Search Results (14)

Rapeseed proteins, due to their quality and wide availability, have great potential for application in human nutrition. However, their high content of antinutritional compounds poses significant economic and environmental challenges for food industry applications. To overcome these obstacles, various extraction and modification techniques, including enzymatic and ultrasound-assisted methods, were used to enhance protein functionality and improve both nutritional and sensory properties. In this study, the effects of dephenolization on the structural, physicochemical, and functional properties of rapeseed protein isolate obtained from defatted rapeseed cake were investigated through four different protocols. All obtained protein isolates (PIs) exhibited high protein purity (above 65%), with a notable difference in extraction yield. Furthermore, the extraction process was optimized using an artificial neural network (ANN) model, which demonstrated high predictive performance. The optimal extraction conditions for the dephenolization of rapeseed oil cake were 84% ethanol concentration, a solid-to-liquid ratio of 1/60 w/v, and 15 min of ultrasound treatment, resulting in an impressive protein purity of 90.68% with a yield of 29.17%. The obtained proteins were further characterized and compared in terms of protein profile (FTIR and SDS-PAGE), amino acid composition, solubility, and digestibility. The protein isolate (PI) obtained under optimized conditions displayed superior functional properties, underscoring the relevance and necessity of a data-driven, mathematical approach for scale-up and industrial implementation. Full article

This study investigated the effects of replacing soybean meal (SBM) with high-protein cottonseed meal (CSM) and de-phenolized cottonseed meal (DPCSM) on growth performance, apparent nutrient digestibility, serum biochemical parameters, slaughter traits, and meat quality in yellow-feathered broilers. A total of 5760 one-day-old male Liangfeng Hua broilers were randomly divided into five groups with eight replicates per group. The control group was fed a corn-SBM diet (SBM group), while the CSM₅₀, CSM₁₀₀, DPCSM₅₀, and DPCSM₁₀₀ groups replaced 50% and 100% of the equivalent protein from SBM with CSM and DPCSM, respectively. Compared to the control group, the CSM₅₀ and DPCSM₅₀ groups showed no significant negative effect on growth performance; however, dietary calcium digestibility was significantly reduced on day 21. Furthermore, CSM₁₀₀ and DPCSM₁₀₀ adversely impacted growth performance, significantly reducing crude fat digestibility and increasing serum urea nitrogen levels on day 42. The broilers in these groups also had reduced pre- and post-slaughter body weights, while those in the CSM₅₀ and DPCSM₁₀₀ groups exhibited decreased half-clearance rates. In addition, the CSM₁₀₀ group had significantly increased pectoral muscle drip loss and a* (24 h) values. pH values measured at 45 min and 24 h were significantly elevated in the DPCSM₅₀ and DPCSM₁₀₀ groups. In conclusion, the replacement of SBM with CSM and DPCSM in yellow-feathered broiler diets should be limited to 50%. Full article

Dephenolized cottonseed protein is a high-protein product obtained through the further dephenolization of cottonseed meal or by removing the lint and shell of cottonseed, extracting the oil at a low temperature, and subsequently eliminating toxic substances (gossypol). This paper presents a review of the latest advancements in the dephenolization methods, quality characteristics, and application domains of dephenolized cottonseed protein. It focuses on enhanced dephenolization methods, and summarizes the composition, structural characteristics, functional properties, and recent research developments. Additionally, it identifies challenges, opportunities, and new directions for future research on dephenolized cottonseed protein, which will contribute to advancing the field of dephenolized cottonseed protein research. Full article

Large quantities of wine lees are produced annually by the wine industry. The high phenolic content makes them unsuitable for disposal in the environment or animal feed without a suitable treatment. In this study, wine lees were treated by Pleurotus ostreatus in submerged cultivation, producing a high-value biomass and elevated levels of laccase, an important industrial enzyme. Biomass and laccase production reached 21 g/L and 74,000 Units/L, respectively, at the optimal conditions of initial pH 6.0, 20% v/v wine lees, 30 g/L glucose, and 20 g/L yeast extract, while decolorization and dephenolization rates of the waste were over 90%. The mycelial biomass was rich in proteins and essential amino acids reaching up to 43% and 16% per dry weight, respectively. Carbohydrates and lipids were the second richest bioactive compound in biomass, with values of 29.4 ± 2.7% and 29.5 ± 2.7%, respectively. The crude laccase in the culture supernatant was purified via a simple two-step purification procedure by 4.4-fold with a recovery of 44%. The molecular weight of the enzyme was determined to be 62 kDa via SDS electrophoresis. Enzyme activity was optimal at pH 5.0 and 70 °C. The activation energy of the enzyme was calculated at a value of 20.0 ± 0.2 kJ/mol. The pH stability and thermostability of the purified laccase were studied. The enzyme was remarkably stable at pH 8.0 and at temperatures up to 40 °C. The thermal inactivation energy of the enzyme was determined to be 76.0 ± 1.2 kJ/mol. The thermodynamic parameters (ΔH*, ΔG*, and ΔS*) for the thermal deactivation of the purified laccase at a temperature range of 20–60 °C were: 73.8 ≤ ΔH* ≤ 74.3 kJ·mol⁻¹, 98.7 ≤ ΔG* ≤ 101.9 kJ·mol⁻¹, and −90.5 ≤ ΔS* ≤ −84.3 J·mol⁻¹·K⁻¹. Wine lees could be ideal substrates of fungal cultivation for laccase production and biomass with a high protein content in an eco-friendlier way. Full article

