Search Results (155)

Kombucha is a fermented tea beverage of Asian origin, widely consumed due to its functional properties; yet, it typically lacks sufficient levels of probiotic micro-organisms to be classified as a probiotic product. This review analyzes the occurrence of lactic acid bacteria (LAB) in kombucha, reporting that concentrations rarely exceed 4–5 log CFU/mL and often decline during fermentation or storage. Strategies to enhance probiotic viability, including the use of robust LAB strains and encapsulation technologies, are critically evaluated. Notably, encapsulation using pea and whey protein has been shown to sustain LAB levels above 6 log CFU/mL during fermentation and up to 21 days under refrigerated storage for whey protein. Fortified kombucha beverages with probiotic strains have also been shown to possess enhanced functional and health-promoting benefits compared to traditional control samples. Despite promising approaches, inconsistencies in microbial survival and regulatory constraints remain key challenges. Future research should focus on the optimization of delivery systems for probiotic cultures, identification of kombucha-compatible LAB strains and standardized protocols to validate probiotic efficacy in real-world beverage conditions. Full article

A high intake of saturated fats and cholesterol from processed meats is associated with increased cardiovascular disease risk. This study aimed to develop a nutritionally enhanced Bologna-type sausage by partially replacing the beef content with a structured emulsion gel (EG) formulated from pine nut oil, inulin, carrageenan, and whey protein concentrate. The objective was to improve its lipid quality and functional performance while maintaining product integrity and consumer acceptability. Three sausage formulations were prepared: a control and two variants with 7% and 10% EG, which substituted for the beef content. The emulsion gel was characterized regarding its physical and thermal stability. Sausages were evaluated for their proximate composition, fatty acid profile, cholesterol content, pH, cooking yield, water-holding capacity, emulsion stability, instrumental texture, microstructure (via SEM), oxidative stability (TBARSs), and sensory attributes. Data were analyzed using a one-way and two-way ANOVA with Duncan’s test (p < 0.05). The EG’s inclusion significantly reduced the total and saturated fat and cholesterol, while increasing protein and unsaturated fatty acids. The 10% EG sample achieved a PUFA/SFA ratio of 1.00 and an over 80% reduction in atherogenic and thrombogenic indices. Functional improvements were observed in emulsion stability, cooking yield, and water retention. Textural and visual characteristics remained within acceptable sensory thresholds. SEM images showed more homogenous matrix structures in the EG samples. TBARS values increased slightly over 18 days of refrigeration but remained below rancidity thresholds. This period was considered a pilot-scale evaluation of oxidative trends. Sensory testing confirmed that product acceptability was not negatively affected. The partial substitution of beef content with pine nut oil-based emulsion gel offers a clean-label strategy to enhance the nutritional quality of Bologna-type sausages while preserving functional and sensory performance. This approach may support the development of health-conscious processed meat products aligned with consumer and regulatory demands. Full article

Whey protein isolate (WPI) hydrogel is a promising candidate as a biomaterial for tissue engineering. Previously, WPI hydrogels containing poly-γ-glutamic acid (γ-PGA) with a molecular weight (MW) of 440 kDa demonstrated potential as scaffolds for bone tissue engineering. Here, the study compares different γ-PGA preparations of differing MW. WPI-γ-PGA hydrogels containing 40% WPI and 0%, 2.5%, 5%, 7.5%, and 10% γ-PGA were synthesised. Three γ-PGA MWs were compared, namely 10 kDa, 700 kDa, and 1100 kDa. Evidence of successful γ-PGA incorporation was demonstrated by scanning electron microscopy and Fourier transform infrared spectroscopy. Increasing γ-PGA concentration significantly improved the swelling potential of the hydrogels, as demonstrated by ratio mass increases of between 85 and 90% for each 10% variable group. Results suggested that γ-PGA delayed enzymatic proteolysis, potentially decreasing the rate of degradation. The addition of γ-PGA significantly decreased the Young’s modulus and compressive strength of hydrogels. Dental pulp mesenchymal stem cells proliferated on all hydrogels. The highest cellular growth was observed for the WPI-700 kDa γ-PGA group. Additionally, superior cell attachment was observed on all WPI hydrogels containing γ-PGA compared to the WPI control. These results further suggest the potential of WPI hydrogels containing γ-PGA as biomaterials for bone tissue engineering. Full article

