Search Results (652)

Palm kernel cake (PKC), a byproduct of palm kernel oil extraction, is processed into palm kernel meal (PKM), which contains hemicellulose rich in mannose, a versatile sugar with applications in the pharmaceutical and food industries. However, its association within the lignin–cellulose matrix is a challenge for industrial extraction. This study proposes an optimized enzymatic hydrolysis method utilizing mannanase to maximize the mannose content from PKM powder to produce palm kernel mannose syrup. A 3³ Box–Behnken design within a response surface methodology coupled with a desirability function method was used to optimize hydrolysis parameters to maximize mannose and solids content while minimizing enzyme concentration and hydrolysis time. The optimal conditions for enzymatic hydrolysis were established as a reaction time of 16 h, 5% (w/v) solids, and 5% (w/w) enzyme, resulting in 4.325 g/L of mannose and a mannose yield of 24.33 ± 0.5%. The palm kernel mannose syrup was evaluated, resulting in a moisture content of 15.85 ± 0.07%, water activity of 0.6918 ± 0.003, and a pH of 4.05 ± 0.282, demonstrating shelf-life stability. These findings demonstrate the technical feasibility of valorizing PKC and PKM into a stable, mannose-rich syrup, offering a sustainable and scalable pathway for converting agro-industrial waste into high-value ingredients for multiple value-added applications. Full article

Oxidative stress generates oxidized phospholipids (OxPLs) that alter membrane structure and inflammatory lipid signaling, yet the underlying biophysical mechanisms remain poorly understood. Here, we examine how two structurally distinct truncated oxidized phosphatidylcholines (OxPCs), 1-palmitoyl-2-(5′-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) and 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine (PGPC), remodel membrane lateral organization and regulate secretory phospholipase A₂ (sPLA₂) activity. Large unilamellar vesicles composed of sphingomyelin, cholesterol, and either monounsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or polyunsaturated 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (PDPC) were used to reconstitute the liquid-ordered/liquid-disordered (L_o/L_d) phase coexistence characteristic of eukaryotic plasma membranes. Fluorescence spectroscopy revealed that OxPLs modulate lipid packing and nanodomain organization in a structure- and composition-dependent manner. POVPC promoted pronounced membrane ordering and L_o domain stabilization compared with PGPC, particularly in monounsaturated membranes with low cholesterol content. In contrast, PDPC-containing membranes, especially at elevated cholesterol, exhibited enhanced structural resilience to OxPL-induced perturbations. These biophysical changes were associated with distinct functional outcomes. Notably, the relationship between membrane structural parameters and sPLA₂ activity was not linear, indicating a decoupling between bulk membrane properties and enzymatic response. sPLA₂ activity was linked to membrane lateral organization: the size of L_o domains modulate hydrolysis by influencing the physicochemical properties of L_o/L_d interfaces, which may represent preferential sites for enzyme activation. Consistent with this, POVPC reduced sPLA₂ activity through stabilization of ordered domains at both low and high cholesterol, while PGPC enhanced hydrolysis at high cholesterol. Importantly, PDPC-containing membranes attenuated sPLA₂ activity and exhibited a protective effect against OxPC-induced enzymatic activation. Together, these findings identify membrane lateral organization as a key regulator of sPLA₂ function and provide mechanistic insight into how oxidative stress can differentially modulate inflammatory lipid signaling depending on membrane composition. This work highlights membrane organization as an active determinant of enzyme activity and a potential target in pathologies associated with oxidative stress, including atherosclerosis, neuroinflammation, and metabolic disease. Full article

