In this study, we characterized the chemical properties of golden berries, which contain various functional substances and bioactive components, to develop a yogurt dressing using golden berry juice. The total polyphenol content of golden berry was 35.29 mg GAE/g, the total flavonoid content was 28.93 mg QE/g, and the DPPH radical scavenging activity was 94.81%. The chromaticity of yogurt dressing with golden berry juice decreased in L value and increased in a and b values with growing amounts of golden berry juice (p<0.001); viscosity decreased significantly with increasing amounts of golden berry juice (p<0.001). Electronic tongue analysis showed that sourness, umami taste, and saltiness increased upon increasing the quantity of golden berry juice, while sweetness and bitterness increased with less golden berry juice. PCA analysis determined that PC1 and PC2 accounted for 63.45% and 35.29% of the variance, respectively. Furthermore, the addition of golden berry juice impacted the analysis of taste patterns. Sensory evaluation showed that color, flavor, sweetness, sourness, bitterness, and overall acceptability were highest in the 30% golden berry juice group. As a result, it was confirmed that adding golden berry juice is suitable for developing yogurt dressings that can improve health functions and palatability.

Recently, consumers’ awareness of the importance of the intestinal action of lactic acid bacteria and intestinal microbes is increasing, as well as interest in yogurt. In this study, yogurt was prepared with three mixed strains (lactic acid bacteria combination, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp., and Bulgaricus, Streptococcus thermophilussei, 1:1:1) by adding oats flour, and the quality characteristics of yogurt were investigated, while stored at a storage temperature of 4℃ for 12 days. According to the storage period, the control as wel as the oat yogurt showed slight decrease in pH, and no significant change in acidity. Sugar content slightly increased. and brightness decreased, in the control and the oat yogurt. Visible cell numbers increased during storage, and decreased on the 12th day. Viscosity in the oat yogurt was 7,580 cP, which was approximately eight times higher than that of the control group, and decreased gradually according to the storage period. Antioxidant activity (DPPH) was approximately two times higher in the oat-added yogurt, and slightly increased with the storage period, decreased on the 12th day of storage, and β-glucan was detected only in oat-added yogurt.

This research aims to investigate pudding with grain-added yogurt for its quality characteristics and viability during cold storage. The yogurt was fermented until its pH was 5.10±0.05 after inoculating the probiotic strain (Bifidobacterium lactis, BB-12) into the milk base containing grains. The yogurt was added to prepare probiotic puddings. During cold storage of the puddings at 4±1oC for 4 week, the quality characteristics (pH, acidity, texture) and the viability of BB-12 in pudding were determined and compared to control (only milk base). As a result, MR had a significantly lower pH and higher acidity than those of other samples. In texture properties, including hardness, gumminess, and chewiness, MSIR showed the significantly highest value, and the pudding with inulin was significantly higher than rice flour in all textures. For the viability of BB-12, pudding with milk was significantly lower than pudding containing milk and soymilk, suggesting that soymilk helps maintain viability. MR showed significantly higher viability than MI in the milk-based pudding, indicating that rice flour is more effective than inulin. Therefore, the addition of soymilk, inulin, and rice can maintain quality characteristics and viability of BB-12 in the pudding.

The purpose of this study is to compare the quality characteristics and antioxidant activities of the tagatose yogurt with different contents (6, 8, 10%) of cold brew liquid coffee. Tagatose is a low-calorie food ingredient with putative health-promoting benefits. The tagatose yogurt was fermented with Lactobacillus delbrueckii subsp. bulgaricus at 37±1oC for 20 h. The changes in acid production (pH and titratable acidity), viscosity, and lactic acid bacteria were determined every 5 h during fermentation. Color value was determined before and after fermentation, and antioxidant activities were performed after fermentation in triplicate. The yogurts containing cold brew liquid coffee had lower pH, higher acidity, and viscosity than the control, regardless of the liquid coffee contents. All samples had increasing levels of lactic acid bacteria over the fermentation period, but lactic acid bacteria of yogurts with the addition of cold brew liquid coffee increased further than the control. The total polyphenol/flavonoid content, DPPH/ ABTS/H2O2 radical scavenging activities, and reducing power increased when the liquid coffee content of the yogurt rose. Consequently, the optimal quality of tagatose yogurt was found when 6-8% of cold brew liquid coffee was added according to the overall results of quality properties and antioxidant activity.

