Search Results (167)

Agri-food by-products such as sweet potato peel (SP) represent a sustainable and valuable source of bioactive compounds for improving gluten-free (GF) foods. This study evaluated the nutritional and functional impact of incorporating SP at 8% and 16%, either untreated or ultrasound-assisted extraction (UAE)-treated, into GF brownies. An untargeted metabolomics approach combined with chemometrics was applied to characterize phytochemical modulation after in vitro digestion of the brownies, while antioxidant and anti-inflammatory effects were assessed using RAW264.7 macrophages. SP incorporation increased the dietary fiber (reaching a content of 7.86%) and glycosylated flavonoid content in reformulated brownies, leading to a reduction of inflammatory markers in the cellular model. Sensory evaluation showed that SP addition did not significantly affect texture-related attributes or extract-related perception. In contrast, UAE acted as an efficient extraction strategy, enhancing terpenoid-like compounds and total phenolic content (TPC), reaching values of 401.97 mg GAE 100 g⁻¹ after 16% incorporation. Overall, combining SP valorization with UAE represents a promising strategy to develop nutritionally enhanced GF products, providing a foodomics-based framework for next-generation functional bakery products. Full article

Starch-degrading enzymes are key biocatalysts in industrial applications, particularly when derived from thermophilic microorganisms with potential to operate under elevated temperatures. In this study, three recombinant starch-degrading enzymes were heterologously produced, purified, and biochemically characterized: an α-amylase from Geobacillus kaustophilus, and an α-glucosidase and a type I pullulanase from Geobacillus sp. G4, a thermophilic strain isolated from a geothermal field in southern Peru. The three enzymes were successfully expressed in soluble form in Escherichia coli and purified by one-step affinity chromatography. Biochemical characterization showed that α-glucosidase and α-amylase displayed optimum activity at pH 6–7, whereas pullulanase exhibited a broader pH profile, retaining high activity up to pH 9. All three enzymes reached maximum activity at 60 °C, although their thermal stability profiles differed markedly, with pullulanase showing the highest thermostability. Metal ion assays revealed enzyme-dependent effects, with pullulanase being stimulated by Ca²⁺ and Mg²⁺, while α-amylase and α-glucosidase showed limited responses to divalent ions. Kinetic analysis using soluble potato starch indicated that α-amylase had the most favorable catalytic profile, with the lowest K_m and the highest catalytic efficiency among the three enzymes. Functional hydrolysis assays demonstrated that all enzymes were active on soluble starch and pretreated potato peel, while the enzymatic mixture consistently released the highest concentration of reducing sugars. These results expand the biochemical knowledge of thermophilic amylolytic enzymes from Geobacillus and support their potential use in future enzymatic systems for the conversion of starch-rich residues. Full article

Oxidative stress contributes to skin aging. Potato peels contain various functional components, and potato peel extract (PPE) promotes type I collagen synthesis in normal human dermal fibroblasts (NHDFs). In this study, we investigated the effects of PPE under oxidative stress conditions. NHDFs were exposed to hydrogen peroxide, followed by treatment with PPE prepared by ethanol extraction of potato peel residues. Exposure to hydrogen peroxide reduced type I collagen secretion in NHDF. However, this reduction was suppressed by the addition of PPE. The expression level of the type I collagen gene, COL1A2, showed a tendency to improve with PPE treatment. The promotion of collagen synthesis by PPE appears to involve the TGFBR2, ERK, and Akt signaling pathways. PPE also reduced the increased production of MMP-1 induced by hydrogen peroxide exposure and suppressed the upregulation of AP-1, a transcription factor upstream of MMP-1. While PPE exhibited antioxidant activity at high concentrations, it did not reduce intracellular ROS levels at the concentrations used for cell treatment. These findings suggest that PPE suppresses the reduction in collagen levels under oxidative stress conditions by promoting type I collagen synthesis and modulating MMP-1/AP-1/TIMP-1-related pathways, suggesting decreased collagen breakdown under oxidative stress conditions. PPE may serve as a potential material for maintaining collagen levels. Full article

