Search Results (393)

Soft spread cheese is highly perishable, and conventional packaging offers limited protection against surface spoilage. Here, we present a sustainable, multifunctional solution: edible films made from whey protein concentrate (WPC), a valuable by-product of the cheese industry, incorporated with the probiotic Lactobacillus acidophilus LA5 (LA5). The objective of this study was to evaluate these films as active coatings for soft cheese, specifically assessing their physicochemical properties, probiotic viability during storage and simulated gastric transit, and their impact on cheese microbial stability and sensory quality over 60 days. Applied as active coatings on soft cheese stored at 4 °C for 60 days, these films were evaluated for their physicochemical properties, probiotic viability, microbial stability, and sensory acceptance. The incorporation of LA5 did not significantly alter film thickness (control: 0.20 ± 0.03 mm; test: 0.18 ± 0.02 mm), moisture content (control: 33.42 ± 0.54%; test: 32.34 ± 1.28%), or water solubility (control: 21.44 ± 1.14%; test: 22.89 ± 0.75%) (p > 0.05). However, mechanical properties were markedly modified: tensile strength decreased from 35.42 ± 5.38 MPa (control) to 6.04 ± 0.55 MPa (test), while elongation at break increased from 4.87 ± 0.93% to 68.23 ± 3.46% (p < 0.05), indicating a transition from rigidity to flexibility upon probiotic incorporation. The probiotic strain exhibited exceptional resilience, retaining 100% viability during simulated gastric exposure at both day 0 and day 30 of storage. During cheese storage, LA5 counts in test film-coated samples remained above the recommended therapeutic threshold (10⁶ cfu/g), starting at 7.44 ± 0.15 log(cfu/g) on day 0 and maintaining 6.56 ± 0.20 log(cfu/g) after 60 days. Critically, yeast and mold spoilage were delayed in probiotic-coated cheese, with detectable growth appearing only at day 60 (1.64 ± 1.34 log(cfu/g)), whereas uncoated cheese showed spoilage as early as day 28 (1.33 ± 1.62 log(cfu/g)). Sensory evaluation revealed no significant differences (p > 0.05) between the coated and uncoated samples for color, appearance, texture, flavor, or overall acceptability. By valorizing a dairy by-product into an active, probiotic-loaded edible film, this approach offers a sustainable, waste-reducing strategy that enhances cheese preservation while delivering added functional value—bridging the gap between food packaging and nutrition. Sensory evaluation (n = 8, preliminary) indicated no significant differences between coated and uncoated samples, but these results require confirmation with a larger, validated panel. Full article

Cheese whey, a byproduct of the dairy industry, has a high organic load and nutrient availability, associated with parameters such as chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP), representing an environmental problem when improperly disposed, and even considering the traditional biological wastewater treatment (secondary treatment), a polishing step (tertiary treatment) could be required in order to meet legislation parameters of discharge in water bodies. This study evaluated the efficiency of co-cultivation between the microalga Tetradesmus obliquus and the yeast Saccharomyces cerevisiae during the tertiary (advanced) treatment of dairy effluent. The process was operated in batch mode to optimize the COD:N ratio and, subsequently, in semicontinuous mode applying the volumetric replacement rates (VRRs) of 40% and 60%. In the batch stage, the COD:N ratio of 20 stood out as the most balanced in terms of nutritional requirement, achieving removal rates of 85.49% for COD, 96.23% for total Kjeldahl nitrogen (TKN), and 100% for TP. In the semicontinuous system, a VRR of 40% optimized nitrogen (91.67%) and phosphorus (95.93%) recovery while COD was also removed (71.68%). The pH remained stable within the range of 7.0 to 7.5 at the end of the process, indicating self-buffering of the consortium. Biomass production reached 915 mg·L⁻¹ (dry cell weight) in batch operation mode and 720 mg·L⁻¹ in semicontinuous mode (VRR of 40%). The results confirmed that the T. obliquus and S. cerevisiae co-cultivation constitutes a stable and sustainable strategy for nutrient recovery during dairy wastewater treatment, aligning with the principles of circular bioeconomy. Full article

