Sensory Properties Of Probiotic Yoghurt Research Articles

Iranian grape syrup used as a prebiotic and its effect on the physicochemical, microbiological, and sensory properties of probiotic yogurt

Yogurt is known as a suitable carrier of probiotics. Its supplementation with Iranian grape syrup used as a prebiotic can enhance its sensory and physicochemical properties, as well as improve the viability and growth of probiotics. Therefore, we aimed to investigate the effect of Iranian grape syrup on stirred probiotic yogurt’s rheological, physicochemical, and microbial properties. Probiotic yogurt samples were fortified with 3, 6, and 9% of Iranian grape syrup and evaluated in terms of pH, acidity, syneresis, viscosity, total phenolic and anthocyanin contents, as well as probiotic bacterial counts during 21 days of storage in a refrigerator at 4°C. The results revealed that increasing concentrations of grape syrup inversely affected the yogurt’s pH, so the lowest and highest pH levels were recorded in the samples with the highest syrup concentration and the control (without syrup), respectively. No general trend was observed in acidity despite significant differences in acidity among the syrup-supplemented yogurts and the control (p ≤ 0.05). Syneresis demonstrated an inverse correlation, while viscosity exhibited a direct relationship, with a grape syrup concentration. Monitoring microbial changes in the samples throughout storage revealed a better growth in microbial colonies in the yogurts with higher grape syrup concentrations. According to consumer preferences and physicochemical qualities, the optimal concentration of Iranian grape syrup was found to be 9%. Supplementing yogurt with grape syrup enhances its probiotic viability and metabolic activity. Considering its positive impact on both consumer preferences and product properties, Iranian grape syrup can be utilized as a prebiotic in future research to develop functional and symbiotic yogurts.

Enhancement structure probiotic yoghurt made from whole milk powder by psyllium husk

Psyllium husk is a bioactive source that provides health benefits and is new best possible use in the dairy industry as a texture enhancer for its hydrochloride properties. The current study focuses on the optimization of a suitable amount of psyllium husk powder (PHP) with whole milk powder (WMP) to produce bioactive probiotic yoghurt and keep it stable during the storage period. The different levels of PHP (0, 0.5, 1.0, and 1.5 % w/w) with WMP were used to prepare the bioactive probiotic yoghurt as a functional food. We made four different mixtures and tested them for their chemical makeup (pH, titratable acidity, moisture, total solids, ash, fat, and protein), colour (L*, a*, b*, and C*), ability to hold water (WHC), and how they tasted after 1, 7, and 14 days at 5°C. The PHP probiotic yoghurt showed a significant decrease (p < 0.05) in pH, protein, and fat. While titratable acidity and ash contents were increased compared with the control. Also, the texture profile, like adhesive and hardiness, had better flow properties and more WHC than the control. Additionally, the color parameter showed an increase in a*, b*, and C* values and a decrease in the L* value. The sensory evaluators preferred the 1% PHP samples. The current study found that samples fortified with 1% PHP improved the physicochemical, texture, and sensory properties of probiotic yoghurt and maintained probiotic yoghurt structure during storage compared with the control. Probiotic yoghurt prepared from PHP has provided new dairy industrial applications.

Physicochemical, functional and sensory properties of probiotic yoghurt flavored with white sapote fruit (Casimiroa edulis).

The online version contains supplementary material available at 10.1007/s13197-022-05393-5.

Bioactivity, Physicochemical and Sensory Properties of Probiotic Yoghurt Made from Whole Milk Powder Reconstituted in Aqueous Fennel Extract

