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Algerians are among the largest consumers of bread throughout the year and produce large amounts of bread waste. As bread is made from imported wheat, these losses on currency are a heavy loss for the national economy. To minimize these losses, Algeria needs to encourage the recycling of stale bread to minimize the cost of importing soft wheat and valorize it for farmers. This paper presents a framework based on the Internet of Things (IoT) to monitor and collect waste bread from recycling bins. This system could assist Small and Medium Enterprises (SMEs) in Algeria in bread waste collection, by monitoring the level of filling of the outdoor waste bins. The proposed system's architecture used a Mega 2560 microcontroller, HC-SR04 ultrasonic sensors, and SIM 808/900 modules.

Waste bread hydrolysate was used as a biosource for xanthan production by various isolates and standard bacteria (Xanthomonas campestris DSM 19000). Influence of operational conditions used in the process of xanthan production were evaluated through yield of xanthan, rheological properties of aqueous solution and fermentation kinetics. For the highest yield and viscosity, optimum conditions including carbon source concentration, inoculum volume and agitation rate were determined for 4 different strains by using response surface methodology. The highest gum yield as 14.3 g/L was obtained by Xanthomonas axonopodis vesicatoria and the highest conversion rate of waste bread to xanthan gum was found as %14.1 for Xanthomonas hortorum pv. pelargonii. Whereas, the highest aqueous solution viscosity of gum produced from standard bacteria was 11.2 Pa.sn at glucose ratio of 4%, inoculum volume of 5% and mixing rate of 225 rpm. For fermentation kinetics; the values of growth associated parameters revealed that they are mostly affected by the rate of xanthan gum production and substrate consumption. In general, optimum conditions to obtain the highest xanthan gum yield were different from that to achieve the highest viscosity. This study shows the potential of waste bread hydrolyzates as the promising economic carbon source for xanthan gum production. © 2018 Elsevier Ltd Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: TOVAG-114O429 We thank The Scientific and Technological Research Council of Turkey (TUBITAK) for financial support (Project Number TOVAG-114O429 ). 2-s2.0-85056672890

A recent trend in sustainable bioethanol production is the use of agricultural waste or food waste as an inexpensive and the most available feedstock. Bread waste is the major food waste that could be successfully used for the production of bioethanol. The aim of this study was to optimize ethanol production by the response surface methodology (RSM) using waste bread hydrolysate. Waste bread hydrolysate was obtained using crude hydrolytic enzymes that produce bacterial isolate Hymenobacter sp. CKS3. The influence of time of fermentation (24?72 h) and waste brewer?s yeast inoculum (1?4 %) on ethanol production was studied. The optimal conditions, obtained by central composite design (CCD), were 48.6 h of fermentation and 2.85 % of inoculum. Under these conditions, a maximum of 2.06 % of ethanol concentration was reached. The obtained ethanol concentration was in good correlation, coefficient of 0.858, with yeast cell yield. The results obtained in this study imply that waste bread hydrolysate could be used as a biomass source for biofuel production with multiple benefits relating to environmental protection, reduction of production costs, and saving fossil fuels.

Parageobacillus thermoglucosidasius is a genetically tractable thermophile that grows rapidly at elevated temperatures, with a doubling time at 65 °C comparable to the shortest doubling times of Escherichia coli. It is capable of using a wide variety of substrates, including carbohydrate oligomers, and has been developed for the industrial production of ethanol. In this study, P. thermoglucosidasius NCIMB11955 has been engineered to produce the sesquiterpene τ-muurolol by introduction of a heterologous mevalonate pathway constructed using genes from several thermophilic archaea together with a recently characterised thermostable τ-muurolol synthase. P. thermoglucosidasius naturally uses the methylerythritol phosphate pathway for production of the terpene precursor, isopentenyl pyrophosphate, while archaea use a version of the mevalonate pathway. By introducing the orthogonal archaeal pathway it was possible to increase the flux through to sesquiterpene biosynthesis. Construction of such a large metabolic pathway created problems with genetic vector introduction and stability, so recombinant plasmids were introduced by conjugation, and a thermostable serine integrase system was developed for integration of large pathways onto the chromosome. Finally, by making the heterologous pathway maltose-inducible we demonstrate that the new strain is capable of using waste bread directly as an autoinduction carbon source for the production of terpenes in a consolidated bioprocess.