In this study, we investigated the effects of adding oat and lactic acid bacteria on the quality and functionality of yogurt. Yogurt was fermented with various lactic acid bacteria,; Lactobacillus acidophilus (LA), Lactobacillus delbrueckii sub. bulgaricus (LB), and Streptococcus thermophilussei (ST) and quality properties, β-glucan content, antioxidant activity were estimated. The quality of control and oat added yogurt (OY) showed significant differences depending on the type of strain and combination. The addition of oats significantly accelerated the lactic acid bacteria production, decreased the pH, and increased the titratable acidity and count of the viable cells compared to the control. Acid production was highest in ST, with the complex strains containing ST and LALBST showing high quality characteristics. The viscosity of oat yogurt was higher than that of the control group, and LALBST was also significantly higher than that of the control group. The β-glucan content of OY was 0.14-0.2%, and the organic acid content and antioxidant activity were also significantly increased by the addition of oats. As a result, it is thought that the addition of oats and a combination of lactic acid bacteria can be used for improving the quality and functionality of yogurt.

This research investigated the quality properties of yogurts added to barley (1, 2, and 3%) and tagatose or sucrose. After inoculation of S. thermophilus, pH, titratable acidity (TA), viscosity, and viable cell count were measured at 4 h intervals for 16 h and color value, antioxidant activity, and sensory evaluation were determined after fermentation in triplicate. In the case of yogurt containing only tagatose or sucrose, the pH was hardly decreased, but when 2-3% barley was added, the pH reached below 4.5 before 16 h. In addition, TA and viscosity tended to increase as barely was added. Viable cell count increased slowly in yogurt with tagatose, but rapidly increased when barley was added. As barley content increased, yellowness, redness, and antioxidant activity tended to increase, and significantly higher antioxidant activity in barley tagatose yogurt. Sour strength increased and significant difference in the sweetness was not observed when barley amount increased. Although there was no significant difference in overall acceptability, tagatose yogurt containing 3% barley scored the highest in preference. In conclusion, the fermentation rate of yogurt inhibited by the addition of tagatose is improved by the addition of barley, and the growth rate of lactic acid bacteria is considered to play a role.

To investigate the effects of tagatose added to yogurt fermented with Streptococcus thermophiles (ST) or Lactobacillus delbrueckii subsp. Bulgaricus (LB), pH, titratable acidity (TA), sugar content, color value, viable cell number, and sensory evaluation were determined on yogurts added with 7% sucrose, tagatose, or a mixture of sucrose and tagatose in triplicate. After 24 h, pH and sugar content of sucrose-added yogurt reached nearly 4.5 and 4.2 respectively, and were lower than those of yogurt with tagatose (above 5.6 and 8.6, respectively). Also, TA of sucroseadded yogurt (1.51%) was much higher than that of yogurt with tagatose (0.59%). There were no significant differences in color value and viable cell count after 24 h. However, the addition of tagatose seems to slow the growth rate of LB more than that of ST. Sensory preference revealed that mixture-added yogurts scored significantly higher in taste (5.90), texture (5.86), and overall acceptability (6.16) than yogurts with tagatose (5.20, 5.02, and 5.36, respectively), but there was no significant difference from the sucrose-added yogurts. In conclusion, tagatose inhibited the fermentation rate, but the mixture of tagatose and sucrose could be used for yogurts with lower calories and glucose index (GI) without a sensory difference from sucrose-added yogurt.

