This research paper delves into the effects of noni juice concentration, fermentation temperature, and incubation time on the physicochemical and sensory properties of noni juice-fortified yogurt. The study found that increasing the concentration of noni juice leads to higher acidity in the yogurt, resulting in a decrease in pH, total soluble solids content, and syneresis. The optimal concentration for achieving the desired physical and sensory qualities is 3%. Incubation time and temperature were also found to significantly influence the yogurt’s pH, acidity, total soluble solids content, and syneresis, with higher incubation time and temperature consistently producing higher-quality yogurt. The best incubation time and temperature for noni juice-fortified yogurt were determined to be 10 h at 42oC. Therefore, the research suggests that adding 3% Bestone noni juice and incubating for 10 h at 42oC using the starter culture powder Yogourmet can lead to the production of consistently high-quality noni juice-fortified yogurt, which is of significant relevance and importance to the dairy and fermentation industries.

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.

This study was conducted to investigate the effects of sugars and stabilizers on the qualitative properties of frozen-yogurt. To prepare the yogurt mix, market milk was fermented using a commercial starter culture and sugars, trehalose and sucrose, and to prepare the ice cream mix, stabilizers, carboxy methyl cellulose (CMC) and guar gum, were used. The yogurt and ice cream preparations were mixed in a 1:1 (v/v) ratio to produce frozen-yogurt. Yogurt prepared using trehalose showed a significantly faster increase in pH, titratable acidity, and viable cell count than that prepared using sucrose (p<0.05). Ice cream prepared using guar gum showed a significantly higher viscosity and overrun than the CMC-stabilized preparation (p<0.05). Frozen-yogurt produced using the yogurt-trehalose mix and ice cream-CMC mix showed the highest hardness and lowest overrun. The melt-down rate of frozen-yogurt prepared with the yogurt-trehalose mix was significantly slow (p<0.05). However, there were no significant differences among the yogurt mixes in terms of changes in the viable cell count at 0, 7, 15, 30, and 45 days (p>0.05). In a sensory evaluation, most panels preferred the frozen-yogurt with sucrose over that with trehalose. However, it is expected that using trehalose with other sugar substitutions and guar gums in manufacture of frozen-yogurt have high potentiality than using sucrose and CMC, and it is considered that it could reignite the stagnant domestic milk processing industry.

Recently, many studies have shown that propolis has diverse health beneficial effects such as anti-cancer, anti-bacterial, anti-inflammation, and anti-oxidant activities. Water-insolubility of propolis has made it extremely difficult in manufacturing health beneficial beverages containing propolis. In this study, the solubility of propolis was dramatically improved by entrapping with beta-cyclodextrin and the prebiotics effect of water-soluble propolis on the yogurt fermentation was investigated. Lactobacillus pentosus SC60 was selected as a starter for the yogurt fermentation due to its high DPPH radical scavenging activity. Low-fat milk which was supplemented with different concentrations of propolis (0.01, 0.05, 0.1, or 0.5% (w/v)) was fermented with L. pentosus SC60 for 30 h and the viable cell number, pH, and titratable acidity were checked. The rates of decrease in pH and increase in titratable acidity of yogurt after 12 h of fermentation were the highest when 0.5% (w/v) propolis were supplemented. Meanwhile pH and titratable acidity of yogurt without propolis reached 4.54 and 0.73%, respectively, most slowly after 30 hoffer mentation when compared with other yogurts supple mented with propolis. The viable cell number of L. pentosus SC60 in yogurt with 0.5% (w/v) propolis increased with highest rate and it exceeded 9 log CFU/mL at 8 h of fermentation, but that of yogurt with no propolis was only 8.54 log CFU/mL at 30 h of fermentation. This results showed that L. pentosus SC60 grew very well in the presence of water-soluble propolis and it is proposed that propolis acts as prebiotics