• 한국식품영양과학회지
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• 제25권3호
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• pp.441-452
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• 1996

The effects of chlorophyll, tocopherols($\alpha$-tocopherol, ${\gamma}$-tocopherol and $\delta$-tocopherol), carotenoids ($\beta$-carotene and lutein), light sources, light intensities and strage temperatures on the photooxidative stability of soymilk were studied by measuring TBA value and depleted headspace oxygen(DHO) of soymilk. The samples were stored in the light storage box for 6 days and evaluated for the photooxidative stabilities. As the concentrations of chlorophyll increased, TBA value and DHO of the sample increased significantly(p<0.05), indicating chlorophyll acting as a photosensitizer. However, as the concentrations of tocopherols ($\alpha$-tocopherol, ${\gamma}$-tocopherol and $\delta$-tocopherol) and carotenoids ($\beta$-carotene and lutein) increased, TBA values and DHO of the samples decreased significantly(p<0.05). The light screening effects of carotenoids on DHO in the samples were not significantly different from the control at p>0.05. Therefore, there was no light screening effects of carotenoids on the oxidative stability of soymilk. The results indicate that tocopherols and carotenoids reduce the photooxidative stability of soymilk. $\delta$-Tocopherol was the most effective in photosensitized oxidation followed by ${\gamma}$-and $\alpha$-tocopherols in the order of increasing stability. $\beta$-Carotene was significantly(p<0.05) more effective than lutein in minimizing the chlorophyll-sensitized photooxidation of soymilk. Visible light was more effective than UV light in decreasing the photooxidative stability of soymilk. Therefore, photooxidation of soymilk containing chlorophyll is mainly due to photosensitized oxidation rather than photolysis reaction. As the intensities of fluorescence light increased, TBA values and DHO of the samples increased significantly at P<0.05. However, as the storage temperatures increased, TBA values and DHO of soymilk did not change significantly at p>0.05.

• Journal of Dairy Science and Biotechnology
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• 제30권2호
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• pp.83-92
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• 2012

This study was performed for analyzing the general composition and the change in the quality of soymilk-derived yogurts manufactured by adding skim milk and whey powder to soymilk heat-treated at $95^{\circ}C$/5 min and $120^{\circ}C$/10 min, respectively. 1. During the storage of soymilk yogurt, the concentrations of total solids, protein, fat, and lactose slightly decreased, whereas viscosity, content of ash and NPN, and the number of lactic acid bacteria remained unchanged. 2. The pH and titratable acidity changed rapidly in all soymilk yogurts after 3 h of incubation. 3. We found $7.8{\times}10^8$ lactic acid bacteria in the control sample, $4.7{\times}10^8$ and $5.02{\times}10^8$ in soymilk yogurt with skim milk, respectively, and $5.9{\times}10^8$ and $5.5{\times}10^8$, respectively in soymilk yogurt with whey powder according to degree of heat treatment with $95^{\circ}C$/5 min and $120^{\circ}C$/10 min. 4. The viscosity of yogurt samples became lower as the heat treatment increased in temperature and in the length of time. 5. The value of sensory evaluation was relatively high in soymilk yogurt with the added skim milk, which was heat-treated $95^{\circ}C$/5 min; however, the value was significantly lower than that of the control sample. 6. Lactose, glucose, and galactose were detected in all samples because lactose is degraded into glucose and galactose within 3 h of inoculation.

• Food Science and Biotechnology
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• 제18권2호
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• pp.294-298
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• 2009

Distribution of isoflavones and fatty acids in soymilk fermented with 7 Lactobacilli (L-type), 7 Bifidobacteria (B-type), or 5 Streptococci (S-type) were monitored. Total isoflavones in fermented soymilk ranged from 5.24 to $8.59{\mu}mol/g$ dry basis while those in unfermented soymilk were $8.06{\mu}mol/g$ dry basis. Depending on the types of inoculated microorganisms, fermented soymilk showed different profiles in isoflavones, especially aglycones and $\beta$-glucosides. Four L-type fermented soymilk had significantly higher aglycone content (33.69-46.21%) and low $\beta$-glucosides compared to control (p<0.05). All B-type fermented soymilk showed significantly high aglycone levels (p<0.05). Out of 5 Streptococci, 4 strains produced over 82.2% aglycones. Lipid content ranged from 162 to 224 mg/g and linoleic acid was the highest, followed by oleic, linolenic, palmitic, and stearic acids. Average ratio of unsaturated to saturated fatty acids in control, L-, B-, and S-type fermented soymilks was 6.30, 6.09, 6.30, and 5.94, respectively. This study can help to develop a fermented soymilk containing high isoflavone aglycones and low fat content.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1430-1436
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• 2007

