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Sustainable biomass-based carbon aerogels have attracted extensive concerns in the area of energy storage and wearable sensory electronics. However, the pristine porosity and low weight of aerogels result in unsatisfactory mechanical and electrical properties, limiting their practical applications. Herein, activated porous carbon (APC), reduced graphene oxide (rGO) and carbon nanoparticles (CNP) are utilized as raw materials to develop a novel type of hierarchically waste bread-derived carbon aerogel via a stepwise activation/calcination strategy. The obtained bread-derived carbon aerogels, named APC-rGO/CNP, exhibits an outstanding electrical conductivity (∼3.23 S cm−1) and a high compressive modulus (∼124.60 MPa) by the synergistic bonding interactions. As a supercapacitor electrode, the APC-rGO/CNP composite manifests an excellent capacitance of 474.8 F g−1 (1.0 A g−1). Furthermore, an all-solid-state symmetric APC-rGO/CNP//APC-rGO/CNP supercapacitor with polyvinyl alcohol/potassium hydroxide (PVA/KOH) gel electrolyte realizes an energy density of 17.4 Wh kg−1 at 895 W kg−1. Notably, even under large compressive stress of 20 kPa, the supercapacitor still achieves a high energy density of 25.6 Wh kg−1 at a power density of 822.8 W kg−1, as well as an excellent capacitance retention of 93.8 % over 10,000 cycles. Finally, we demonstrate the potential of the APC-rGO/CNP composite as a responsive pressure sensor with an ultra-wide detecting span of 0–3 MPa and a moderate sensitivity of 0.22 kPa−1, which can detect keyboard pressing and fist clenching movements distinctively. Overall, the desirable mechanical performances and electrical conductivity of the APC-rGO/CNP composites facilitate the development of versatile nanomaterials to exploit state-of-the-art wearable electronics. • Waste bread-derived APC-rGO/CNP by a facile activation/calcination strategy. • Outstanding mechanical, conductive and capacitance properties of APC-rGO/CNP. • Superior properties of supercapacitor under deformation and long-term service. • APC-rGO/CNP pressure sensor with a wide detecting span and moderate sensitivity. [ABSTRACT FROM AUTHOR]

Microbial hydrolytic enzymes are relevant biotechnological products that can be applied in various industries. In this study, we have tested the activity of hydrolytic enzymes of a newly isolated Hymenobacter sp. CKS3 strain and showed, for the first time, that members of Hymenobacter genus have still unexplored hydrolytic potential. Crude hydrolytic enzymes, produced by the strain CKS3 on a waste medium, were incorporated into a process of bioethanol production using waste bread. The conditions for bread hydrolysis were optimized using statistical design. Waste bread hydrolysate obtained under optimal conditions (100.73 h of hydrolysis, waste bread concentration 20.36% and agitation speed 200 rpm) contained 19.89 g/l of reducing sugars. A high performance liquid chromatography of hydrolyzed waste bread samples showed that the main components of the hydrolysate were dextrins, maltotriose, maltose and glucose. When using this substrate and waste baker's yeast for ethanol production under non-optimized conditions 1.73% of ethanol was produced. The results of this study showed that a newly isolated Hymenobacter sp. CKS3 can be utilized for enzymatic hydrolysis and bioethanol production in a process relying on waste materials. Furthermore, it was demonstrated that members of Hymenobacter genus have a significant and currently unexplored potential for bio-based industrial applications. Image 1 • First report of Hymenobacter enzymatic potential for waste bread hydrolysis. • Production of enzymes by novel red pigment bacterial strain Hymenobacter sp. CKS3. • An optimal design was used for optimize enzymatic hydrolysis of waste bread. • 19.89 g/l of reducing sugars was released from waste bread by CKS3 crude amylase. • The optimized waste bread hydrolysate was used for ethanol production. [ABSTRACT FROM AUTHOR]

