Search Results (13)

To meet global food demand, agricultural systems must enhance crop performance, productivity, and sustainability. Biostimulants have emerged as a promising strategy, particularly in vegetable production, due to their ability to enhance plant growth and resilience. This study characterized milk-derived protein hydrolysates (MPH) produced from expired milk and evaluated their potential as biostimulants for hydroponic cos lettuce. Hydrolysis of expired milk with hydrochloric acid achieved 94.55% hydrolysis and yielded 80.77% free amino acids. MPH was applied at volumes of 0, 1, 3, and 5 mL L⁻¹ in combination with Hoagland and Arnon nutrient solution. The 1 mL L⁻¹ (MPH1) treatment significantly increased shoot and root biomass and canopy size while reducing nitrate accumulation and enhancing total flavonoid and ascorbic acid content, as well as antioxidant capacity. HPLC analysis showed that MPH1 treatment promoted the accumulation of key metabolites, including vanillic acid, para-coumaric acid, salicylic acid, ferulic acid, gallic acid, syringic acid, quercetin, myricetin, and naringenin. MPH1 improved uptake of phosphorus, potassium, calcium, magnesium, and iron, contributing to mineral biofortification and nutritional quality. These results demonstrate that MPH at 1 mL L⁻¹ is an effective biostimulant, improving yield and quality while reducing nitrate levels in hydroponically grown cos lettuce, offering a sustainable solution for food waste valorization. Full article

As global milk production continues to rise, the disposal of expired milk contributes to environmental pollution and valuable resource wastage. This study presents the development of a novel L-arabinose isomerase, designated BmAIase12, and its application in the enzymatic recycling of expired milk. BmAIase12 exhibited a specific activity of 10.7 U/mg and showed optimal performance at 50 °C and pH 7.0. Furthermore, it exhibited higher activity than most other L-arabinose isomerases. It converted D-galactose into D-tagatose with a high conversion ratio of 53.3% after 48 h at 50 °C. The conversion efficiency of expired milk to D-tagatose was recorded at 40.62%, resulting in a maximum tagatose yield of 1.625 g/L. This was accomplished through the incorporation of β-galactosidase (120 U/mL) and Saccharomyces cerevisiae (30 mg/mL) to hydrolyze lactose and metabolize glucose, followed by the addition of 3 U/mL of BmAIase12. Ultimately, following purification, the purity of tagatose was determined to be 98%, and the final yield was 29.8%. These results suggest that BmAIase12 may serve as a promising enzyme for D-tagatose production due to its high conversion yield. Full article

The increasing global concern over plastic waste and its environmental impact has led to a growing interest in the development of sustainable packaging alternatives. This study focuses on the innovative use of expired dairy products as a potential resource for producing edible packaging materials. Expired milk and yogurt were selected as the primary raw materials due to their protein and carbohydrate content. The extracted casein was combined with various concentrations of chitosan, glycerol, and squid ink, leading to the studied samples. Chitosan was chosen due to its appealing characteristics, including biodegradability, and film-forming properties, and casein was utilized for its superior barrier and film-forming properties, as well as its biodegradability and non-toxic nature. Glycerol was used to further improve the flexibility of the materials. The prepared hydrogels were characterized using various instrumental methods, and the findings reveal that the expired dairy-based edible packaging materials exhibited promising mechanical properties comparable to conventional plastic packaging and improved barrier properties with zero-oxygen permeability of the hydrogel membranes, indicating that these materials have the potential to effectively protect food products from external factors that could compromise quality and shelf life. Full article