Fermented dairy products have long been associated with positive health benefits. The present study was undertaken to evaluate the physicochemical and sensory properties, viable probiotic counts, antioxidant activity and total phenolic content of probiotic yoghurt made by reconstituting of whole milk powder in aqueous fennel seed extract. Different concentrations of fennel aqueous seeds extract (2%, 4% and 6% w/v) were used as a substitute for water to reconstitute whole milk powder in formulations of yoghurt as functional additives. Interestingly, the use of aqueous extract of fennel seeds in the reconstituted yoghurt milk did not affect yoghurt composition (moisture, protein, fat and ash contents) compared to plain yoghurt. The titratable acidity significantly decreased after using aqueous fennel seed extract in the yogurt manufacture. In this regard, the titratable acidity value was 0.85 in the control yogurt at the fresh period and 1.14 after 21 days of storage, while this value significantly decreased in the yogurt treatments with 2%, 4% and 6% aqueous fennel seed extract to 80, 0.77 and 0.72, respectively, at fresh period and reached 1.03, 0.96 and 0.94, respectively, after 21 days of storage (p < 0.05). Conversely, the pH values significantly increased (p < 0.05) following the addition of aqueous fennel seed extract in the yogurt manufacture. Moreover, the total phenolic content significantly increased (p < 0.05) from 38.60 (mg GAE/L), in fresh plain yogurt, to 44.80, 53.20 and 64.30 (mg GAE/L), in 2% fennel extract yoghurt (FEY2), 4% fennel extract yoghurt (FEY4) and 6% fennel extract yoghurt (FEY6), respectively. Likewise, the antioxidant activity significantly increased (p < 0.05) from 0.11 (mM TE) in fresh plain yogurt to 0.18, 0.26 and 0.32 (mM TE) in (FEY2), (FEY4) and (FEY6), respectively. The survival of Lactobacillus acidophilus, Streptococcus thermophilus and Bifidobacterium bifidum decreased during storage time in all yoghurt treatments, although it stood at recommended levels for health effects (at least 106 cfu/mL in traditional yoghurt). For sensory evaluation, FEY4 was more acceptable, followed by FEY6, FEY2 and PY, respectively. Collectively, the present study provides useful information about the bioactivity, physicochemical and sensory properties of probiotic yoghurt made from whole milk powder reconstituted in aqueous fennel extract.

Influence of red grape pomace powder on physiochemical, antioxidant, nutritional, microbial, and sensory properties of probiotic yoghurt

Yoghurt is a fermented milk that consume all over the world. Yoghurt provide many health benefits. The benefits can be increased if prebiotic and probiotic bacteria included in its formulation. In this study, we investigated the effect of 2 and 4 % grape pomace powder (GPP) on the physiochemical, nutritional, microbial and sensory properties of probiotic yoghurt (contains Lactobacillus acidophilus and Bifidobacterium Bifidum) within the storage period per 7-day intervals (for 28 days). The results revealed that the pH, fat, protein, syneresis and sensory scores of samples decreased with elevation the grape pomace powder (GPP) level and also storage time. Ash, fiber, energy, total flavonoid, antioxidant activity, total phenol and the counting (log cfu/mL) of probiotic microorganisms decreased during storage, but the treatments with higher GPP had higher ash, fiber, energy, total flavonoid, antioxidant activity, total phenol content and probiotic counts. In converse, the acidity and viscosity increased with time storage and increase the GPP level. The probiotic yoghurt supplanted with 4% GPP in 0 day had the highest ash (1.2), fiber (0.75), energy (73.8), total flavonoid (4.9) and antioxidant activity (42.4). The highest viable count at the end of storage period (28 day) were obtained for probiotic yoghurt contains 4% GPP (8.03 log cfu/mL) and the lowest for control (6.2 log cfu/mL). Also the highest organoleptical scores belonged to yoghurt supplemented with 2% GPP at 0 day. The results of this research showed that grape pomace can use in the production of probiotic yogurt as a functional food.

