Fermented Whey Research Articles

Novel Antioxidant Peptides from Fermented Whey Protein by Lactobacillus rhamnosus B2-1: Separation and Identification by in Vitro and in Silico Approaches.

Whey is a byproduct of the dairy industry and is rich in protein. To enhance the significance of such byproducts and find efficacious antioxidants for combating oxidative stress, this study reported on the preparation, purification, and identification of novel peptides with antioxidant activities from whey protein metabolites following fermentation by Lactobacillus rhamnosus B2-1. The isolation and identification processes involved macroporous adsorption resin column chromatography, gel filtration column chromatography, and liquid chromatography-tandem mass spectrometry. Therein, three novel antioxidant peptides (PKYPVEPF, LEASPEVI, and YPFPGPIHNS) were selected to be synthesized, and they demonstrated remarkable antioxidant activities in vitro chemical assays. PKYPVEPF, LEASPEVI, and YPFPGPIHNS (100 μg/mL) displayed a notable cytoprotective impact on HepG2 cells under oxidative stress induced by H2O2, increasing the cell viability from 49.02 ± 3.05% to 88.59 ± 10.49%, 82.38 ± 19.16%, and 85.15 ± 7.19%, respectively. Moreover, the peptides boosted the activities of catalase and superoxide dismutase in damaged cells and reduced reactive oxygen species levels. The molecular docking studies highlighted that these antioxidant peptides efficiently bound to key amino acids in the Kelch domain of Keap1, thereby preventing the interaction between Keap1 and Nrf2. In conclusion, PKYPVEPF, LEASPEVI, and YPFPGPIHNS demonstrated substantial antioxidant activity, suggesting their potential for widespread application as functional food additives and ingredients.

A CASE STUDY OF IMPLEMENTATION OF CIRCULAR ECONOMY PRINCIPLES TO WASTE MANAGEMENT: INTEGRATED TREATMENT OF CHEESE WHEY AND HI-TECH WASTE

In a global context characterized by severe environmental problems and increasing resource scarcity, waste represents both a challenge and an opportunity. This study aims to demonstrate with a real case the potential for optimizing the waste valorization action attainable through the synergic application of different treatments to residues of equally different nature and origin. In particular, bio-chemical (dark fermentation), chemical-physical (selective leaching) and thermo-chemical (hydrothermal carbonization) treatments were applied for the integrated valorization of whey from sheep cheese production and Hi-Tech waste (discarded electrical and electronic equipment). The treatments were applied at a laboratory scale on real samples of these residues. The organic acids used for selective leaching of valuable metals from Hi-Tech waste were obtained by dark fermentation of the cheese whey, while hydrothermal carbonization was used to convert the waste from previous stages into hydrochar feasible as solid fuel or soil improver. The dark fermentation tests have highlighted the possibility of recovering ≈ 100 g of organic acids from 1 L of whey; furthermore, it is also possible to recover bio-hydrogen depending on the operating conditions applied and the type of targeted organic acids. The leaching tests have demonstrated how the organic acids from whey fermentation have selective and quantitative mobilization capacities comparable to those of the same acids available on the market. The carbonization tests produced carbon-enriched hydrochar with promising fuel properties, as well as process waters suitable for anaerobic digestion with methane production. The results of the project led to the filing of an international patent.

The effect of organic fruit juices on physicochemical, microbiological and antioxidative aspects of organic goat's and cow's fermented whey beverages produced on laboratory and industrial scale

Fermented milk beverages have been known for years and are characterized by excellent health-promoting properties. Therefore, consumer attention has been drawn to this product type in recent years. In the presented research, the technology of production in laboratory and industrial scale of controlled fermentation of whey beverages containing sweet and sour organic cow's or goat's whey with the addition of organic fruit juices (apple, blackcurrant juice or Kamchatka berry), has been described. Food production on a laboratory scale involves small batch processes designed for experimentation and refinement, often with precise control over variables and conditions. In contrast, industrial-scale food production in enterprises focuses on large volume output with an emphasis on efficiency, consistency, and adherence to regulatory standards for mass consumption. In this study was examined the amino acid content and nutritional value of the obtained products. Tests were carried out on fermented whey drinks' microbiology and antioxidant properties. The significance was determined using an ANOVA (ANOVA)-each prepared drink was characterized by better antioxidant properties and nutritional values compared with product without juice addition. Microbiological examination proved that only one product was not fit for consumption according to the Polish norm. Using whey (goat and cow) as a base for a fermented beverage with enhanced health benefits is a positive step toward using products commonly regarded as waste.