[ ${\alpha}$ ]-Galactosidase was immobilized in a mixture of k-carrageenan and locust bean gum. The properties of the free and immobilized enzyme were then determined. The optimum pH for both the soluble and immobilized enzyme was 4.8. The optimum temperature for the soluble enzymes was $50^{\circ}C$, whereas that for the immobilized enzyme was $55^{\circ}C$. The immobilized enzyme was used in batch, repeated batch, and continuous modes to degrade the raffinose-family sugars present in soymilk. Two hours of incubation with the free and immobilized ${\alpha}$-galactosidases resulted in an 80% and 68% reduction in the raffinose oligo saccharides in the soymilk, respectively. In the repeated batch, a 73% reduction was obtained in the fourth cycle. A fluidized bed reactor was also designed to treat soymilk continuously and the performance of the immobilized ${\alpha}$-galactosidase tested at different flow rates, resulting in a 90% reduction of raffinose-family oligosaccharides in the soymilk at a flow rate 40 ml/h. Therefore, the present study demonstrated that immobilized ${\alpha}$-galactosidase in a continuous mode is efficient for reducing the oligosaccharides present in soymilk, which may be of considerable interest for industrial application.

• 한국식품영양과학회지
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• 제42권10호
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• pp.1533-1538
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• 2013

본 연구에서는 인삼 추출물이 용수로 사용된 두유를 Lactobacillus 5가지 균주를 이용하여 발효 인삼두유를 제조하였으며, 발효 균주에 따른 두유의 미생물학적 및 이화학적 특성과 항산화 활성에 대해 알아보았다. 인삼두유에서의 젖산균 생장은 L. acidophilus KCTC 3168이 가장 우수한 것으로 나타났으며 젖산균의 산 생성에 따른 pH 변화는 L. kefir ATCC 35411에서 가장 낮게 측정되었다. 관능검사 결과는 신맛이 강하면서 쓴맛, 콩비린내 및 쉰내 등이 비교적 약하게 평가된 L. kefir ATCC 35411이 가장 높게 선호되었다. 두유제조에 사용된 인삼의 기능성 성분인 진세노사이드 함량과 항산화 활성에 대해 분석한 결과 총 진세노사이드는 L. casei ATCC 393에서 유의적으로 가장 높게 함유되어 있었으며, 발효홍삼에 주로 존재하며 발효가 진행됨에 따라 함량이 증가하는 것으로 알려진 Rg2, Rg3 및 Rh1 함량 또한 L. casei ATCC 393에서 가장 높게 정량되었다. 인삼두유의 superoxide anion 라디칼 소거활성과 hydroxyl 라디칼 소거활성을 측정한 결과 발효두유에서 발효하지 않은 인삼두유에 비해 각각 2~4배 및 4~5배 정도 항산화 활성이 증진되었음을 알 수 있었으며, 특히 L. kefir ATCC 35411에서 가장 높은 활성을 보이는 것으로 나타났다. 이상의 결과로부터 인삼두유는 젖산균 발효에 의해 관능적, 기능적 측면에서 우수한 두유를 제조할 수 있을 것으로 사료되며, 발효균주로서 L. kefir ATCC 35411이 가장 적합할 것으로 판단되었다.

• 한국식품영양학회지
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• 제33권2호
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• pp.194-203
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• 2020

The purpose of this study was to develop a functional senior mixed soymilk for seniors and to provide functional senior-mixed soymilk to prevent disease outbreaks. The isoflavone content of senior soymilk was 0.15±0.01 mg/g. The β-glucan content of senior soymilk was 9.82±0.01 mg/g. The weight gain of mice were significantly higher in the high-fat diet group than in the other groups. The serum triglyceride content was high at 102.67±40.61 mg/dL in the high-fat diet group, but significantly lower at 83.00±42.43 mg/dL in the 20% senior soymilk group. Thus, the results of this study comprehensively suggest that food intake should be ingested for each life cycle with reference to the dietary reference intakes for Koreans. In particular, the elderly in their 50s and older are deficient in protein and weakened immune capacity, so it is imperative that they maintain their health through various foods such as soymilk, which is evenly nutritious.

