• 한국식품영양학회지
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• 제35권6호
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• pp.521-530
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• 2022

This study was conducted to compare the quality characteristics of commercial tofu products from the market in Korea. Seventeen types of commercial tofu samples were taken and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity and moisture (total solid contents), were analyzed. The hardness of tofu was negatively correlated with the moisture contents of tofu (r=-0.667^**). The commercial tofu showed pH 5.80~6.24, total acidity of 0.016~0.034%, soluble solids of 1.50~3.45°Brix, salinity of 1.20~2.30%, and moisture content of 79.91~87.57%, respectively. All 17 tofu samples sold in the Korean market were prepared using crude MgCl₂ and sea water as a coagulant. The quality characteristics vary depending on the constituent's of soybeans, and the ratio and amount of coagulants of tofu used. The origin of soybean seeds affected the yellowness of tofu; tofu made from imported soybean showed a higher b value than domestic soybean. These results are expected to be useful for understanding trends in the domestic tofu industry.

• 한국식품영양학회지
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• 제33권5호
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• pp.576-583
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• 2020

The purpose of this study was to compare the quality characteristics of silken tofu products from the commercial market in Korea. Seven types of commercial silken tofu were sampled and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity, moisture contents (total solid contents), crude protein and fat contents were evaluated. The TPA results suggest that the texture of silken tofu was very different from one another according to the type of and the amount of coagulant. The commercial silken tofu showed a range of pH 5.53~6.48, total acidity of 0.12~0.32%, soluble solid contents of 2.62~5.07 °Brix, salinity of 2.28~4.30%, and moisture contents of 87.10~92.24%, respectively. In terms of the coagulant of tofu, besides the GDL (glucono-δ- lactone), other coagulants such as MgCl₂ for making 'silken tofu' in the Korean tofu market. The quality characteristics differed depending on the constituents of sample and the coagulants of tofu used. These results are expected to be useful in identifying new trends in the domestic silken tofu industry.

• 한국수산과학회지
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• 제42권6호
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• pp.580-584
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• 2009

The effect of freshwater crab meat additive on protein quality of tofu was studied. Tofu containing freshwater crab meat(TCM) prepared by the formulation for the best sensory qualities had about 20% more lipid and ash content than those of commercial tofu. TCM showed a higher content of lysine, methionine, cysteine and tyrosine compared with those in commercial tofu. TCM was comparable to commercial tofu(CT) regarding the in vitro protein digestibility(95%). A considerable difference in computed protein efficiency ratio(C-PER) resulted between CT(1.76-1.81) and TCM(2.61). Therefore, crab meat has potential as an ingredient for enriching essential amino acid and improving protein quality of CT.

• 한국수산과학회지
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• 제42권3호
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• pp.190-196
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• 2009

To optimize the mixing ratio of ingredients for optimal sensory qualities of seasoned tofu, a response surface methodology with a central composite design was performed on tofu containing freshwater crab meat (TCM). Using the desirability function technique, the optimal formulation was determined to be 3.67 g of freeze dried meat, 5.54 g of garlic powder, and 2,120 mL of soymilk. In the texture profile analysis, tofu prepared using the optimal ingredient ratio had a higher hardness, cohesiveness and gumminess than commercial tofu but TCM value for adhesiveness, springiness and chewiness were lower. However, the texture properties of TCM were not significantly different than those of commercial tofu.

• 한국식품조리과학회지
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• 제24권2호
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• pp.258-265
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• 2008

This study investigated the quality characteristics of tofu(soybean curd) samples prepared with differing amounts of commercial chungkukjang powder(0, 1, 2, 3, 4%). According to the results the 3% chungkukjang tofu 3%(C3) had the highest yield, and the tofus containing chungkukjang powder had higher pH and acidity levels than the control. Turbidity increased and moisture content decreased with increasing chungkukjang powder concentration. And pH, acidity, and turbidity were negatively correlated with moisture content. In terms of color, the L value decreased, and a and b values increased with increasing chungkukjang concentration. For texture, the 1% chungkukjang tofu(C1) had higher hardness, springiness, and cohesiveness values than the other samples. C1 also had the highest overall acceptability score. Finally, sensory properties of taste, texture, and overall quality were positively correlated with the mechanical properties of moisture content, hardness, springiness, cohesiveness, chewiness, and brittleness.