Beer lees (BL), a by-product of beer production, consist mainly of dead yeast cells with potential nutritional value. On the other hand, yeast extract (YE), obtained through the lysis of yeast cells, is commonly used as a nutrient-rich supplement for the growth of fastidious microorganisms such as lactic acid bacteria (LAB). However, YE is a high-cost ingredient. Therefore, the aim of this study was to optimize the use of BL as a low-cost alternative source of YE through different lysis treatments, evaluating its suitability to support the growth of UNQLpc 10 and UNQLp 11 strains in a whey permeate (WP)-based medium. Growth kinetics and cell viability were compared with those obtained in MRS broth. The best results were observed with sonicated BL, up to 10 logarithmic units, which supported LAB growth comparable to MRS. Although autolyzed BL promoted lower bacterial growth than sonicated BL, it showed greater cell disruption and higher levels of nitrogen, proteins, and amino acids (5.32%, 26.0%, and 277 nM, respectively). Additionally, autolyzed BL exhibited lower concentrations of reducing sugars and a higher presence of Maillard reaction products, as indicated by colorimetric analysis. These changes, which may be related to the formation of Maillard reaction products during the autolysis process, could have negatively affected the nutritional quality of the extract and, thus, reduced its effectiveness as a bacterial growth promoter. Full article

The pathogenesis of Parkinson’s disease (PD) consists of the apoptosis of dopaminergic neurons in the substantia nigra pars compacta (SNpc) due to oxidative stress. The present study aimed to evaluate the potential antioxidant activity of whey protein isolate (WPI) in PD models, using neurotoxin-exposed SH-SY5Y cells differentiated into dopaminergic-like neurons. Our research shows that WPI’s high glutamic acid, aspartic acid, and leucine contribute to its antioxidant and neuroprotective effects, with glutamic acid crucial for glutathione synthesis. In vitro studies found that WPI, at concentrations of 5–1000 µg/mL, is non-toxic to differentiated SH-SY5Y cells. Notably, the lowest con-centration of WPI (5 µg/mL) significantly decreased intracellular reactive oxygen species (ROS) levels in these cells following a 24 h co-treatment with 1-methyl-4-phenylpyridinium (MPP⁺). The antioxidant effects of WPI were also confirmed by the increased expression of HO1 and GPx antioxidant enzymes, which are Nrf2 pathway target genes and were evaluated by real-time PCR. Furthermore, Nrf2 nuclear translocation in the differentiated SH-SY5Y cells was also increased when the cells were exposed to 5 µg/mL of WPI with MPP⁺. These results together suggest that WPI has antioxidant effects on dopaminergic-like neurons in a Parkinson’s disease model. Full article

This work concerns the spray drying of probiotic bacteria Lacticaseibacillus rhamnosus GG suspended in a solution of starch, whey protein concentrate, soy lecithin, and ascorbic acid, with additional selected natural plant-origin liquid oils. The aim of this study was to examine these oils and their concentrations (20% and 30%) on bacterial viability during the spray drying (inlet temperature was 180 °C, outlet temperature from 50 to 54 °C, feed rate around 9 mL/min) and storage for 4 weeks at 4 °C and 20 °C, with attempts to explain the protective mechanism in respect including their fatty acid composition. The viability of microencapsulated bacteria, moisture content, water activity, color properties, morphology, particle size of obtained powders, and thermal properties of encapsulated oils were evaluated. The highest viability of bacterial cells after spray drying 83.7% and 86.0%, was recorded with added borage oil respectively with 20% and 30% oil content. This oil has a lower content of oleic and linoleic acid compared to other applied oils, but a high content of both vitamin E and γ- linoleic acid. However, this study did not confirm unambiguously whether and which of the components present in natural plant oils specifically affect the overall viability of bacteria during spray drying. Full article