• Preventive Nutrition and Food Science
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• 제10권3호
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• pp.224-230
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• 2005

The effects of low viscosity chitosan on the rheological properties of soymilk using a model system and on tofu qualities were examined. The flow behavior of soy milk with chitosan closed the Newtonian flow and stabilized according to increasing chitosan concentration. The soymilk containing $glucono-\delta-lactone$ exhibited a more pseudoplastic flow behavior compared with that of the control soymilk. The addition of low viscosity chitosan to the tofu preparation did not significantly affect its physicochemical properties. However, the results of the TEM image and instrumental textural properties showed that low viscosity chitosan affected the construction of the tofu structure. Chitosan tofu had low scores across the whole field of appearance in the sensory evaluation, and its overall eating quality was scored significantly lower. These results suggest that the addition of low viscosity chit os an affects the quality of tofu, which changes according to the degree of polymerization and concentration of chitosan.

• Food Science and Biotechnology
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• 제17권5호
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• pp.1122-1127
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• 2008

A high dietary oxalate intake may lead to calcium oxalate (CaOx) kidney stones in the gastrointestinal tract. Most soy foods contain high concentrations of oxalate and/or phytate. This study analyzed the changes in oxalate (Ox), phytate ($InsP_6$), and calcium (Ca) during soymilk processing from the seeds of Korean recommended soybean cultivars (cvs). The contents of Ox, $InsP_6$, and Ca in 21 cvs ranged from 14, 108, and 148 to 231, 279, and 246 mg/100 g of dry seed, respectively. Seven cultivars were selected from the 21 cvs by the distributions of Ox, $InsP_6$, and Ca. Then, each contents of soymilk prepared from the 7 cvs were determined. All contents were lower in soymilk than in seeds, but the Ox to $InsP_6$ ratios changed from varying ratios (0.1-0.8) to normal ratios (0.8-1.0) in all cvs except 'Paldalkong'. Consequently, during soymilk processing, the Ox content was decreased and the $InsP_6$ content was remained higher than the Ox content although the Ox was likely to be less reductive than the $InsP_6$. These results may provide better information for minimizing the risk of formation of Ox kidney stones due to consumption of soy products.

• Preventive Nutrition and Food Science
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• 제14권1호
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• pp.76-85
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• 2009

This study determined the effect of refrigerated and thermal storage on the volatile profile of commercial aseptic soymilk. Volatile components in commercial aseptic soymilk stored either under refrigerated ($4^{\circ}C$) or thermal ($55^{\circ}C$) conditions for 30 days were periodically analyzed by combined solvent-assisted flavor evaporation-gas chromatography-mass spectrometry (SAFE-GC-MS). The concentrations of most of the volatile components, including aldehydes, ketones, alcohols, acids, nitrogen- and sulfur-containing compounds, alkylfurans, furan derivatives and phenolic compounds, were affected to a greater extent by thermal storage compared with refrigerated storage. Profound increases in some volatile compounds with low odor detection thresholds, such as hexanal, octanal, (E)-2-octenal, (E,E)-2,4-decadienal, 1-octen-3-ol, 3-ethyl-2,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 2-pentylfuran, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, dimethyl trisulfide, guaiacol, 4-vinylguaiacol and 4-vinylphenol, were observed in thermal stored soymilk. The volatile profile changes caused by thermal storage may influence the aroma quality of thermal-stored aseptic soymilk.

• Preventive Nutrition and Food Science
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• 제14권1호
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• pp.54-59
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• 2009

To improve the functional and organoleptic properties of the fermented soymilk with Bacillus subtilis 2829PNU015 which has chungkukjang like flavor, functional materials from the edible plant extracts with well-known health promoting effects were examined by fibrinolytic activity and sensory evaluation. Among five samples such as Corni fructus, garlic, purple sweet potato, aged garlic, and pumpanini were tested, Corni fructus showed the highest fibrinolytic activity. The appearance and taste of the fermented soymilk (FS) was varied to the amount of Corni fructus added, and the highest acceptability of FS was observed from FS containing 1% Corni fructus extracts ($10^{\circ}$Brix) in it. Best way of applying Corni fructus to the fermented soymilk (FFS) was found to be incubating the mixture of soymilk and Corni fructus with Bacillus subtilis. FFS demonstrated dose dependent radical scavenging activities and these activities were found to be higher than those of FS at designated concentration.