• 농업과학연구
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• 제25권2호
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• pp.181-198
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• 1998

원유를 $50^{\circ}C$, $55^{\circ}C$, $60^{\circ}C$, $65^{\circ}C$ 및 $70^{\circ}C$에서 30분간 microwave 열처리(MW)하고 $65^{\circ}C$에서 30분간 water bath(WB)에서 열처리 하였을때의 화학적 및 미생물학적인 성상의 변화와 $5^{\circ}C$의 냉장상태에서 10일간 보존하면서 화학적 및 미생물학적인 변화상태를 시험한 결과는 다음과 같다. 1. 원료유를 MW와 WB 열처리를 실시하였을 때에는 유지방, 유단백질, 유당, 및 총고형분 함량의 변화는 나타나지 않았다. 2. 원료유의 pH와 산도는 각각 6.75 및 0.16%이었으며, MW와 WB가열시의 pH와 산도는 6.75~6.50 및 0.16%~0.19%이었으며, phosphatase 시험결과는 $61^{\circ}C$에서 20분, $62^{\circ}C$에서 15분, $63^{\circ}C$에서 10분, $64^{\circ}C$에서 5분, $65^{\circ}C$에서 5분 이후의 MW가열과 $65^{\circ}C$ 30분간 WB가열에서 음성으로 나타났다. 3. 가열처리온도가 높아짐에 따라 whey protein의 항량은 감소하였으며, proteolytic activity는 MW가열에서 94%이었으며, $65^{\circ}C$, 30분간 WB가열에서는 44%로 낮게 나타났다. 4. 원유의 총균수는 $2.8{\times}10^5CFU/m{\ell}$로서, MW $65^{\circ}C$ 가열에서 $2.8{\times}10^3CFU/m{\ell}$, $70^{\circ}C$에서 $2.4{\times}10^3CFU/m{\ell}$, WB $65^{\circ}C$ 가열에서 $3.0{\times}10^3CFU/m{\ell}$로 나타났으며, $65^{\circ}C$ 및 $70^{\circ}C$ 30분간 MW가열과 $65^{\circ}C$, WB가열시에 저장 10일 동안 미생물수가 크게 증가하지 않아 보존성이 우수한것으로 나타났다. 또한 $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$에서 5분 내지 30분 동안 MW가열시에 총균수가 5분 이후에 크게 감소하였다. 5. 원료유의 대장균수는 $2.6{\times}10^3CFU/m{\ell}$이었으며, $55^{\circ}C$, $60^{\circ}C$, $65^{\circ}C$ 및 $70^{\circ}C$에서 MW가열과 $65^{\circ}C$, WB가열시에 대장균이 검출되지 않았다. 또한 $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$ 및 $65^{\circ}C$에서 5~30분 동안 MW가열시에 5분 이후부터 검출되지 않았다. 6. 원료유의 내열성균수는 $5.2{\times}10^4CFU/m{\ell}$이었으나, MW $65^{\circ}C$ 가열에서 $2.0{\times}10^3CFU/m{\ell}$, $70^{\circ}C$에서 $1.9{\times}10^3CFU/m{\ell}$, WB $65^{\circ}C$ 가열에서는 $2.2{\times}10^3CFU/m{\ell}$로 나타났고, $65^{\circ}C$ 및 $70^{\circ}C$ 30분간 MW가열시와 $65^{\circ}C$ WB가열시에 저장 10일 동안 미생물수가 크게 증가하지 않아 보존성이 우수한 것으로 나타났다. 또한 $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$에서 5분 간격으로 30분 동안 MW가열시 총 균수가 5분 이후에 크게 감소하였다. 7. 원료유의 내냉성 미생물수는 $2.8{\times}10^5CFU/m{\ell}$이었으나, MW $65^{\circ}C$ 가열에서 $2.0{\times}10^1CFU/m{\ell}$, $70^{\circ}C$에서 $2.0{\times}10^1CFU/m{\ell}$, WB $65^{\circ}C$ 가열에서는 $3.0{\times}10^1CFU/m{\ell}$로 나타났고, $65^{\circ}C$ 및 $70^{\circ}C$ 30분간 MW가열시와 $65^{\circ}C$ WB가열시에 저장 10일 동안 미생물수가 크게 증가하지 않아 보존성이 우수한 것으로 나타났다. 또한 $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$에서 5분 간격으로 30분 동안 MW가열시 총균수가 5분 이후에 크게 감소하였다.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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• pp.89-119
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• 2004