The rapid expansion of edible insect production has focused primarily on rearing, processing efficiency, safety, and nutritional composition, while the slaughter of insects has received comparatively little scientific and ethical scrutiny. This narrative review examines insect slaughter as a critical control point linking bioethics, physiology, and ingredient quality. The review synthesizes evidence from neurobiology, food science, and processing studies to evaluate how commonly used slaughter methods interact with biological aspects of insects. Existing literature shows that slaughter techniques influence protein stability and hydrolysis, lipid oxidation, antioxidant retention, techno-functional properties such as emulsification and gelation, as well as sensory attributes and consumer acceptance. Available evidence suggests that methods designed to rapidly suppress metabolic activity may be associated with improved preservation of certain nutritional and functional parameters, although findings remain species- and context-dependent. The review further highlights major knowledge gaps, including the lack of species- and life-stage-specific welfare indicators and standardized assessment protocols. Overall, the findings support the need to reconceptualize insect slaughter as a strategic upstream decision rather than a neutral processing step. Integrating ethical considerations with nutritional, functional, and regulatory perspectives is essential for establishing science-based standards and ensuring the responsible development of edible insect-based food and feed systems. Full article

The present study aimed to investigate the migration of potentially hazardous compounds from plastic food packaging into edible oils, bottled water and soft drinks available on the market in the Republic of Moldova. GC–MS screening was applied to identify plastic additives and unintentionally added substances (NIAS). The influence of key extraction parameters, including solvent type, extraction time, pH, alcohol content and sugar concentration, was systematically investigated. The optimized procedure demonstrated satisfactory analytical performances, with recoveries ranging from 81 to 96%, repeatability below 5% and detection limits between 0.006 and 0.01 mg/L. To allow a comprehensive assessment of total phthalate contamination, an additional analytical approach based on the hydrolysis of phthalate esters and the determination of o-phthalic acid using capillary electrophoresis with spectrophotometric detection was proposed. The method showed a linearity range of 0.1–5.0 mg/L and a limit of quantification of 0.07 mg/L. The combined chromatographic and hydrolysis-capillary electrophoresis approaches provide a reliable tool for the integrated determination and evaluation of phthalate residues in aqueous-alcoholic systems and beverages, accessible to laboratories performing food quality control. Full article

C₁₃-Norisoprenoids are important contributors to the aroma of Riesling wine. Their quantification is analytically challenging due to their low concentrations, the lack of commercial standards and their pronounced sensitivity to analytical conditions, reflecting their chemical lability, as well as the dynamic nature of the wine matrix, leading to high reactivity and, consequently, remarkable structural diversity. Here, we developed an assay for the analysis of C₁₃-norisoprenoids in wine using headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME–GC-MS/MS). After evaluating different fiber materials, a statistical design of experiments (DoE) approach was employed to systematically optimize key HS-SPME parameters, including incubation, extraction and desorption conditions. Selected reaction monitoring (SRM) transitions were established for all targeted C₁₃-norisoprenoids, allowing the assay to provide relative quantification of more than 40 compounds using representative labeled and unlabeled standards to generate linear calibration curves. Following method validation, this approach was applied to a young German Riesling wine to investigate the effect of various acidic hydrolysis conditions on the norisoprenoid profile as well as on specific compounds. A central composite design (CCD) was used to systematically study the impact of pH, temperature, and hydrolysis time. Quantitative data were obtained for 22 C₁₃-norisoprenoids demonstrating that hydrolysis conditions strongly affected the norisoprenoid composition. pH and temperature showed a greater influence than reaction time. Response surface models (RSM) indicated that TDN, Vitispirane and TPB in particular are predominantly formed under strongly acidic and high-temperature conditions, whereas others such as Riesling acetal and actinidols are formed under milder conditions. The results indicate that hydrolysis conditions should be tailored to the specific norisoprenoid under investigation and the research question, particularly when simulating conditions of accelerated wine ageing for analytical purposes. Full article