The pH, acidity, viscosity, viable cell counts of lactic acid bacteria, and Hunter color value of yoghurt and also over-run and melting-down of yoghurt ice cream added with rice or puffed rice powder in instead of sugar were investigated. For the pH of yoghurt and ice cream, the control’s was higher than others’. The pH of rice powder and short grain was higher than that of puffed and long rice powders, respectively. Yoghurt acidity was consistent with the pH. Higher viscosity of yoghurt and over-run of ice cream were observed in the puffed rice powder with more gelatinization and the short rice powder with more amylopectin. Yoghurt and ice cream of the long rice powder showed higher viable cell counts than others. Lower Hunter “L” and “a” values of the puffed rice powder may be due to high temperature and pressure. Lower melting-down of higher over-run samples (p<0.05) might be caused by air insulation. Rice powder and puffed rice powder could be a good substitute for table sugar in yoghurt and ice cream production.

팽이버섯 내에 존재하는 GAD 효소를 발효를 통해 활 성화 시켜 MSG를 GABA로의 전환율을 높이고자 하였다. 효과적인 고농도 GABA를 생산하기 위해 나노분말 팽이 버섯에다가 수경재배한 인삼을 첨가하여 야쿠르트발효기 에서 발효한 결과 GABA 전환율은 팽이나노인삼분말 발 효군(88%) > 팽이분말 발효군(52%) > 팽이나노분말 발 효군(44%) 순으로 나타났다. 이러한 결과는 MSG를 기질 로 첨가하는 식품에서 활용할 가치가 있으리라 사료된다.

Quality characteristics were evaluated for whole barley yogurt prepared with lactic acid bacteria combination such as Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. Bulgaricus, and Streptococcus thermophilussei (1:1:1) with the addition of whole barley flour at 3%. The barley yogurt had lower pH, higher titratable acidity, and higher sugar content than control yogurt. The viable cell number of the barley yogurt was lower than the control yogurt. However, the viscosity and antioxidant activity of the barley yogurt were higher than those of the control yogurt. In up to 12 d of storage at 4oC, pH decreased while titratable acidity increased in both control yogurt and barley yogurt. The sugar content and brightness increased slightly. The viable cell number of the barley yogurt decreased during storage. However, the viable cell number of the barley yogurt met the standard suggested by the KFDA. Although the viscosity of the barley yogurt decreased, it corresponded to the required viscosity of a curd yogurt. Antioxidant activity slightly increased up to 9 d and then decreased, but the decrease of antioxidant activity was smaller in barley yogurt than in the control yogurt. During storage, there was no curd separation, change in scent, etc. Thus the storage quality of barley yogurt was relatively good.

The purpose of this study was to evaluate the jujube hot-water extraction and antioxidant. After extraction of hot-water jujube, general composition analysis and functional tests were performed. The results of general composition analysis showed 22.33% of moisture content, 0.71% of crude lipid, 5.21% of crude protein, and 3.87% of ash. From DPPH test results, in concentrations of 1,000 μg/mL of jujube extracts, electron donating ability was shown with 68.24%. The SOD ability in concentrations of 1,000 μg/mL was 13.12%. The nitrite scavenging ability of jujube extracts was 11.79% at 1,000 μg/mL. The yogurt with 0, 1, 2, 3 and 4% of jujube extracts was made, and the general composition analysis and the functional tests were performed. The results of the general composition analysis of jujube yogurt, showed 74.71~76.56% of moisture contents, 1.31~3.38% of crude lipid, 2.13~3.40% of crude protein, and 1.18~1.28% of ash. The DPPH test results showed 46.33% for 1% added jujube extract, 53.78% for 2% added jujube extract, 90.87% for 3% added jujube extract, and 89.58% for 4% added jujube extract. The SOD ability showed 4.93% for 1% added jujube extract, 7.28% for 2% added jujube extract, 11.38% for 3% added jujube extract, and 11.50% for 4% added jujube extract.

