Effects of tropical fruit pulps and partially hydrolysed galactomannan from Caesalpinia pulcherrima seeds on the dietary fibre content,probiotic viability,texture and sensory features of goat dairy beverages

The use of cheese whey and probiotic cultures in the production of dairy beverages has been highly attractive; nonetheless, whey-based goat beverages tend to be poor and watery when compared to fermented milks. The addition of fruits and fibre ingredients might improve texture and mouthfeel of this kind of product. Fermented whey-based goat beverages prepared using Streptococcus thermophilus TA-40 as starter culture, with added guava or soursop pulps, and with or without addition of partially hydrolysed galactomannan from Caesalpinia pulcherrima seeds (PHGM), showed to be good vehicles for Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus rhamnosus Lr-32, maintaining their viability above 7 log CFU/ml during 21 days. PHGM increased the dietary fibre content and enhanced the instrumental texture and sensory features of both guava and soursop dairy beverages, especially texture, appearance, and overall acceptability. The PHGM might be recommended to improve nutritional and sensory quality of fermented probiotic beverages produced with goat milk and cheese whey.     

Comparative study of the phenolics,antioxidant and metagenomic composition of novel soy whey-based beverages produced using three different water kefir microbiota

Water kefir microbiota was used to develop novel soy whey-based beverages that have antioxidant activity. In the present study, comparative phenolics, antioxidant and metagenomic composition of the soy whey beverages fermented using three different water kefir microbiota, named WKFS-A, WKFS-B and WKFS-C were investigated. WKFS-B beverage had the highest concentrations of isoflavone aglycones (208.73 ± 2.78 mg L⁻¹) and phenolic acids (132.33 ± 3.41 mg L⁻¹) compared with WKFS-A (193.88 ± 1.15 mg L⁻¹) and (91.73 ± 2.34 mg L⁻¹) and WKFS-C (160.63 ± 1.76 mg L⁻¹) and (97.13 ± 2.63 mg L⁻¹), respectively. The WKFS-B also showed higher DPPH and ABTS radical scavenging activity and ferric reducing antioxidant power compared with WKFS-A and WKFS-C beverages. Microbial species diversity index analysis showed that a higher concentration of isoflavone aglycones, phenolic acids and increased antioxidant activity in the WKFS-B beverage correlates with the higher relative abundance of Lactobacillus genus. This study thus revealed that Lactobacillus dominated water kefir microbiota produces soy whey beverages with high phenolic acids, isoflavone aglycones and antioxidant activity.     

Microencapsulation of ginsenosides using polymerised whey protein (PWP) as wall material and its application in probiotic fermented milk

Ginsenosides was microencapsulated using heat‐induced polymerised whey protein as wall material. The entrapment yield was 95.46 ± 1.95% and release rates were about 20% and 100% in gastric and intestine juices, respectively. Microencapsulated ginsenosides (0.03% ginsenosides, w/v) were used for fermented milk formulation. Samples with microencapsulated ginsenosides had much higher acceptability compared with those with ginsenoside extract (P < 0.01). Addition of microencapsulated ginsenosides significantly decreased the syneresis of the sample (P < 0.01). The probiotics remained above 10⁶ CFU mL^?1 during the first 6 weeks, and no significant difference was observed in probiotics population during 10‐week storage for all samples. SEM micrograph revealed that addition of microcapsules did not change the structure of the samples considerably. The polymerised whey protein‐based microencapsulation might be an effective technique to deliver ginsenosides to small intestine through stomach. It also masked bitter taste and improved the colour of the fermented milks containing ginsenosides.     

A physical stability study of whey-based prickly pear beverages

This study aimed at the development of whey-based prickly pear (WBP) beverages. Prickly pear juice and acid whey were characterized and a factorial design was used to study the effect of three factors. Four formulations of whey-based prickly pear beverages were prepared using the fractional 2^3-1 factorial design. To note, the three factors considered were whey treatment (WT) and added sugar and pectin (S and P). Two levels for each factor were tested, namely added sugar (5 or 10%), whey treatment (with or without heat treatment) and added pectin (0 or 0.05%). The turbidity percentage increase, the color-index percentage decrease, the sedimentation percentage increase, as well as the serum separation percentage were evaluated after 40 days of storage condition at 4 °C. The three factors optimization for the beverages' maximum stability were implemented by testing the main and interaction effects plots, the analysis of variance (ANOVA), the normal probability plots of standardized effects and residuals, the Pareto charts and the contour plots. The achieved results showed that the beverages were physically stabilized by sugar and HM-pectin amount increase using the heat-treated whey. Hence, regression models were suggested, which fitted the experimental data very well (R² >75% and p < 0.05).     