Whey is a major by-product of the dairy industry and represents a valuable source of proteins that can be enzymatically converted into bioactive peptides with diverse health-related functions. In recent years, increasing attention has been given to whey-derived peptides due to their antioxidant, antihypertensive, antimicrobial, anti-inflammatory, antithrombotic, immunomodulatory, and anticancer activities, highlighting their potential use as functional ingredients and nutraceutical compounds. The generation and biological functionality of these peptides are strongly influenced by the protein source, processing conditions, enzymatic or microbial hydrolysis strategies, and peptide structure. Unlike the existing literature, this review provides an analysis of individual peptide sequences, meticulously linking their specific chemical structures to their diverse biological activities, such as antioxidants, antihypertensive, and immunomodulatory effects. By moving beyond general protein hydrolysis, this work offers a unique comparative framework that evaluates how these distinct peptide fractions perform under industrial conditions. Furthermore, it bridges the gap between laboratory discovery and commercial implementation, focusing on critical parameters for large-scale production, stability in functional food matrices, and the regulatory pathways required for market-ready nutraceuticals. This integrated approach provides a strategic roadmap for translating molecular bioactivity into high-value industrial applications. This review provides an applied overview of recent advances in the production of whey bioactive peptides, emphasizing enzymatic generation methods, structure–activity relationships, and underlying mechanisms of action associated with their biological effects. In addition, current and emerging applications of whey-derived peptides in functional foods, nutraceuticals, and health-oriented formulations are critically discussed. Finally, key challenges related to peptide stability, bioavailability, industrial scalability, and regulatory aspects are addressed to identify future perspectives for the effective translation of whey bioactive peptides from research to practical applications. Full article

Rainbow trout (Oncorhynchus mykiss) is one of the most widely farmed and consumed aquaculture species worldwide. Processing generates large amounts of by-products, including heads, frames, skin, and viscera, which are often discarded. However, these by-products are a valuable source of high-quality protein that can be converted into bioactive peptides through controlled hydrolysis. Numerous studies have shown that trout-derived peptides exhibit a wide range of functional properties, including antioxidant, antihypertensive, antimicrobial, and anti-inflammatory activities. From this perspective, the article provides a critical, up-to-date review of recent advances in the valorization of proteins from rainbow trout by-products, with an emphasis on the most efficient processing methods (including enzymatic, chemical, and microbial hydrolysis) and their potential applications in the food and nutraceutical industries. In addition, downstream processes such as ultrafiltration and chromatographic separation are discussed in the context of peptide purification and recovery. Finally, a systematized industrial process for the integral utilization of these by-products is proposed. Therefore, the objective of this review is to analyze and synthesize the available scientific evidence on the production, functionality, and applications of bioactive peptides derived from rainbow trout by-products, highlighting key process parameters such as enzyme type, pH, temperature, and degree of hydrolysis and their influence on peptide size (typically <5 kDa), yield, and bioactivity, and to propose a viable industrial process for their sustainable valorization. Despite these advances, challenges related to process standardization, cost efficiency, and industrial scalability remain. Full article

Background: The enzymatic saccharification of cellulose is governed by heterogeneous reaction environments that deviate from classical Michaelis–Menten behavior. Methods: Fractal kinetics were applied to describe the hydrolysis of microcrystalline cellulose (Avicel PH-101) and pretreated hemp hurds using Cellic CTec2. Optimal enzyme loading was first established on Avicel, and the influence of mixing regimes was evaluated. Results: Rotational agitation markedly improved hydrolysis efficiency. Organosolv-based pretreatments generated cellulose-enriched substrates that exhibited higher reactivity than Avicel, while redeposited lignin showed minimal inhibitory effects. Enzyme adsorption studies revealed substantial binding to lignocellulosic substrates, suggesting nonspecific interactions and crowding effects that influence kinetic parameters. Conclusions: Fractal coefficients k and h successfully captured differences in substrate accessibility and reactivity, demonstrating the suitability of fractal models for describing cellulose saccharification in complex solid–liquid systems. Organosolv pretreatment allows a high degree of saccharification, whereas redeposited lignin does not interfere with the enzymatic reaction. Full article