본 연구에서는 3%의 통보릿가루를 첨가하여 Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. Bulgaricus와 treptococcus thermophilussei 등 3종의 균주를 단일균 또는 혼합균 조합별로 이용하여 요구르트를 제조하고 젖산균주에 따른 요구르트 품질 특성을 알아보았다. 대조군과 보릿가루 첨가군의 요구르트 품질특성은 균주 종류 및 조합에 따라 유의적인 차이를 나타내었다. 보릿가루 무첨가군인 대조군에서는 LBST 복합균으로 제조한 요구르트가 적정pH, 산도, 점도, 항산화활성 등에서 좋은 특성을 나타내었으며, 다음으로 LALBST 복합균이 좋았다. 보릿가루 첨가군에서는 LALBST가 다른 균주조합에 비하여 낮은 pH, 적합 범위의 적정산도, 높은 항산화활성 등 좋은 요구르트 품질특성을 나타내었으며 β-glucan 함량은 약 0.15%이었다. 대조군과 보릿가루첨가군에서 단독균보다는 복합균이 좋은요구르트 품질특성을 보였고, 보릿가루를 첨가함에 따라 대조군에 비하여 pH는 감소하였고, 적정산도와 당도는 증가하였으며 젖산균수는 감소하였고 점도는 상당한 증가를 보였다. 색도의 경우 L값은 낮았고, a값과 b값은 높았으며 연구결과 LALBST 혼합균주가 보릿가루 첨가 요구르트 제조시 가장 적합한 것으로 판단되었다.

The purpose of this study was to determine the optimal amounts and mixing condition of skim milk powder (A), and roselle (B) for the production of yogurt prepared with roselle. The experiment was designed according to the central composite design for estimating the response surface method, which yielded ten experimental points, including two replicates for the skim milk powder and roselle. The physicochemical and mechanical analysis of each sample, including pH (P<0.001), titratable acidity (P<0.001), color (P<0.05), viscosity (P<0.001), showed significant differences. Antioxidant properties (total phenolic content, DPPH free radical scavenging activity) and viable cell counts of lactic acid were significantly different (P<0.05). The sensory measurements were significantly different in color, flavor, sourness, texture, and overall quality (P<0.05). The optimal formulation, calculated by numerical and graphical methods, was 7.82 g of skim milk powder and 2.09 g of roselle. From findings of this study, the roselle may be used in yogurt and can be applied for other food industries.

본 연구에서는 단백질이 풍부한 원료 콩에 청국장에서 분리한 Bacillus subtilis와 김치에서 분리한 Lactobacillus plantarum을 이용한 혼합 발효를 통해 대두 발효 제품의 개발을 목표로 한 연구결과는 다음과 같은 분석 결과를 얻었다.Bacillus subtilis 단독 배양 발효 두유, Lactobacillus plantarum 단독 배양 발효 두유, 또한 두 균을 혼합 배양한 발효 두유의 항산화 활성을 상호 비교하였다. 그 결과, Bacillus subtilis 단독 배양 발효 두유의 총 폴리페놀 함량, DPPH 라디칼 소거능,환원력, 아질산염 소거능이 각각 3580.91 ㎍/㎖, 67.14%, 6.54㎎/㎖, 83.63%로 가장 높았다.혼합 발효 두유의 기능성을 증진시키기 위하여 토마토 추출물을 첨가하여 발효 두유를 제조하였고, 토마토 에탄올 추출물을 0, 0.25, 0.5, 그리고 1.0% 첨가한 토마토 요구르트의 항산화력은 토마토 첨가량 농도 의존적으로 항산화력이 유의적으로 증가하였다. 특히 DPPH 라디칼 소거능은 토마토 무첨가구는 28.39%인데 비해, 토마토 요구르트는 33.46~57.12%까지 증가하였다.