Background and objectives: Globally, about 70% of the adult population is lactase non-persistent (LNP), lacking the enzyme required for lactose digestion. The main consequence of intolerance is withholding nutrient-rich dairy foods, while the literature shows that many LNPers are able to consume ≤12 g of lactose, comparable to 250 mL of milk, without experiencing gastrointestinal discomfort. Repetitive consumption of lactose may improve intolerance symptoms even further via colonic adaptation. This study aimed to assess the effects of daily consumption of incremental lactose doses on microbiota composition and function, and intolerance symptoms. Methods: Twenty-five healthy adults of Asian origin (age 22–44 yrs, BMI 19–28 kg/m²), carrying the LNP genotype and avoiding lactose in their habitual diet, were included in this 12-week single-blinded intervention trial. Participants consumed lactose twice daily, with doses being gradually increased from 3 to 6 g, to finally 12 g twice daily, each dose being provided for 4 consecutive weeks. Before and after the 12-week intervention, participants underwent a 25 g lactose challenge hydrogen breath test (HBT) and handed in stool samples. Daily gastrointestinal symptoms and acute intolerance symptoms during the HBT were recorded. Results: There was a significant increase in Bifidobacterium after 12 weeks of lactose consumption (p = 0.009), accompanied by a two-fold increase (p < 0.001) in fecal β-galactosidase activity. There was a 1.5-fold decrease (AUC; p = 0.01) in expired hydrogen during the second compared to the baseline HBT. There was a non-significant decrease in total symptom score (p = 0.09) during this second HBT, which was already relatively low during the baseline HBT. Daily consumption of lactose was generally well tolerated, with mild to no gastrointestinal complaints reported during the intervention. Discussion: Repetitive consumption of incremental doses of lactose increases lactose tolerance in LNP individuals via colonic adaptation, most likely through increasing the relative abundance of lactose-fermenting Bifidobacterium. Repetitive lactose consumption is well tolerated and able to reduce expired hydrogen during a 25 g lactose HBT. Here, we show that regular and incremental exposure to lactose in LNP individuals leads to colonic adaptation without any increase in gastrointestinal symptoms. This lifts the necessity to remove dairy foods completely from the diet. Full article

The consumer rejection threshold (RjT) method was applied to determine the total microbial numbers (TMNs) where consumers find that the quality of whole fresh chilled pasteurised milk (WFCPM) and skim milk (Trim) stored at 4.5 ± 0.5 °C is no longer acceptable. Food spoilage progression was supported by measurements of VOCs and the terms consumers used to describe the ageing fresh chilled pasteurised milk (FCPM). RjTs for TMN of 7.43 and 7.34 log10 CFU.mL⁻¹ for WFCPM and Trim, respectively were derived using Hill’s equation from a series of paired preference tests comparing fresh and aged milks (3–26 days) assessed by consumers (WFCPM, n = 55; Trim, n = 52). A poor relationship between storage time and TMN was found, owing mainly to batch-to-batch and within-batch variation in the milk’s post-pasteurization contamination (PPC) levels. At the RjT, there was a significant change in the signal intensities for a number of spoilage-related VOCs that occurred in the FCPM headspace (p ≤ 0.05), which were measured using proton transfer reaction–mass spectrometry (PTR-MS), including m/z 33, 45, 47, 61, 63, 69, 71, 87, and 89, tentatively identified as methanol; acetaldehyde; ethanol; acetate (acetic acid and acetate esters); dimethyl sulphide (DMS); isoprene, furan, and aldehydes; 2-butanone; and pentanal and butyrates (butyric acid and butyrate esters), respectively. Consumers described the milks at TMN greater than the RjTs using terms like off, expired, sour, spoilt or rancid. This multidisciplinary study has provided data on the importance of PPC and subsequent increases in TMN on VOCs associated with FCPM and consumer’s preferences and highlighted the value of measuring a range of variables when investigating consumer’s perception of food quality and shelf-life. Full article