A dual-chamber Microbial Electrolysis Cell for electromethanosynthesis from the effluent of cheese whey dark fermentation

Dark fermentation of cheese whey (CW) for the production of biohydrogen generates an acidic effluent, containing high concentrations of volatile fatty acids, which needs to be further treated before disposal and possibly further valorised. This study develops a dual-chamber Microbial Electrolysis Cell (MEC) that achieves simultaneously the reduction of the organic content of this effluent to environmentally acceptable levels, along with bio-electrochemical reduction of CO2 to CH4. The MEC was operated for 140 days and the effect of the following conditions on the MEC performance was examined: (a) the feed concentration of the acidic fermentate (in the range 6–81 gCOD/L), (b) the conductivity of the feed modified via KCl addition (range 2–22 mS/cm), (c) the MEC operation mode (with or without catholyte renewal) and (d) the solids content (modified via CW filtration prior to its use). The results showed that high COD removal (>95 %) was achieved in all cases, along with a CH4 production of up to 1.1 mmol/gCODconsumed. The best performance of the cell was obtained for a feed COD concentration of ∼30 gCOD/L and a feed conductivity of ∼15 mS/cm; these conditions resulted in a COD removal exceeding 99 %, a CH4 production of 1.1 mmolCH4/gCODconsumed and a net energy production of 15.8 % compared to the energy demand of the system. The electrochemical study of the system revealed that higher and lower feed COD concentrations were characterized by higher internal resistances. The results indicate that the MEC can be exploited for further treatment and valorization of a high-strength effluent along with the production of CH4 with an energy surplus, as an efficient waste-to-energy technology.

Effect of Bioactive Ingredients on Urinary Excretion of Aflatoxin B1 and Ochratoxin A in Rats, as Measured by Liquid Chromatography with Fluorescence Detection.

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are highly toxic mycotoxins present in food and feed, posing serious health risks to humans and animals. This study aimed to validate an efficient and cost-effective analytical method for quantifying AFB1 and OTA in rat urine using immunoaffinity column extraction and liquid chromatography with fluorescence detection (IAC-LC-FD). Additionally, the study evaluated the effect of incorporating fermented whey and pumpkin into the feed on the urinary excretion of these mycotoxins. The limits of detection and quantification were determined to be 0.1 µg/kg and 0.3 µg/kg, respectively, for both mycotoxins in feed, and 0.2 ng/mL and 0.6 ng/mL, respectively, in urine. The method demonstrated robust recovery rates ranging from 74% to 119% for both AFB1 and OTA in both matrices. In feed samples, the levels of AFB1 and OTA ranged from 4.3 to 5.2 µg/g and from 5.4 to 8.8 µg/g, respectively. This validated method was successfully applied to analyze 116 urine samples from rats collected during the fourth week of an in vivo trial. The results indicated that the addition of fermented whey and pumpkin to the feed influenced mycotoxin excretion in urine, with variations observed based on the sex of the rats, type of mycotoxin, and exposure dosage.

Assessing a Fermented Whey Beverage Biofortified with Folate as a Potential Folate Source for Humans.

Folate, a vital water-soluble vitamin (B9), requires specific attention as its recommended daily intake frequently is not reached in countries without mandatory fortification. In this regard, biofortification with microorganisms like Bifidobacterium and Streptococcus offers a compelling approach for enhancing food with natural folates. A randomized, nonblinded, and monocentric human pilot study is conducted to assess the bioavailability of a folate-biofortified fermented whey beverage, comprising 3 intervention days and a controlled replenishment phase before and during the assay. Folate plasma concentration (5-CH3-H4folate) is determined using a stable isotope dilution assay and LC-MS/MS detection. Biokinetic parameters (cmax and tmax) are determined, and areas under the curve (AUC) normalized to the basal folate plasma concentration are calculated. An average bioavailability of 17.1% in relation to the 5-CH3-H4folate supplement, ranging from 0% to 39.8%, is obtained. These results reiterate the significance of additional research into folate bioavailability in general and dairy products. Further investigations are warranted into folate-binding proteins (FBP) and other potential limiting factors within the food and individual factors. In summary, biofortification via fermentation emerges as a promising avenue for enhancing the natural folate content in dairy and other food products.