Hizikia fusiforme has a long history of consumption and medicinal use in China. It has been found that natural plants containing polyphenol–polysaccharide complexes have better activity compared with polyphenols and polysaccharides. Therefore, in this study on enzymatic hydrolysis and fractional alcohol precipitation, two kinds of polyphenol–polysaccharide complexes (PPC), PPC1 and PPC2, were initially obtained from Hizikia fusiforme, while the dephenolization of PPC1 and PPC2 produced PPC3 and PPC4. Through in vitro assays, PPC2 and PPC4 were found to have higher antioxidant activity, and thus were selected for testing the PPCs’ anti-aging activity in a subsequent in vivo experiment with D-gal-induced aging in mice. The results indicated that PPCs could regulate the expressions of antioxidant enzymes and products of oxidation, elevate the expressions of genes and proteins related to the Nrf2 pathway in the mouse brain, enrich the gut microbiota species and increase the Bacteroidota–Firmicute (B/F) ratio. Above all, the Hizikia fusiforme polyphenol–polysaccharide complex has potential in the development of natural anti-aging drugs. Full article

This research evaluates process instability together with microbial population dynamics of the startup of an anaerobic digestion of a mild pretreated solid olive oil waste. The pretreatment consisted of a mild thermal treatment called thermo-malaxation and a subsequent dephenolized process of the olive mill solid waste. The anaerobic digestion process of the mild pretreated and partially dephenolized biomass was studied for three Hydraulic Retention Times (HRTs), with 21 days each HRT, with an organic load rate of 1 g VS/L d, carried out at mesophilic temperature (35 ± 1 °C). The average value of methane yield decreased from 204 ± 9 mL CH₄/g VS d on day 21, the last day of the first HRT, to 87 ± 24 mL CH₄/g VS d on day 60, the last day of the third HRT. The alkalinity decreased drastically, indicating instability of the anaerobic digestion process. Although phenolic compounds were partially extracted in the pretreatment, the observed increase in phenolic compounds during reactor operation might be contributed to the methane production decay. Interestingly, volatile fatty acids decreased with time, indicating that not only the methanogenic stage but also the hydrolysis stage was affected. Indeed, the microbial analysis showed that the abundance of hydrolytic bacteria decreased over time. It is also worth noticing that hydrogenotrophic methanogens, while present during the first two HRTs, were not observed at the end of the last HRT. This observation, together with the increase in the relative abundance of acetoclastic methanogens, showed a shift in the methane production pathway from hydrogenotrophic methanogenesis to acetotrophic methanogenesis. Full article

In the context of human food shortages, the incorporation of non-grain feedstuff in fish feed deserves more research attention. Here, the feasibility and appropriate ratio of non-grain compound protein (NGCP, containing bovine bone meal, dephenolized cottonseed protein, and blood cell meal) for dietary fishmeal (FM) replacement were explored in golden pompano (Trachinotus ovatus). Four isonitrogenous (45%) and isolipidic (12%) diets (Control, 25NGP, 50NGP, and 75NGP) were prepared. Control contained 24% FM, whereas the FM content of 25NGP, 50NGP, and 75NGP was 18%, 12%, and 6%, respectively, representing a 25%, 50%, and 75% replacement of FM in Control by NGCP. Juvenile golden pompano (initial weight: 9.71 ± 0.04 g) were fed the four diets for 65 days in sea cages. There was no significant difference between the 25NGP and Control groups in terms of weight gain, weight gain rate, and specific growth rate; contents of crude protein, crude lipid, moisture, and ash in muscle and whole fish; muscle textural properties including hardness, chewiness, gumminess, tenderness, springiness, and cohesiveness; and serum biochemical indexes including total protein, albumin, blood urea nitrogen, HDL cholesterol, total cholesterol, and triglycerides. However, the golden pompano in 50NGP and 75NGP experienced nutritional stress, and thus some indicators were negatively affected. In addition, compared to the Control group, the expression levels of genes related to protein metabolism (mtor, s6k1, and 4e-bp1) and lipid metabolism (pparγ, fas, srebp1, and acc1) of the 25NGP group showed no significant difference, but the 4e-bp1 and pparγ of the 75NGP group were significantly upregulated and downregulated, respectively (p < 0.05), which may explain the decline in fish growth performance and muscle quality after 75% FM was replaced by NGCP. The results suggest that at least 25% FM of Control can be replaced by NGCP, achieving a dietary FM content of as low as 18%; however, the replacement of more than 50% of the dietary FM negatively affects the growth and muscle quality of golden pompano. Full article