Raw milk and pasteurized milk are characterized by a short shelf life, and drinking expired raw milk and pasteurized milk causes illness. In the study, Plantaricin FB-2 (extracted from Lactiplantibacillus plantarum FB-2) was added to liquid milk. By evaluating the microbial growth, acidity changes, protein content, and sensory changes in raw milk and pasteurized milk during storage, it was found that when Plantaricin FB-2 was added at 0.4 g/kg, the shelf life of raw milk was extended by 3 days (7 days if not added). The shelf life of pasteurized milk with Plantaricin FB-2 was extended to 31 days (25 days in the control group), and the optimal amount was 0.3 g/kg. This confirmed that Plantaricin FB-2 can effectively prolong the shelf life of raw and pasteurized milk. This study provides valuable information for the application of bacteriocins produced by Lactiplantibacillus plantarum in raw milk and pasteurized milk to improve their shelf life. Full article

Ultra-High Temperature (UHT) pasteurized milk is the most diffused variety of milk in Europe. In this paper, a method is presented, employing Electrical Impedance Spectroscopy to characterize the different commercial milks commonly available in grocery stores and supermarkets. The curves of the measured admittance allow for the classification of the type of milk (whole, semi-skimmed, fat-free) and to distinguish lactose-free milk. An electrical circuit model has been derived and different values of circuit parameters add interesting information on the classification of the samples. Furthermore, the characterization allows for the identification of the degradation of the milk before it is visible to the eye, thus highlighting the difference between storage in the fridge and at room temperature, and identifying expired milk. Full article

Sustainable agricultural development depends mainly on the recycling of organic wastes to reduce environmental pollution, as well as to reduce the use of mineral fertilizers. Expired milk products are rich in organic carbon and nitrogen, so they are good raw materials for making organic fertilizers. In this study, expired milk products were converted to organic fertilizer (EDPF) by gravity and thermal treatments. The extracted EDPF was used in the nutrition of Williams banana plants under field conditions for two growing seasons. The field experiment consisted of four treatments including: C = control without N fertilization, U = traditional urea, SRU = slow-release urea, and EDPF. EDPF significantly (p < 0.05) improved the growth and yield of Williams banana in comparison to U and SRU. EDPF significantly minimized the soil pH and increased the soil organic-C and cation exchange capacity compared to the other treatments. EDPF increased the total yield of bunches by 20% and 17% in the first and second years, respectively, above U and SRU. EDPF surpassed the traditional and slow-release urea in its ability to supply the banana plants with nitrogen. NH₃-N loss from U, SRU, and EDPF reached 172, 132, and 100 kg N ha⁻¹, respectively, which accounted for 34%, 26%, and 20% of the total added nitrogen. Nitrogen loss from the investigated treatments was in the order: U > SRU > EDPF > C. EDPF significantly reduced the ammonia volatilization compared to U and SRU by reducing the soil pH and increasing the soil organic matter. The dynamic of NH₃ emissions not only depends on the nitrogen form but also on climatic conditions and concentrations of NH₄⁺ in the soil solution. Protecting the ecosystem and maximizing the benefits of wastes utilization can be done through the recycling of expired dairy products to organic fertilizers. Full article

An understanding of the consumer perception of health risks related to food expiration is a prerequisite for future food labeling system improvement in order to reduce environmental burdens. The aim of the study was identification, analysis, and assessment of consumer behavior in the context of food waste in households. The study was conducted using the direct interview method (face to face interviews) among a group of 1145 Polish consumers of food. The results show that consumers do not understand the differences between the concept of “use by” and “best before” labeling. Although rice, tea, and coffee were correctly perceived as safe during storage, there is a dissonance between consumer attitudes and behavior. The highest health risk was perceived as being due to consumption of expired “use by” dated milk (out of UHT milk, rice milk dessert, “best before” ready-to-eat meals and “use by” ready-to-heat meals, canned fruits, and fresh-cut salad). However, 51% of respondents still considered consuming it. Irrational consumer behavior poses a health threat as well as contributing to avoidable food waste. Social awareness campaigns are necessary to inform consumers about the monetary value of wasted food as well as about the environmental, social, and ethical impact of their behavior. Full article