Sheep and goat milk are mainly used for cheese manufacture in small livestock farms, giving rise to a large volume of whey. Sheep and goat cheese whey possess excellent and specific functional and nutritional characteristics. The valorization of these valuable by-products through physicochemical or biotechnological processes compatible with artisanal production are important in terms of sustainability, i.e., economic, social, and environmental impacts. The main challenges for whey processing in small and medium-size enterprises (SMEs) are the lack of equipment, construction and information as well as the small amounts of cheese whey generated from these plants. Membrane technology can be convenient to produce valuable by-products for small dairy plants in the presence of enough investment cost and whey amount. Biotechnological treatments covering anaerobic digestion systems and fermentation processes are advantageous for SMEs over physicochemical methods on investment cost. In these processes, efficient microorganisms are able to produce high-value natural products, biofuels, and biopolymers. Anaerobic digestion is a suitable method for goat and sheep cheese whey valorization in SMEs due to the small volumes. Additionally, bioconversion into fermented beverages is a good choice for cheese whey valorization in SMEs because of its low operational and equipment cost. Full article

This study investigated the valorization of chicken feet, an underutilized poultry by-product, through enzymatic hydrolysis to obtain a protein hydrolysate with improved functional properties. Enzymatic treatment was carried out using Enzy-Mix U100 and collagenase from Streptomyces lavendulae, with cheese whey applied as a process medium. The resulting protein hydrolysate contained 59.1% protein and was characterized by high levels of glycine (31.64 g/100 g protein), hydroxyproline (10.91 g/100 g protein), and alanine (10.58 g/100 g protein). The hydrolysate exhibited strong techno-functional performance, with a water-binding capacity of 580%, an emulsifying activity index of 166 m²/g, and an emulsion stability index of 31 min. Microstructural analysis revealed irregular porous particles typical of freeze-dried protein hydrolysates, reflecting structural modification of collagen during enzymatic treatment. Mineral analysis showed notable levels of sodium (463.1 mg/100 g) and magnesium (351.8 mg/100 g). Microbiological evaluation demonstrated high sanitary quality, with a total viable count of 100 CFU/g and absence of coliforms, Escherichia coli, yeasts, and molds in 1 g of product. The technological process reduced the characteristic odor of chicken feet while maintaining a light color and good dispersibility. These findings confirm the potential of enzymatic hydrolysis as a sustainable strategy for converting poultry by-products into safe, value-added functional protein ingredients for food applications. Full article

Cheese whey, a low-value by-product of cheese production, has gained renewed attention within the transition toward sustainable and circular food systems. Despite posing environmental challenges due to its high biochemical and chemical oxygen demand, whey retains a substantial proportion of milk nutrients, notably high-quality proteins that can be converted into bioactive peptides with potential health benefits. These peptides have been shown to modulate key biological pathways, including angiotensin-converting enzyme inhibition, nitric oxide bioavailability, oxidative stress balance, and inflammatory signaling, providing mechanistic plausibility for cardioprotective and immunomodulatory effects. However, the translation of promising in vitro and animal findings into consistent human health outcomes remains constrained by variability in peptide composition, processing conditions, bioavailability, and study design. This narrative review critically synthesizes current evidence on the functional properties of whey-derived peptides, with particular emphasis on cardiovascular and immunomodulatory outcomes across experimental models. In addition, the review situates whey upcycling within the Portuguese agro-food context, highlighting regional cheese production as both an environmental challenge and an opportunity for sustainable innovation. By integrating mechanistic evidence with sustainability-driven valorization strategies, this review aims to clarify the translational potential of whey-derived peptides as functional food ingredients. Full article