An emulsion gel was developed to replace animal fats in meat products while preserving desirable sensory and structural attributes. The gel was prepared by emulsifying pine nut oil and sunflower oil with whey protein concentrate (WPC) and polysaccharides (inulin and carrageenan). Process parameters, including the inulin-to-water ratio, homogenization speed, and temperature, were optimized to achieve stable gels exhibiting high water- and fat-binding capacities. Scanning electron micrographs revealed a cohesive network containing uniformly dispersed lipid droplets, with carrageenan promoting a denser matrix. Chemical assessments demonstrated a notably lower saturated fatty acid content (10.85%) and only 0.179% trans-isomers, alongside an elevated proportion (71.17%) of polyunsaturated fatty acids. This fatty acid profile suggests potential cardiovascular health benefits compared with conventional animal fats. Texture analyses showed that carrageenan increased gel strength and hardness; Experiment 4 recorded values of 15.87 N and 279.62 N, respectively. Incorporation of WPC at moderate levels (3–4%) further enhanced the yield stress, reflecting a robust protein–polysaccharide network. These findings indicate that the developed emulsion gel offers a viable alternative to animal fats in meat products, combining superior nutritional attributes with acceptable textural properties. The substantial polyunsaturated fatty acid content and minimal trans-isomers, coupled with the gel’s mechanical stability, support the feasibility of creating reduced-fat, functional formulations that align with consumer demands for healthier alternatives. Full article

The biological and nutritional value of kefir makes it imperative to widen its customer reach by extending its shelf life, enabling its storage and transport at ambient temperatures, and reducing its packaging cost requirements. A well-documented and widely used food processing method that can achieve the above-mentioned outcomes is spray drying through the formulation of kefir powder, with quality attributes that will closely resemble that of the original product. In the present work, a variety of drying carriers (trehalose, fructo-oligosaccharides, maltodextrin, gum arabic, and whey proteins) were studied with regard to their effect on the properties of powdered and reconstituted kefir samples. Particularly, the physicochemical characteristics (moisture content, pH, acidity, color), powder properties (bulk density, tapped density, water solubility index, insoluble matter), adsorption isotherms, particle size distribution, microbiological properties, and structural characteristics of the samples were evaluated. Gum arabic and maltodextrin produced kefir powder samples with the lowest moisture content. Spray drying affected a reduced acidity and, as a consequence, an increased pH in the reconstituted samples, especially without any carrier addition and with trehalose and fructo-oligosaccharides irrespective of their concentration. Desirable color attributes were achieved on the kefir powder samples with trehalose, fructo-oligosaccharides, and maltodextrin regardless of their concentration in the product. Fructo-oligosaccharides, added at 3%, gave the highest values of bulk density, while whey proteins, due to their nature, exhibited the lowest. All carriers tested improved the water solubility index when compared to the control sample. The sample with 10% whey proteins exhibited the lowest moisture adsorption compared to the control at the highest relative humidity environments employed for the test. In the absence of agglomeration, powder granule size and structural morphology were not affected by the carriers. The survival of lactococci in the powdered kefir samples, in comparison to the control product, was higher in the case where 4% trehalose or 5 to 10% whey proteins were added. On the contrary, yeast populations decreased significantly during drying and they were not affected by the presence of the different carriers. As shown by the findings of the present study, trehalose proved to be the most effective carrier, among the others used, for producing high-quality kefir powder products. However, further work is required with regard to the keeping quality of the product during long-term storage. Full article

The present study examines the effect of low-temperature thermal treatment before drying, through storage at −10 °C and 4 °C for 72 h, respectively, on the physicochemical and microbiological properties of spray-dried kefir powder. Furthermore, with the intention of improving the rheological behavior of the reconstituted product, texture modifiers were employed including milk proteins (milk proteins, sodium caseinates, and whey protein concentrates) and carrageenan. According to the results, the low-temperature thermal treatment of kefir, prior to drying, resulted to an increased moisture content and yellowness of the kefir powder samples, with a simultaneous drop to the whiteness index and an increase of the particle size in both the powder and the reconstituted samples. The sample with prior treatment at 4 °C for 72 h, exhibited decreased pH values and increased acidity for both kefir and reconstituted product, while it also improved post drying population survival of lactobacilli and yeasts. The reconstituted sample with prior treatment at −10 °C for 72 h, exhibited evident pseudoplastic behavior, which, at low shear rates, yielded viscosity values very close to those of the fresh control kefir. Addition of sodium caseinates, in the absence and/or simultaneous presence of carrageenan, resulted to the highest viscosity increase of the reconstituted products. Milk proteins with the combined presence of carrageenan exhibited similar apparent viscosity values to the control. Full article