Effect of Ziziphora clinopodioides Essential Oil Stress on Viability of Lactobacillus acidophilus and Bifidobacterium bifidum Microencapsulated with Alginate-Chitosan and Physicochemical and Sensory Properties of Probiotic Yoghurt

BACKGROUND: The probiotics must be alive in sufficient numbers and one of the main stress factors that probiotic strains should tolerate is food preservatives, like herbal essential oils (EOs). To provide a balance between sensory accept-ability and antimicrobial efficacy, the use of sub-lethal concentrations of EOs in combination with other preservation methods has been proposed. OBJECTIVES: The aim of this study was to evaluate the effect of sub-lethal level of Ziziphora clinopodioides essential oil (ZEO) stress on viability of microencapsulated Lactobacillus acidophilus, and Bifidobacterium bifidum, and examine physicochemical and sensory properties of probiotic yoghurt during 28 days of storage. Moreover, the survival of probi-otics was evaluated in gastrointestinal conditions. METHODS: The sub-lethal and lethal levels of ZEO were determined for Lactobacillus acidophilus and Bifidobacterium bifidum. Both probiotics (109 CFU/mL) were exposed to sub-lethal dose of ZEO on MRS broth for about 2 h and then microencapsulated with alginate-chitosan. First, viability of encapsulated probiotics was estimated in simulated gastrointestinal conditions. After preparation of yoghurt, enumeration of free and encapsulated probiotics in yoghurt was done. Finally, physicochemical and sensory properties of probiotic yoghurt were measured. RESULTS: According to the GC-MS, Thymol (41.70%), alpha-terpineol (7.31%) and carvacrol (5.39%) were the most commonly detected components in the ZEO. The lethal doses of ZEO for L. acidophilus and B. bifidum probiotic bacteria were 1750 and 1500 ppm, respectively. Encapsulation and exposure of probiotics to sub-lethal dose of ZEO increased significantly the survival of probiotics in both gastrointestinal conditions and during 28 days of yoghurt storage (p 0.05). On the other hand, syneresis was not significantly different in all samples (p >0.05). The group exposed to ZEO obtained the lowest score for flavor. However, significant differences were observed between the exposed and other groups in the term of flavor, texture and overall acceptability (p <0.05). CONCLUSIONS: Exposure to sublethal concentration of ZEO could be used as a prebiotic in probiotic yoghurt contain-ing probiotics so as to improve the survival and viability of microcapsulated probiotics and enhance some of the physico-chemical and sensory properties.

The effect of microencapsulated extract of pennyroyal (Mentha pulegium. L) on the physicochemical, sensory, and viability of probiotic bacteria in yogurt

In this study, the effect of free and microencapsulated extract of pennyroyal on the viability of Bifidobacterium bifidum and physicochemical and sensory properties of probiotic yogurt were evaluated. For this purpose, pennyroyal extract (PE) was extracted using ultrasound method. The amount of phenolic compounds of PE was 75.64 ± 1.25 mg/g gallic acid and the PE was microencapsulated with maltodextrin-whey protein concentrate. According to the results, the particle size was 100.14 nm, zeta potential was 17.44 mV and microencapsulation efficiency was 60.06%. Then, the antioxidant properties of the PE and nano-PE were determined. The results showed that the both of them had high antioxidant properties and the antioxidant activity of nano-PE was significantly higher than the PE (P < 0.05). In order to evaluate the effect of PE on the properties of probiotic yogurt 5 treatments including control, PE and nano-PE with a concentration of 750 and 1000 ppm, production and physicochemical, antioxidant properties, and viability of probiotic bacteria were evaluated during a 15-day storage period. The results showed that adding the PE to yogurt decreased pH, syneresis, and increased acidity, viscosity, and antioxidant properties of yogurt (P < 0.05). At the end of the storage period, the treatments containing the PE had higher viability of probiotic bacteria than the control treatment (P < 0.05). In most cases, better results were observed in the treatments containing nano-PE and also these treatments had a higher sensory score than the treatments containing the PE (P < 0.05). Overall, the results of this study show that microencapsulated of PE can be used to improve antioxidant capacity, probiotic bacterial viability and the quality of yogurt.

