Yogurt Flavor Research Articles

Bioactive compounds in yogurt obtained from Alpine goats fed with seagrass debris

The use of alternative feeds in dairy goat farming in the Mediterranean region could be a very promising solution to ensure the sustainability of this activity. These feeds can not only reduce production costs, but also improve product quality and market value. The objective of this study is to compare the quality of yogurt obtained from milk of dairy goats fed with oat hay (group C) or Posidonia oceanica seagrass debris (group E). Results showed that yogurt samples from group E had higher fat content and viscosity (P < 0.05) than the control group, whereas protein and lactose levels, as well as pH and acidity, were similar for both batches. A significant richness (P < 0.05) in total polyphenols, flavonoids, antioxidant agents DPPH, ABTS and ferric reducing antioxidant power, was observed in yogurt samples of group E. No differences were observed for total lactic microflora and L. delbrueckii subsp. Bulgaricus counts, but a significant increase of S. thermophilus count was detected (P < 0.05) when goats were fed Posidonia oceanica. The sensory analysis showed that yogurt from group E had a significant improved quality, which was reflected by higher scores for odor, flavor, texture and overall acceptability than group C. These findings reveal the positive role of feeding Posidonia oceanica to dairy goats and the remarkable improvements it has made to the nutritional properties and flavor of yogurt.

Stability and flavor of set yogurt fortified with Tremella fuciformis polysaccharide during cold storage

Tremella fuciformis is an edible and medicinal fungus containing excellent nutritional value. T. fuciformis polysaccharide (TFP) is the important bioactive ingredients of T. fuciformis, which has gained great attention. The aim of this study was to investigate the effect of TFP on the stability and flavor of set yogurt. Our results revealed that the addition of 0.1% TFP had a positive effect on improving the stability of set yogurt including the water holding capacity, texture, rheological properties and microstructure at the cold storage period of 1, 7, 14 and 21 days. It is remarkable that the hardness, gumminess and chewiness of the set yogurt were significantly improved by the addition of TFP during the cold storage. Moreover, the set yogurt containing TFP was able to maintain better stability in the three intervals thixotropy test. In particular, the addition of 0.1% TFP had no adverse effects on the flavor of set yogurt, including sourness, sweetness, umami, bitterness, richness and saltiness. These data suggested that TFP can be used as a natural potential stabilizer for the set yogurt.

Brown goat yogurt: Metabolomics, peptidomics, and sensory changes during production

Brown goat milk products have gained popularity for their unique taste and flavor. The emergence of chain-reversal phenomenon makes the design and development of goat milk products gradually tend to a consumer-oriented model. However, the precise mechanism of how browning and fermentation process causes characteristics is not clear. In an effort to understand how the treatments potentially lead to certain metabolite profile changes in goat milk, comprehensive, quantitative metabolomics and peptidomics analysis of goat milk samples after browning and fermentation were undertaken. An intelligent hybrid z-score standardization-principal components algorithm-multimodal denoizing autoencoder was used for feature fusion and hidden layer fusion in high-dimensional variable space. The fermentation process significantly improved the flavor of brown goat yogurt through the tricarboxylic acid-urea-glycolysis composite pathway. Bitter peptides HPFLEWAR, PPGLPDKY, and PPPPPKK have strong interactions with both putative dipeptidyl peptidase IV and angiotensin-converting enzyme, proving that brown goat yogurt can be considered as effective provider of potential putative dipeptidyl peptidase IV and angiotensin-converting enzyme inhibitors. The level of health-promoting bioactive components and sensory contributed to consumer selection. The proposed multimodal data integrative analysis platform was applicable to explain the effect of the dynamic changes of metabolites and peptides on consumer preferences.

