenderness (p<0.05). There are no problems in microbiological stability and lipid oxidation of cooked pork hams with 40% replacement of sodium chloride by potassium chloride, potassium lactate and calcium ascorbate during cold storage. Therefore, it is possible to use potassium chloride, potassium lactate and calcium ascorbate as partial substitutes of sodium chloride in cooked pork ham.

Product Characteristics and Shelf-Life Effect of Low-Fat Functional Sausages Manufactured with Sodium Lactate and Chitosans During Storage at 10°C

최순희,진구복,Choi, Soon-Hee,Chin, Koo-Bok Korean Society for Food Science of Animal Resource 2009 한국축산식품학회지 Vol.29 No.1

Product quality and shelf-life effect of sodium lactate (SL) in combined with chitosans with various molecular weights (MW) in low-fat sausages (LFSs) stored at $10^{\circ}C$ were evaluated. LFSs with SL and chitosans had 75-76% moisture, 1-2% fat, and 15.8-17.1% protein with a pH range of 6.3-6.6. Water holding capacity was decreased, but most textural properties were increased with the addition of chitosan with MW of 30-40 kDa. Hunter a (redness) values were also increased with the addition of sodium lactate and chitosans in combination with laccaic acid at the level of 0.05%, resulting in similar Hunter a value of 150 ppm of sodium nitrite. The combination of SL and chitosans slightly extended the shelf-life of LFSs approximately 3-6 days at $10^{\circ}C$, resulting in inhibition the growth of L. monocytogenes and E. coli O157:H7, as compared to the control. However, the inhibition of microbial growth at $10^{\circ}C$ was not as strong as that at $4^{\circ}C$. Thus, the storage temperature should be as low ($<4^{\circ}C$) as possible to have a maximum antimicrobial activity in LFS containing SL and various chitosans.