This study was aimed at producing galactooligosaccharides (GOS) from Porungo cheese whey in immobilized enzyme bioreactors. The β-galactosidase was produced, concentrated, and immobilized on chitosan–genipin supports. Initially, GOS production was conducted in conical flasks, investigating three different variables: enzyme concentration (50–150 U/mL), Porungo cheese whey concentration (200–400 g/L), and temperature (37–43 °C). The highest GOS yields (15.24%) occurred under intermediate process conditions (100 U/mL, 300 g/L, 40 °C), reaching a GOS concentration of 27.04 g/L. These conditions were then used in a packed-bed column bioreactor operated in batch mode, achieving yields of 19.72%. Repeated batches were carried out, and the system was stable until the fifth cycle, with enzyme activity remaining at 83.56% of the initial level. Continuous bioreactors were conducted, varying feed flow rates (1–3 mL/h), with the highest yields and lactose conversion occurring for the longest residence time (24.63% and 68.38%), respectively, with high GOS concentration (44.14 g/L). Microorganisms isolated from Porungo cheese showed the ability to metabolize the GOS produced, demonstrating its prebiotic potential. This work can contribute to optimizing the production of GOS, an important product for pharmaceuticals and food industries. Full article

The aim of the research was to assess changes in the bioactive status of organic yoghurts produced in the spring/summer season from Simmental cows’ bulk milk during 28-day refrigerated storage, including whey proteins, lipophilic vitamins, and free fatty acids, and to interpret these changes not only in terms of compositional stability but also regarding their nutritional significance, as evaluated using the IYQ (Index of Yoghurt Quality) for vitamins. Raw milk was found to be a significantly richer source of biologically active compounds compared with milk subjected to heat treatment. During the 28-day refrigerated storage of the yoghurts, unfavourable alterations were observed in the levels of selected bioactive components belonging to both the protein and lipid fractions. A reduction in the concentration of the analyzed proteins and vitamins was observed, ranging from 2% for vitamin D₃ to 38% for lactoferrin, while the content of free fatty acids increased, from 8% for monounsaturated free fatty acids (MUFFAs) to 39% for short-chain free fatty acids (SCFFAs). The most pronounced changes were observed in lactoferrin content (p ≤ 0.01), whereas vitamin D₃ exhibited the highest stability throughout the storage period. The stability of vitamin D₃ was further confirmed using the Index of Yoghurt Quality (IYQ). Despite the significant changes observed in the bioactive profile, the yoghurts retained high sensory quality throughout the entire storage period. This indicates that alterations in bioactive status did not compromise the sensory quality of the product, even after 28 days of storage (i.e., at the end of the shelf life). The obtained results indicate the feasibility of developing organic milk processing directly at the farm level while preserving the nutritional value of the products. The possibility of processing organic milk not only into cheese but also into fermented dairy beverages, particularly yoghurts, is of key importance for farmers aiming to diversify production, increase added value, and improve the economic sustainability of small-scale organic farms. Full article

The aim of the circular economy for plastics is to replace some of them with bio-based polymers in the future. In this work, second cheese whey (SCW) was used as a low-cost substrate for the production of the natural polyester poly(3-hydroxybutyrate)-hydroxybutyrate (PHB) by three Pseudomonas sp. phDV1 strains, namely, the wild type, a depolymerase PhaZ and PhaR knockout mutants. SCW has high polluting loads, characterized by high levels of lactose, phosphorus, nitrogen and salinity, as well as high turbidity due to the presence of whey solids. Initially, SCW was evaluated as the sole carbon source for the growth of the bacterial strains and the production of PHB. Fermentation conditions were screened to maximize polymer synthesis. Small-scale experiments showed that the strains could grow and produce PHB in SCW with and without enzymatic treatment. The formation and intracellular localization of PHB were determined with fluorescence microscopy, using Nile Red staining. Analytical HPLC was also used to quantify the PHB content in the cells and to optimize production. This study demonstrates the efficacy of Pseudomonas sp. phDV1 in SCW treatment and biomass valorization, providing a sustainable solution for dairy wastewater management while producing valuable resources. Full article