The starch in waste bread (WB) from industrial sandwich production was directly converted to ethanol by an amylolytic, ethanologenic thermophile (Parageobacillus thermoglucosidasius strain TM333) under 5 different simultaneous saccharification and fermentation (SSF) regimes. Crude α-amylase from TM333 was used alone or in the presence of amyloglucosidase (AMG), a starch monomerizing enzyme used in industry, with/without prior gelatinisation/liquefaction treatments and P. thermoglucosidasiusTM333 fermentation compared with Saccharomyces cerevisiae as a control. Results suggest that TM333 can ferment WB using SSF with yields of 94-100% of theoretical (based on all sugars in WB) in 48h without the need for AMG addition or any form of heat pre-treatment. This indicates that TM333 can transport and ferment all of the malto-oligosaccharides generated by its α-amylase. In the yeast control experiments, addition of AMG together with the crude α-amylase was necessary for full fermentation over the same time period. This suggests that industrial fermentation of WB starch to bio-ethanol or other products using an enhanced amylolytic P. thermoglucosidasius strain could offer significant cost savings compared to alternatives requiring enzyme supplementation.

The starch in waste bread (WB) from industrial sandwich production was directly converted to ethanol by an amylolytic, ethanologenic thermophile (Parageobacillus thermoglucosidasius strain TM333) under 5 different simultaneous saccharification and fermentation (SSF) regimes. Crude α-amylase from TM333 was used alone or in the presence of amyloglucosidase (AMG), a starch monomerizing enzyme used in industry, with/without prior gelatinisation/liquefaction treatments and P. thermoglucosidasius TM333 fermentation compared with Saccharomyces cerevisiae as a control. Results suggest that TM333 can ferment WB using SSF with yields of 94–100% of theoretical (based on all sugars in WB) in 48 h without the need for AMG addition or any form of heat pre-treatment. This indicates that TM333 can transport and ferment all of the malto-oligosaccharides generated by its α-amylase. In the yeast control experiments, addition of AMG together with the crude α-amylase was necessary for full fermentation over the same time period. This suggests that industrial fermentation of WB starch to bio-ethanol or other products using an enhanced amylolytic P. thermoglucosidasius strain could offer significant cost savings compared to alternatives requiring enzyme supplementation.

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.

Food-grade enzymes (alpha-amylase, amyloglucosidase, maltogenic amylase, and protease) were investigated for recycling waste bread back to wheat bread-making process. Waste bread was efficiently hydrolyzed into sugars (up to 93% glucose yield) and the best combination of enzymes was alpha-amylase (0.05 g/kg bread) and amyloglucosidase (2.5 g/kg bread). Selected enzyme hydrolysis processes were tested in wheat bread making as a (a) hydrolyzed slurry, that is hydrolyzed waste bread without solid/liquid separation and (b) syrup, that is liquid supernatant after centrifugation of the hydrolyzed waste bread. Both hydrolyzed bread slurry and syrup were successfully utilized to replace sucrose (2 and 4%) in bread making without affecting the bread quality when compared to the control bread. Techno-economic assessment revealed that this approach is 12% more economical than the current mean to dispose the bakery waste. This recycling concept showed both technical and economic potential for bakery industries to overcome their excess bread production. Novelty impact statement A new recycling process was developed by using enzymes to efficiently hydrolyze surplus bread into sugars. The use of those sugar-rich slurries and syrups in bread rework did not affect the bread quality when compared to the control bread. The recycling concept was more economical than current means to dispose waste bread, revealing the technical and economic potential for bakery industries to overcome their excess bread production.