Analysis of Icons, Indexes, and Symbols in YouTube Advertisement of SilverQueen Very Berry Yoghurt

Advertising as a material for semiotic study, this article describes the signs found in SilverQueen chocolate advertisements for the very berry yogurt flavor variant on YouTube and also the meaning of the signs between the signifier and signified based on the object. This study aims to find out signifiers and signifieds, find out the meaning contained in SilverQueen chocolate advertisements with very berry yogurt flavors on YouTube, such as how semiotics looks at the meaning of messages in advertisements. The method used in this study uses qualitative analysis methods. With this method, researchers can study and examine the meaning contained in a sign based on the information obtained by researchers, such as video footage in advertisements depicting messages for consumers, creating recognizable products with the intention of attracting consumer interest in the form of names, packaging, logo, price, and the power of image visualization.

Effects of perilla seed oil addition on the physicochemical properties, sensory, and volatile compounds of potato blueberry flavored yogurt and its shelf-life prediction

Fortifying yogurt with blueberries, potatoes, and Perilla seed oil (PO) can enhance the yogurt's nutritional and health-promoting effects. This study aimed to evaluate the development of volatile compounds, physicochemical quality, amino acids, and shelf life of flavored yogurt supplemented with PO. Results revealed that adding PO changed yogurt's flavor composition and free amino acid content. The essential free amino acid of yogurt increased 0.346 times by adding PO. Moreover, PO addition revealed significant differences (P < 0.05) in sensory scores, fat, acidity, color, syneresis, total viable counts, and Bifidobacterium animalis subsp. Lactis BZ11. PO promoted the growth of strain BZ11 but did not affect the growth of LB12 and Q-1. The number of viable Bifidobacterium BZ11 increased 0.89 times by adding PO. Conversely, the differences were insignificant for the rest (pH, protein, total sugar). Furthermore, the flavored-yogurt samples were stored at different temperatures (5–25 °C) and evaluated by pH, titratable acidity, microorganism, and sensory analysis. Accordingly, we established efficient prediction models based on pH, and the sensory score at 5 °C, which were A=A0e−0.00320t and A=A0e−0.00482t, respectively. The data from this study supported the potential industrial application and shelf-life prediction of PO application in yogurt.

Copper inhibits postacidification of yogurt and affects its flavor: A study based on the Cop operon

Yogurt and its related products are popular worldwide. During transportation and storage, Lactobacillus delbrueckii ssp. bulgaricus in yogurt continues to metabolize to form lactic acid, the postacidification phenomenon of yogurt. Postacidification of yogurt is a widespread phenomenon in the dairy industry. Many scholars have done research on controlling the postacidification process, but few report on the molecular mechanisms involved. In this study, we used a molecular-assisted approach to screen food additives that can inhibit postacidification and analyzed its effects on yogurt quality as well as its regulatory mechanism from multi-omics perspectives in combination. The copper ion was found to upregulate the expression of the LDB_RS05285 gene, and the copper transporter-related genes were regulated by copper. Based on the metabolic-level analysis, copper was found to promote lactose hydrolysis, accumulate a large amount of glucose and galactose, inhibit the conversion of glucose to lactic acid, and reduce the production of lactic acid. The significantly greater abundance of l-isoleucine and l-phenylalanine increased the abundance of 3-methylbutyraldehyde (∼1.2 times) and benzaldehyde (∼7.9 times) to different degrees, which contributed to the formation of the overall flavor of yogurt. Copper not only stabilizes the acidity of yogurt, but also it improves the flavor of yogurt. Through this established method involving quantitative and correlation analyses at the transcriptional and metabolic levels, this study provides guidance for the research and development of food additives that inhibit postacidification of yogurt and provide a reference for studying the changes of metabolites during storage of yogurt.