Severe browning often occurs in Multivitamin Iron Oral Solution during storage, which directly leads to the decline of product quality. To clarify the main mechanism of browning in this preparation, the contents of 5-hydroxymethylfurfural (5-HMF) and carbohydrates, as well as the relevant characteristic parameters such as color and fluorescence, were determined at different storage times in this study. Subsequently, four reaction models, namely sucrose-lysine, sucrose-citric acid, sucrose-niacin, and sucrose-folic acid, were constructed according to the formulation of the preparation to systematically investigate the effects of each system on browning. The results showed that the sucrose-lysine model was the main color-forming reaction system of the preparation. Citric acid could significantly promote the hydrolysis of sucrose to produce two reducing sugars, glucose and fructose, which not only provided sufficient substrates for the Maillard reaction (MR), but also led to the massive accumulation of 5-HMF. Further analysis revealed that heating temperature and heating time were significantly positively correlated with the contents of 5-HMF, browning index (BI), color density (CD), and reducing sugars in the solution, while significantly negatively correlated with sucrose content (p < 0.05). Two fractions, P1 and P2, were isolated by Sephadex LH-20 column chromatography. Among them, P1 with a molecular weight of 61,660 Da was identified as the key fluorescent color-forming component, whose ultraviolet and fluorescence characteristics were basically consistent with those of Multivitamin Iron Oral Solution. Ultra-performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) analysis confirmed that P1 contained characteristic fragments of conjugated unsaturated structure, which was the key chromophore responsible for its fluorescence properties. In summary, this study explored the main browning mechanism of Multivitamin Iron Oral Solution. It was found that after citric acid catalyzed the hydrolysis of sucrose, the generated reducing sugars underwent Maillard reaction with lysine to produce fluorescent color-forming substances, and heat treatment significantly aggravated the browning process. The results of this study not only provide a solid theoretical basis for optimizing the preparation process and improving the storage stability of Multivitamin Iron Oral Solution, but also offer an important reference for the research on the browning mechanism and stability of other sugar-containing liquid preparations. Full article

Agro-industrial waste impacts populations worldwide. Food waste, in turn, is a major source of complex lipids, carbohydrates, and other substances. Therefore, it is crucial to convert food waste into products that reduce environmental problems. Enzymatic hydrolysis has advantages over chemical hydrolysis. Examples include the enzymatic hydrolysis of starch by α-amylase and the hydrolysis of inulin by inulinase, which occur under milder environmental and temperature conditions than acid hydrolysis of starch or inulin. Despite these milder temperature conditions, during substate hydrolysis, enzyme deactivation occurs under exposure to temperature. As temperature increases above $T_{opt}$ (which maximizes catalytic activity), enzyme deactivation becomes more pronounced, leading to a decrease in enzyme activity. Therefore, determining the rate constant of deactivation $k_d$, during biotransformation is an important aspect in understanding enzyme kinetics. Most experimental studies focus on changes in enzyme activity with time and temperature. However, enzyme deactivation also occurs during enzymatic reactions conducted at different temperatures, and this process is characterized by specific deactivation parameters. The study is to present the rate constants of deactivation $k_d$, for selected biotransformation processes. The selected biotransformation processes are hydrolysis of olive oil by lipase, hydrolysis of inulin by inulinase, and hydrolysis of starch by α-amylase. Given the widespread use of enzymes in industry, the information on enzyme deactivation presented in this study can be used by engineers involved in modeling and optimizing enzymatic processes. This knowledge is also essential for the effective and sustainable use of enzymes in industrial applications. It is important to emphasize that the deactivation parameters discussed in this study also carry significant economic, social, and environmental implications. Full article