Effect of storage time on the microbial,physicochemical and sensory characteristics of ovine whey-based fruit beverages

The aim of this study was to establish the physicochemical, sensory and microbiological quality of ovine whey-based fruit beverages produced from pasteurised ovine whey (mango flavoured–sugar sweetened [M-Su], pineapple flavoured–extra sugar sweetened [P-ESu], and tropical fruit flavoured–stevia sweetened [T-St]), and the changes in quality of these beverage types during the 15-day storage. The beverages were evaluated for their pH, colour, sediment and particle size distribution, microbiological count and sensory quality. No significant differences in the pH and the microbial counts among the beverages were noted during the storage period; however, the particle size distribution reflected the sediment formation that significantly decreased during the same period in all beverage types. The beverages were getting lighter during storage, which was evident by increasing L* and decreasing a* values for colour. All three beverage types had very high scores for taste and odour after 9 days, and colour and sediment after 5 days of storage. Beverage-type T-St was most preferred by consumers, with the highest scores for taste, odour and sensory appearance. These results can assist in the better determination of the deteriorative changes in a variety of ovine whey-based beverages, necessary changes in product composition that might result in improved product quality, and yet reducing losses incurred during ovine milk processing. In this sense, this research's findings contribute to the utilisation of whey beverages by the dairy industry to the development of functional products.     

Whey fermentation by thermophilic lactic acid bacteria: evolution of carbohydrates and protein content

Whey, a by-product of the cheese industry usually disposed as waste, is a source of biological and functional valuable proteins. The aim of this work was to evaluate the potentiality of three lactic acid bacteria strains to design a starter culture for developing functional whey-based drinks. Fermentations were performed at 37 and 42 degrees C for 24h in reconstituted whey powder (RW). Carbohydrates, organic acids and amino acids concentrations during fermentation were evaluated by RP-HPLC. Proteolytic activity was measured by the o-phthaldialdehyde test and hydrolysis of whey proteins was analyzed by Tricine SDS-PAGE. The studied strains grew well (2-3log cfu/ml) independently of the temperature used. Streptococcus thermophilus CRL 804 consumed 12% of the initial lactose concentration and produced the highest amount of lactic acid (45 mmol/l) at 24h. Lactobacillus delbrueckii subsp. bulgaricus CRL 454 was the most proteolytic (91 microg Leu/ml) strain and released the branched chain amino acids Leu and Val. In contrast, Lactobacillus acidophilus CRL 636 and S. thermophilus CRL 804 consumed most of the amino acids present in whey. The studied strains were able to degrade the major whey proteins, alpha-lactalbumin being degraded in a greater extent (2.2-3.4-fold) than beta-lactoglobulin. Two starter cultures were evaluated for their metabolic and proteolytic activities in RW. Both cultures acidified and reduced the lactose content in whey in a greater extent than the strains alone. The amino acid release was higher (86 microg/ml) for the starter SLb (strains CRL 804+CRL 454) than for SLa (strains CRL 804+CRL 636, 37 microg/ml). Regarding alpha-lactalbumin and beta-lactoglobulin degradation, no differences were observed as compared to the values obtained with the single cultures. The starter culture SLb showed high potential to be used for developing fermented whey-based beverages.     

Probiotic monocultures in fermented goat milk beverages – sensory quality of final product

The aim of our study was to conduct a selection of the monocultures capable of providing the most attractive sensory features of the final product. Four fermented goat's milk beverages were produced with probiotic monocultures containing Lactobacillus (Lb. acidophilus La‐5, Lb. rhamnosus K3 and Lb. plantarum O20) and Bifidobacterium (Bif. animalis subsp. lactisBB‐12). A sensory analysis and microbiological assessment of fermented goat's milk beverages were made at the beginning of the study and after 3, 7, 10 and 14 days of refrigerated storage (5 ± 1 °C). We found that samples including monocultures Lb. plantarum O20 and Bif. animalis subsp. lactisBB‐12 were differentiated from other goat's milk beverages.     