Comparative studies on the nutritional and physicochemical properties of yoghurts from cows', goats', and camels' milk powder

To clarify the overall quality differences among cows', goats', and camels' milk powder fermented yoghurts, this study evaluated the physical and chemical properties of cow milk yoghurt, goat milk yoghurt, and camel milk yoghurt, and then compared the main components and amino acid composition, volatile aroma components, texture profile analysis, and rheological characteristics. Results showed that cow milk yoghurt had the best structural stability; goat milk yoghurt had the most abundant fat content (4.15 ± 0.40 g 100 g−1) and volatile aroma components, but the relative content of acids was the highest, which is not favourable to the flavour of goat milk yoghurt. Camel milk yoghurt had the highest antioxidant activity, cysteine (0.15 ± 0.05 mg g−1) and protein content (3.69 ± 0.14 g 100 g−1), and lowest lactose content (4.37 ± 0.01 g 100 g−1). The research showed differences in the quality of yoghurts from three different animal sources and will help increase our knowledge of specialty dairy products.

QUALITY COMPARISON BETWEEN YOGHURTS PREPARED WITH INFUSION OF LACTOBACILLUS SPS. AGAINST COMMERCIALLY AVAILABLE YOGHURT

In the present study, physicochemical characteristics of prepared flavoured yoghurt in comparison with the market yoghurt after storage at 5°C for 7 days was studied. More specifically, morphological and biochemical tests were performed for identification of probiotic Lactobacillus acidophilus and Lactobacillus bulgaricus isolated from curd. Furthermore, two different types of yoghurts were produced using the probiotic bacteria Lactobacillus acidophilus and Lactobacillus bulgaricus in combination with 15% w/v strawberry pulp. During storage of yoghurts, several physicochemical characteristics were monitored such as pH, fat, carbohydrate, protein, total solids and moisture content along with antioxidant property and shelf-life and compared with the commercially available strawberry flavoured yoghurt infused with Streptococcus thermophilus and Lactobacillus bulgaricus. The pH value of the yoghurt prepared was slightly less acidic than the market yoghurt and had more moisture and protein content and less total solids. No such differences were observed in shelf-life of both yoghurts (prepared and marketed). The carbohydrate evaluation of the produced yoghurt revealed the superiority of yoghurt for diabetic population with high antioxidant concentration.

Fortification of stirred yoghurt with mucilage-free flaxseed and its physicochemical, microbial, textural and sensory properties

Flaxseed is an excellent source of fibre, protein, and omega-3 fatty acids. Studies have shown its effectiveness in improving yoghurt texture; however, it has adverse effects on sensory properties. This study investigated the prospect of substituting flaxseed powder in its non-mucilage form to produce tasty functional stirred yoghurt. Four yoghurt groups were produced without stabiliser or with (at 3%, w/w) commercial stabiliser, mucilage-free flaxseed powder, or whole flaxseed powder. Microbial, chemical, physical, and sensory properties of samples were analysed weekly during 21 days of storage at 4 °C. Replacing the flaxseed powder with its mucilage-free form can preserve the physicochemical properties and prevent adverse changes in yoghurt flavour usually caused by flaxseed. It can also improve fatty acid profile (increasing polyunsaturated fatty acids, reducing the saturated fatty acids and ω6/ω3 ratio) of yoghurt. Using 3% mucilage-free flaxseed powder is suggested to enhance overall quality and nutritional value of yoghurt.

Physicochemical properties, sensory characteristics, and antioxidant activity of the goat milk yogurt probiotic Pediococcus acidilactici BK01 on the addition of red ginger (Zingiber officinale var. rubrum rhizoma).