• The study exploiting the strengths of submerged and solid-state fermentation. • Waste bread was converted to a protein and pigment-enriched fermented product. • 1.2 kg pigments per ton of waste bread was obtained. • The fermented product has potential to be used as nutrient rich feed. Waste streams from ethanol and bread production present inexpensive, abundant and underutilized renewable substrates that are highly available for valorisation into high-value products. A combined submerged to solid state fermentation strategy was studied using the edible filamentous fungus Neurospora intermedia to biotransform ethanol plant residues 'thin stillage' and waste bread as substrates for the production of additional ethanol, biomass and a feed product rich in pigment. The fungus was able to degrade the stillage during submerged fermentation, producing 81 kg ethanol and 65 kg fungal biomass per ton dry weight of thin stillage. Concurrently, the second solid state fermentation step increased the protein content in waste bread by 161%. Additionally, 1.2 kg pigment per ton waste bread was obtained at the best conditions (6 days solid state fermentation under light at 95% relative humidity at 35 °C with an initial substrate moisture content of 40% using washed fungal biomass to initiate fermentation). This study presents a means of increasing the value of waste bread while reducing the treatment load on thin stillage in ethanol plants. [ABSTRACT FROM AUTHOR]

Simultaneous dark fermentative hydrogen and ethanol production from waste bread in a mixed packed tank reactor (MPTR) was investigated. Waste bread was first hydrolyzed by the produced enzymes to generate the waste bread hydrolysate which was subsequently introduced to the MPTR for dark fermentative hydrogen and ethanol production. The optimal hydrogen and ethanol production rates were 15.01 mmol/(h·L) and 23.25 mmol/(h·L) when the organic loading rate reached 32 g/(L·d). The unit hydrogen and ethanol production were 4.87 mmol hydrogen/g waste bread and 7.54 mmol ethanol/g waste bread, respectively. This study provided a new direction for economic and efficient hydrogen and ethanol production from waste bread. [ABSTRACT FROM AUTHOR]

Biohydrogen production from waste bread in a continuous stirred tank reactor (CSTR) was techno-economically assessed. The treating capacity of the H 2 -producing plant was assumed to be 2 ton waste bread per day with lifetime of 10 years. Aspen Plus was used to simulate the mass and energy balance of the plant. The total capital investment (TCI), total annual production cost (TAPC) and annual revenue of the plant were USD931020, USD299746/year and USD639920/year, respectively. The unit hydrogen production cost was USD1.34/m 3 H 2 (or USD14.89/kg H 2 ). The payback period and net present value (NPV) of the plant were 4.8 years and USD1266654, respectively. Hydrogen price and operators cost were the most important variables on the NPV. It was concluded that biohydrogen production from waste bread in the CSTR was feasible for practical application. [ABSTRACT FROM AUTHOR]

In this study, continuous biohydrogen production from waste bread by anaerobic sludge was performed. The waste bread was first hydrolyzed by the crude enzymes which were generated by Aspergillus awamori and Aspergillus oryzae via solid-state fermentation. It was observed that 49.78 g/L glucose and 284.12 mg/L free amino nitrogen could be produced with waste bread mass ratio of 15% (w/v). The waste bread hydrolysate was then used for biohydrogen production by anaerobic sludge in a continuous stirred tank reactor (CSTR). The optimal hydrogen production rate of 7.4 L/(Ld) was achieved at chemical oxygen demand (COD) of 6000 mg/L. According to the results obtained from this study, 1 g waste bread could generate 0.332 g glucose which could be further utilized to produce 109.5 mL hydrogen. This is the first study which reports continuous biohydrogen production from waste bread by anaerobic sludge. [ABSTRACT FROM AUTHOR]

The subject of this research project was assessment of direct starch to ethanol conversion process course of waste wheat-rye bread using granular starch hydrolyzing enzyme (GSHE). Several pretreatment methods (enzymatic prehydrolysis, microwave irradiation, sonification) were used to improve the course of fermentation and were compared with separate hydrolysis and fermentation (SHF). Due to high water binding capacity of raw material fermentations were conducted at a substrate loading of 150 g kg-1. Only during enzymatic pretreatment and the SHF process the raw material was preliminary liquefied so its higher concentrations could be applied. The dynamics of fermentation was similar in all studied variants. The fermentation of unpretreated waste bread ended with 80.00% ethanol yield (354.36 g kg-1 of raw material). Pretreatment of raw material improved ethanol yield by ca. 3-8%. [ABSTRACT FROM AUTHOR]