This article focuses on the use of a rule-based Mamdani-type fuzzy expert system for the prediction of Pmax, HRRmax, ID, and CD as combustion parameters, BTE and BSFC as engine performance parameters, and CO, CO2, HC, and NOx as exhaust emission parameters of fuel blends formed by blending waste bread bioethanol with gasoline in different proportions. For modeling of 55 test conditions created by being operated test engine with 11 different test fuels under five different engine loads. As a result of the study, while combustion parameters were predicted with correlation coefficients in the range of 0.948–0.973% for waste bread bioethanol-gasoline blends, correlation coefficients for engine performance and exhaust emission parameters were in the range of 0.968–0.977% and 0.955–0.991% respectively. Similarly, the ranges of correlation coefficients obtained for sugar beet bioethanol-gasoline blends with fuzzy expert system were as follows: 0.967–0.971% for engine performance parameters, 0.955–0.978% for exhaust emission parameters, and 0.951–0.964% for combustion parameters. These results prove that costly and labor-intensive engine tests can be predicted with minimum effort and high accuracy with the developed model.

Atık ekmekleri değerlendirmek ve toplam ürünmaliyetini azaltmak için karbon kaynağı olarak atık ekmek hidrolizatınınkullanılmasıyla çeşitli Xanthomonas türleritarafından üretilen ksantan gamların sulu çözeltilerinin teknolojik özellikleriincenlenmiş ve ticari ksantan gam ile karşılaştırılmıştır. E n yüksek su tutma kapasitesi ticariksantan gamda tespit edilirken, yağ tutma kapasitesinin X. campestris DSM 19000 and X.axonopodis pv. begoniae tarafındanüretilen gamlarda ticari gamdan daha yüksek olduğu saptanmıştır. Üretilengamlarla puding örnekleri hazırlanmıştır ve Ostwald de Waele modeline görepudinglerin davranışı başarıyla tanımlanmıştır. En yüksek K değeri gam ilaveedilmeyen örneklerde 161.2Pa.sn olarak elde edilmiş olup bunu sırasıyla X. axonopodis pv.begoniaeve X. hortorum pv.pelargonii tarafından üretilen gamlarınilave edildiği örnekler 139.3 Pa.sn ve 133.2 Pa.sndeğerleri ile takip etmiştir. n değerleri 0,12 ile 0,49 arasında değişmiş olupgam ilavesi ile artmıştır. Sonuç olarak bu çalışma, X.axonopodispv. begoniae ve X.hortorum pv. pelargonii izolatları tarafından,substrat olarak atıkekmeğin kullanılmasıyla üretilen gamlarla hazırlanan pudingörneklerinin açısal frekansa ve kayma hızına daha dayanıklı olduğu ve buörneklerin daha sağlam bir jel yapısına sahip olduğunu göstermiştir., Technological properties of aqueous solutions ofxanthan gums produced by various Xanthomonasspecies using waste bread (WB) hydrolyzate as a carbon source to reduce theoverall product cost and to utilize waste bread were investigatedand compared with commercial xanthan gum. While the highest waterholding capacity was detected in the commercial xanthan gum, oil holdingcapacity was higher in xanthan gums from X. campestris DSM 19000 and X. axonopodis pv. begoniae than commercial gum. Pudding samples were prepared by thegums obtained and Ostwald de Waele model was successfully described thebehavior. The highest K value were obtained by the sample without gum addition as 161.2 Pa.sn,this was followed by the sample with the gum from X. axonopodis pv.begoniaewith 139.3 Pa.sn and X.hortorum pv.pelargonii with 133.2Pa.sn . n values varied between 0.12 and 0.49 and increased with theaddition of the gum. Therefore,this study showed that thepudding samples prepared with the gums from X. axonopodis pv. begoniae and X. hortorum pv. pelargonii isolates using waste bread as substrate werefound to be more resistant to shear rate and angular frequency and had a morerobust gel structure.

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.

This study was undertaken to investigate the effect of temperature (25 °C and 30 °C) and nitrogen supplementation (with 20 g/L peptone or without) on bioethanol production from waste bread, waterme...