Biochemical, microbiological, and sensory properties of probiotic yogurt made from Iranian native strains compared to commercial strains

This study was performed to evaluate the effects of using native and commercial probiotic strains on biochemical, microbiological, and sensory properties of yogurt. The viability of probiotic bacteria in all samples exceeded 6 log CFU/ml required to provide health benefits. The native Iranian Lactobacillus casei showed the highest viability throughout storage (8.5 log CFU/ml at the end of storage). Three distinct phases were observed in pH, acidity, and redox potential during the fermentation of all samples. Commercial L. casei strain had the lowest mean acidity increase rates and the longest incubation times. The growth of Lactobacillus delbrueckii ssp. Bulgaricus and Streptococcus thermophilus in probiotic yogurt was improved compared to the control yogurt. The control sample had the lowest score in all sensory parameters evaluated. Overall, yogurt containing native Iranian L. casei strain is recommended because of its good sensory and microbial properties. Practical applications Among different functional food products, probiotic dairy products are of great interest and yogurt is the most popular probiotic carrier. In most cases, commercial strains of Lactobacillus and bifidobacteria are incorporated into yogurt and native strains have not been studied widely. In this regard, isolation, characterization, and investigation of the effect of their application in dairy products can be promising in the development of functional dairy products with acceptable qualitative characteristics.

Bioactivity and Sensory Properties of Probiotic Yogurt Fortified with Apple Pomace Flour.

To meet the demand for new functional foods in line with the trend of sustainable development, a novel probiotic yogurt fortified with 1%, 3%, and 5% apple pomace flour (APF) added immediately after inoculation with Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium bifidum was developed. Upon fermentation in the presence of APF, a number of probiotic strains remained within the required range, while the syneresis of enriched yogurts was reduced up to 1.8 times in comparison to the control. Supernatants (i.e., extracted whey) obtained from yogurts with 1%, 3%, and 5% APF respectively had 1.4-, 1.8-, and 2.3-fold higher total phenolic content (TPC) than the control, 3.3-, 4.7-, and 8.0-fold higher radical scavenging (DPPH), and 1.3-, 1.6-, and 1.7-fold higher reducing activity (FRAP). Also, probiotic yogurt supernatants (3% and 5%) inhibited colon cancer cells’ viability (HCT 116, 12% and 17%; SW-620, 13% and 19%, respectively). The highest firmness, cohesiveness, and viscosity index values, and the highest scores for color and taste, were obtained for yogurt with 3% APF, indicating that this is the optimal APF amount for the production of novel yogurt with functional properties.

Effects of pine honey on the physicochemical, microbiological and sensory properties of probiotic yoghurt

Abstract In this study, physicochemical, microbiological and sensory properties of probiotic yoghurt samples added different rates (2%, 4% and 6%) of pine honey on days 1, 7, 14, 21 of refrigerated storage were investigated. pH, serum separation values, water holding capacity decreased and titratable acidity increased with increasing the ratio of the added honey during the storage. Lactobacillus. delbrueckii ssp. bulgaricus and Lactobacillus acidophilus counts were statistically significantly (P<0.01) lower than control samples in honey added yoghurt samples from the beginning to the end of storage. Streptococcus thermophilus counts did not change much during storage and were higher than control samples in yoghurt samples with honey from the beginning. The brightness (L*) decreased with increasing honey ratio. The a * and b * values of all honey-added yoghurt samples were higher than those without honey. Although yoghurt with 2% pine honey had the same points as the yoghurt with 4% pine honey in terms of some sensory properties, it was the most liked yoghurt. For people who do not like to consume plain yoghurt, honey added yogurt can be a good alternative functional food. Producers should produce formulations for this type of yogurt and the consumption of yogurt should be increased.

Bioactive properties of probiotic set-yogurt supplemented with Siraitia grosvenorii fruit extract

Siraitia grosvenorii fruit (SGF) has been used as a natural sweetener and traditional medicine in China for more than two centuries. This study evaluated the effect of SGF extract supplementation (0.5%, 1%, and 2%) on the chemical, microbial and sensory properties of probiotic yogurt. The antioxidant, angiotensin-converting-enzyme inhibitory (ACE-I) and antibacterial bioactivities were determined. SGF extract supplementation improved some of the chemical and physicochemical characteristics. Probiotic yogurt with the fruit extract had significantly more Lactobacillus casei and Lactobacillus bulgaricus, whereas there was no significant effect on the number of Streptococcus thermophiles. The bioactivities were significantly increased by SGF extract supplementation. Probiotic yogurt with 2% SGF extract showed the highest antioxidant, ACE-I, and antibacterial activities, whereas the one with 1% SGF extract conferred the highest sensory attributes score. Overall, SGF extract offers a promising option as a dietary supplement to produce novel dairy products that have high nutritional and bioactivity values.