In this study, the operation of a single cylinder, four stroke, SI engine powered by fuels created by blending two different bioethanol with gasoline was evaluated on the basis of energy and exergy analyses. Within the scope of the study, test engine was tested by operating it with fuel blends, prepared by adding both bioethanol, one of them was produced from waste bread and the other, originating from sugar beet, was supplied, to gasoline at different rates by of 5, 10, 15, 85 and 100% under five different engine loads at maximum torque speed, 2500 rpm. The variation of energy and exergy parameters was examined by comparing the blends, prepared to have similar volumetric content, each other and by comparing all with gasoline. As a result of the study, it was determined that the addition of bioethanol had generally decreasing effect on energy loss rate, exergy loss rate and exergy destruction rate. For fuel blends containing low levels of bioethanol, variation of ethanol has created little differences on all energy and exergy parameters but bioethanol type clearly showed its effect when bioethanol rate increased to 85% and 100%. Although waste bread bioethanol could not catch sugar beet bioethanol in terms of thermal efficiency (14.4% for E100b and 16.4% for E100 as load average) and exergetic efficiency (12.9% for E100b and 14.7% for E100 as load average), both bioethanol have been found to improve both thermal efficiency (12.2% for E0) and exergetic efficiency (11.4% for E0) than that of gasoline. [ABSTRACT FROM AUTHOR]

In this study, bioethanol produced from waste bread by fermentation was evaluated as engine fuel comparing with sugar beet bioethanol purchased. Comparison criteria are parameters of combustion analyses, engine performance and exhaust emissions. Therefore, the experiments were carried out in a single cylinder, four stroke, air cooled SI engine fueled with both bioethanol blended with gasoline in different proportions for different test conditions created with different engine load and a constant engine speed. Whether formed with sugar beet or waste bread bioethanol, fuel blends with similar volumetric contents have similar trends in every sense and their position they take relative to pure gasoline is similar. But when the ones with similar content are compared with each other, the differences emerge. These can be summarized as follows: It has been determined that combustion occurs in a shorter time with lower maximum cylinder pressures and maximum heat release rate if the engine runs with fuels containing waste bread bioethanol. In the case of adding waste bread bioethanol, there was a gradual increase in brake specific fuel consumption and a gradual decrease in thermal efficiency compared to sugar beet added fuels. The use of waste bread bioethanol blended with gasoline has seriously positive results in many emissions aspects such that it has less CO up to 70.9%, less HC up to 34.9% and less NOx up to 5.1%, except for the fact that it has more CO 2 up to 3.5%. [ABSTRACT FROM AUTHOR]

Bread is the most consumed food and one of the most wasted foods in the world. Every year, millions of tonnes of bread are wasted worldwide. The reason for this is the rapid spoilage of bakery products. This results in a large amount of unused bread in supermarkets and households. However, waste bread could be used as a renewable raw material. The most discussed strategy for recycling bakery waste is fermentation. But there are other methods to utilise bread waste, which will be discussed in the present review. In this review, we examine the latest trends in bread waste recycling; explore the possibilities for producing new chemicals, foods and other products and materials; and determine the efficiency of using bread waste to produce sugar used to make a new product through fermentation and other technologies. Bread waste is a good feedstock for microorganisms such as bacteria, fungi and yeasts. These microorganisms produce glucose from bread waste. After glucose extraction, the hydrolysate can be further fermented by microorganisms to produce lactic acid, hydrogen, ethanol, 2,3-butanediol, paramylon and syngas. Bread waste is also used to produce textiles and graphene. Already now, the processing of stale bread by extrusion to make a new product is used in manufacturing. In the last decade, craft breweries have learnt to use leftover bread to brew beer, saving millions of slices of bread each year. • Creation of new products from waste bread. • Possibilities of glucose obtaining from waste bread. • Bread waste is a potential feedstock for bacteria, fungi and yeasts. • Bread waste is a promising raw material for chemicals production. • Bread waste fermentation technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • LCA study of fermentative production of succinic acid using bread waste. • GHG emissions and non-renewable energy use (NREU) are evaluated. • Processes using steam and heating oil are found to be environmental hotspots. • GHG emissions and NREU were significantly lower than fossil based succinic acid. According to the US Department of Energy, succinic acid (SA) is a top platform chemical that can be produced from biomass. Bread waste, which has high starch content, is the second most wasted food in the UK and can serve as a potential low cost feedstock for the production of SA. This work evaluates the environmental performance of a proposed biorefinery concept for SA production by fermentation of waste bread using a cradle-to-factory gate life cycle assessment approach. The performance was assessed in terms of greenhouse gas (GHG) emissions and non-renewable energy use (NREU). Waste bread fermentation demonstrated a better environmental profile compared to the fossil-based system, however, GHG emissions were about 50 % higher as compared to processes using other biomass feedstocks such as corn wet mill or sorghum grains. NREU for fermentative SA production using waste bread was significantly lower (~ 46 %) than fossil-based system and about the same as that of established biomass-based processes, thus proving the great potential of waste bread as a valuable feedstock for bioproduction of useful chemicals. The results show that steam and heating oil used in the process were the biggest contributors to the NREU and GHG emissions. Sensitivity analyses highlighted the importance of the solid biomass waste generated in the process which can potentially be used as fish feed. The LCA analysis can be used for targeted optimization of SA production from bread waste, thereby enabling the utilization of an otherwise waste stream and leading to the establishment of a circular economy. [ABSTRACT FROM AUTHOR]