Activated carbon foam was prepared via direct pyrolysis of waste bread (WB) under CO2 atmosphere. The product was characterized by N2 adsorption/desorption and Fourier transform infrared spectroscopy (FTIR). The preparation process was investigated online by a thermogravimetric analyzer coupled with FTIR (TG-FTIR). The adsorption isotherms of methylene blue (MB) by the product were investigated. The experimental data demonstrated that the product had a high surface area of 1575 m2 g−1 and a total pore volume of 0.883 cm3 g−1. Thermal decomposition of polymers in WB mainly occurred between 200 and 500 °C, leading to the release of carbonyl compounds, aliphatic hydrocarbons, alcohols, and furans. The dominant CO2 activation process started at above 800 °C. The MB adsorption equilibrium data followed Langmuir model with a monolayer adsorption capacity of 403 mg g−1. This study provides a reference for the utilization of WB as a promising precursor of activated carbon foam adsorbent, which has highly porous structure and excellent floatability in water.

Finding of optimal hydrolysis conditions is important for increasing the yield of saccharides. The higher yield of saccharides is usable for increase of the following fermentation effectivity. In this study optimal conditions (pH and temperature) for amylolytic enzymes were searched. As raw material was used waste bread. Two analytical methods for analysis were used. Efficiency and process of hydrolysis was analysed spectrophotometrically by Somogyi-Nelson method. Final yields of glucose were analysed by HPLC. As raw material was used waste bread from local cafe. Waste bread was pretreated by grinding into small particles. Hydrolysis was performed in 100 mL of 15 % (w/v) waste bread particles in the form of water suspension. Waste bread was hydrolysed by two commercial enzymes. For the liquefaction was used α‑amylase (BAN 240 L). The saccharification was performed by glucoamylase (AMG 300 L). Optimal conditions for α‑amylase (pH 6; 80 °C) were found. The yield of total sugars was 67.08 g∙L-1 (calculated to maltose). As optimal conditions for glucoamylase (pH 4.2; 60 °C) were found. Amount of glucose was 70.28 g∙L1. The time of waste bread liquefaction was 180 minutes. The time of saccharification was 90 minutes. The results were presented at the conference CECE Junior 2014.

The potential of bioH 2 production using waste bread via a two-stage process was examined. In the first stage, the waste bread was utilized by Aspergillus awamori and Aspergillus oryzae through solid state fermentation to generate glucoamylase and protease which were then utilized to hydrolyze the waste bread to produce the waste bread hydrolysate. The highest starch conversion of 96.6% and glucose yield of 0.521 g glucose/g waste bread were achieved within 24 h. In the second stage, the waste bread hydrolysate was utilized for bioH 2 production by Biohydrogenbacterium R3. The maximum H 2 yield of 103 mL H 2 /g waste bread could be obtained. The proposed two-stage bioprocess, which was able to increase the nutrient conversion efficiency and H 2 production from organic solid wastes, should be a promising way for bioH 2 production in industrial application.

Development of bioprocess routes for production of value-added materials from food waste is very attractive in terms of bioprocess economics and environmental protection. in this study, production of 2-keto-d-gluconic acid, a significant platform chemical, from food waste was performed by Pseudomonas reptilivora NRRL B-6 for the first time. the nitrogen source preference of the strain for 2-keto-d-gluconic acid production under different glucose concentrations in synthetic medium has been elucidated. At higher glucose concentrations, utilization of organic nitrogen source (yeast extract) led to higher product formation while at lower glucose concentration, utilization of inorganic nitrogen source (ammonium chloride) was also very feasible. the results indicated that favorable nitrogen source for 2-keto-d-gluconic acid production can change depending on the glucose concentration. the waste bread hydrolysate (glucose 181.43 g/L, protein 1.21% (w/v)) prepared by sequential application of alpha -amylase, amyloglucosidase, and protease was utilized in medium formulation at different glucose concentrations. Bread hydrolysate without additional supplements provided higher product formation than the optimum medium prepared with the hydrolysate. Utilization of 50 g/L CaCO3 led the maximum product formation. the maximum 2-keto-d-gluconic acid production from waste bread was 142.81 g/L with the productivity of 3.02 g/L/h and molar yield of 0.95. the proposed approach in this study confirms that waste bread as a sole source of nutrients can be valorized for microbial production of various industrially relevant platform chemicals., Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK), The postdoctoral fellowship from"The Scientific and Technological Research Council of Turkey (TUBITAK)" has been gratefully acknowledged (S. Yegin).