Effects of Apricot Fibre on the Physicochemical Characteristics, the Sensory Properties and Bacterial Viability of Nonfat Probiotic Yoghurts.

In this study, the physical, chemical, rheological, and microbiological characteristics and the sensory properties of nonfat probiotic yoghurt produced at two different concentrations of apricot fibre (1% and 2%, w/v) and three different types of probiotic culture (Lactobacillus (L.) acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12), and their mixtures) were investigated. As the fibre content increased, the rheological, structural, and sensory properties of probiotic yoghurt were negatively affected, while counts of L. delbrueckii subsp. bulgaricus, L. acidophilus LA-5, and Bifidobacterium BB-12 increased. When all the results were evaluated, the best results were obtained by using L. acidophilus LA-5 as probiotic culture and adding 1% (w/v) apricot fibre.

Antioxidant, physicochemical, microbiological, and sensory properties of probiotic yoghurt incorporated with various Annona species pulp

In this study, antioxidant, chemical, microbiological, and sensory attributes changes taking place during the production of probiotic yoghurt using pulp of soursop (Annona muricata), sweetsop (Annona squamosa), and custard apple (Annona reticulata) were evaluated. The products were stored at 4 °C for 28 d, during which time physicochemical properties and viability of probiotic bacteria and yoghurt starter cultures were evaluated weekly. Yoghurts prepared with fruit pulps displayed higher antioxidant activities on the first day of storage compared to the control. During the storage, the addition of fruit pulps influenced (p < 0.05) pH, titratable acidity, syneresis and counts of B. animalis ssp. lactis BB-12 of yoghurts, whereas counts of Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus were found to be insignificant. Sensory evaluation results showed that yoghurt containing soursop fruit pulp had better sensory scores than other treatments. Therefore, these results proved that soursop can be used to produce probiotic yoghurt with enhanced physicochemical, microbiological and sensory properties.

Investigating the effect of aqueous extracts of basil and savory on antioxidant activity, microbial and sensory properties of probiotic yogurt

The low viability of probiotics causes the short shelf life of fermented products. Therefore compounds which prolong the viability of probiotic bacteria can increase or at least maintain the health- benefiting properties of these products. On the other hand, the addition of antioxidants is one of the methods to increase the shelf life of food products which has recently become more prevalent. In this respect, herbal extracts which are a good source of antioxidants can be appropriate alternative. The aim of this study was to evaluate the effect of adding basil and savory extracts on antioxidant activity, and on the microbial and organoleptic characteristics of probiotic yogurt. The effect of adding basil extract (8% and 10%) and savory extract (6% and 8%) separately to low fat yogurt (1.5% fat) containing Lactobacillus paracasei subsp. paracasei was investigated. The samples were stored at 4°C. The viability of Lactobacillus paracasei subsp. paracasei, antioxidant activ- ity and sensory properties of probiotic yogurt were evaluated on the 1st, 7th, 14th and 21st days. Basil and savory extracts significantly increased the viability of probiotic bacteria (p < 0.05). Dur- ing storage, probiotic counts markedly decreased (p < 0.05) in comparison to the control sample. The addi- tion of herbal extracts significantly increased antioxidant activity, but this activity decreased during storage (p < 0.05). The scores for taste, odor, color and overall acceptance decreased as herbal extracts increased, but there was no significant difference between the test samples and control sample in terms of the texture score (p > 0.05). During storage, there was no significant difference between the organoleptic scores of the samples (p > 0.05), but the taste score did increase significantly (p < 0.05). It can be concluded that adding herbal extracts had a positive effect on the viability of probiotics and antioxidant activity of probiotic yogurt.