Bread, the most consumed floury product in the world, is one of the most wasted food products across the food supply chain. Yet, there is a paucity of research examining the magnitude of bread waste and behavioural drivers associated with it at the household level. This study analyses the incidence, behavioural drivers and disposal pathways of bread waste using a sample of 1462 households in Australia and a 7-day electronic diary method. Behavioural drivers related to bread waste were modelled using logistic regression models. The findings suggest that bread rolls, sliced bread and flat bread are the three most wasted bread products in Australian households. Higher grocery shopping frequency, 'just-in-case' buying, family households with young children and takeaway meal ordering are associated with higher bread waste. Bread disposal pathway analysis revealed that 55% of bread and bakery products are discarded through general waste bins, highlighting the immense potential of utilising bread waste in industrial processes such as biofuel production. Addressing bread and bakery waste can significantly contribute to achieving the SDG12.3 goal of halving the per capita food waste by 2030. • Household bread waste behaviours and disposal pathways analysed. • Bread and bakery waste represent 12% of total edible food wasted. • Sliced bread, bread rolls and flatbread are the most commonly discarded breads. • Just-in-case buying, and family households are associated with high bread waste. • 55% of bread and bakery waste is discarded through general waste bins. [ABSTRACT FROM AUTHOR]

[Display omitted] • 5-Hydroxymethyl-2-furanamine was prepared from bread waste via chemoenzymatic way. • Betaine:malonic acid (18%) catalyzed bread waste (40 g/L) to HMF (30.3% yield). • HNILGD-AlaDH cell expressed L -alanine dehydrogenase and ω-transaminase mutant HNILGD. • Bioamination of HMF was conducted with a low dose of amine donor (D- Ala/5-HMF = 2/1). • The yield was 0.28 g 5-hydroxymethyl-2-furanamine/(g bread waste). In this study, efficient and sustainable conversion of waste bread (WB) to 5-hydroxymethyl-2-furoamine (HMFA) was achieved in a cascade reaction in betaine:malonic acid (B:MA) − water. 5-HMF (30.3 wt% yield) was synthesized from WB (40.0 g/L) in B:MA − water (B:MA, 18 wt%) in 45 min at 190 °C. By using the newly created recombinant E. coli HNILGD-AlaDH cells expressing L -alanine dehydrogenase (AlaDH) and ω-transaminase mutant HNILGD as biocatalyst, the WB-valorized 5-HMF was biologically aminated into HMFA in a high yield (92.1%) at 35 °C for 12 h through in situ removal of the amino transfer by-products of the amine donor, greatly reducing amine donor dosage (from D- Ala/5-HMF = 16/1 to D- Ala/5-HMF = 2/1, mol/mol) and improving the productivity of HMFA (0.282 g HMFA per g WB). This two-step chemical-enzymatic cascade reaction strategy with B:MA and HNILGD-AlaDH whole-cell provides a new idea for the chemoenzymatic synthesis of valuable furan chemicals from waste biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2,5-Diformylfuran (DFF) was prepared from biobased substrates in [BA][LA]–H 2 O. • Bread waste (50 g/L) was catalyzed to HMF (33% yield) in [BA][LA]–H 2 O. • Fructose (18 g/L) was catalyzed to HMF (92% yield) in [BA][LA]–H 2 O. • The prepared HMF was biologically oxidized to DFF by E. coli pRSFDuet-GOase. • Bread waste and fructose were efficiently catalyzed to DFF. 2,5-Diformylfuran, which can be prepared via the oxidation of biobased HMF, has received considerable attention because of its potential applications in producing furan-based chemicals and functional