Background and Aim:Yogurt contains beneficial probiotics. Addition of red ginger to yogurt as an antioxidant source becomes a way to improve the flavor and functional properties of yogurt. This study aimed to examine yogurt processing and the effect of adding red ginger (Zingiber officinale var. rubrum rhizoma), as an antioxidant source, on Pediococcus acidilactici BK01. It sought to observe the physicochemical and sensory qualities during storage (4°C).Materials and Methods:Goat milk was obtained from local farmers in Lubuk Minturun, Padang, West Sumatra, Indonesia. The yogurt was divided into two factors. Factor A was supplemented with red ginger in various concentrations: A (0% – as control), B (1%), C (2%), and D (3%). On the other hand, Factor B was subjected to variations in storage time: A (1 day), B (15 days), and C (30 days). Each treatment was conducted in triplicate. Physicochemical properties (pH, titratable acidity [TTA], and proximate analysis), sensory characteristics, and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were measured using the standard tests. The data were analyzed through analyzing multivariate (analysis of variance) supported by Duncan’s multiple range test.Results:The addition of red ginger juice increased the antioxidant activity, TTA, and water holding capacity (WHC) (p<0.05), while syneresis was significantly decreased; however, it had no effect on the total lactic acid bacteria. At the end of this research (day 30), the yogurt was still suitable for consumption, with the following composition: Antioxidant activity 48.39%, pH 4.3, TTA 1.716, water content 80%, protein 3%, fat 3%, syneresis 28%, WHC 63%, and total lactic acid bacteria 89×108 colony-forming units/mL. Furthermore, yogurt supplemented with red ginger changed its color into red blush.Conclusion:Yogurt red ginger juice is recommended as a functional drink, as it contains probiotics P. acidilactici BK01 and antioxidants to support human health. The addition of up to 3% ginger juice and a storage period of 30 days are still favored by the panelists and meet the quality standard of yogurt. We have not conducted the study on active compounds so, further research could be conducted on the components of the active compounds found in red ginger yogurt.

Impact of Auricularia cornea var. Li polysaccharides on the physicochemical, textual, flavor, and antioxidant properties of set yogurt

This study evaluated quality attributes and in vivo antioxidant activity of Auricularia cornea var. Li polysaccharide (ACP)-fortified set yogurt during 21 days of storage (4 °C). Set yogurt was manufactured using a commercial yogurt culture, and 3% (w/v) ACP was added. Physicochemical (pH, titratable acidity, and water-holding capacity), textural, rheological, microstructural, flavor, and antioxidant properties of set yogurt were investigated. The results showed that the addition of ACP significantly enhanced WHC, viscosity, firmness, and cohesiveness, while inhibiting post-acidification of set yogurt during storage. The yogurt supplemented with ACP showed a larger hysteresis area and higher G′ and G″ values, formed a porous, dense, mesh-like structure and exhibited a unique mushroom flavor. Antioxidant results showed that administration of ACP-fortified yogurt significantly decreased serum alanine aminotransferase and aspartate aminotransferase enzyme activities and malondialdehyde levels, while increasing superoxide dismutase, catalase, phospholipid hydroperoxide glutathione peroxidase, and total antioxidant capacity in the liver and hippocampus of the mice. ACP-fortified yogurt might alleviate hepatic damage and hippocampal neuroinflammation induced by d-galactose. Additionally, ACP-fortified yogurt downregulated the expression of Keap1 and upregulated the expression of Nrf2 and HO-1 in the liver. In conclusion, ACP may be used as an ingredient to produce yogurt with desired properties.

Effect of Addition of Coffee Extract on Microbial Growth and Functional Properties of Yoghurt

Yoghurt is a popular probiotic milk product. Coffee flavoured yoghurt was developed to enrich the product with functional properties and help enhance local coffee consumption. The aim of the research was to study potential interaction of polyphenolic compounds present in coffee extract on the viability of lactic acid bacteria, yeast and moulds and, functional properties of coffee flavored yoghurt. Coffee flavoured yoghurt was prepared by adding coffee flavour extract to the yoghurt in varying amounts; 0.0%, 0.1%, 0.2%, and 0.3%. Treatment 0.0% was the control. A complete randomized design (CRD) was used, in which yoghurt was divided into 4 treatments in triplicate and was randomly assigned to 12 experimental units. The sampling for analysis was done at intervals of one week for 28 days from day one. Microbial analysis was done using standard AOAC 2016 method using MRS and PDA media and results were reported as CFU/ml of the coffee flavored yoghurt. Functional properties were determined by evaluation of total polyphenols and antioxidant activity using the Free radical scavenging activity by DPPH method and Folin ciocateau method. Data was analyzed by use of ANOVA, means separated by LSD at p&lt;0.05 level of significance. From the findings, lactic acid bacteria in coffee flavoured yoghurt ranged between 3.7x107-1.09x108CFU/ml. Yeast and moulds ranged between 3.6x101-8.33x100 CFU/ml. TPC between 5.76±0.4-97.89±0.6mgGAE/ml while Antioxidant properties ranged from 15.82±0.9- 68.55±0.9 % DPPH. There were significant differences between coffee flavoured yoghurt and the control on the functional properties. In conclusion, addition of coffee flavour extract into the yoghurt improved the keeping quality of the yoghurt while maintaining its probiotic potential. More studies on addition of natural coffee flavour into other milk products are recommended.