This study presents the first comprehensive assessment of a bacteriophage P100-activated edible whey-protein solution (WPS) applied to the rind of Sicilian Canestrato Fresco (SCF) cheese. Beyond evaluating its anti-Listeria efficacy in pre- and post-packaging contamination contexts, the work investigates the coating’s effects on chemical composition, volatilome, sensory properties, and consumer responses, including willingness to pay. To assess anti-Listeria activity, all samples were stored at 4 °C for 30 days. Contamination was carried out either before or after coating application, depending on the specific treatment. Listeria monocytogenes was monitored at 0, 1, 3, 7, 15, and 30 days of refrigerated storage. The active coating reduced the pathogen from approximately 3 log CFU/g to undetectable levels (0 log CFU/g) within 3 days, whereas the untreated controls reached about 5 log CFU/g after 30 days. WPS-coated cheeses showed no significant changes in chemical composition (moisture ~33%, protein ~29%, fat ~33%) or fatty acid profile compared to traditional SCF. The volatilome was dominated by hexanoic and butanoic acids and ethyl esters, without significant differences between coated and control samples, as confirmed by Smart Nose^® analysis. Sensory evaluation by trained assessors demonstrated that the bioactive coating did not alter the traditional sensory profile of SCF cheese. A consumer survey conducted with 240 participants from two retail formats revealed significant differences in product familiarity and perceived food safety, while openness to innovation and willingness to pay were similar. More than 90% of respondents were willing to pay a 10% price premium. Overall, phage-based edible coatings appear to be edible, renewable, and biodegradable packaging alternative to improve cheese safety without compromising quality. Full article

This study investigated the diversity and functional potential of lactic acid bacteria isolated from traditional lamb rennet, cheese, and whey collected from seven artisanal sheep farms in southern Romania. A total of 31 samples were analyzed, yielding 118 Gram-positive, catalase-negative isolates. Following dereplication by rep-PCR and 16S rRNA gene sequencing, 63 unique strains were identified across nine genera, with Lactiplantibacillus, Lactococcus, and Leuconostoc being the most prevalent. Strain distribution varied by sample type and manufacturer, with rennet and whey showing greater species diversity than cheese. Technological characterization showed strain-dependent differences in acidification and growth in cow’s and goat’s milk. Genetic screening revealed a high prevalence of functional genes such as ribA, gad, and α-amy, while genes associated with bacteriocin (nisA, pln) and folate (folK) production were less common. Most strains carried multiple functional genes, indicating a genetic potential for diverse functional traits. Antibacterial activity assays demonstrated that nearly all strains inhibited at least three indicator pathogens, with ten strains, particularly Lactiplantibacillus plantarum and Lactococcus lactis strains, exhibiting strong inhibitory effects. Bacteriocin production was confirmed for three Lact. lactis strains. Exopolysaccharide (EPS) production was confirmed in two strains, with yields varying by growth medium and sucrose supplementation. Overall, the results underscore the rich microbial diversity and promising biotechnological potential of LAB from traditional Romanian dairy ecosystems, supporting their use in food fermentation and functional product development. Full article

The purpose of this study was to examine how hydraulic retention time (HRT) influences biohydrogen generation and the formation of end-products during the co-digestion of olive mill wastewater (OMW), cheese whey (CW), and sewage sludge (SS) mixed in a 40:40:20 (v/v/v) ratio. The relationship between the substrates, resulting metabolites, and microbial communities was also explored. Continuous fermentation trials were carried out under both mesophilic (37 °C) and thermophilic conditions using HRTs of 12, 24 and 48 h. Acetic, propionic, and butyric acids were identified as the main end-products. The highest hydrogen production rate (4.4 ± 0.5 L H₂/L_reactor/day) occurred under thermophilic conditions at an HRT of 24 h, whereas under mesophilic operation at the same HRT the hydrogen production reached 3.0 ± 0.3 L H₂/L_reactor/day. In contrast, the greatest accumulation of volatile fatty acids (VFAs) was observed under mesophilic conditions (10.02 g/L), while thermophilic operation at 24 h HRT resulted in 5.54 g/L of total VFAs. The improved performance under thermophilic fermentation is likely linked to the suppression of hydrogen-consuming bacteria at elevated temperatures, which favors rapid hydrogen producers. Microbial community analysis indicated dominance of Firmicutes and persistent Lactobacillus prevalence across conditions. Shorter HRT at 37 °C promoted community diversification with genera such as Olsenella, Dialister, and Prevotella increasing in relative contribution. Under thermophilic operation, consortia remained Lactobacillus-dominant but showed significant temporal restructuring. The predominance of acetic acid (~2.80 g/L) and butyric acid (~2.60 g/L) indicates that hydrogen generation mainly followed the acetic and butyric pathways. This study reveals how targeted control of HRT and temperature can steer microbial communities toward highly hydrogen-productive consortia in the continuous dark fermentation of mixed agro-industrial wastes. Full article