Among diverse industrial wastes, antibiotic fermentation residues containing high concentrations of nosiheptide pose significant environmental and health risks. This study demonstrates that black soldier fly larvae (BSFL) can effectively degrade the nosiheptide residues within this fermentation matrix when blended with potato peel waste. Optimal degradation efficiency was achieved at a dry weight ratio of 3:5 (antibiotic fermentation residue to potato peel waste), yielding a 40.02% material reduction, an 8.63% bioconversion rate, and a 55.74% nosiheptide degradation rate. Further optimization of the larva-to-feed ratio enhanced nosiheptide degradation to 58.21%. Following 48 h of gut emptying period, no detectable nosiheptide remained within the tissues of the treated BSFL. The harvested larvae demonstrated high nutritional value, with crude protein and crude fat contents reaching up to 35.64% and 32.65%, respectively. The larvae also contained a comprehensive profile of essential amino acids, with the glutamic acid content exceeding 3%, which enhances feed palatability. Highly concentrated antibiotic treatments significantly increased the relative abundance of Bacteroidetes within the BSFL gut microbiota, with Dysgonomonas emerging as the dominant genus. This study highlights a novel strategy for degrading residual nosiheptide and converting waste into a valuable protein source, offering an eco-friendly solution for industrial waste management. Full article

In this study, phenol adsorption from aqueous solutions was investigated using a carbonized adsorbent derived from a 1:1:1 mixture of banana, carrot, and potato peels, representing a major fraction of municipal bio-waste in Serbia. The material (CARB_BCP) was characterized by pH_pzc, SEM, FTIR, and BET analyses. The results indicated a highly porous structure with developed micro- and mesoporosity and a high specific surface area (S_BET = 483 m²/g). FTIR confirmed the formation of a stable aromatic carbon structure, while the high pH_pzc value (10.55) suggested a limited role of electrostatic interactions. Adsorption experiments performed at an initial phenol concentration of 1858 mg/L, room temperature, and an adsorbent dose of 0.1 g achieved a removal efficiency of 20.5%. The Langmuir model provided the best fit, indicating monolayer adsorption, with good agreement between theoretical (≈187 mg/g) and experimental (≈190 mg/g) capacities. Kinetic analysis followed the pseudo-second-order model, suggesting chemisorption as the rate-controlling step. The adsorption mechanism was mainly governed by π–π interactions, hydrophobic effects, and hydrogen bonding. These results demonstrate that CARB_BCP, derived from biodegradable waste, is a promising low-cost adsorbent for wastewater treatment. Full article

Potato (Solanum tuberosum L.) peel, a by-product of the food processing industry, has attracted attention as a potential source of bioactive compounds. This study evaluated the antioxidant and anti-photoaging-related effects of potato peel extracts in human skin cells. Solanum tuberosum L. peel water extract (PPW) and Solanum tuberosum L. ethanol extract (PPE) were prepared and examined in UVB-irradiated human dermal fibroblasts (HDFs) and human keratinocyte cell line (HaCaT) cells. Intracellular reactive oxygen species (ROS) production, matrix metalloproteinase-1 (MMP-1) expression, pro-collagen type I production, and cellular senescence were evaluated in HDF cells, whereas wound closure was assessed in HaCaT cells using a scratch assay. PPE showed higher polyphenol and flavonoid contents and stronger radical scavenging activity. In HDFs, PPW significantly reduced intracellular ROS production, whereas both extracts reduced MMP-1 expression under UVB-irradiated conditions. PPE significantly increased pro-collagen type I production. Both extracts reduced cellular senescence under UVB-irradiated conditions. In addition, PPE enhanced wound closure in HaCaT cells, suggesting a possible improvement in cell migration-related responses. Taken together, these findings suggest that potato peel extracts may exert protective effects against UVB-induced oxidative stress and photoaging-related cellular changes and may serve as potential functional materials associated with skin-protective and anti-photoaging-related cellular effects. Full article