Expired dairy products are often disposed of due to the potential health hazard they pose to living organisms. Lack of methods to recover valuable components from them are also a reason for manufactures to dispose of the expired dairy products. Milk encompasses several different components with their own functional properties that can be applied in production of food and non-food technical products. This study aims to investigate the novel approach of using liquid biphasic flotation (LBF) method for protein extraction from expired milk products and obtaining the optimal operating conditions for protein extraction. The optimized conditions were found at 80% concentration ethanol as top phase, 150 g/L dipotassium hydrogen phosphate along with 10% (w/v) milk as bottom phase, and a flotation time of 7.5 min. The protein recovery yield and separation efficiency after optimization were 94.97% and 86.289%, respectively. The experiment has been scaled up by 40 times to ensure it can be commercialized, and the protein recovery yield and separation efficiency were found to be 78.92% and 85.62%, respectively. This novel approach gives a chance for expired milk products to be changed from waste to raw materials which is beneficial for the environment and the economy. Full article

An olive leaf extract (OLE) has been tested in vitro for its antibacterial activity and ability to inhibit α-glucosidase enzyme. OLE was also evaluated for its potential, when added to pasteurized milk, to preserve nutritional parameters and to limit microbial growth, thus prolonging shelf life. In vitro assays demonstrated a strong antibacterial efficacy of OLE mainly against Bacillus cereus and the capacity to inhibit α-glucosidase enzyme (IC₅₀) when used at 0.2 mg oleuropein/mL. The milk fortification with OLE at 3.6 mg of oleuropein/mL of milk reduced total mesophilic bacteria at undetectable level after 6 d (expiration date) and by 1 log CFU/mL after 10 d. Moreover, OLE addition at 1.44 and 3.6 mg of oleuropein/mL of milk significantly reduced fat and lactose losses up to 10 d. The results motivate the use of the OLE to make a new functional milk with an extended shelf life. Full article

The basidiomycete brown rot fungus Neolentinus lepideus is capable of assimilating and fermenting lactose to ethanol with a conversion yield comparable to those of lactose-fermenting yeasts. The ability of the fungus to ferment lactose is not influenced by the addition of glucose or calcium. Therefore, N. lepideus may be useful in ethanol production from materials composed mainly of lactose, such as cheese whey or expired cow’s milk. Whey is a by-product of cheese manufacturing, and approximately 50% of the total worldwide production of whey is normally disposed of without being utilized. We found that N. lepideus produced ethanol directly from cheese whey with a yield of 0.35 g of ethanol per gram of lactose consumed, and it also fermented expired milk containing lactose, protein, and fat with a similar yield. Our findings revealed that the naturally occurring basidiomycete fungus possesses a unique ability to produce ethanol from cheese whey and expired milk. Thus, N. lepideus may be useful in facilitating ethanol production from dairy wastes in a cost-effective and environmentally friendly manner. Full article

Around 29 million tons of milk end as waste yearly in Europe, representing an environmental issue but also a potential substrate for biological valorization given its nutritional value. Aspergillus oryzae and Neurospora intermedia are edible filamentous fungi with dissimilar metabolism when grown in expired milk. Neurospora intermedia is more devoted to lactose consumption; 68 and 57% of lactose was consumed after cultivation in expired milk and its liquid fraction, respectively. Aspergillus oryzae consumed less lactose in expired milk (14%), but led to better microfiltration characteristics of the final effluent due to fat and protein degradation. A two-stage fed-batch cultivation using membrane bioreactors (MBRs) was developed, bringing together both fungal metabolic characteristics when grown in 70% diluted expired milk. In the first MBR, A.oryzae degraded fat and protein, improved microfiltration, and produced ca 11 g/L of biomass. In the second MBR, N. intermedia consumed the remaining lactose in the permeate and originated ca 7 g/L of biomass. The developed system was successful for valorization of non-sterile milk due to the balance between consumption of bacterial growth-derived acids, consequent pH, and fungal enzymatic activities. Besides, a final clear effluent (83% reduction of COD) was obtained, which is of interest considering wastewater treatment. Full article