Acidification kinetics, physicochemical properties and sensory attributes of yoghurts prepared from mixtures of goat and buffalo milks

In vitro digestive system simulation and anticancer activity of soymilk fermented by probiotics and synbiotics immobilised on agro-industrial residues

In this study, a variety of probiotic strains, including Lactiplantibacillus plantarum, Lacticaseibacillus casei, Lactobacillus acidophilus, Streptococcus thermophilus, Bifidobacterium longum, Limosilactobacillus reuteri, Lactobacillus delbrueckii subsp. bulgaricus, Lacticaseibacillus rhamnosus, and Bifidobacterium bifidum, were utilized for soymilk fermentation both as free cells and as synbiotics on agro-industrial residuals such as okara, whey protein, banana peels, apple pomace, sugarcane bagasse, orange peels, and lemon peels. Among these, Lacticaseibacillus rhamnosus emerged as the most significant strain for soymilk fermentation, exhibiting a viability of 10.47 log cfu/mL, a pH of 4.41, total acidity of 1.12%, and organic acid contents (lactic and acetic acid) of 11.20 and 7.50 g/L, respectively. As a synbiotic Lacticaseibacillus rhamnosus immobilised on okara, showed even more impressive results, with a viability of 12.98 log cfu/mL, a pH of 4.31, total acidity of 1.27%, and organic acid contents of 13.90 and 9.30 g/L, respectively. Over a 12-h fermentation period, cell viability values increased by 10.47-fold in free cells and 11.19-fold in synbiotics. Synbiotic supplementation of fermented soymilk proved more beneficial than free cells in terms of viability, acidity, and organic acid content. Furthermore, when synbiotic fermented soymilk was freeze-dried to simulate the digestive system in vitro, synbiotics and freeze-dried cells demonstrated superior gastrointestinal tract survival compared to free cells. Both the probiotic bacteria and the synbiotics exhibited cytotoxicity against colon and liver cancer cell lines, with half-maximal inhibitory concentrations ranging from 41.96 to 61.52 μL/well.

The effects of Trametes versicolor fermented Rosa roxburghii tratt and coix seed quild on the nutrition, sensory characteristics and physical and chemical parameters of yogurt

Trametes versicolor can produce aromatic flavor in growth and development, widely used in food fermentation. This study used a One-Factor-at-a-Time (OFAT) test and response surface analysis to study the optimum fermentation parameters of Rosa roxburghii tratt and coix seed yogurt by Trametes versicolor. The best fermentation process is as follows: skim milk powder 17 %, sucrose content 4 %, Rosa roxburghii tratt and coix seed liquid 36 %, fermentation temperature 39 °C, inoculum 2 %, strain ratio 2:1:1(LB12: BLH1: Q-1), fermentation time 9.5 h. Under this fermentation process, the sensory score was 82.11, the contents of vitamin C, GABA, and total live bacteria in this yogurt were 13.89, 2.58, and 1.02 times higher than in common yogurt. Correlation analyses showed a significant contribution of the leavening agent to the GABA content of yogurt. This study provides a foundation for producing Rosa roxburghii tratt and coix seed yogurt with high sensory and nutritional value.

Comprehensive studies on the stability of yogurt-type fermented soy beverages during refrigerated storage using dairy starter cultures

Introduction

This study aimed to assess the feasibility of utilizing commercially available dairy starter cultures to produce yogurt-type fermented soy beverages and evaluate the fundamental properties of the resulting products.

Methods

Sixteen different starter cultures commonly used in the dairy industry for producing fermented milks, such as yogurt, were employed in the study. The study investigated the acidification curves, acidification kinetics, live cell population of starter microflora during refrigerated storage, pH changes, water-holding capacity, texture analysis, carbohydrates content, and fatty acid profile of the yogurt-type fermented soy beverage.

Results and Discussion

The results demonstrated that the starter cultures exhibited distinct pH changes during the fermentation process, and these changes were statistically significant among the cultures. The acidification kinetics of different cultures of lactic acid bacteria showed characteristic patterns, which can be used to select the most suitable cultures for specific product production. The study also revealed that the choice of starter culture significantly influenced the starter microorganisms population in the yogurt-type fermented soy beverage. Additionally, the pH values and water-holding capacity of the beverages were affected by both the starter cultures and the duration of refrigerated storage. Texture analysis indicated that storage time had a significant impact on hardness and adhesiveness, with stabilization of these parameters observed after 7-21 days of storage. Furthermore, the fermentation process resulted in changes in the carbohydrate content of the soy beverages, which varied depending on the starter culture used.

High resolution melting is a useful tool to detect animal species sources of various milk types

Accurate identification of animal species sources in milk have become quite important due to adulteration of high-priced milk types in the dairy industry. To date, milk identification methods have mainly depended on biochemical properties or physical properties detected by spectroscopic methods. The current study aimed to develop an easy to use and sensitive DNA-based High resolution melting (HRM) assay to identify animal species and detect cross-adulteration of water buffalo, bovine, goat, sheep, camel and donkey milks. HRM compatible designed primer set, targeted mitochondrial region, successfully amplified the specific targeted region for six animal species DNA and showed a high degree of specificity based on nucleotide variations. Capillary electrophoresis analysis validated the specific amplicons and determined the amplicon lengths as 114 bp for bovine, goat, sheep, and camel, 115 bp for water buffalo, and 121 bp for donkey. HRM analysis showed a clear discrimination for water buffalo-bovine, camel-bovine and donkey-bovine adulteration down to 0.5%, and goat-sheep adulteration down to 1% in the milk admixtures. The efficacy of the method was also confirmed by its standard curve with a very high correlation coefficient In conclusion, the designed HRM assay allows for the rapid, sensitive and cost-effective authentication of milk and dairy products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05705-3.