In this research, cattle manure, macroalgae, and cheese whey were mixed in various proportions (cattle manure:macroalgae:cheese whey ratios of 50:30:20, 30:20:50 and 20:50:30) and subjected to co-digestion under laboratory conditions at two different digestion temperatures (30 and 45 °C). The modified Gompertz and first-order kinetic models were used to predict biomethane potentials. The highest experimental biochemical methane potential of 0.373 Nm³CH₄/kgVS was obtained from Mixture-2 at 45 °C, while the lowest, 0.154 Nm³CH₄/kgVS, was achieved with Mixture-1 at 30 °C. Feedstock rates in the mixture and digestion temperature significantly influenced the biochemical methane potential (p < 0.05). Cheese whey was observed to positively contribute to increasing biomethane potential. Increasing the whey ratio in the mixture from 20% to 50% resulted in a 62.5% increase in biomethane production. While R² values for the modified Gompertz model ranged from 0.993 to 0.999, those of the first-order model varied between 0.968 and 0.984. Of the two kinetic models employed for estimating biomethane potentials, the modified Gompertz model yielded values closer to the experimental biomethane potentials. Full article

The use of food packaging derived from petroleum-based polymers has developed significant environmental problems, as these materials require centuries to degrade and release hazardous pollutants. Consequently, the food industry is shifting toward biodegradable alternatives developed from agro-industrial by-products, such as proteins, polysaccharides, and lipids. Whey protein is a by-product of the cheese industry, which is emerging as a promising material for producing edible and biodegradable films with effective barrier properties. Whey-based films can be incorporated with bioactive compounds, particularly phenolic compounds. These substances, naturally present in fruits, legumes, and vegetable waste, possess potent antimicrobial and antioxidant activities that are essential for extending the shelf life of perishable foods. This review provides a systematic evaluation of how the incorporation of phenolic compounds influences the physicochemical and bioactive properties of whey-based films. Thus, an analysis of film-forming methods, the interaction between protein matrices and phenolic compounds, and a critical discussion of the challenges remaining for their industrial application as active food packaging were evaluated. The discussion focuses on how the incorporation of phenolic extracts influences the physicochemical, mechanical, and barrier properties of the films, as well as their antioxidant and antimicrobial efficiency. The novelty of this review lies in its comprehensive focus on the sustained release of phenolic compounds from a whey protein film and their application in real food systems. By utilizing these natural additives, the industry can provide sustainable alternatives to synthetic preservatives. Active whey protein packaging represents a viable strategy to inhibit food spoilage, prevent lipid oxidation, and maintain sensory quality, while reducing the environmental problems. Full article

Large amounts of agro-industrial residues—such as grape pomace, olive mill wastewater, wheat straw, and cheese whey—pose disposal challenges and generate substantial environmental and economic burdens. Incorporating these by-products into ruminant diets may reduce feeding costs while supporting sustainability within a circular bioeconomy. Two experiments were conducted to evaluate: (i) the characteristics of a mixed raw agro-industrial by-product silage (BPS) in cylindrical bale silos (50 kg) and (ii) its effects as dietary supplementation on metabolic profile, oxidative status, milk yield, and milk quality in lactating goats. The BPS was formulated from raw wheat straw, grape pomace, olive mill wastewater, and cheese whey and tested at a 30% inclusion level (dry-matter basis). The combined by-products produced in 50 kg cylindrical bale silos were positively characterized and exhibited a nutritionally suitable silage with relevant antioxidant potential. Dietary BPS improved oxidative status, as evidenced by increased TAS and vitamin E and reduced ROMs, and positively influenced lipid and immunological blood markers of goats. Milk yield was higher in goats receiving the BPS. Moreover, milk quality was improved through a more favorable fatty acid profile, higher vitamin E content, reduced cholesterol levels, and enhanced oxidative stability, as evidenced by lower TBARS values. Overall, BPS supplementation enhanced animal health indicators and milk nutritional properties, demonstrating that this silage can contribute to more sustainable dairy goat production while offering potential benefits for human nutrition. Full article