Changes of phenolic profile and antioxidant activity during cold storage of functional flavored yogurt supplemented with mulberry pomace

The purpose of this study was to investigate the changes in the main phenolic compounds and in vitro antioxidant activity of functional flavored yogurt supplemented with mulberry pomace (MP) during cold storage. Three anthocyanins (cyanidin-3- O -glucoside, cyanidin-3- O -rutinoside and pelargonidin-3- O -glucoside) and six non-anthocyanin monomeric phenolics (resveratrol, catechol, catechin, rutin, quercitrin and quercetin) were identified in the MP. The MP powder addition significantly and dose-dependently increased the contents of total phenol (TPC), total anthocyanin (TAC) and individual phenolics and DPPH and ABTS free radical scavenging activity of the products. During the cold storage, TPC, TAC and contents of individual phenolics and antioxidant activity of MP-fortified yogurts gradually and significantly increased. Antioxidant activity of MP-fortified yogurts is highly related to TPC/TAC. MP-fortified yogurts exhibited the highest antioxidant activity on the 21st day of storage. The results showed that MP can be used as a natural antioxidant, providing a promising natural ingredient for the production of functional dairy products with improved nutritional value and biological activity. • Mulberry pomace (MP) is rich in anthocyanin and non-anthocyanin phenolic compounds. • Total phenolics and antioxidant activity of yogurt enhanced by the addition of MP. • Free phenolics and antioxidant activity increased during cold storage of MP-yogurt.

Effects of Lactobacillus fermentum HY01 on the quality characteristics and storage stability of yak yogurt

Lactobacillus fermentum HY01 is a probiotic strain screened from traditional yak yogurt, which can effectively relieve enteritis and constipation. This study aimed to evaluate the effects of HY01 as an adjunct starter on the quality and storage of yak yogurt. A total of 36 main volatile flavor substances were detected in all samples. In particular, more aldehydes, esters, and alcohols were detected in yak yogurt prepared by mixed fermentation of L. fermentum HY01 and starter MY105 (including Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus). The rheological results showed that the yak yogurt prepared by mixed fermentation of L. fermentum HY01 and starter MY105 had higher apparent viscosity and lower tan δ value compared with compared with traditional yak yogurt, yak yogurt with only L. fermentum HY01, and cow yogurt with L. fermentum HY01 and starter MY105. Meanwhile, the conjugated linoleic acid in the yak yogurt prepared by mixed fermentation of L. fermentum HY01 and starter was significantly higher than those in the HY01 group or the yogurt starter group alone. After 28 d of storage at 4°C, the number of HY01 in the yak yogurt prepared by mixed fermentation of L. fermentum HY01 and starter was still higher than 107 cfu/mL, its acidity was lower than 110°T, and its syneresis was the lowest. The results indicated that L. fermentum HY01 could improve the flavor, texture, and storage properties of yak yogurt.

Novel Millet-Based Flavored Yogurt Enriched With Superoxide Dismutase.