Development and characterization of lactose-free probiotic goat milk beverage with bioactive rich jambo pulp

Goat milk is considered a suitable matrix for the successful incorporation of probiotics, also obtaining new lactose-free fermented products can expand its use. This study aimed to develop and characterize formulations of lactose-free probiotic fermented goat dairy beverages as well as to determine the most appropriate concentration of red jambo pulp to be added. The beverages were developed with different concentrations of lactose-free goat milk and frozen jambo pulp (12, 15 and 18% w/v) and lyophilized (3, 6 and 9% w/v), corresponding to formulations F1 to F6, respectively, as source of bioactive compounds. Probiotics counts decreased significantly (from 8.58 to 7.38 log CFU mL-1). The formulation with a higher proportion of lyophilized (F6) pulp showed the highest levels of phenolic compounds (72.08 mg GAE 100 g-1), anthocyanins (50.80 mg cyanidin-3-glycoside 100 g-1), ascorbic acid (41.68 mg 100 g-1), and antioxidant activity (16.21 μmol TE g-1) (P < 0.05). On the other hand, F3 presented the highest global acceptance and purchase intention (P < 0.05). However, the principal component analysis (PCA) indicated that the components related to bioactive compounds (PC1) stood out on sensory attributes (PC3 and PC4) and, therefore, F6 was most appropriate for obtaining a lactose-free goat probiotic fermented milk with improved bioactive properties targeting lactose intolerant consumers and those who are allergic to bovine milk proteins.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05399-z.

Effects of polymerized whey protein on goaty flavor and texture properties of fermented goat milk in comparison with β-cyclodextrin

Goaty flavor and poor consistency may impact consumer acceptance of fermented goat milk. The undesirable characteristics can mainly be attributed to the presence of short-medium chain free fatty acid (SM-FFA) especially C6-C10 fatty acids and low αs1-casein content in goat milk. This study aimed to investigate the effects of polymerized whey protein (PWP) on goaty flavor as well as the texture properties of fermented goat milk in comparison with β-cyclodextrin (β-CD). Samples were evaluated on sensory properties, SM-FFA contents, texture, and apparent viscosity. Compared with control, the fatty acids contents (C6, C8, C10) decreased significantly in fermented goat milk with 0·5% β-CD (22, 71, 54%, respectively) and with 0·7% PWP (45, 58, 71%, respectively). There was a synergistic effect of 0·3% β-CD and 0·6% PWP in decreasing the contents of SM-FFA (C6, C8, C10) sharply by 89, 90, 79%. Under the same percentage of addition, yogurts made with β-CD showed a higher (P < 0·05) apparent viscosity than those with PWP. However, the addition of PWP could increase the texture parameters of fermented goat milk (P < 0·05). Combination of PWP and β-CD presented a more desirable texture and consistency in fermented goat milk. Results indicated that polymerized whey protein can be used to reduce the goaty flavor and improve the texture of fermented goat milk.

The effect of Isabel grape addition on the physicochemical, microbiological and sensory characteristics of probiotic goat milk yogurt

Goat milk is an attractive food because of its nutritional properties, easy digestibility and hypoallergenicity. Goat milk yogurt is an appropriate matrix for the inclusion of new ingredients such as probiotic cultures, fruit and its derivatives. Grapes are rich in polyphenols and recognized for their health benefits. The aim of this study was to improve the quality characteristics of probiotic goat milk yogurt by the addition of an Isabel grape (Vitis labrusca L.) preparation (IGP). For this, the influence of the addition of IGP on the physicochemical, microbiological and sensory characteristics of goat milk yogurt containing the probiotic Lactobacillus acidophilus LA-05 was evaluated during 28 days of refrigerated storage (5 ± 0.5 °C). Four yogurt formulations were prepared, each varying in the added IGP amount, as follows: Y0 (not containing IGP), YG15 (containing 15 g per 100 mL of IGP), YG20 (containing 20 g per 100 mL of IGP), and YG25 (containing 25 g per 100 mL of IGP). All formulations showed probiotic counts ranging from 7 to 8 log CFU mL^-1 over the assessed storage period. The addition of 20 g per 100 mL of IGP affected positively the colour, viscosity, and sensory acceptance of the yogurt formulations. The production of goat milk yogurt containing L. acidophilus LA-05 and IGP is an option for developing a new goat dairy product with added value due to the inclusion of components with potential functional properties.

Physicochemical and sensory characteristics of yoghurts made from goat and cow milk

Substituting goats' milk for cows' milk could improve the quality of dairy products, because it adds new sensorial characteristics. The aim of this study was to develop a type of yoghurt using goats' milk (25, 50, 75 and 100%) in place of cows' milk and to compare their characteristics. Physicochemical, microbiological and sensory characteristics were evaluated using a nine-point hedonic scale and purchase intention test. The data obtained in the physicochemical analysis were submitted to regression analysis and the sensory results were evaluated through analysis of variance. Among the physicochemical characteristics of the yoghurts, variation (P < 0.05) of ash, acidity and lactose was observed. Tasters in the sensory analysis indicated that yoghurts up to 50% of goats' milk received favorable averages; with lower scores for higher goats' milk concentrations (75% and 100%). No difference was reported in acidity. Replacing cows' milk with goats' milk in yoghurt preparation promotes variations in the physicochemical characteristics for ash, acidity and lactose. However, it does not cause alterations in the sensory attributes (50% goat milk) and therefore could be considered as an alternative for the production of dairy products. © 2016 Japanese Society of Animal Science.

Quality attributes of a fermented whey-based beverage enriched with milk and a probiotic strain

Milk andL. rhamnosusincrease the probiotic character and stability of a beverage and greatly improve its viscosity and syneresis. The first use of ABY-6 culture in whey fermentation was successfully performed.