젖산나트륨과 키토산을 첨가한 저지방 기능성 소시지의 냉장 저장 중의 품질 및 저장성 증진 효과

국성호,최순희,강상미,박성용,진구복 한국축산식품학회 2003 한국축산식품학회지 Vol.23 No.2

본 연구는 젖산나트륨과 분자량에 따른 키토산을 저지방 기능성 소시지의 제조 시 첨가하여 냉장 저장 중 물리화학적 및 조직적인 성상과 항균효과에 미치는 영향을 조사하기 위해서 실시하였으며 락색소를 첨가하여 아질산염과 대체할 수 있는 발색효과를 나타내는지 알아보기 위하여 실시하였다. 제조한 저지방 기능성 소시지의 일반성분을 분석한 결과 수분 76-78, 지방 1~2 그리고 단백질은 14~15%의 수준이었다. 각 처리구별 pH는 6.37~6.50 범위였으며 냉장 저장중의 뚜렷한 변화는 보이지 않았다. 중분자 키토산을 첨가한 처리구의 보수력이 저분자와 고분자 키토산 처리구보다 낮았으나 저분자와 고분자 키토산의 처리구 사이에서는 차이를 보이지 않았으며 저장기간 중에 보수력은 차이가 없었다 (p>0.05). 젖산나트륨의 첨가에 의한 진공감량은 증가하였으나 0.3%의 키토산 첨가에 의하여 진공감량의 차이는 상쇄되었고, 냉장 저장 중의 진공감량은 대체적으로 증가하였다. 키토산 첨가에 의한 명도와 황색도가 낮았으며 락색소를 0.05% 첨가한 처리구의 적색도는 아질산염 75와 150 ppm 사이였다. 냉장 저장기간 동안에 명도와 적색도는 차이가 없었으며 황색도는 저장기간이 길어질수록 증가하는 경향을 보였다. 젖산나트륨에 저분자와 중분자 키토산을 각각 첨가한 처리구는 아질산염을 75와 150 ppm을 첨가한 대조구에 비하여 경도와 탄력성에서 높았으며 중분자의 경우 탄력성, 검성 및 저작성에서 다른 처리구들과 뚜렷한 차이를 보였다(p<0.05). 젖산나트륨의 첨가에 의한 Listeria monocytogenes에 대한 유의차는 있었으나(p<0.05) 키토산 첨가에 의한 상승효과는 없었다. 저장기간 중에 아질산염 75나 150 ppm을 첨가한 처리구의 경우 3주후에 $10^{6}$ CFU/g이상을 기록한 반면, 젖산나트륨과 키토산을 첨가할 경우 4~5주 후에 $10^{6}$CFU/g이상이 나타나 저장기간을 1~2주간 연장시킬 수 있었다. 하지만 Salmonella typhimurium과 E. coli O157:H7의 병원성 미생물은 냉장조건의 저장기간 중에 감소하는 추세를 보임으로써 저지방 기능성 소시지의 경우 냉장저장이 필수적이라고 사료된다. 결론적으로 젖산나트륨과 키토산을 첨가한 처리구의 항 미생물적 효과는 아질산염 75나 150ppm을 첨가한 처리구보다 훨씬 높았고 젖산나트륨에 중분자 키토산을 첨가한 처리구는 대부분의 조직적 성상에서 다른 처리구들보다 높았으며, 락색소에 의한 발색효과는 아질산염 75에서 150 ppm 사이로서 일부는 대체가 가능하였으나 완전 대체는 불가한 것으로 나타났다. This study was peformed to evaluate physico-chemical and textural properties, and shelf-life effect of low-fat functional sausages(LFFS) manufactured with sodium lactate(SL), lac color and various molecular weights of chitosans(low=1.5 kDa, medium=30∼40 kDa and high=200 kDa) during storage at 4$^{\circ}C$ for 8 weeks. LFFS had a pH range of 6.39∼6.50, 76∼78% moisture, <2% fat, 14∼15% protein. The combination of SL and low molecular weight(MW) of chitosan improved water holding capacity(WHC), however those of SL and medium MW of chitosan reduced WHC. Vacuum purge(VP) reduced with increased MW of chitosans during refrigerated storage. The addition of chitosans reduced the lightness and yellowness, but increased the redness values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm. LFFS containing SL and medium MW of chitosan increased most texture profile analysis(TPA) values, as compared to controls with 75 and 150 ppm. The addition of SL in LFFS retarded the microbial growth for Listeria monocytogenes, however no synergistic effect with the addition of chitosans were observed. E coli O157:H7 and Salmonella typhimurium reduced during refrigerated storage, regardless of SL and chitosan treatments. Increased storage time increased values for VP, yellowness and textural properties. These results indicated that the combination of SL and various MW of chitosans affected the functional and textural properties, and inhibited the microbial growth for LM effectively. In addition, 0.5% lac color as a replacer for sodium nitrite improved the color development, resulting in similar hunter color values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm.

Glucose Prediction in the Interstitial Fluid Based on Infrared Absorption Spectroscopy Using Multi-component Analysis

Hyejeong Kim,노인섭,윤길원 한국광학회 2009 Current Optics and Photonics Vol.13 No.2

Prediction of glucose concentration in the interstitial fluid (ISF) based on mid-infrared absorption spectroscopy was examined at the glucose fundamental absorption band of 1000 - 1500/cm (10 - 6.67 um) using multi-component analysis. Simulated ISF samples were prepared by including four major ISF components. Sodium lactate had absorption spectra that interfere with those of glucose. The rest NaCl, KCl and CaCl2 did not have any signatures. A preliminary experiment based on Design of Experiment, an optimization method, proved that sodium lactate influenced the prediction accuracy of glucose. For the main experiment, 54 samples were prepared whose glucose and sodium lactate concentration varied independently. A partial least squares regression (PLSR) analysis was used to build calibration models. The prediction accuracy was dependent on spectrum preprocessing methods, and Mean Centering produced the best results. Depending on calibration sample sets whose sodium lactate had different concentration levels, the standard error prediction (SEP) of glucose ranged 17.19 ~ 21.02 mg/dl.