Superoxide dismutase (SOD) is an important antioxidant enzyme with different physiological functions, which can be used as a nutritional fortifier in food. Cereal-based fermented products are becoming popular worldwide. In this study, novel millet-based flavored yogurt enriched with SOD was developed. Lactiplantibacillus plantarum subsp. plantarum was screened, which manufactured SOD activity of 2476.21 ± 1.52 U g−1. The SOD content of millet yogurt was 19.827 ± 0.323 U mL−1, which was 63.01, 50.11, and 146.79% higher than that of Bright Dairy Yogurt 1911, Junlebao and Nanjing Weigang, respectively. Fifty-four volatile flavor substances and 22,571 non-volatile flavor substances were found in yogurt. Compared to traditional fermented yogurt, 37 non-volatile metabolites in yogurt with millet enzymatic fermentation broth were significantly upregulated, including 2-phenyl ethanol, hesperidin, N-acetylornithine and L-methionine, which were upregulated by 3169.6, 228.36, 271.22, and 55.67 times, respectively, thereby enriching the sensory and nutritional value of yogurt. Moreover, the manufacture of unpleasant volatile flavor substances was masked, making the product more compatible with consumers' tastes.

Effects of dairy bioactive peptides and lotus seeds/lily bulb powder on flavor and quality characteristics of goat milk yogurt

The objective of this study was to evaluate the changes on flavor and quality characteristics of goat yogurt during storage with the addition of dairy bioactive peptides and a mixture of lotus seed and lily bulb powder. Both the addition of dairy bioactive peptides and lotus seeds/lily bulb powder resulted in a fermentation time reduction, water holding capacity (WHC) improvement, and inhibition of post-acidification of goat yogurt during storage. A total of 50 volatile flavor components were detected in the goat milk yogurt samples, and the addition of the above two supplements were shown to be effective in improving the flavor and the textural properties of the goat milk yogurt during storage. The group added with lotus seeds/lily bulb powder showed the best WHC and textural properties, followed by the group added with dairy bioactive peptides alone and the group with both added. The addition of both supplements was found to be useful in making up for the two defects of goat yogurt, prolonged fermentation and soft curds. Therefore, dairy bioactive peptides and lotus seeds/lily bulb powder are recommended to be added to goat yogurt as nutritional supplements.

Inhibition of Advanced Glycation End Products in Yogurt by Lotus Seedpod Oligomeric Procyanidin.

The basic ingredients of yogurt include lactose and protein. Yogurt undergoes the Maillard reaction easily, producing many advanced glycation end products (AGEs) that cause some chronic diseases. Lotus seedpod oligomeric procyanidin (LSOPC) have demonstrated a strong inhibitory effect on AGE formation in simulated models; however, the inhibition of procyanidin on AGE formation and the subsequent effects on yogurt quality remains unknown. Our study demonstrated that LSOPC had a good inhibitory effect on the formation of fluorescent AGEs and Nε-carboxymethyl lysine (P < 0.05). The inhibitory capacity on AGEs and antioxidant activity of yogurt were positively correlated with the concentration of LSOPC. The effect of LSOPC on the physicochemical properties of yogurt was also evaluated. Bound water content, viscosity, and flavor of yogurt were significantly increased after LSOPC addition (P < 0.05). Therefore, LSOPC may lead to significant benefits for controlling AGE formation and improving the quality of yogurt.

Noni juice-fortified yogurt mitigates dextran sodium sulfate-induced colitis in mice through the modulation of inflammatory cytokines

• Noni juice (NJ) addition did not alter the fermentation time of stirred yogurt. • NJ addition improved the viable starter count and antioxidant properties of yogurt. • Dietary NJ-fortified yogurt (NY) attenuated DSS induced colitis in mice. • NY regulated the balance between pro-inflammatory and anti-inflammatory cytokines. This study investigated the effect of noni juice (NJ) addition on physico-chemical, sensory, and bioactive properties of yogurt. NJ addition increased the acidity, yogurt starter count, total phenolics, total flavonoids, antioxidant activity, and flavor of yogurt. However, it reduced the viscosity, syneresis, and color parameters. Furthermore, whether feeding yogurt with or without NJ (7%, v/v) (NY or Y) (20 g/kg of diet) could alter the response of mice to dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) was investigated. Intriguingly, dietary NY significantly ameliorated body weight loss, colon length, and histopathological changes in the UC mice. This relief of symptoms might be associated with the decreased mRNA expression of pro-inflammatory cytokines including IL-6 and IFN-γ and the increased mRNA expression of anti-inflammatory cytokine, IL-10. These results suggest the feasibility of NJ addition into yogurt which could serve as a potential adjuvant dietary therapy for reducing inflammation in UC patients.