• 한국식품영양과학회지
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• 제28권1호
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• pp.74-80
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• 1999

Growth and bacteriocin production by Lactobacillus sp. GM7311 in tofu residue treated with two commercial amylases were investigated. The optimal condition of amylase Ⅰ(liquefied enzyme for sauce) and Ⅱ(multienzyme 2,000) for the enzyme reaction was showed at pH 6.0 and 4.0, respectively. The optimal temperature was 40oC both. At the enzyme dosage 4% and 3% and reaction time 1hr, about 2% of reduced sugar needed bacteriocin production was obtained. The enzymatic treatment of tofu residue enhanced bacteriocin production by lactic acid bacteria, particularly in the tofu residues added 2.0% yeast extract. But, we couldn't see the increment of bacteriocin activity in the tofu residues added other nitrogen sources such as proteose peptone No. 3 and lab lemco powder. Also, in the comparision of amylase I and Ⅱ, bacteriocin activity in the tofu residue treated with amylase Ⅰ was better than that of amylase Ⅱ.

• 한국식품저장유통학회지
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• 제20권5호
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• pp.636-642
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• 2013

해양 암반 심층수의 두부 응고제로서 활용 가능성을 확인하기 위하여 시판 두부 응고제 3종($MgCl_2$, $CaSO_4$ 및 glucono-${\delta}$-lactone)으로 제조한 두부와 농축하여 8 $^{\circ}Brix$로 농도 조절한 해양 암반 심층수를 두유 L당 20, 25 및 30g씩(SW-20, 25, 30) 첨가하여 제조한 두부의 품질특성을 분석하였다. 두부의 제조 수율은 SW-30에서 유의적으로 높았으며, 순물의 탁도는 해양 암반 심층수를 응고제로 사용한 실험군에서 유의적으로 높았다. 두부의 수분은 72.72~74.86%, pH는 6.09~7.01이었는데, glucono-${\delta}$-lactone을 응고제로 사용한 두부에서 유의적으로 낮았으며, 여타 시료간에는 유의차가 없었다. 두부의 무기물 함량은 응고제에 함유되어 있는 무기물의 영향을 많이 받아 응고제의 주요 무기물이 두부에서도 다량 검출되었으나, 25 mg/kg 미만의 미량 무기질은 응고제의 영향이 적었다. 두부의 명도와 황색도는 해양 암반 심층수로 응고한 실험군간에는 유의차가 없었다. 두부의 물성 중 경도는 시판 응고제를 사용한 두부에 비해 해양 암반 심층수를 사용한 두부에서 유의적으로 낮았다. 관능평가 결과 두부의 응고제는 질감과 맛에 영향을 미쳤는데, 경도가 낮거나 높을 경우 질감에 대한 기호도도 감소하였으며, 응고제로부터 유래한 쓴맛이나 신맛도 관능적 특성을 크게 저해하였다. 이상의 결과를 종합하여 볼 때 해양 암반 심층수는 두부의 이화학적 특성에 있어 시판 응고제로 제조한 두부와 유사한 특성을 나타내었으며, 관능적 특성은 오히려 우수하여 두부 응고제로 활용 가능성이 충분하였다.