Production of a whey‐based functional beverage supplemented with soy isoflavones and phytosterols

Reconstituted whey beverages were prepared from whey powder by adding either soy isoflavones or phytosterols as functional compounds (at levels of 0%, 0.25%, 0.50% or 1.0% w/v) and probiotic bacteria (Lactobacillus acidophilus LA‐5 or Lactobacillus casei LBC‐81). The addition of nutraceuticals did not change the basic composition of the products. However, a time‐dependent increase in sedimentation/phase separation and acidity of fermented functional beverages was observed. Samples supplemented with phytosterols were more preferred by the panel group than the samples supplemented with isoflavones, and no considerable differences were noted between the control and phytosterol‐added samples in terms of overall perception.     

Pulsed electric field processing of a pomegranate (Punica granatum L.) fermented beverage

The aim of this study was to evaluate the effect of pulsed electric field (PEF) (11.7 or 18 kV/cm) and pasteurization (batch or slow (VAT) and high-temperature-short time (HTST)) on the microbial, physicochemical, bioactive and sensory characteristics of a pomegranate (Punica granatum) fermented beverage (PFB) through storage at 4 °C. Bioactive compounds (antioxidant capacity, phenolic compounds, flavonoids, anthocyanins content) and color were measured. The microbiological counts (initial mesophilic aerobic bacteria (MAB) of 9.77 × 10³ CFU/mL and initial molds plus yeasts (MY) of 2.04 × 10³ CFU/mL) showed that applying 6 ms of bipolar PEFs at 18 kV/cm with 200 Hz repetition frequency reduced the microbial loads in approximately 4-log cycles, remaining <10 CFU/mL of both types of microorganisms in the PFB. PEF barely affected the total soluble solids, pH, ethanol, total acidity and color. All PEF-treated and pasteurization samples showed a slight reduction in bioactive compounds during storage. In sensory acceptability, the lowest score was given to the VAT pasteurized sample; however, still acceptable (between like slightly and like moderately).Industrial relevanceThis research provides essential information on the microbiological, physicochemical, bioactive and sensory characteristics of a pomegranate fermented beverage processed with pulsed electric fields. The pulsed electric field processing of fermented beverages may provide criteria to the processing industry to use this novel technology as a processing method for delivering a microbiological safe beverage with good sensory and antioxidant characteristics to consumers.     

Effect of nutrient supplements on growth and viability of Lactobacillus johnsonii NRRL B-2178 in whey

The main objectives of the paper were to study the effects of nutrient supplementation of cows' whey on the growth and viability of the probiotic microorganism Lactobacillus johnsonii NRRL B-2178. Because of the short lifespan of probiotics, this study was aimed at the evaluation of the contribution of nutrients in the improvement of growth and viability of the microorganism for the purpose of its further application in the formulation of whey-based beverages. A maximal cell growth of 8.70 log₁₀ cfu mL⁻¹ and viability of less than 5 days were achieved during the fermentation of whey supplemented with yeast extract (3.0%) and inulin (1.0%), including the synergistic effect of temperature 39 °C. Elimination of inulin from the fermentation process reduced the viable cell count by 0.2 log₁₀ cfu mL⁻¹, but the addition of 1.0% inulin after fermentation extended the viability of Lb. johnsonii NRRL B-2178 by 10 days.     

Effects of fat replacement with a mixture of collagen and dietary fibre on small calibre fermented sausages

Effects of fat replacement on physicochemical, microbial and sensory properties of fermented sausages were determined after drying process and 4 weeks of storage. Fermented sausages were formulated with 20% pork back fat (control), and three reduced‐fat treatments were prepared by replacing 25%, 50%, and 75% of fat with a mixture of collagen, dietary fibre and ice (1:1:8). TBARS values of reduced‐fat treatments were significantly lower compared with control after drying (P ≤ 0.05). As fat replacing ratio increased, fat content decreased significantly (P ≤ 0.05), whereas moisture, protein and ash content increased significantly (P ≤ 0.05). There was no marked difference between the treatments in terms of microbial analysis, sensory colour, flavour, off‐flavour or overall acceptability (P > 0.05) during refrigerated storage. Therefore, replacing pork back fat with a mixture of collagen and dietary fibre in fermented sausages may contribute to reduce lipid oxidation and maintain sensory properties during storage.     