Valorization of Cheese Whey through Bioethanol Production and Probiotic Drink Development: A Sustainable Approach for Organic Waste Management

Cheese whey, a significant byproduct of the dairy industry, poses a substantial environmental challenge due to its organic pollutant load and large size demands for effective and affordable valorization methods. The abundance of lactose and other organic compounds in whey contributes to its elevated Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), further straining natural ecosystems. This study aimed to investigate the nutritional potential of whey and its conversion into value-added products: bioethanol and probiotic drinks. To achieve this, Bacillus megaterium and Bacillus subtilis strains, isolated from soil samples in Nepal, were co-cultured with Lactobacillus sp. and Saccharomyces cerevisiae in the whey broth for fermentation. Ethanol distillation was done using a rotary evaporator to maintain the viability of the fermenting organisms in the broth. Moreover, the probiotic criteria of the fermenting strains were extensively examined. Experimental observations revealed a remarkable concentration of 9.2 g/L of ethanol, resulting in an ethanol yield of 0.23 g/L (42% compared to theoretical yield). Extrapolating this rate, it is theoretically possible to produce an annual global bioethanol output of 5 million tons using whey as a sustainable and abundant resource. Furthermore, the study explores novel advancements in the distillation process, demonstrating the successful extraction of ethanol at room temperature. Additionally, the fermentation organisms employed in this research exhibit robust viability, surviving various in-vitro stresstolerance tests, including temperature, bile salt, pH fluctuations, and gastric juice. These resilient strains also demonstrated long-term stability in fermented whey broth, making them promising candidates for the development of probiotic beverages. This dual approach enables sustainable management of organic waste and presents an opportunity to create value-added products with positive implications for the environment and human health.

Bio-treatment of Cheese Whey by Black Soldier Fly Larvae (Hermetia illucens) reared in Algeria

Whey, a by-product of cheese industry, poses environmental challenges when discharged untreated. This study aimed to mitigate whey pollution and transform it into value-added products using black soldier fly larvae (BSFL). By investigating whey effects on BSFL growth and performance, an innovative waste management strategy was explored. The five-old-day larvae were fed with four diets; dry spent coffee ground (SCG) as the control diet, while SCG wetted with acid, sweet and fermented whey were the test diets. The results showed that whey types increased significantly (p < 0.05) BSFL growth compared to the control, the dry weight (53.83±0.49 Vs 25.10±0.18 mg/larva), growth rate (1.59±0.06 Vs 0.44±0.01 mg/day) and survival rate (78.83±1.25 Vs 68.50±1.5 %) of larvae and reduced their development time (28.00±01 Vs 37.00±01 day). Furthermore, mixing SCG diet with whey enhanced positively their performance by increasing the waste reduction (26.73±0.81 Vs 16.87±0.37 %), waste reduction index (0.85±0.03 Vs 0.45±0.01 %/day), approximate digestibility (36.49±1.52 Vs 20.29±0.53 %) and bioconversion rate (17.94±0.47 Vs11.65±0.52%). Adding whey to SCG diet increased protein content of BSFL (40.11% vs. 34.18%) and reduced fat (36.06 vs. 37.87 %) in dry mass. Whey also improved the composition of frass by increasing the phosphorus and total nitrogen levels. This approach demonstrates a sustainable solution for dairy industries waste, contributing to the circular economy and offering potential applications in animal feed and fertilizer production.

Conversion of Sweet Whey to Bioethanol: A Bioremediation Alternative for Dairy Industry

In many countries, whey from the dairy industry is an abundant waste that generates an important environmental impact. Alternative processes to use the whey and minimize the environmental impact are needed. This work considered six formulations with different ammonium sulfate and L-phenylalanine (L-Phe) concentrations to produce bioethanol in sweet whey fermentation by Kluyveromyces marxianus. The results showed a maximum bioethanol concentration equal to 25.13 ± 0.37 g L−1 (p < 0.05) for formulation F6, with 1 g L−1 of L-Phe and 1.350 g L−1 of ammonium sulfate (96 h). For these conditions, the chemical oxygen demand removal percentage (CODR%) was 67%. The maximum CODR% obtained was 97.5% for formulation F3 (1 g L−1 of L-Phe) at 96 h; however, a significant decrease in bioethanol concentration (14.33 ± 2.58 g L−1) was observed. On the other hand, for formulation, F3, at 48 h of fermentation time, a bioethanol concentration of 23.71 ± 1.26 g L−1 was observed, with 76.5% CODR%. Based on these results, we suggest that the best conditions to obtain a significant bioethanol concentration and CODR% value are those used on the configuration F3 at 48 h.