In this study, we investigated the formation of protein–phenolic complexes from dephenolized hazelnut meal protein isolates (dHPI) and hazelnut skin phenolic extracts (HSE) and their effects on the bioaccessibility of both hazelnut proteins and phenolics. The dHPI–HSE complexes were of considerable size and were dependent on HSE concentration due to aggregation. Although catechin was the main component of HSE, it did not cause aggregation, except for a slight rise in particle size. According to fluorescence quenching, the hazelnut protein–phenolic extract complex had a linear Stern–Volmer plot expressing static quenching between 0–0.5 mM concentration; the interaction was mainly dependent on hydrogen bonding and van der Waals forces (ΔH < 0 and ΔS < 0), and the reaction was spontaneous (ΔG < 0). According to Fourier transform infrared (FTIR) spectroscopy results, higher phenolic extract concentration caused an increase in irregular structures in hazelnut protein, while the lowest catechin and phenolic concentration altered the regular structure. Skin extracts did not alter the digestibility of dephenolized proteins, but dephenolization reduced the degree of hydrolysis by pancreatin. The formation of the protein–phenolic complex had a beneficial effect on the bioaccessibility of hazelnut skin phenols, predominantly those on the galloylated form of the catechins, such as gallocatechin gallate and epigallocatechin gallate. Thus, the bioaccessibility and antioxidant activity analysis results showed that protein–phenolic complexes obtained from hazelnut meal and skin may promote the transition of phenolic compounds from the gastrointestinal tract without degradation. Full article

Grape seeds are the wineries’ main by-products, and their disposal causes ecological and environmental problems. In this study seeds from the pomace waste of autochthonous grape varieties from Lebanon, Obeidi (white variety) and Asswad Karech (red variety) were used for a multi-step biomass fractionation. For the first step, a lipid extraction was performed, and the obtained yield was 12.33% (w/w) for Obeidi and 13.04% (w/w) for Asswad Karech. For the second step, polyphenols’ recovery from the defatted seeds was carried out, resulting in 12.0% (w/w) for Obeidi and 6.6% (w/w) for Asswad Karech, with Obeidi’s extract having the highest total phenolic content (333.1 ± 1.6 mg GAE/g dry matter) and antioxidant activity (662.17 ± 0.01 µg/mL of Trolox equivalent). In the third step, the defatted and dephenolized seeds were subsequently extracted under alkaline conditions and the proteins were isoelectric precipitated. The recovered protein extract was 3.90% (w/w) for Obeidi and 4.11% (w/w) for Asswad Karech seeds, with Asswad Karech’s extract having the highest protein content (64 ± 0.2 mg protein/g dry matter). The remaining exhausted residue can be valorized in cosmetic scrubs formulations as a replacement for plastic microbeads. The designed zero-waste approach multi-step biomass fractionation has the potential to improve the valorization of the side products (grape seeds) of these two Lebanese autochthonous grape varieties. Full article

The effect of polyphenol removal (“dephenol”) combined with an alkaline pH shift treatment on the O/W interfacial and emulsifying properties of canola seed protein isolate (CPI) was investigated. Canola seed flour was subjected to solvent extraction to remove phenolic compounds, from which prepared CPI was exposed to a pH₁₂ shift to modify the protein structure. Dephenoled CPI had a light color when compared with an intense dark color for the control CPI. Up to 53% of phenolics were removed from the CPI after the extraction with 70% ethanol. Dephenoled CPI showed a partially unfolded structure and increased surface hydrophobicity and solubility. The particle size increased slightly, indicating that soluble protein aggregates formed after the phenol removal. The pH₁₂ shift induced further unfolding and decreased protein particle size. Dephenoled CPI had a reduced β subunit content but an enrichment of disulfide-linked oligopeptides. Dephenol improved the interfacial rheology and emulsifying properties of CPI. Although phenol removal did not promote peptic digestion and lipolysis, it facilitated tryptic disruption of the emulsion particles due to enhanced proteolysis. In summary, dephenol accentuated the effect of the pH shift to improve the overall emulsifying properties of CPI and emulsion in in vitro digestion. Full article

