• Food Science of Animal Resources
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• v.35 no.6
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• pp.807-814
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• 2015

This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h. The total polyphenol and anthocyanin content of FDMJ yogurt was higher than that of control due to the presence of phytochemical contents in mulberry. Moreover, antioxidant activity such as DPPH and reducing power was highest 5% FDMJ yogurt. During cold storage, pH decreased or remained constant in all yogurts with values ranging from 4.08 to 4.78 units. In sensory evaluation, the score of 1% FDMJ yogurt was ranked higher when compared with other yogurts. It is proposed that mulberry fruit juice powder can be used to improve sensory evaluation and enhance functionality of yogurt.

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.63-68
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• 1993

The healthy yogurt containing pumpkin was developed and evaluated an antioxidant effect of pumpkin in yogurt during storage. For the preparation of pumpkin yogurts, 15, 20 or 25 g of pumpkin level. and 5, 6 or 7 g of sugar level were added to 100 ml milk. There was a trend for more desirable color and texture of pumpkin yogurt at 20 g pumpkin level than 15 or 25 g pumpkin level. Pumpkin yogurt contained 7 g sugar level had a more desirable flavor, texture and overall accetability than those contained 5 or 6 g sugar level. To evaluate antioxidant effect of pumkin in yogurt during stroage, yogurts were prepared by milk alone, with pumpkin, with sugar, and with sugar and pumpkin. The sugar and pumpkin levels in yogurt were 7 g and 20 g per 100 ml milk. The malondialdehyde(MDA) content of yogurt prepared by milk alone were significandy affected by days of storage. During 13 days storage of yogurt, pumpkin and sugar exhibited antioxidant effect.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.289-295
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• 2009

To develop a safer yogurt for immuno-compromised or allergy patients and to extend shelf-life, a plain yogurt was irradiated with doses of 0, 1, 3, 5, and 10 kGy using a gamma ray and the chemical and microbiological quality and allergenicity change were investigated. There was no difference in the content of protein, total solid, and amino acids of the plain yogurt by irradiation treatment and different storage temperatures (4, 20, and $35^{\circ}C$). The lactic acid bacterial counts of irradiated plain yogurt had approximately 3-decimal reduction at 3 kGy, and no viable cell at 10 kGy regardless of storage time and temperature. The binding ability of rabbit antiserum to milk proteins in irradiated plain yogurt showed that 10 kGy of irradiation produced significantly higher binding ability than other treatments. Sensory evaluation indicated that only appearance of the plain yogurt irradiated at 3 kGy or higher had a lower value than the non-irradiated control when stored at $20^{\circ}C$. Results suggest that irradiation of plain yogurt does not significantly affect the chemical and sensory quality of plain yogurt, but can extend the shelf-life, possibly reduce allergenicity, and provide a safer product.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.363-368
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• 2013

The main attributes of yogurt that affect consumer satisfaction are taste, consistency, and a firm texture. This study evaluates the influence of xanthan gum, barley beta-glucan, and guar gum in concentrations of 0.05%, 0.1%, 0.2%, and 0.3% on probiotic yogurt. The set-type yogurt samples were prepared by using raw cow's milk. The statistical analysis showed that none of these gum additions had any marked effect on pH, titratable acidity, total solids content, and probiotic bacteria counts of yogurt samples. Evaluations for syneresis and water-holding capacity (WHC) in the yogurt samples were affected by the type and concentration of the stabilizer. Yogurts treated with 0.1% xanthan gum and 0.3% beta-glucan recorded the highest WHC and the least syneresis. The largest amount of gel firmness was recorded in yogurt samples treated with 0.2% xanthan gum and 0.3% beta-glucan. Yogurt samples treated with 0.1% xanthan gum and 0.3% beta-glucan were considered acceptable by trained panelists and gained the highest scores in sensory evaluations. The correlation coefficient between the amount of syneresis, WHC and stiffness of texture was significant compared to scores for sensory evaluation (p<0.01). Results for effects of guar gum on the tested parameters were contrary to the results expected from a gum. According to this study, the use of xanthan gum and beta-glucan are highly recommended for low-fat yogurt production.

• Korean journal of food and cookery science
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• v.24 no.1
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• pp.59-67
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• 2008

In an effort to make a functional and stable yogurt, this study investigated the improvement effects of sea tangle extract and sea tangle yogurt on intestinal function. The intestinal improvement effect of the extract was measured by the charcoal meal transit method, employing Balb/C mice. And constipation relief was compared utilizing the loperamide-induced constipation method, employing SD rats. Charcoal meal transit was remarkably increased in the mice receiving sea tangle extract as compared to the controls. The constipation relief effects of the sea tangle and sea tangle yogurt were evaluated by measuring fecal amounts in the rats after adding them to water. The fecal contents increased remarkably in the sea tangle administered rat groups as compared to the control group. In addition, different yogurt samples were used to evaluate the characteristics of the sea tangle yogurt. During storage, pH slightly decreased in the yogurt with sea tangle as well as without. At the same time, acidity slowly increased as the storage duration increased. As time elapsed, the amounts of viable cells increased in both yogurts (with and without sea tangle). In the sensory evaluation, significant differences were shown between the sea tangle yogurt and the control for color, flavor, sweetness, and overall quality. Overall, based on the combined results of the intestinal function effects and sensory evaluation, the 0.25% sea tangle yogurt proved to be superior.