Sensorial Attributes of Fermented Whey Drinks with Either Natural or Artificial Flavoring Agents

Abstract A clear-yellowish liquid, resulting from the separation and pressing of curds in the cheese-making process, is obtained, and it is commonly known as whey. Despite being commonly regarded as waste, whey still contains some nutrients such as protein, lactose, and minerals. These compounds endow whey with the potential to be processed into a food product. However, an unwanted sensory aspect can be caused by the presence of these organic compounds. This is a consequence of chemical changes in organic compounds within whey during production and storage, which can impact flavor and lead to the formation of off flavors. One alternative that can be employed to reduce off-flavors is the conversion of whey into probiotic drinks through a fermentation process involving lactic acid bacteria (LAB). Although a fermentation process could impart a more favorable sensory aspect to whey, it is still deemed necessary to incorporate natural or artificial flavorings. Orange (citrus) is a common flavor used in food products. Consequently, this study was conducted to enhance the sensory aspect of whey by fermenting it and adding natural and artificial citrus flavorings, with subsequent evaluation through consumer acceptance. According to the study results, significant findings were observed in flavored fermented whey, exhibiting higher consumer acceptance compared to fermented whey without flavor. In conclusion, the addition of both natural and artificial citrus flavorings to fermented whey served to enhance its sensory aspect and elevate consumer acceptance.

Explorative Characterization of GI Complaints, General Physical and Mental Wellbeing, and Gut Microbiota in Trained Recreative and Competitive Athletes with or without Self-Reported Gastrointestinal Symptoms.

The current state of the literature lacks a clear characterization of gastrointestinal (GI) symptoms, gut microbiota composition, and general physical and mental wellbeing in well-trained athletes. Therefore, this study aimed to characterize differences in self-reported symptoms, gut microbiota composition, and wellbeing (i.e., sleep quality, mood, and physical (PHQ) and mental wellbeing) between athletes with and without GI symptoms. In addition, we assessed the potential impact of a 3-week multi-ingredient fermented whey supplement in the GI complaints group, without a control group, on the gut microbiota and self-reported GI symptoms and wellbeing. A total of 50 athletes (24.7 ± 4.5 years) with GI issues (GI group at baseline, GI-B) and 21 athletes (25.4 ± 5.3 years) without GI issues (non-GI group, NGI) were included. At baseline, there was a significant difference in the total gastrointestinal symptom rating scale (GSRS) score (24.1 ± 8.48 vs. 30.3 ± 8.82, p = 0.008) and a trend difference in PHQ (33.9 ± 10.7 vs. 30.3 ± 8.82, p = 0.081), but no differences (p > 0.05) were seen for other outcomes, including gut microbiota metrics, between groups. After 3-week supplementation, the GI group (GI-S) showed increased Bifidobacterium relative abundance (p < 0.05), reported a lower number of severe GI complaints (from 72% to 54%, p < 0.001), and PHQ declined (p = 0.010). In conclusion, well-trained athletes with GI complaints reported more severe GI symptoms than an athletic reference group, without showing clear differences in wellbeing or microbiota composition. Future controlled research should further investigate the impact of such multi-ingredient supplements on GI complaints and the associated changes in gut health-related markers.

Influence of Kluyveromyces lactis and Enterococcus faecalis on Obtaining Lactic Acid by Cheese Whey Fermentation

Cheese whey is a byproduct of the cheese industry that causes high levels of pollution in the environment, but its high lactose content means that it can be used as a source to obtain lactic acid. In this study, two strains, one belonging to a yeast and the other one to a bacteria (Kluyveromyces lactis and Enterococcus faecalis), were isolated from cheese whey and molecularly characterized, and the optimal growth conditions were determined. Then, using proteinized and deproteinized cheese whey, batch fermentation was carried out with the strains arranged in suspension and immobilized. The consumption of lactose and the production of lactic acid were measured through Brix degrees and acidity analysis. Afterwards, the lactic acid was purified, and its yield and physical and chemical characteristics were determined. It was proven that there were differences between each of the strains; arranged in free or encapsulated cells, the proteinized and deproteinized cheese wheys, under the same purification conditions, achieved different yields, colors, and densities of lactic acid. Immobilized Enterococcus faecalis had the highest yield (50.61 ± 34.94 g/L) using the deproteinized cheese whey compared to the immobilized Kluyveromyces lactis (35.70 ± 0.15 g/L) using the proteinized cheese whey.