materials, such as biofuels, polymers, fluorescent material, vitrimers, surfactants, antifungal agents and medicines. This work aimed to develop an efficient one-pot process for chemoenzymatic transformation of biobased substrate to 2,5-diformylfuran with deep eutectic solvent (DES) Betaine:Lactic acid ([BA][LA]) catalyst and oxidase biocatalyst in [BA][LA]–H 2 O. Using waste bread (50 g/L) and D -fructose (18.0 g/L) as feedstocks in [BA][LA]–H 2 O (15:85, vol/vol), the yields of HMF were 32.8% (15 min) and 91.6% (90 min) at 150 °C, respectively. These prepared HMF could be biologically oxidized to 2,5-diformylfuran by Escherichia coli pRSFDuet-GOase, achieving a productivity of 0.631 g 2,5-diformylfuran/(g fructose) and 0.323 g 2,5-diformylfuran/(g bread) after 6 h under the mild performance condition. This bioresourced intermediate 2,5-diformylfuran was effectively synthesized from biobased feedstock in an environmentally-friendly system. [ABSTRACT FROM AUTHOR]

The catalytic activity of engineered biochar was scrutinized for generation of glucose and hydroxymethylfurfural (HMF) from starch-rich food waste (bread, rice, and spaghetti). The biochar catalysts were synthesized by chemical activation of pinewood sawdust with phosphoric acid at 400–600 °C. Higher activation temperatures enhanced the development of porosity and acidity (characterized by C O PO 3 and C PO 3 surface groups), which imparted higher catalytic activity of H 3 PO 4 -activated biochar towards starch hydrolysis and fructose dehydration. Positive correlations were observed between HMF selectivity and ratio of mesopore to micropore volume, and between fructose conversion and total acid density. High yields of glucose (86.5 Cmol% at 150 °C, 20 min) and HMF (30.2 Cmol% at 180 °C, 20 min) were produced from rice starch and bread waste, respectively, over H 3 PO 4 -activated biochar. These results highlighted the potential of biochar catalyst in biorefinery as an emerging application of engineered biochar. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-pot manufacturing of 2,5-bis(hydroxymethyl)furan from bread was constructed. • HMF yield reached 32.8 % from bread by lactic acid:betaine (15 wt%) at 180 °C. • HMFOMUT cells transformed HMF (150 mM) to BHMF (84.5 % yield) after 1 day at 37 °C. • Bread-derived HMF was converted to BHMF in a productivity of 0.23 g BHMF/g bread. • Chemoenzymatic cascade catalysis of waste bread to valuable furans was developed. Via combination catalysis with deep eutectic solvent lactic acid:betaine (chemocatalyst) and HMFOMUT cell (biocatalyst: E. coli HMFOMUT whole-cell), one-pot manufacture of 2,5-furandimethanol from waste bioresource was constructed in a chemoenzymatic approach. With bread waste (50 g/L) as substrate, the 5-hydroxymethylfuran yield reached 44.2 Cmol% (based on bread waste) by lactic acid:betaine (15 wt%) at 180 °C for 15 min. With glucose as co-substrate, HMFOMUT could transform 5-hydroxymethylfurfural (150 mM) to 2,5-furandimethanol (84.5 % yield) after 1 day at 37 °C and pH 7.0. In lactic acid:betaine–H 2 O, HMFOMUT effectively converted bread-derived 5-hydroxymethylfurfural into 2,5-furandimethanol in a productivity of 700 kg 2,5-furandimethanol per kg 5-hydroxymethylfurfural (230 kg 2,5-furandimethanol per kg bread). In an eco-friendly lactic acid:betaine system, an effective one-pot chemoenzymatic strategy was firstly developed to convert bread waste into 2,5-furandimethanol, which would reduce the operation cost and has potential application value for valorizing waste food bioresource into value-added furan. [ABSTRACT FROM AUTHOR]