Survival of Escherichia coli O157:H7, nitrite content and sensory acceptance of low‐salt Chinese paocai fermented by screened lactic acid bacteria

Starter cultures of low‐salt Chinese paocai were screened from 135 lactic acid bacteria (LAB) by evaluating their antimicrobial activity and growth characteristics. Furthermore, the survival of Escherichia coli O157:H7, nitrite contents and sensory acceptability of the starter‐fermented paocai were evaluated. LAB BC92, which was identified as Lactobacillus pentosus, was used as a starter culture to produce paocai. In comparison with naturally fermented paocai, the disappearance time of E. coli O157:H7 in starter‐fermented paocai decreased from 5.29 to 3.82 days, and the maximum nitrite content decreased from 11.73 to 8.64 mg kg^?1, and the nitrite reduction time decreased from 4 to 3 days. In addition, starter fermentations were able to accelerate the flavour formation and shorten the paocai ripening period. The paocai that was fermented naturally and fermented by BC92 all had good sensory acceptance, and no significant difference (P > 0.05) was observed.     

Effects of various whey proteins on the physicochemical and textural properties of set type nonfat yoghurt

In this study, the changes during storage in the physicochemical, textural and sensory properties of nonfat yoghurts fortified with whey proteins, namely whey protein concentrates (WPC), whey protein isolates and whey protein hydrolysates, were investigated. Enrichment of nonfat yoghurt with the whey protein additives (1% w/v) had a noticeable effect on pH, titratable acidity, syneresis, water‐holding capacity, protein contents and colour values on the 14th day of storage (P < 0.01). The addition of whey proteins to the yoghurt milk led to increases in the hardness, cohesiveness and elasticity values, resulting in improved textural properties. The addition of WPC improved the texture of set‐type nonfat yoghurt with greater sizes in the gel network as well as lower syneresis and higher water holding capacity. This study suggests that the addition of whey protein additives used for fortification of yoghurt gave the best textural and sensory properties that were maintained constant during the shelf life.     

Interactions between whey proteins and calcium salts and implications for the formulation of dairy protein-based nutritional beverage products: A review

Whey-based nutritional beverages are often fortified with calcium (Ca) in order to deliver the recommended intake of Ca. However, technical and product quality challenges are often experienced with Ca fortification of whey protein-based nutritional solutions, such as poor heat stability, high viscosity, colloidal instability, and impaired heat transfer. Understanding of the relationships and interactions between whey proteins and Ca relative to liquid process (e.g., ready to feed products, feed material prior to drying) is essential to designing and formulating nutritional whey-based products with desired physicochemical and colloidal stability properties. This article reviews the interactions between whey proteins and Ca salts used in the formulation of nutritional whey-based products as well as major processing implications associated with Ca fortification of whey-based solutions.     

Diversity in growth and protein degradation by dairy relevant lactic acid bacteria species in reconstituted whey

The high nutritional value of whey makes it an interesting substrate for the development of fermented foods. The aim of this work was to evaluate the growth and proteolytic activity of sixty-four strains of lactic acid bacteria in whey to further formulate a starter culture for the development of fermented whey-based beverages. Fermentations were performed at 37 °C for 24 h in 10 and 16% (w/v) reconstituted whey powder. Cultivable populations, pH, and proteolytic activity (o-phthaldialdehyde test) were determined at 6 and 24 h incubation. Hydrolysis of whey proteins was analysed by Tricine SDS-PAGE. A principal component analysis (PCA) was applied to evaluate the behaviour of strains. Forty-six percent of the strains grew between 1 and 2 Δlog CFU/ml while 19% grew less than 0·9 Δlog CFU/ml in both reconstituted whey solutions. Regarding the proteolytic activity, most of the lactobacilli released amino acids and small peptides during the first 6 h incubation while streptococci consumed the amino acids initially present in whey to sustain growth. Whey proteins were degraded by the studied strains although to different extents. Special attention was paid to the main allergenic whey protein, β-lactoglobulin, which was degraded the most by Lactobacillus acidophilus CRL 636 and Lb. delbrueckii subsp. bulgaricus CRL 656. The strain variability observed and the PCA applied in this study allowed selecting appropriate strains able to improve the nutritional characteristics (through amino group release and protein degradation) and storage (decrease in pH) of whey.     