Immobilization of alkaline protease produced by Streptomyces rochei strain NAM-19 in solid state fermentation based on medium optimization using central composite design.

This study evaluated Streptomyces rochei strain NAM-19 solid-state fermentation of agricultural wastes to produce alkaline protease. Alkaline protease production increased with flaxseed, rice bran, and cheese whey fermentation reaching 147U/mL at 48h. Statistical optimization of alkaline protease production was performed using the central composite design (CDD). Results of CDD and the optimization plot showed that 4.59g/L flaxseed, 4.31g/L rice bran, 4.17mL cheese whey, and a vegetative inoculum size of 7.0% increased alkaline protease production by 27.2% reaching 186U/mL. Using the 20-70% ammonium sulfate fractionation method, the optimally produced enzyme was partially purified to fivefold. The partially purified alkaline protease was then covalently immobilized on a biopolymer carrier, glutaraldehyde-polyethylene-imine-κ-carrageenan (GA-PEI-Carr), with 90% immobilization efficiency. Characterizations revealed that immobilization improved thermostability, reusability, optimum temperature, and sensitivity towards metal ions of the free enzyme. The optimal temperature for free and immobilized enzymes was 40 and 50°C, respectively. Both enzymes had the same optimum pH of 10. Immobilization increased Km from 19.73 to 26.52mM and Vmax from 56.7 to 62.5mmolmin-1L-1. The immobilized enzyme retained 35% of its initial activity at 70°C, while the free enzyme retained only 5%. The immobilized enzyme kept 80% of its initial activity at the 20th cycle. After 7weeks of storage, the free enzyme lost all its initial activity, whereas the immobilized enzyme retained 50%. The free and immobilized enzymes were able to hydrolyze gelatin, and azo-casein demonstrating different relative activity, 85, 80, 90 and 95%, respectively, compared to casein (100%).

A comparison of free amino nitrogen and yeast-assimilable nitrogen measurement methods for use in alcoholic fermentation of whey

The continued efficient use of whey as a fermentable substrate to produce alcoholic beverages will benefit from improving the measurement of key components relevant to the fermentability of whey. One component of fermentation that is not well studied in whey is the concentration of fermentable nitrogen, either as free amino nitrogen (FAN) or yeast-assimilable nitrogen (YAN). Fermentable nitrogen in media is essential for yeast cells to replicate. Insufficient concentrations of FAN or YAN to support the growing yeast population can result in sluggish or "stuck" fermentations. We evaluated 3 common methods of fermentable nitrogen determination and compared them for use in whey fermentation systems, based on ninhydrin, nitrogen by o-phthalaldehyde (NOPA), and formaldehyde pH (Sørensen titration) values. Each measurement method was evaluated independently using standard addition curves and compared for overall accuracy using paired t-tests (α = 0.05). Although the formaldehyde pH method showed high precision, it did not measure nitrogen accurately, as it overestimated YAN in whey by up to 6 times relative to other tests. The ninhydrin and NOPA methods both showed accuracy for fermentable nitrogen determination in whey based on analysis of standardized nitrogen sources. We concluded that either the ninhydrin FAN or NOPA YAN method may be used to determine the fermentable nitrogen content in whey. This is expected to improve the ability of producers to use whey as a fermentation medium.

Effect of biogenic exopolysaccharides in characteristics and stability of a novel Requeson-type cheese

Whey is a by-product of the dairy industry with considerable nutritional value but tends to be discarded with industrial effluents. One of the alternatives for its use is the production of whey cheeses, although they need to add extra ingredients to raise the yields, which elevates production costs. A less expensive alternative is using exopolysaccharides (EPS), carbohydrate polymers microorganisms produce. This research aimed to formulate and evaluate the stability of a Requeson-type cheese employing whey that has EPS produced biogenically by in situ fermentation with lactic acid bacteria. Two EPS-producing strains, Lactobacillus delbrueckii subsp bulgaricus NCFB 2772 and Streptococcus thermophilus SY-102, were used separately and in coculture (1:1 ratio). We found that coculture had the highest EPS production (1.49 mg/mL of whey) compared to the monocultures. This influenced the yield of the processed Requeson-type cheese (5.56%), which was higher than the produced with unfermented whey (3.77%). Similarly, the physicochemical and sensory parameters of the developed product showed differences. Furthermore, none of the Requeson-type cheeses made with fermented whey showed microbial growth after 21 days of storage (4 °C). Therefore, EPS is a potential strategy for producing Requeson-type whey cheeses with a high yield and stability.