Food waste and fashion pollution are two of the most prominent global environmental issues. To alleviate the problems associated with food waste, while simultaneously contributing to sustainable fashion, the feasibility of making an alternative textile material with leather-like properties from fungal biomass cultivated on bread waste was investigated. The filamentous fungus, Rhizopus delemar , was successfully grown on waste bread in a submerged cultivation process, and fungal biomass was treated with vegetable tannin of chestnut wood. NMR and FTIR confirmed interactions between tannin and fungal biomass, while OM, SEM and AFM visualised the changes in the hyphae upon the tannin treatment. Thermal stability was assessed using TGA analysis. The wet-laid technique commonly utilised for paper-making was used to prepare sheets of hyphae. Some of the sheets were treated with glycerol and/or a biobased binder as post-treatment. Overall, three of the produced materials exhibited leather-like properties comparable to that of natural leather. Sheets from untreated biomass with only glycerol post-treatment showed a tensile strength of 7.7 MPa and an elongation at break of 5%. Whereas sheets from untreated biomass and tannin treated biomass with both glycerol and binder treatments led to tensile strengths of 7.1 MPa and 6.9 MPa, and the elongation at break of 12% and 17%, respectively. The enhancement of hydrophobicity after the binder treatment, helped to preserve the absorbed glycerol within the sheet and thereby the flexibility was retained when in contact with moisture. These findings demonstrate that bread waste-derived fungal sheets have great potential as environmentally friendly materials with leather-like properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: In traditional cereal-based industrial processes, component separation is often incomplete resulting in a residue of mixed macromolecules including largely starch, protein, phytic acid and many others. The development of a viable cereal-based biorefinery would involve effective bioconversion of cereal components for the production of a nutrient-complete fermentation feedstock. Simultaneous starch and protein hydrolysis represents an effective approach to the production of platform chemicals from wheat. Solid state fermentations of wheat pieces and waste bread by Aspergillus oryzae and Aspergillus awamori have been combined in this study to enhance starch and protein hydrolysis. Kinetic studies confirmed that the proteolytic enzymes from A. oryzae introduced no negative effect on the stability of the amylolytic enzymes from A. awamori under the optimal conditions for starch hydrolysis. When applied to hydrolyse wheat flour, the enzyme solution from A. awamori converted nearly all of the starch into glucose and 23% of the total nitrogen (TN) into free amino nitrogen (FAN). Under the same reaction conditions the enzyme solution from A. oryzae hydrolysed 38% of the protein but only 18.5% of the starch. A mixture of the two enzyme solutions hydrolysed 34.1% of the protein, a 1.5-fold increase from that achieved by the enzyme solution from A. awamori, while maintaining a near completion of starch hydrolysis. [Copyright &y& Elsevier]

Abstract: Fish waste (FW) obtained from a fish processor was ensiled for biogas production. The FW silages were prepared by mixing FW with bread waste (BW) and brewery grain waste (BGW), and the quality of the prepared silages were evaluated. The biogas potentials of BW, BGW, three different types of FW, and FW silages were measured. A first-order kinetic model and the modified Gompertz model were also used to predict methane yield. The biogas and methane yield for FW silages after 96days was calculated to be 671–763mL/g VS and 441–482mL/g VS, respectively. There were smaller differences between measured and predicted methane yield for FW silages when using a modified Gompertz model (1.1–4.3%) than when using a first-order kinetic model (22.5–32.4%). The critical HRTs and technical digestion times (T 80–90) for the FW silages were calculated to be 21.0–23.8days and 40.5–52.8days, respectively. [Copyright &y& Elsevier]