Purpose: Whey protein (WP) consumption prior to a meal curbs appetite and reduces postprandial glucose (PPG) through stimulating endogenous GLP-1 secretion and insulin. Methods: We assessed the metabolic effects of a concentrated WP, using a new micelle-technology (WPM), in people with type 2 diabetes (T2D) and overweight or obesity (NCT04639726). In a randomized-crossover design, participants performed two 240 min lunch meal (622 kcal) tests 7 ± 4 days apart. After an overnight fast and a standardized breakfast, 10 g (125 mL) WPM (40 kcal) or placebo (125 mL water, 0 kcal) was consumed 15 min ahead of the mixed-nutrient meal. Effects on PPG (primary endpoint), insulin, GLP-1, and branched-chain amino acids (BCAAs) were evaluated with frequent blood sampling. Changes in incremental areas under the concentration curve (iAUC) were compared using a mixed model. Results: Twenty-six individuals (14 females, mean ± SD age 62.0 ± 8.3 years, HbA1c 58 ± 12 mmol/mol/7.5 ± 1.1%, BMI 29.2 ± 4.8 kg/m²) completed both tests. WPM significantly reduced PPG iAUC_0–2h by 22% (p = 0.028), and iAUC_0–3h numerically by −18% (p = 0.090) vs. placebo. WPM also increased insulin iAUC_0–1h by 61% (p < 0.001), and iAUC_0–3h by 30% (p = 0.004), respectively. Total GLP-1 iAUC_0–2h was enhanced by 66% (p < 0.001). Postprandial plasma BCAA patterns were characterized by a rapid increase and larger iAUC_0–2h (all p < 0.001) after WPM. No adverse events were ascribed to consuming WPM. Conclusions: A 125 mL pre-meal drink containing just 10 g WPM before a mixed meal reduced PPG and increased insulin, GLP-1, and BCAAs. WPM may therefore serve as a metabolic modulator in people with T2D living with overweight or obesity. Full article

Protein-enriched yogurts have become increasingly popular among consumers seeking to boost their daily protein intake. The incorporation of milk proteins and protein preparations in yogurt production not only enhances nutritional value but also improves texture, viscosity, and overall sensory properties—key factors that influence consumer acceptance. The main objective of this study was to evaluate the influence of casein and whey protein preparations on the physicochemical properties, viability of lactic acid bacteria, and sensory attributes of yogurts. Yogurts were enriched with 2% (w/w) protein preparations, including micellar casein preparation (CN85), whey protein isolate (WPI), whey protein concentrate (WPC60), and protein preparations obtained from skim milk by membrane filtration: micellar casein concentrate (CN75) and serum protein concentrate (SPC). The yogurts were produced using the thermostatic method, and their chemical composition, rheological properties, syneresis, firmness, lactic acid bacteria population, and sensory attributes were evaluated. The effects of high-protein preparations derived from skim milk through laboratory-scale membrane filtration processes (SPC, CN75) were compared with those of commercially available protein preparations (SMP, CN85, WPI, and WPC). Obtained results demonstrated that the membrane filtration-derived preparations (SPC and CN75) exhibited advantageous physicochemical properties and supported robust viability of yogurt and probiotic bacteria. However, their sensory quality was marginally inferior compared to the commercial preparations (SMP, CN85, WPI, and WPC). These findings indicate the potential applicability of membrane filtration-derived protein preparations in yogurt production while underscoring the necessity for further investigation to enhance and optimize their sensory characteristics. Full article

The amino acid (AA) content of multiple samples of various dairy powders was determined, providing a comprehensive evaluation of the differences in AA profiles attributable to distinct manufacturing processes. Products examined included whole milk powder (WMP), skim milk powder (SMP), cheese whey protein concentrate (WPC-C), lactic acid casein whey protein concentrate (WPC-L), high-fat whey protein concentrate (WPC-HF), hydrolyzed whey protein concentrate (WPH), whey protein isolate (WPI), and demineralized whey protein (D90). WMP and SMP exhibited broadly similar AA profiles, with minor differences likely due to the minimal milk fat protein content, which is nearly absent from SMP. Comparative analysis of WPC-C and WPC-L indicated higher levels of threonine, serine, glutamic acid, and proline in WPC-C but lower levels of tyrosine, phenylalanine, and tryptophan, attributed to the different methods of separation from casein proteins. WPI and WPC-HF originate from similar sweet whey streams but follow divergent processing methods; consequent on this were variations in the levels of all AAs except histidine. The nanofiltration step in D90 production retains its non-protein nitrogen content and affects its AA profile; consequently, D90 consistently exhibited lower AA levels than WPC-C. These findings underscore the significant impact of manufacturing processes on dairy powder AA composition. Full article