The increasing generation of agri-food waste represents a significant environmental challenge, but also a valuable source of bioactive compounds with potential industrial applications. In this study, selected minimally processed agri-food wastes from the food processing industry were evaluated as potential sources of bioactive compounds and antioxidants. Seven types of agri-food waste were investigated: green bean cutting waste, yellow bean cutting waste, sweet corn waste from the air selector, edamame pods, pepper seed by-products, potato peels, and potato waste from the air selector. Solid–liquid extraction was performed using ethanol at different concentrations (20, 40, 60, 80, and 96%, w/w) as a green solvent. Total polyphenol content (TPC) and antioxidant activity (DPPH, FRAP, and ABTS assays) were determined. The results demonstrated significant differences among the investigated raw materials, with the highest antioxidant activity observed in the potato peel extracts. Specifically, the strongest activity was recorded using 40% ethanol, yielding values of 3.9596 mg TE/g DW for DPPH and 11.4555 mg TE/g DW for ABTS assays. In contrast, the highest FRAP value (2.3970 mg Fe²⁺/g DW) was obtained with 60% ethanol. The highest TPC was detected in pepper seed by-products, reaching 6.7829 mg GAE/g DW when extracted with 20% ethanol. Furthermore, selected extracts were subjected to LC-MS analysis to obtain a preliminary characterization of their chemical profiles. Untargeted LC-MS analysis identified 115 metabolites belonging to different chemical classes, highlighting agri-food waste as a rich source of bioactive compounds, particularly flavonoids and phenolic acids. These findings demonstrate agri-food wastes as sustainable sources of bioactive compounds and support their valorization within circular economy and green processing frameworks. Full article

The growing worldwide need for sustainable, high-quality protein sources has intensified interest in single-cell protein (SCP) production, particularly mycoproteins derived from filamentous fungi. This shift is further driven by global sustainability priorities articulated by regulatory bodies, which promote resource efficiency, waste valorization, and sustainable food systems. Despite their high carbohydrate potential, the agricultural sector generates vast quantities of starch-rich by-products. Examples include broken rice, cassava peels, potato waste, and cereal-processing residues, which remain largely underutilized and thereby contribute substantially to environmental pollution. This literature review examines the potential of starch-based agricultural by-products as low-cost, renewable feedstocks for fungal SCP production in support of the Sustainable Development Goals (SDGs). These by-products include broken rice, cassava peels, potato waste, and cereal processing residues, which remain largely underutilized despite their high carbohydrate content. Key topics include pretreatment strategies, fungal fermentation with Neurospora and Fusarium spp., and process optimization to maximize biomass yield and feedstock valorization. Life cycle assessments (LCAs) indicate reduced greenhouse gas emissions compared with conventional protein sources, highlighting the potential of starch residues in circular bioeconomy systems. Furthermore, considerations related to process design, environmental benefits, and techno-economic feasibility are evaluated in the context of converting starch residues into fungal protein. In summary, the evidence suggests that valorizing starch by-products for mycoprotein fermentation, used both as a protein alternative and as an ingredient, represents a promising strategy to reduce waste management and production costs and support global food sustainability. Full article