This study was on the comparison of hydrothermal treatments at 170 °C (steam injection) and 220 °C (steam explosion) to solubilize the organic matter contained in residual strawberry extrudate, focusing on phenolic compounds that were susceptible to be extracted and on sugars. After the extraction step, the remaining strawberry extrudate phases were subjected to anaerobic digestion to generate biogas that would compensate the energy requirements of the suggested hydrothermal treatments and to stabilize the remaining waste. Hydrothermal treatment at 220 °C allowed the recovery of 2053 mg of gallic acid eq. per kg of residual strawberry extrudate. By contrast, after hydrothermal treatment at 170 °C, only 394 mg of gallic acid eq. per kg of residual strawberry extrudate was recovered. Anaerobic digestion processes were applied to the de-phenolized liquid phase and the solid phase together, which generated similar methane productions, i.e., around 430 mL CH₄/g volatile solids, after both 170 °C and 220 °C hydrothermal treatments. Considering the latest observation, hydrothermal treatment at 220 °C is a preferable option for the valorization of residual strawberry extrudate (RSE) due to the high solubilization of valuable phenolic compounds that can be recovered. Full article

Six yeast strains belonging to Rhodosporidium toruloides, Lipomyces starkeyi, Rhodotorula glutinis and Cryptococcus curvatus were shake-flask cultured on xylose (initial sugar—S₀ = 70 ± 10 g/L) under nitrogen-limited conditions. C. curvatus ATCC 20509 and L. starkeyi DSM 70296 were further cultured in media where process waters were partially replaced by the phenol-containing olive mill wastewaters (OMWs). In flasks with S₀ ≈ 100 g/L and OMWs added yielding to initial phenolic compounds concentration (PCC₀) between 0.0 g/L (blank experiment) and 2.0 g/L, C. curvatus presented maximum total dry cell weight—TDCW_max ≈ 27 g/L, in all cases. The more the PCC₀ increased, the fewer lipids were produced. In OMW-enriched media with PCC₀ ≈ 1.2 g/L, TDCW = 20.9 g/L containing ≈ 40% w/w of lipids was recorded. In L. starkeyi cultures, when PCC₀ ≈ 2.0 g/L, TDCW ≈ 25 g/L was synthesized, whereas lipids in TDCW = 24–28% w/w, similar to the experiments without OMWs, were recorded. Non-negligible dephenolization and species-dependent decolorization of the wastewater occurred. A batch-bioreactor trial by C. curvatus only with xylose (S₀ ≈ 110 g/L) was performed and TDCW = 35.1 g/L (lipids in TDCW = 44.3% w/w) was produced. Yeast total lipids were composed of oleic and palmitic and to lesser extent linoleic and stearic acids. C. curvatus lipids were mainly composed of nonpolar fractions (i.e., triacylglycerols). Full article

Steam-explosion is a promising technology for recovering phenolic compounds from olive mill solid waste (OMSW) due to its high impact on the structure of the fibre. Moreover, the recovery of the phenols, which are well-known microbial inhibitors, could improve the subsequent biomethanization of the dephenolized OMSW to produce energy. However, there is a considerable lack of knowledge about how the remaining phenolic compounds could affect a long-term biomethanization process of steam-exploded OMSW. This work evaluated a semi-continuous mesophilic anaerobic digestion of dephenolized steam-exploited OMSW during a long operational period (275 days), assessing different organic loading rates (OLRs). The process was stable at an OLR of 1 gVS/(L·d), with a specific production rate of 163 ± 28 mL CH₄/(gVS·d). However, the increment of the OLR up to 2 gVS/(L·d) resulted in total exhaust of the methane production. The increment in the propionic acid concentration up to 1486 mg/L could be the main responsible factor for the inhibition. Regardless of the OLR, the concentration of phenolic compounds was always lower than the inhibition limits. Therefore, steam-exploited OMSW could be a suitable substrate for anaerobic digestion at a suitable OLR. Full article

A device (prototype) with a working volume of 200 L was used to deplete olive mill wastewater (OMW) of polyphenols. The OMW transformed into feedstock by means of the device was then used for feeding a lab-scale photobioreactor, just for testing the production of bioH₂. The main novelty of this prototype consists in the combination of several adsorbent matrices and the exploitation of their synergic action. In this investigation, three matrices have been used: active carbon, Azolla and zeolite. The device was operated at an olive oil company located in the heart of the Chianti zone (Province of Florence, Italy). The efficiency of polyphenol removal obtained using the device was ≥96%. The multi-matrix effluent (MM_eff) generated was then used to obtain three different culture broths containing 25%, 50% and 100% of MM_eff, respectively. The diluted (with water) culture broths were suitable for hydrogen generation, with the highest hydrogen production rate (12.7 mL H₂/L_culture/h) being obtained using 50% MM_eff. The hydrogen yields were: 334 mL H₂/L of MM_eff, when feeding the photofermenter with pure effluent (100%); 1308 mL H₂/L of MM_eff, with the half-diluted effluent (50%, v/v); and 432 mL H₂/L of MM_eff, with the highest-diluted effluent (25%, v/v). Full article