The valorization of agricultural by-products as functional feed additives represents a promising strategy for sustainable aquaculture. This study evaluated the effects of dietary fermented longan peel (FLP), produced through enzymatic hydrolysis and Lactiplantibacillus plantarum fermentation, on growth performance, digestive physiology, gut morphology, innate immunity, and gene expression in Nile tilapia (Oreochromis niloticus) cultured under a biofloc system. Five experimental diets were formulated with graded FLP levels (0, 5, 10, 20, and 40 g kg⁻¹) and fed to fish for eight weeks. Growth indices, including final weight, weight gain, and specific growth rate, improved significantly in fish receiving 20 g kg⁻¹ FLP, following a strong quadratic response pattern. In vitro digestibility assays showed enhanced carbohydrate and protein digestibility, coinciding with increased intestinal amylase and protease activities. Histological analysis indicated that moderate FLP inclusion (10–20 g kg⁻¹) promoted villus height, crypt depth, and epithelial organization. Innate immune parameters, including lysozyme, peroxidase, and alternative complement activity, were markedly elevated in serum and mucus, particularly at 20–40 g kg⁻¹ after eight weeks. Gene expression profiling revealed significant up-regulation of growth-related (IGF-1, GH, NPY-α, Galanin), immune-related (TLR-7, TNF-α, NFκB), and antioxidant-related (hsp70, Keap-1, nrf-2, GST-α) genes in fish fed higher FLP levels, with responses plateauing beyond 20 g kg⁻¹. Overall, FLP supplementation at 20 g kg⁻¹ optimally enhanced growth, digestive efficiency, intestinal health, and innate immune status. These findings demonstrate the potential of fermented longan peel as a cost-effective, bioactive, and sustainable functional feed ingredient for tilapia and other warm-water aquaculture species. Full article

Lutein and zeaxanthin are macular carotenoids known for their protective role against major eye diseases. The bio-accessibility of these macular carotenoids is extremely low, with a limited amount synthesised in plants. Quantifying these compounds in plants/biological samples is challenging because of their structural similarity. Although numerous methods have been reported for quantifying macular carotenoids, there is currently no unified chromatographic technique that can be applied for the separation and quantification of these carotenoids across diverse matrices over a broad dynamic range while also incorporating an effective extraction step. Biochemical processes during digestion and absorption further lower carotenoid levels in the body (bioavailability), making precise measurement of their esterified forms necessary. Here, we incorporate an alkaline hydrolysis extraction and present a single liquid chromatographic method applicable to both PDA and MS detection for the separation and quantification of lutein and zeaxanthin across various matrices (food, digesta, and Caco-2 cells) and concentration ranges. It utilises common solvents for the mobile phase system and a C30 column. The reverse-phase method achieved excellent recoveries in spiked samples, acceptable relative standard deviations (RSDs) for validation parameters, and offers potential for high-throughput analysis while being transferable between matrices (from plant to Caco-2 cells). Full article

Increasing demands for improved energy efficiency and resource recovery in wastewater management have driven intensified research on microalgal–bacterial consortia (M-BC). This technological approach represents one of the most promising and continuously evolving concepts for integrated wastewater treatment and energy recovery. M-BC systems exploit complementary processes, including photosynthesis, oxygen production, nutrient uptake by microalgae, as well as heterotrophic degradation of organic contaminants and CO₂ generation by bacteria. Laboratory- and pilot-scale studies demonstrate that such integration can substantially reduce energy demand while significantly improving technological performance. Metabolic synergy, metabolite exchange, intercellular communication, and the specific aggregate architecture collectively determine the stability and high productivity of these consortia. Depending on operational conditions, M-BC may occur as suspended cultures, biofilm-based systems, or granules, which differ in process characteristics and biomass recovery potential. Available evidence indicates that M-BC biomass can serve as a highly efficient substrate for anaerobic digestion (AD). The methane production potential of M-BC reaches 350–365 mL CH₄/gVS, and following pretreatment may increase to 530–560 mL CH₄/gVS, exceeding typical ranges reported for conventional sewage sludge. These values were obtained under specific process conditions and depend on biomass characteristics, consortium structure, inoculum type, and operational parameters; therefore, their generalisation should be interpreted with caution. However, practical implementation remains constrained by process-related barriers directly affecting AD performance, including extracellular polymeric substance (EPS)-mediated hydrolysis limitation and nitrogen-associated inhibition linked to low C/N ratios and ammonia accumulation. Additional challenges include seasonal variability in biomass composition and incomplete understanding of M-BC behaviour under anaerobic conditions, particularly at scale. This paper provides a comprehensive and integrative analysis of the structure and biochemistry of M-BC biomass, their ecological mechanisms, technological configurations, and current knowledge regarding their susceptibility to anaerobic digestion. The review identifies the key biological, chemical, and process-related barriers and highlights research directions required for future integration of M-BC into circular wastewater treatment systems and energy-oriented biomass valorisation. Full article