Bioadsorbents derived from food waste can not only help reduce the amount of such waste but also demonstrate significant potential for CO₂ capture from both the energy sector and other industries. This study evaluates the feasibility of using bioadsorbents obtained from various types of household biowaste—including black and green coffee grounds, tea grounds, potato peels, walnut shells and green walnut shells—for CO₂ capture from flue gas. The bioadsorbents were produced through a two-step process consisting of carbonization followed by KOH activation. The physicochemical properties of the bioadsorbents were characterized using SEM, FTIR, XRD, TGA and BET techniques. The CO₂ sorption capacity was examined for bioadsorbents and for the original biowaste and the biocarbons obtained after carbonization. Isothermal CO₂ adsorption tests were carried out at 25 °C under 100% CO₂ atmosphere. The influence of porous properties—such as specific surface area, total pore volume, micropore volume and average pore diameter—on the CO₂ sorption capacity was assessed for bioadsorbents, biocarbons and raw biowastes. The results showed that the most effective bioadsorbent for CO₂ capture was derived from spent dark roast coffee grounds, with a sorption capacity of 115.8 mg_CO2/g_A. The favorable sorption performance of this bioadsorbent was attributed to its high specific surface area (1580 m²/g), the largest total pore volume (0.84 cm³/g) and micropore volume (0.5 cm³/g) among the tested materials, as well as an optimal average pore diameter (0.96 nm). Similarly favorable structural properties were observed for the potato peel-derived bioadsorbent (APP—1604 m²/g; 0.65 cm³/g) and the bioadsorbent derived from green walnut shells (AGWS—1376 m²/g; 0.64 cm³/g). Their CO₂ adsorption capacities reached 104.1 mg_CO2/g_A and 73.2 mg_CO2/g_A, respectively, for AGWS and APP. Full article

The aim of the study was to determine, under field conditions, the effects of O₃, H₂O₂, and fungicide protection on potato late blight severity, SPAD values, tuber yield, and mineral composition, and additionally to assess whether the number of ozone applications modifies selected tuber quality traits. Two complementary field experiments were conducted in 2017 and 2018. In the main experiment, control, fungicide protection, ozone fumigation, and foliar H₂O₂ treatments were compared with respect to late blight severity, SPAD response, yield, and macro- and micronutrient contents in tuber peel and flesh. In the supplementary experiment, single, double, and triple ozonation were compared in relation to starch content, vitamin C concentration, and tuber mineral composition. Fungicide treatment most effectively limited late blight symptoms, particularly at later assessment dates, and was associated with the highest tuber yield. SPAD values, yield, and several mineral traits were strongly dependent on the study year, indicating a major contribution of environmental conditions. The response to O₃ and H₂O₂ was selective and less stable than that observed under fungicide protection. In the supplementary experiment, the number of ozone applications did not significantly affect starch content. Vitamin C concentration depended mainly on the study year, whereas tuber mineral composition depended mainly on year and tissue type. The results indicate that, under field conditions, fungicide protection remained the most effective option for limiting late blight and achieving the highest tuber yield, whereas O₃ and H₂O₂ should be regarded as factors capable of modifying selected plant and tuber traits, but not as direct substitutes for standard chemical protection. Full article

Potato sensory quality is a key determinant of consumer acceptance and processing suitability; however, it remains insufficiently explored in Bulgarian potato breeding programs. This study aimed to characterize the sensory profiles of advanced Bulgarian mutant potato lines developed through induced mutagenesis, in comparison with their parental genotypes and untreated controls, after steaming and oven-frying. A trained descriptive sensory panel evaluated attributes related to appearance, aroma, flavor, texture, taste, and aftertaste, and the resulting data were explored using principal component analysis (PCA). Steamed samples were mainly associated with potato identity, earthy and raw potato peel aromatics, and potato-like flavor, whereas oven-fried samples were more strongly associated with overall sweet impression, buttery, earthy, and potato flavors, together with nutty aftertaste. Texture-related attributes were expressed in both culinary preparations, while undesirable bitter, sour, and astringent aftertastes occurred less frequently and were mainly linked to specific genotypes rather than to the overall sensory profile. Exploratory PCA supported the visualization of genotype-related sensory tendencies across both datasets. Several mutant lines showed favorable sensory profiles aligned with desirable parental characteristics, whereas others were more often associated with less favorable attributes, including increased bitter and astringent aftertastes. Overall, steaming emphasized inherent potato like, earthy, and raw-related notes, whereas oven-frying enhanced color development, sweet–buttery flavor impressions, and richer texture expression. Full article