본 연구에서는 단백질이 풍부한 원료 콩에 청국장에서 분리한 Bacillus subtilis와 김치에서 분리한 Lactobacillus plantarum을 이용한 혼합발효를 통해 대두 발효 제품의 개발을 목표로한 연구결과는 다음과 같은 분석 결과를 얻었다. 우수 균주 선별을 위한 연구로 고초균의 경우 단백질 분해능이 높은 균주를 청국장에서 분리하였고, 유산균의 경우 산도 생성이 높은 균주를 김치에서 분리하였다. 그리고 청국장에서 분리한 균주는 Bacillus subtilis로, 김치에서 분리한 균주는 Lactobacillus plantarum으로 동정되었다. 두유 발효에서 pH는 Lactobacillus plantarum를 이용한 두유 발효와 혼합 배양의 경우가 급격한 낮은 경향을 나타내었고, Bacillus subtilis 단독 배양일 경우가 다른 처리구에 비해 완만한 변화를 보였다. Lactobacillus plantarum을 이용한 두유 발효와 혼합 배양의 경우가 lactic acid의 생성은 배양 8시간 이후에 급격히 증가하였으며, Bacillus subtilis 단독 배양의 경우가 완만하게 증가한 경향을 나타내었으며, 이는 pH 분석에서 나타난 결과와 일치하였다. 두유 요구르트 생육도 측정 결과는 혼합 배양의 경우 단독배양에 비해 증식이 더 우수하였으며, 배양 32시간째 각 처리구별 총 균수는 Lactobacillus plantarum의 경우 1.02×108 cfu/㎖, Bacillus subtilis의 경우 2.12×108 cfu/㎖인데 비해 혼합 배양의 경우는 4.09×108 cfu/㎖로 가장 높았다. α-Amylase의 활성은 Bacillus subtilis 단독 배양과 혼합 배양일 경우는 8시간 이후 효소 활성이 증가되면서 24시간 동안 발효시 22.01 unit/㎖, 8.13 unit/㎖로 가장 높았다. Protease의 경우는 Bacillus subtilis 단독 배양과 혼합 배양일 경우는 8시간 이후 활성이 증가하기 시작하여 발효 32시간째 103.08unit/㎖, 85.84 unit/㎖로 활성이 높게 나타났다, Lactobacillusplantarum 단독 배양일 경우는 가수분해효소 활성이 없는 것으로 나타났다.

The objective of this study was to examine the quality characteristics and antioxidant activity of yogurt containing hot water extract from maca. Four different levels (0, 4, 8, 12%) of maca extract were added to milk followed by fermentation with lactic acid bacteria at 37℃ for 12 hrs, and then the physicochemical properties of the samples were investigated. During 7 days of storage at 4±1℃, the acid production (pH and titratable acidity) of the yogurt increased with the addition of maca extract. The Hunter L value (lightness) decreased, while the b value (yellowness) increased as the maca extract level in the yogurt increased. Viable cell counts were not significantly different among the samples. The results of consumer acceptance tests showed that no significant differences in overall acceptability were observed between the yogurts containing 4% and 8% of maca extract and a control yogurt. The yogurt containing maca extract exhibited higher DPPH radical and superoxide anion radical scavenging activities than the control yogurt over the storage period.

마늘 분말을 첨가한 요구르트의 품질특성 평가를 위하여 탈지분유에 0.1~0.5%(w/v) 마늘 분말을 혼합하고 Streptococcus thermophilus와 Lactobacillus delbrueckii subsp. bulgaricus의 혼합균주를 접종하여 42℃ 에서 24시간 배양하였다. 마늘 분말 첨가량에 따른 유산균의 생육정도, 요구르트의 이화학적 및 관능적 특성 을 검토하였다. 마늘 분말이 첨가된 요구르트의 적정산도는 0.78~0.81%로 마늘 분말이 첨가되지 않은 대조 군(0.73%)보다 높았다. 마늘 분말을 첨가한 요구르트의 생균수는 0.3% 첨가군에서만 상대적으로 낮았고 여 타 실험군은 대조군과 유의적인 차이가 없었다. 마늘분말의 첨가량이 증가함에 따라 요구르트의 점도도 상승 하여 0.5% 마늘 분말이 첨가된 요구르트의 점도가 가장 높았으며, 색도는 대조군과 마늘 분말 첨가 요구르트 사이에 유의적인 차이가 없었다. 관능적 특성을 조사한 결과 마늘 분말의 첨가에 따라 색은 더 높은 선호도를 보였고, 마늘 맛이나 향은 마늘 분말의 첨가량에 비례적으로 증가하였으며, 전반적인 기호도는 0.1%와 0.3% 첨가시는 대조군과 유의차가 없었다. 이상의 결과를 종합하여 볼 때 요구르트 고유의 품질특성이나 유산균의 생육 및 관능적 특성에 영향을 미치지 않는 범위에서 첨가 가능한 마늘 분말의 적정 수준은 0.3% 미만으로 판단된다.