Fermented beverage obtained from hydroSOStainable pistachios

Currently, consumers increasingly demand healthy foods, such as “vegetable drinks” made from nuts and cereals. In this scenario, the potential use of pistachios, grown under conventional and regulated deficit irrigation conditions (hydroSOStainable), to prepare fermented beverages was evaluated. This work addressed three important aspects: (i) water savings, (ii) use of noncommercial products, and (iii) expansion of the offer of vegetable drinks. Two commercial cultures of lactic acid bacteria (MA400 and MY800) and two sugars (glucose and fructose) were tested. Fermented drinks were evaluated by analyzing the following parameters: microbial counts, pH, titratable acidity, CIE (L^*, a^*, and b^*) color, and total fatty acid, volatile and sensory profiles; all parameters were evaluated at 1, 15, and 30 days of cold storage (4 °C). Pistachio-based beverages proved to be excellent substrates for the growth and survival of lactic acid bacteria. The fatty acid profile was not affected by the studied factors. However, the volatile profile was more complex for the treatments conventional-MY800 (80 µg/L) and hydroSOS-MA400 (72 µg/L). HydroSOS beverages fermented with MA400 culture were less sour and had higher intensity of umami and pistachio flavor; however, hydroSOS pistachios fermented with MY800 culture had lower pistachio odor intensity. All tested factors can be considered suitable for the preparation of fermented pistachios-based beverages, considering both technological and quality aspects.     

Effects of probiotic L. plantarum 299v on consumer quality,accumulation of phenolics,antioxidant capacity and biochemical changes in legume sprouts

This study evaluated the influence of Lactobacillus plantarum 299v on the consumer quality of legume sprouts. The probiotic-rich sprouts were produced by soaking the seeds in probiotic water suspension and further sprouting at 25 °C for 4 days. The enrichment of the sprouts with L. plantarum 299v only slightly affected the sensory quality - the overall acceptability of the probiotic-rich sprouts was usually higher. The probiotic-rich sprouts exhibited increased activity of polyphenol oxidase (the highest activity in the mung bean preparations - 73.97 U mg⁻¹ of protein). The peroxidase activity was not altered. The probiotic enrichment increased the phenolic content by 25%, 31% and 23% in the soybean, adzuki and mung bean preparations; however, it was not reflected in the antioxidant activities. The changes in the activity of enzymes involved in mobilisation of stored material (starch and proteins) and the increased content of phenolics only slightly modified the bioavailability of nutrients.     

Physiochemical,textural, sensory properties and probiotic survivability of Chinese Laosuan Nai (protein‐fortified set yoghurt) using polymerised whey protein as a co‐thickening agent

A new Chinese Laosuan Nai (protein‐fortified set yoghurt) was developed using polymerised whey protein (PWP, 0.4%, w/v) as a co‐thickening agent. The prototype was analysed for physiochemical, textural, sensory properties and probiotic survivability and compared with a commercial sample. Experimental yoghurts were significantly higher in pH, protein content, hardness and viscosity (P < 0.01). Microstructure indicated a uniform and denser protein network. Probiotics remained stable for Bifidobacterium during a 10‐week storage period. Results indicated that polymerised whey protein may be a novel protein‐based co‐thickening agent for making Chinese Laosuan Nai.     

Optimal production of fermented whey presenting bifidogenic growth stimulator activity

Various culture conditions for the production of fermented whey presenting bifidogenic growth stimulator (BGS) activity were evaluated using Leuconostoc mesenteroides CJNU 0147 and Lactobacillus casei CJNU 0588. The BGS activity of fermented whey produced with mixed culture of Leu. mesenteroides CJNU 0147 and L. Casei CJNU 0588 was higher than those of single cultures. The optimal temperature for the production of the fermented whey was 20°C. The anaerobic culture conditions via nitrogen gas supply had no influence on the BGS activity of fermented whey. The BGS activity of the heat-treated fermented whey samples was slightly decreased by 7.63, 11.66, and 15.12% at 80, 100, and 121°C, respectively for 15 min. Pilot-scale (75 L) fermented whey was produced using the 2 freeze-dried cell powders of CJNU 0147 and CJNU 0588 and spray-dried. The spray-dried fermented whey presented BGS activity, indicating it can be used as a functional food material.