• Korean journal of food and cookery science
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• v.24 no.2
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• pp.212-221
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• 2008

This study was performed in an effort to create a functional and stable yogurt product containing slander glasswort extract. The extract was added to milk at concentrations of 0.25, 0.5, and 1.0% (w/v), which was then fermented with lactic acid bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus) at $42^{\circ}C$ for 6 hr. During a period of 15 days of storage, the quality characteristics of the yogurt samples were evaluated in terms of acid production (pH and titratable acidity), levels of lactic acid bacteria, color values, viscosity, and sensory characteristics. There were no significant differences in pH during the storage period; however, the control yogurt presented the highest pH value. The 1.0% slander glasswort yogurt had the highest titratable acidity; but again, there were no significant differences among the yogurts. The 1.0% slander glasswort yogurt also had the highest level of lactic acid bacteria, and both the control and slander glasswort-containing yogurts had increasing levels of lactic acid bacteria over the storage period. The 1.0% slander glasswort yogurt had the lowest L-value and highest a- and b-values. And the slander glasswort yogurts presented lower viscosity values than the control. In sensory evaluations, the 0.25% slander glasswort yogurt scored higher than the other groups for color, flavor, viscosity, sweetness, sourness, and overall palatability. The final sensory results indicated that the 0.25% slander glasswort yogurt was superior.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.24-30
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• 2013

This study was conducted to compare the physicochemical and sensory properties of yogurt added with nanopowdered ginseng (NPG) and powdered ginseng (PG) of different concentrations (0.1, 0.3, 0.5, and 0.7%) (w/v) during the storage at $7^{\circ}C$ for 20 d. The pH and viscosity values of yogurt added NPG or PG decreased during the storage. The pH values of the yogurt samples were ranged from 4.0 to 4.6 as a reflective of the fresh state. Viscosity values of yogurt with NPG at lower concentrations 0.1 and 0.3% (w/v) showed higher values during increased storage time. DPPH radical scavenging activity was significantly higher in the NPG-added yogurt than in the PG during the storage period (p<0.05). The lactic acid bacteria (LAB) counts ranged from $3.0{\times}10^9$ to $1.3{\times}10^9$ and $2.2{\times}10^9$ to $1.1{\times}10^9CFU/mL$ in 0.3% NPG and PG-added yogurts, respectively. Increased storage period showed decrease in LAB counts irrespective of the type of ginseng powder and storage period. In sensory test, 0.1 and 0.3% NPG-added yogurt showed similar results to control in yellowness, viscosity, and bitterness. Based on the data obtained from the present study, it was concluded that the concentrations 0.1 and 0.3% (w/v) of NPG could be used to produce NPG-added yogurt without significant adverse effects on physicochemical and sensory properties, and enhance functional value of yogurt.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.792-803
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• 2019

The supplementation with natural ingredients that are rich in polyphenols could improve the quality and functionality of yogurt. Lotus leaf (LL) are abundant in phenolic compounds. We aimed to investigate the effects of LL powder on the quality properties, total phenolic content (TPC), and antioxidant activity of yogurt. Yogurt was supplemented with four different concentrations (0%, 0.2%, 0.5%, and 1%) of LL powder and evaluated for 14 d refrigerated storage. During storage, the titratable acidity (TA) of all LL yogurt groups was higher than that of the control (p<0.05). The $L^*$ and $a^*$ values decreased by LL addition to the yogurts, while the $b^*$ values increased. All LL yogurt groups indicated better viscosity than that of control, and among them, 0.2% LL yogurts had the highest viscosity without significant decrease until the end of the storage duration. The addition of LL into yogurt enhanced the water-holding capacity (WHC) by at least 1.5-fold than that of control for the entire storage duration. The TPC of yogurts gradually increased with the addition of LL (p<0.05) and continued to increase during storage; the 1% LL yogurt at 14 d showed the highest value of $61.94{\pm}1.68{\mu}g$ GAE/g. The DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and reducing power of the yogurts were also significantly enhanced with increasing LL concentrations (p<0.05). These results suggest that lotus leaf may be useful as a natural ingredient for improving the quality and antioxidant activity of yogurt.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.324-331
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• 2022

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.

• Journal of the Korean Society of Food Culture
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• v.21 no.2
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• pp.179-186
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• 2006

To investigate the production of yogurt added with desalted bamboo shoots, the component analysis was conducted. Desalted bamboo shoots contained 82.59 % of moisture, 4.56 % of protein, 0.52 % of lipid, 0.50 % of ash and 11.72 % of total dietary fiber. The main mineral elements were Ca, P, S, Na, Mg and K. Yogurt base fermented with 0.005 % ABT-5 starter inoculum at $40\;^{\circ}C$ for 13 hr. For the preparation of bamboo shoots yogurt, various sugaring bamboo shoots were added to the yogurt base. Results of sensory evaluation of the yogurt containing bamboo shoots indicated that color, odor, taste, flesh size, flesh amount, mouth feel, and overall acceptability of the 15 %(w/v) bamboo shoots dicing $(5{\times}5{\times}5\;mm)$ showed higher preference than others. When bamboo shoot yogurt was kept at $4\;^{\circ}C$ for 15 days, pH, titratable acidity, viable counts of lactic acid bacteria and Bifidobacterium bifidum of yogurt were not changed.