This study was conducted to evaluate the influence of Lactobacillus bulgaricus and/or Sterptococcus thermophilus on the fermentation of yoghurt containing 5% (w/v) buckwheat sprouts. The results revealed that after 12 hours of fermentation the appropriate pH, titratable acidity and number of viable cells were attained. At that time, the rutin content of the buckwheat sprout-added yoghurt prepared by the mixed culture method was not changed, but the quercetin content increased greatly. Conversely, the rutin content of yoghurt that only contained Streptococcus thermophilus was decreased while the quercetin content was increased. The total phenol contents as well as the DPPH radical scavenging activities of both the mixed culture and Streptococcus thermophilus yoghurt did not differ significantly. Taken together, the results revealed that the use of a mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus during the preparation of buchwheat sprout-added yoghurt was desirable due to the decrease in pH and increase in titratable acidity and viable cells that occurred after 12 hr of fermentation. Moreover, phytochemicals in buckwheat sprouts such as rutin, quercetin and phenol compounds were comparatively increased during fermentation and influenced the antioxidant activity in buckwheat sprout-added yoghurt.

본 연구에서는 냉동요구르트 제조 시 trehalose와 sorbitol 첨가가 유산균의 동결변성방지 및 향기성분의 변화에 미치는 영향을 조사하고자 실시하였다. 요구르트를 L. bulgaricus와 S. thermophilus 단독균주 및 혼합균주로 발효시켰을 때 처리구 모두 trehalose와 sorbitol 첨가에 의한 발효과정 중 유산균의 증식효과는 나타나지 않았다. 요구르트를 6주간 냉동저장하는 동안 trehalose와 sorbitol 첨가에 의한 모든 처리구에서 유산균수의 차이가 없었으며, MRS 액상배지에 trehalose와 sorbitol을 각각 2%, 5% 첨가하여 6주간 냉동저장하였을 때는 5% trehalose 처리구의 동결변성방지 효과가 가장 우수한 것으로 나타났다. 냉동저장 기간 동안 고형분 함량이 12%인 처리구와 20%인 처리구의 생균수는 큰 차이가 나타나지 않아 고형분 함량 차이에 의한 trehalose와 sorbitol 효과에는 차이가 없는 결과를 나타내었다. 요구르트의 동결과 해동을 반복하였을 경우 trehalose와 sorbitol 모두 2% 첨가구보다 5% 첨가구가 우수한 동결변성방지 효과를 나타내었다. 전반적으로 Trehalose 첨가구가 sorbitol 첨가구보다 2%, 5% 모두 동결변성방지 효과가 좋은 결과를 나타내었다. Trehalose와 sorbitol을 첨가하여 요구르트를 제조하였을 때 향미성분의 함량은 대조구와 유사하였으며 일반적인 요구르트의 향미를 나타내었다. 냉동저장 중 요구르트 향미성분은 손실되거나, 함량비율의 변화가 발생하지 않았다. 이상의 결과로부터 요구르트의 풍미에는 영향을 미치지 않으면서 냉동저장에 의한 유산균의 동결변성방지제로서의 trehalose첨가가 냉동요구르트의 유산균 안정화에 효과가 있다고 하겠다.

We conducted growth inhibition tests on oral microorganisms using three strains of Lactobacillus spp. which are widely known as their probiotic properties. In these experiments, we measured the number of oral microorganisms after directly contacting lactobacillus with them. In addition, we conducted a similar study using yogurts which are well known as a p robiotic food. I n these yogurts, w e identified t he t ype o f lactobacilli by 1 6s r RN A nucleotide analysis. In o ur study, the growth of most of oral microorganisms were inhibited by lactobacilli, and we also found that yogurts had the highest effectiveness in inhibiting the growth of most of oral microorganisms. The lactobacilli contained in the yogurts were identified as Lactobacillus casei, Lactobacillus paracasei, Lactobacillus helveticus, Lactobacillus casei, and Lactobacillus helveticus