Effect of Various Types of Sugars on Antioxidant Activity and Physico-chemical Properties of Kombucha Fermented Whey

Kombucha or known as SCOBY (Symbiotic Culture of Bacteria and Yeast) is a fermented tea beverage with the addition of sugar then fermented for 7-14 days. Recent studies showed kombucha conceivably used for milk fermentation, such as fermented whey, yogurt, and fermented milks. Sugar is added to kombucha as carbon source for microorganisms in kombucha. Type of sugar, sugar concentration, tea concentration, temperature and incubation time are factors that affect kombucha fermentation. The aims of this study were to determine the effect of various types of sugars on antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH)) and physicochemical properties (pH, titratable acidity, total dissolved solid, and CIE L* a* b* color space value). The various types of sugars were granulated white sugar (G1), coconut sugar (G2), palm sugar (G3) and no sugar addition as control (G0). Fermented whey using 10% kombucha liquor, 3% kombucha cellulose and 10% sugar addition, whey then fermented at 37oC for 14 hours. Result demonstrated that using of various types of sugars significantly affected antioxidant activity, CIE L*a*b* color space value, pH, titratable acidity, total dissolved solid and vitamin C content. The highest vitamin C content was G3 (0.91±0.05 mg/100ml), kombucha fermented whey using palm sugar. Any type of sugar could be used on kombucha fermented whey, and the highest antioxidant activity (DPPH) was fermented whey kombucha with the addition of coconut sugar (G2) (86.79±10.94%).

Using LAB‐fermented whey for developing bioactive edible films based on purple sweet potato flour/potato starch

SummaryDuring edible film production, several processes are carried out to maintain the probiotic viability, increasing its cost. However, fermentation to culture probiotics that will be later used for edible film production may increase their resistance during production, application and storage. Therefore, this study aimed to develop edible films based on potato starch or sweet potato flour and non‐fermented or fermented (Lactobacillus rhamnosus) whey solution. Edible films were evaluated for their physical, probiotic survival, antioxidant capacity and structural characteristics after 28 days of storage (4 and 20 °C). Selected films were used for covering commercial surimi to evaluate their effect on some quality properties. The edible films presented a moisture content of 12.68–18.97%, colour characteristics according to the powder used in their formulation, and a probiotic count higher than 9‐log cycles. The fermentation process improved the stability of antioxidant compounds in edible films during storage and gastrointestinal simulation. According to the handling characteristics, edible films based on potato starch (100%) and potato starch/sweet potato (90/10% and 80/20%) were formulated and applied. Although the consumers well‐accepted covered surimi, the probiotic counts were lower than 6‐log after storage, values below the threshold required to exert its beneficial effects in humans.

Exploring protein derivative profiles in cheese whey through native Candida tropicalis fermentation

ABSTRACT Native yeasts produce most peptides and amino acids from cheese whey fermentation. The research aimed to determine the protein, peptides, and amino acid profiles regarding whey fermentation by spontaneous fermentation and re-inoculation by native yeasts as a basis for determining potential yeasts in amino acid production. The selected native yeasts were identified through genome-based analysis on the DNA base sequence of the Internal Transcribed Spacer (ITS) region. The molecular identification shows that isolate CT1 is 95.62% comparable to Candida tropicalis strain VIT-NN02, CT2 is 98.85% same to stain NB5Y, and CT3 is 99.42% similar to GT 6. Whey fermentation was conducted by inoculating 3% each native C. tropicalis and without inoculation for spontaneous fermentation, then incubated for 48 hours at ambient temperature (26 ± 2°C). Unlike the other samples, the spontaneously fermented mozzarella whey was incubated without inoculation after cheese separation. After 48 hours, fermented whey was kept at 4°C for examination. The Kjeldahl method evaluated protein concentration, Folin-Ciocalteau determined peptide levels, and HPLC determined amino acid composition. C.tropicalis was identified as cheese whey native yeasts, and all treatments decreased protein and peptides while increased the total amino acid includes every single amino acid value except histidine during isolate CT1 whey fermentation. Candida tropicalis CT2 shown as potential isolate for the amino acid production from whey, with the protein contents of 0.846 ± 0.151%, protein decreases of 0.384 ± 0.186, peptide levels of 264.75 ± 40.40ppm, peptide decreases of 99.87 ± 37.96 and the highest total amino acid of 6149.56ppm.