This study was conducted to isolate lactobacilli having probiotic characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from 80 healthy persons (infants, children and adults). And bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. By estimation above characteristics, the strains No. 27, which was isolated from adult feces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing. It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at $37^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by $0.9{\sim}1.0%$ at $37^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced $23{\sim}38%$ of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 hours at $37^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with $15{\sim}25$ mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. Purified ${\alpha}$-galactosidase was obtained by DEAE-Sephadex A-50 ion exchange chromatography, Mono-Q ion exchange chromatography and HPLC column chromatography from L. salivarius subsp. salivarius 27. The specific activity of the purified enzyme was 8,994 units/mg protein, representing an 17.09 folds purification of the original cell crude extract. The molecular weight of enzyme was identified about 53,000 dalton by 12% SDS-PAGE. Optimal temperature and pH for activity of this enzyme were $40^{\circ}C$ and 7.0 respectively. The enzyme was found to be stable between 25 and $50^{\circ}C$. ${\alpha}$-galactosidase activity was lost rapidly below pH 5.0 and above pH 9.0. This enzyme was liberated galactose from melibiose, raffinose, and stachyose, and also the hydrolysis rate of substrate was compound by HPLC. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1153-1153
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• 2001

Directive 79/373/EEC on the marketing of compound feeding stuffs, provided far a flexible declaration arrangement confined to the indication of the feed materials without stating their quantity and the possibility was retained to declare categories of feed materials instead of declaring the feed materials themselves. However, the BSE (Bovine Spongiform Encephalopathy) and the dioxin crisis have demonstrated the inadequacy of the current provisions and the need of detailed qualitative and quantitative information. On 10 January 2000 the Commission submitted to the Council a proposal for a Directive related to the marketing of compound feeding stuffs and the Council adopted a Common Position (EC N$^{\circ}$/2001) published at the Official Journal of the European Communities of 2. 2. 2001. According to the EC (EC N$^{\circ}$ 6/2001) the feeds material contained in compound feeding stufs intended for animals other than pets must be declared according to their percentage by weight, by descending order of weight and within the following brackets (I :< 30%; II :> 15 to 30%; III :> 5 to 15%; IV : 2% to 5%; V: < 2%). For practical reasons, it shall be allowed that the declarations of feed materials included in the compound feeding stuffs are provided on an ad hoc label or accompanying document. However, documents alone will not be sufficient to restore public confidence on the animal feed industry. The objective of the present work is to obtain calibration equations fur the instanteneous and simultaneous prediction of the chemical composition and the percentage of ingredients of unground compound feeding stuffs. A total of 287 samples of unground compound feeds marketed in Spain were scanned in a FOSS-NIR Systems 6500 monochromator using a rectangular cup with a quartz window (16 $\times$ 3.5 cm). Calibration equations were obtained for the prediction of moisture ($R^2$= 0.84, SECV = 0.54), crude protein ($R^2$= 0.96, SECV = 0.75), fat ($R^2$= 0.86, SECV = 0.54), crude fiber ($R^2$= 0.97, SECV = 0.63) and ashes ($R^2$= 0.86, SECV = 0.83). The sane set of spectroscopic data was used to predict the ingredient composition of the compound feeds. The preliminary results show that NIRS has an excellent ability ($r^2$$\geq$ 0, 9; RPD $\geq$ 3) for the prediction of the percentage of inclusion of alfalfa, sunflower meal, gluten meal, sugar beet pulp, palm meal, poultry meal, total meat meal (meat and bone meal and poultry meal) and whey. Other equations with a good predictive performance ($R^2$$\geq$0, 7; 2$\leq$RPD$\leq$3) were the obtained for the prediction of soya bean meal, corn, molasses, animal fat and lupin meal. The equations obtained for the prediction of other constituents (barley, bran, rice, manioc, meat and bone meal, fish meal, calcium carbonate, ammonium clorure and salt have an accuracy enough to fulfill the requirements layed down by the Common Position (EC Nº 6/2001). NIRS technology should be considered as an essential tool in food Safety Programs.