Investigating the effect of aqueous extracts of basil and savory on antioxidant activity, microbial and sensory properties of probiotic yogurt [pdf

Investigating the effect of aqueous extracts of basil and savory on antioxidant activity, microbial and sensory properties of probiotic yogurt [pdf

Effect of green banana pulp on physicochemical and sensory properties of probiotic yoghurt

In order to investigate the potential of the green banana as a prebiotic, and for its content of resistant starch, fermented yogurts were produced by cultures composed of Lactobacillus delbrueckii, Streptococcus thermophilus, Bifidobacterium bifidum and Lactobacillus acidophilus as well as being enriched with three concentrations of industrialized green banana pulp (GBP) (3%, 5% and 10% w/v). The green banana pulp added to the yogurt stimulated the multiplication of L. acidophilus after the first day of fermentation and B. bifidum after seven days in cold storage compared to the control that consisted of yogurt without the addition of green banana pulp. The dose-response effect was not observed; however, the results show that the green banana pulp has a prebiotic potential without interfering with either the physicochemical or sensorial characteristics.

The Effect of Stevia rebaudiana on the Growth and Survival of Lactobacillus rhamnosus GR-1 and Sensory Properties of Probiotic Yogurt

&lt;span style="font-family: Times New Roman; font-size: small;"&gt;&lt;/span&gt;&lt;strong&gt;&lt;span style="font-family: &amp;quot;Times New Roman&amp;quot;,&amp;quot;serif&amp;quot;; font-size: 10pt;" lang="EN-US"&gt;&lt;/span&gt;&lt;/strong&gt;This study evaluated the effect of various sweetening agents on sensory properties of probiotic yogurt. The growth and survival of &lt;em&gt;Lactobacillus rhamnosus&lt;/em&gt;&lt;em&gt; &lt;/em&gt;GR-1 in yogurt was measured at 1, 14 and 28 days of storage. Bacterial growth reached a range of 10&lt;sup&gt;8&lt;/sup&gt;-10&lt;sup&gt;9&lt;/sup&gt; Colony Forming Units (CFU) ml&lt;sup&gt;-1&lt;/sup&gt; over the storage period for six probiotic yogurt samples (0.12% stevia, 0.12% stevia-inulin-chromium (SIC), 1.0% sucralose, 5.0% sucrose, 6.0% xylitol and a control). Sensory panelists (n = 109) used a 9-point hedonic scale and evaluated five sensory characteristics (flavour, appearance, sweetness, texture, and overall quality) of the four sweetened probiotic yogurts (0.12% stevia, 0.12% SIC, 1.0% sucralose and 5.0% sucrose). The sucralose sample was significantly preferred for all five characteristics (P &amp;lt; 0.001) and the sucrose sample was significantly liked more than both the stevia and SIC samples for all characteristics except flavour (P &amp;lt; 0.001). Overall, the stevia sample received higher mean scores than the SIC sample.&lt;span style="font-family: Times New Roman; font-size: small;"&gt; &lt;/span&gt;

Sensory properties of probiotic yogurt is comparable to standard yogurt

Consumers are becoming more interested in incorporating healthy foods into their diet. Both Lactobacillus reuteri RC-14 and Lactobacillus rhamnosus GR-1 are probiotic agents with proven therapeutic properties. Dairy products such as yogurt are a good vehicle to transfer these beneficial microorganisms to consumers; however, to date, little work has been done on measuring the acceptability of probiotic dairy products compared with regular yogurt. Consumer taste panels were conducted to evaluate and compare the sensory properties of probiotic and standard yogurt. The results showed that the appearance, flavor, texture, and overall quality of probiotic 1% fat yogurt were comparable and similar to standard 1% fat yogurt (control). The standard yogurt with higher fat content (3.25%) was rated better ( P < .05) than the low-fat yogurts. These findings indicate acceptability of probiotic yogurt containing L rhamnosus GR-1 and L reuteri RC-14 among consumers.