Metagenetic analysis of the bacterial diversity of Kazakh koumiss and assessment of its anti-Candida albicans activity.

Koumiss, a five-thousand-year-old fermented mare's milk beverage, is widely recognized for its beneficial nutrient and medicinal properties. The microbiota of Chinese and Mongolian koumiss have been largely characterized in recent years, but little is known concerning Kazakh koumiss despite this drink historically originates from the modern Kazakhstan territory. In addition, while koumiss is regarded as a drink with therapeutic potential, there are also no data on koumiss anti-Candida activity. In this context, the aims of the present study were to investigate the bacterial diversity and anti-Candida albicans activity of homemade Kazakh koumiss samples as well as fermented whey and cow's milk, derived from koumiss and propagated for several months. Koumiss bacterial communities were largely dominated by lactic acid bacteria including Lactobacillus sensu lato spp. (69% of total reads), Streptococcus (8.0%) and Lactococcus (6.1%), while other subdominant genera included Acetobacter (2.6%), Enterobacter (2.4%), and Klebsiella (1.5%). Several but not all koumiss samples as well as fermented whey and cow's milk showed antagonistic activities towards C. albicans. Linear discriminant effect size (LEfSe) analysis showed that their bacterial communities were characterized by a significantly higher abundance of amplicon sequence variants (ASV) belonging to the genus Acetobacter. In conclusion, this study allowed to identify the key microorganisms of Kazakh koumiss and provided new information on the possible underestimated contribution of acetic acid bacteria to its probiotic properties.

In Vitro Digestibility Assessment of Whey from Goat and Camel Milk Fermented with Lactobacillus helveticus for Use as a Base in Formulating Follow-On Formula.

Follow-on formulas are necessary for newborns that are unable to breastfeed. Thus, the development of formulas more tailored to infants' needs is highly important. Recently, using camel milk, goat milk, and sweet milk whey in the formulation of follow-on formulas has gained researchers' attention. Moreover, developing postbiotic systems to create formulas that mimic human milk, are easy to digest, improve compatibility with an infant's gut, and boost immunity is crucial. Thus, this study aimed to create and assess different formulations using fermented whey from camel and goat milks. The fermentation process involved the use of Lactobacillus helveticus as a probiotic and proteolytic lactic acid bacterium strain. The study monitored the proteolytic activity and antioxidant properties of sweet whey produced from cow, camel, and goat milks during the fermentation process with L. helveticus. Also, three different milk fat blends were recombined using edible vegetable oils (coconut oil, rice bran oil, and canola oil) and then they were used to formulate follow-on formulas with a similar fat composition to human milk. Finally, the prepared formulas were tested for their in vitro digestibility and antioxidant activity before and after digestion. The L. helveticus strain had high proteolytic activity towards whey proteins from all the types of milk used in the study. A fermentation time of 6 h produced a higher proteolytic degree and antioxidant activity than 2 and 4 h of fermentation. No significant differences were observed for proteolytic degree and antioxidant activity between 6 and 12 h of fermentation for the cow, camel, and goat whey samples. Regarding the fat blends, animal milk fat, rice bran oil, and canola oil in a fat combination were essential to provide the required amount of unsaturated fatty acids in the follow-on formulas, especially the linoleic acid-α-linolenic acid (LA:ALA) ratio. Adding coconut oil in small amounts to the follow-on formulas provided the required amounts of saturated fatty acids, especially lauric and meristic acids. The follow-on formula based on cow or goat milk whey fermented with L. helveticus released more free amino acids (mmol tyrosine equivalent mL-1) with high levels of antioxidants compared to unfermented ones. The release of free amino acids in the follow-on formula based on camel milk whey was not affected by fermentation. Our results recommend using L. helveticus in the fermentation of follow-on formulas based on camel and goat whey instead of formulas based on cow milk proteins.