Black soldier fly (Hermetia illucens) larvae (BSFL) represent a sustainable protein source for animal feed, efficiently converting organic waste into high-value biomass. This study aimed to valorize agricultural by-products (apple, potato, and red beetroot peels) as rearing substrates to obtain larvae enriched with bioactive phenolic compounds, while evaluating their nutritional, functional, and safety characteristics. Larvae were reared on diets with varying inclusion levels of each peel’s by-products. Proximate analysis showed that the substrate type and inclusion level significantly (p < 0.05) influenced larval composition, with consistently high protein and variable ash and fat contents. Colorimetric measurements indicated that phenolic-rich diets, particularly apple by-products, promoted cuticle darkening, reflecting the impact of dietary phenols on pigmentation. Functional properties were also modulated by the substrates: 2% potato peel yielded the highest phenolic content, while 20% apple peel produced the highest flavonoid concentration, both enhancing antioxidant capacity across CUPRAC-Cupric Ion Reducing Antioxidant Capacity, ABTS-2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid, and DPPH-1,1-diphenyl-2-picrylhydrazyl assays. Rheological analysis confirmed desirable non-Newtonian, shear-thinning behavior, suggesting improved technological quality. Mycotoxin testing revealed low Aflatoxin B1 but variable Zearalenone levels, highlighting the influence of substrate composition on toxin metabolism. Overall, agricultural by-products can produce enriched BSFL with enhanced nutritional and antioxidant properties, as long as the substrate choice and inclusion levels are carefully optimized for safety. Full article

Organic residues from households and food-service facilities, such as orange peels, spent coffee grounds, banana peels and potato skins, represent abundant biomass resources that can release undesirable compounds during degradation. Their conversion into carbonized materials through thermochemical processes offers a sustainable route for waste valorization. In this study, residues were characterized by proximate and elemental analyses, density, porosity, and calorific value. Valorization was performed using microwave-assisted pyrolysis and two hydrothermal carbonization (HTC) routes. Pyrolysis experiments were conducted at 450, 600 and 800 W with residence times of 20–70 min. Conventional HTC was carried out at 180, 200 and 220 °C for 20 h, while autoclave HTC was performed at 134 °C for 2 and 4 h. The resulting biochars and hydrochars were evaluated for their physicochemical and energetic properties and ANOVA was applied to assess the influence of operating conditions. Conventional HTC at higher temperatures produced the highest calorific values, whereas microwave-assisted pyrolysis at 800 W provided competitive HHVs with high solid yields. Autoclave HTC enhanced solid retention and carbon preservation. Among the investigated residues, spent coffee grounds exhibited the most favorable solid-phase energetic performance. These findings demonstrate that thermochemical conversion enables the transformation of common residues into carbon-rich materials with physicochemical and energetic properties relevant for comparative assessment and future application-oriented studies. It should be noted that conventional hydrothermal carbonization experiments were conducted using pre-dried biomass, which represents a methodological limitation of the comparative assessment. Full article

Second-generation bioethanol from food industry lignocellulosic residues offers a promising route toward low-carbon, circular bioenergy systems. However, the reported environmental impacts differ markedly across studies, challenging efforts to assess the true sustainability of these waste-derived bioethanol routes. This review synthesizes current knowledge on the production of bioethanol from key agro-industrial wastes including oil palm empty fruit bunches, sugarcane bagasse, brewers’ spent grain, spent coffee grounds, tea waste, citrus residues, and potato peel waste. We outline feedstock characteristics, availability, and prevailing management practices, and map the principal biochemical conversion routes to identify process steps that drive environmental performance. A systematic comparison of life cycle assessments reveals substantial methodological heterogeneity across functional units, system boundaries, allocation procedures, and impact assessment methods. Nonetheless, consistent hotspots emerge, particularly associated with pretreatment severity, enzyme production, thermal energy demand, and co-product handling. The review highlights robust cross-study trends, pinpoints methodological gaps, and proposes recommendations for harmonized LCA practice. By integrating technological and methodological perspectives, this work aims to support the development and policy uptake of sustainable, waste-based bioethanol within circular bioeconomies. Full article