• 한국식품영양과학회지
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• 제33권3호
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• pp.603-608
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• 2004

제주 전통두부의 산업 를 위한 최적 공정을 확립하고 해수를 대용할 수 있는 응고제를 사용하여 맛과 영양성 및 저장성이 향상된 고품질의 전통두부를 생산할 수 있었다. 즉 대두원료의 침지는 동절기 및 하절기에 각각 12∼16시간, 8∼10시간이 적합하였다. 가수량은 원료 대두량의 8배가 적합하였으며, 이 때의 두유농도는 8$^{\circ}$Brix였다. 두유는 10$0^{\circ}C$에서 2분 정도 가열하는 것이 단백질의 유리 thiol잔기의 노출을 최대화하였다. 연속 가열솥 대신 진공솥으로 대치한 결과 압력과 온도조절이 용이하여 수율이 21% 증가하였으며, 제품의 품질관리가 용이하였다. 마른두부의 응고제로는 6% 죽염액과 다시마침출액을 1 : 1의 비율로 혼합하여 1차 응고제를 만들고, 키토산 1 L에 CaCl$_2$8g과 MgCl$_2$ 2g의 비율로 혼합하여 응고제를 얻었다. 최종 마른 두부의 소비자의 기호도는 60%이상이 보통 이상으로 평가하였으며, 고소한 맛과 견고성이 우수하면서 전체적인 기호도가 시판두부에 비해서 유의적인 차이를 보이면서 우수하였다.

• 한국식품영양과학회지
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• 제36권4호
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• pp.458-463
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• 2007

항균활성, 항산화성 등 다양한 생리활성이 있는 황금 에탄올 추출물의 두부 저장성 증진 효과를 검토하기 위하여 황금에탄올 추출물을 0.05%, 0.1%를 첨가하고, Bacillus sp. KN-4포자를 접종한 두부를 $25^{\circ}C$에서 저장하면서 품질변화를 측정한 결과, 총균수가 $10^7 CFU/mL$에 도달하는 시간이 대조구는 24시간, 황금 에탄을 추출물 0.05% 첨가구는 36시간, 0.1% 첨가구는 48시간이 소요되었다. pH와 산도는 12시간까지는 큰 차이를 보이지 않았으나, 저장 24시간 이후의 대조구에서는 pH가 급격하게 감소되었고, 산도는 증가하였다. Strength, hardness는 저장초기 대조구보다 황금 에탄올 추출물 첨가구가 높게 나타났으며, 대조구는 저장 초기부터, 0.05% 첨가구는 24시간부터 다소 낮아지는 경향을 나타내었으나, 0.1% 첨가구는 저장기간 중 뚜렷한 변화가 관찰되지 않았다. 관능적인 평가는 대조구에 비해 조직감은 첨가구가, 맛은 대조구가 높았으며, 그 외 색상, 풍미 등에서는 첨가구와 대조구간의 유의적인 차이를 나타내지 않았다.

• 한국지역사회생활과학회지
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• 제26권3호
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• pp.489-498
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• 2015

This study investigates the effects of a China root (Smilax china L.) extract on the chemical and microbiological characteristics and antioxidant activity of the sausage stew sauce and the soft-tofu stew sauce over a 5-week storage period. Commercial sauces were obtained from the market, and samples were prepared using four different concentrations of the China root extract (0% (control), 0.5%, 1.0%, and 1.5%) and stored at $5^{\circ}C$ and $20^{\circ}C$. Over the 5-week storage period, pH and salinity showed slight changes in both the sausage and soft-tofu stew sauces, but there was no significant difference (p<0.05) regardless of the extract amount and temperature. At 5 weeks, there were significant decreases in the total microbial count in groups with the China root extract (p<0.05) for both the sausage and soft-tofu stew sauces at $5^{\circ}C$. Over the whole storage period, no coliform, yeast, and mold were detected in any sample. S. aureus counts were not detected in 1.0% and 1.5% China root groups at $5^{\circ}C$, but 1.00-1.60 log CFU/g was found in the control and 0.5% groups. DPPH radical scavenging activity at 5 weeks showed an increase with an increase in the amount of the China root extract in both sauces. These results indicate that the China root extract inhibited microbial growth during storage as well as scavenging activity and thus that it can be considered to prolong the shelf life of commercial sauces.