In this study, different molecular weight cut-off ultrafiltration membranes (100 and 50 kDa) were used to concentrate and separate whey protein and blueberry juice fermented system by lactic acid bacteria (LAB) to demonstrate that the mixed fermentation had a protective effect on LAB and antioxidant activity during in vitro gastrointestinal digestion. The antioxidant activity after gastrointestinal digestion, the survival rate of LAB after membrane filtration, and their ability to reflect ultraviolet light of the membrane concentrated fermented components were investigated. It was found that the ABTS cationic free radical scavenging ability of L. plantarum 67 and L. paracasei W125 fermented group increased by 7.85%, especially after digestion, which increased by 3.17% compared with the unfermented blueberry and whey protein mixed group. The survival rates of L. plantarum 67 and L. paracasei W125 in the blueberry-whey protein mixture were greater than 82.45% after digestion. The ultrafiltration membrane concentration process had little effect on the viability of LAB during 0–50 min. The mixture of L. bulgaricus 134 and S. thermophiles Grx02 fermented blueberry-whey protein showed strong UV reflection at 300 nm, reaching 27.39%. The mixture of L. plantarum 67 and L. paracasei W125 fermented blueberry-whey protein showed strong UV reflection at 335 nm, reaching 34.29%. Full article

The present work reports on the microencapsulation of Lacticaseibacillus rhamnosus GG (LGG) by the spray-drying process using a solution of starch, whey protein concentrate (WPC), soy lecithin and ascorbic acid as a carrier, with addition of different types of butters. The aim of this study was to examine the protective mechanism of six different butter samples on the viability rate of LGG bacteria directly after the spray-drying process and during storage for 4 weeks at 4 °C and 20 °C (±1 °C) based on hypothetical factors—the fatty acid’s chemical character and content, and its melting enthalpy. The viability of bacteria, moisture content, water activity, color properties, morphology, particle size of powder, melting enthalpy of butters and their fatty acids composition were evaluated. It is assumed that the highest viability may be indirectly influenced by the relationship between the highest content of proteins and sugars and the lowest content of fats and fatty acids, which is characteristic for butter with a reduced fat content. This butter contained also the least monounsaturated and polyunsaturated fatty acids. The highest number of viable LGG (for systems with reduced-fat butter, as well as salted and lactose-free butter) may be caused by (among other factors) by the lower content of palmitic acid (C16: 0). For these butters, it was also observed that cell viability increased with the increase in melting enthalpy. The results confirmed the protective role of selected butters, which indicates the possibility of using them in industrial processes to increase the durability of additives and products using probiotic powders obtained by spray-drying. Full article

Different solvents water, ethanol and ethanol/water (6:4 v/v), were compared in the extraction of pomegranate peels and seeds (PPS) in terms of recovery yields, antioxidant properties, and antimicrobial action against typical spoilage bacterial and fungal species. The best performing extract (ethanol/water (6:4 v/v) was shown to contain mostly ellagic acid and punicalagin as phenolic compounds (5% overall) and hydrolysable tannins (16% as ellagic acid equivalents) and was able to inhibit the growth of the acidophilic Alicyclobacillus acidoterrestris at a concentration as low as 1%. The preservation of the organoleptic profile of A. acidoterrestris-inoculated apple juice with extract at 1% over 20 days was also observed thanks to the complete inhibition of bacterial growth, while the extract at 0.1% warranted a significant (40%) inhibition of the enzymatic browning of apple smoothies over the first 30 min. When incorporated in whey proteins’ isolate (WPI) at 5% w/w, the hydroalcoholic extract conferred well appreciable antioxidant properties to the resulting coating-forming hydrogel, comparable to those expected for the pure extract considering the amount present. The WPI coatings loaded with the hydroalcoholic extract at 5% were able to delay the browning of cut fruit by ca. 33% against a 22% inhibition observed with the sole WPI. In addition, the functionalized coating showed an inhibition of lipid peroxidation of Gouda cheese 2-fold higher with respect to that observed with WPI alone. These results open good perspectives toward sustainable food preservation strategies, highlighting the potential of PPS extract for the implementation of WPI-based active packaging. Full article