Optimization of Fermentation Process and Evaluation of Quality and Flavor of Quinoa Yogurt Produced by Mixed Lactic Acid Bacteria

In this study, Streptococcus thermophilus 6063, Lactobacillus bulgaricus 6064 and Bifidobacterium animalis B15 were selected to ferment quinoa yogurt, and the puffed quinoa powder and milk were used as raw materials. Fermentation process was optimized by orthogonal experiment on the basis of single-factor experiments. And the effects of puffed quinoa powder on quality and flavor of yogurt were also evaluated. Results indicated that the optimal fermentation conditions were as follows: Streptococcus thermophilus: Lactobacillus bulgaricus: Bifidobacterium animalis=2:1:2, inoculation amount 2%(v/v), quinoa powder 5%(w/v) and fermentation temperature 41 ℃. Under these conditions, quinoa yogurt had good flavor, and the total viable number of lactic acid bacteria reached 109 CFU/mL. From the beginning of fermentation to the end of storage for 21 days, the titratable acidity of quinoa yogurt was always higher than that of plain yogurt, but the total number of viable lactic acid bacteria was opposite trend. Compared with plain yogurt, the contents of protein, polyphenols and flavonoids in quinoa yogurt increased respectively by 88.67%, 166.67%, and 284.62%. The contents of lactic acid, formic acid, acetic acid and pyruvate in quinoa yogurt were 5.80, 1.42, 0.11 and 0.01 mg/g, respectively. 74 kinds of volatile substances were detected in quinoa yogurt by GC-MS. Compared with pure yogurt, 30 kinds of new volatile substances were discovered. The research results would provide a technology support for further research and new product development of quinoa yogurt, promoting the application and development of quinoa.

Effects of mulberry pomace on physicochemical and textural properties of stirred-type flavored yogurt

Adding functional ingredients is an important method to develop functional dairy products. Mulberry pomace (MPo), a byproduct of mulberry fruit processing, is rich in phenolic compounds and anthocyanins and can be served as the functional ingredient in functional dairy products. The aim of this work was to prepare a functional flavored yogurt by incorporating MPo into stirred yogurt and to investigate the effects of MPo on the physicochemical and textural properties of the product during cold storage. We supplemented MPo powder up to 3% (wt/wt) in fermented milk, and the changes in color, pH, titratable acidity (TA), total phenol content (TPC), total anthocyanin content (TAC), water-holding capacity, rheological behavior, texture, and microstructure of the functional flavored yogurt were monitored during storage under 4°C for 28 d. The MPo powder brought a pink to dark red color to the yogurt, decreased the lightness (L*) and yellow-blue color (b*) values, increased the red-green color (a*) values, decreased the pH value, and increased the contents of TA, TPC, and TAC in a dose-dependent manner. The addition of MPo at 1%, 2%, and 3% (wt/wt) significantly increased water-holding capacity, consistency, viscosity, and viscosity index, and reduced firmness of yogurt samples. Supplementation of MPo significantly reduced the pore spaces and channels inside the samples and improved microstructure of the functional yogurt. During the 28 d of cold storage, MPo-fortified yogurt samples kept relatively constant color, although their L*, a*, and b* showed a decreasing tendency. The pH of all yogurt samples gradually decreased with increasing of TA. Interestingly, TPC and TAC contents and the texture parameters of MPo-fortified yogurt increased gradually and continuously during the 28 d of cold storage. Mulberry pomace is beneficial to improve the physicochemical and textural properties of yogurt and has the potential as a natural stabilizer to be used in functional yogurt rich in phytochemicals.