Cellulases catalyze the hydrolysis of cellulose and can be produced through fermentation processes, such as sequential fermentation (SeqF), which combines submerged and solid-state fermentation. The objective of this study was to evaluate the production of cellulases (endoglucanase and β-glycosidase) by fungi of the genus Aspergillus using coffee husks as substrate. Three Aspergillus strains were evaluated, with A. japonicus URM5620 showing the highest endoglucanase (0.368 U mL⁻¹) and β-glucosidase (0.652 U mL⁻¹) activities by SeqF. Based on the complete factorial design 2², a 9-fold and 3-fold increase in the production of endoglucanase (3.44 U mL⁻¹) and β-glucosidase (2.12 U mL⁻¹), respectively, was observed. Both enzymes showed maximum activity at 60 °C and pH 5.0. The kinetic/thermodynamic parameters indicated a high affinity of the enzymes for their respective substrates and a high catalytic potential. In addition, the half-life and decimal reduction values demonstrate the good thermal stability of endoglucanase (t_1/2 = 8.82 ± 0.34 and D = 29.32 ± 1.13 h) and β-glucosidase (t_1/2 = 26.61 ± 0.74 and D = 88.38 ± 2.47 h) at 60 °C. The thermostability results indicate potential for use in the pretreatment of raw materials. Full article

Freeze–thaw cycles on the Qinghai–Tibetan Plateau inhibit microbial activity and challenge silage preservation. This paper aimed to elucidate how an indigenous, freeze–thaw-resistant Lactobacillus plantarum strain (LP160) improves oat silage quality under such stress. Oats were ensiled for 60 days under constant 20 °C (t) or freeze–thaw cycles (12 h at 20 °C/−5 °C; s) with or without LP160 inoculation. Samples after ensiling and 5-day aerobic exposure were analyzed for fermentation parameters, nutrients, microbiome, and non-targeted metabolomics using liquid chromatography–tandem mass spectrometry (LC-MS/MS). LP160 inoculation improved silage quality, as shown by the lower pH, ammoniacal nitrogen, neutral detergent fiber, acid detergent fiber contents as well as the greater amount of lactic acid. Key findings demonstrated that LP160 inoculation significantly enhanced Lactobacillus dominance, effectively curbed the growth of detrimental bacteria like Mucor, and regulated the microbial structure. During the aerobic exposure phase, the microbial community structures and successions varied under different temperature treatments. When inoculated under freeze–thaw conditions, the genus Bacillus increased, while Paenibacillus was not impeded. A total of 943 metabolites were identified, predominantly comprising amino acids, fatty acids, and the like. The expressions of metabolites with antioxidant and antibacterial properties were upregulated with LP160 inoculation. This led to the inhibition of protein hydrolysis and a reduction in ammonia–nitrogen production. The results of correlation analysis indicated that inoculating LP160 suppressed the proliferation of Mucor and enhanced the abundance of Torulaspora; meanwhile, the expression of L-palmitoylcarnitine involved in the fatty acid degradation pathway and fatty acid metabolism pathway was inhibited along with the generation of ammonia–nitrogen. Consequently, the degradation of fatty acids and proteins was restrained. The results of this paper provided new insights into the silage under freeze–thaw conditions. Full article