Bu tez çalışmasında, atık ekmek biyoetanolü-benzin karışımları (E5e, E10e, E15e, E85e, E100e) ve şeker pancarı biyoetanolü-benzin karışımları (E5, E10, E15, E85, E100) tek silindirli, dört zamanlı bir buji ateşlemeli motorda test edilmiştir. Motor testleri sıkıştırma oranı 7 ve ateşleme avansı -25 °KMA ve maksimum tork devri olan 2500 rpm'de farklı motor yüklerinde (2, 2.5, 3, 3.5, 4Nm) gerçekleştirilmiştir. Yakıt karışımları benzinle karşılaştırmalı biçimde yanma davranışı, motor performansı, egzoz emisyonları, termodinamik ve termoekonomik analizler açısından değerlendirilmiştir. Yanma analizi, biyoetanol ilaveli yakıtların genellikle benzine nazaran daha düşük silindir basınçları ve daha yüksek ısı salım hızlarına neden olduğunu göstermiştir. Termal verim maksimum değerlerini motorun 4 Nm yük altında E0, E100 ve E100e (sırasıyla %13.2, %17.1 ve %16.1) yakıtları ile çalıştırılması durumunda almıştır. Her iki biyoetanolün benzine ilavesinin egzoz emisyonları bakımından yüksek O2, CO2, NOx ve düşük CO, HC salımına neden olduğu görülmüştür. Şeker pancarı ve atık ekmek biyoetanolü ilaveli yakıtlar kendi aralarında değerlendirildiğinde, termodinamik açıdan hem kayıp akımlarının daha az olması hem de yakıt enerjisinin ve yakıt ekserjisinin fren gücüne dönüşme oranının fazla olması bakımından en optimum iki yakıtın E100 ve E100e olduğu tespit edilmiştir. E100 için benzine kıyasla %8.13 daha az olan yakıt maliyeti, E100e için %21.57 oranı ile belirgin şekilde artmıştr., In this thesis, waste bread bioethanol-gasoline blends (E5e, E10e, E15e, E85e, E100e) and sugar beet bioethanol-gasoline blends (E5, E10, E15, E85, E100) were tested in a single-cylinder, four-stroke spark ignition engine. Engine tests were carried out at different engine loads (2, 2.5, 3, 3.5, 4Nm) while the compression ratio was 7 and the ignition advance was -25 ° KMA and engine speed was 2500 rpm, corresponding to the maximum torque. Fuel blends were evaluated in terms of combustion behavior, engine performance, exhaust emissions, thermodynamic and thermoeconomic analysis in comparison with gasoline. Combustion analysis has shown that fuels with added bioethanol generally cause lower cylinder pressures and higher heat release rates than gasoline. Thermal efficiency has taken its maximum values when the engine is operated under 4 Nm load with E0, E100 and E100e (13.2%, 17.1% and 16.1% respectively). The addition of both bioethanol to gasoline has been shown to cause high O2, CO2, NOx and low CO, HC emissions in terms of exhaust emissions. Thermodynamically, it is determined that the most optimum fuels are E100 and E100e in terms of having less loss rates and high rate of conversion of fuel energy and exergy to brake power when sugar beet bioethanol and waste bread bioethanol supplemented fuels are evaluated among themselves. The fuel cost, which was 8.13% lower for E100 compared to gasoline, increased significantly with 21.57% for E100e.

The objective of this study was to purify and characterize the α-amylase for industrial perspective. The production of α-amylase through solid-state fermentation by Ganoderma tsuage was investigated by using waste bread as substrates. Production parameters were optimized as 2 mL of inoculum size, moisture 50%, additional carbon source (glucose) and nitrogen source (ammonium nitrate) 10:1, 1 mM/mL MgSO4, 0.75 mM/mL CaCl2 and 0.50 mM/mL KH2PO4. The purification value of α-amylase was observed as 1.2 fold with specific activity of 112 U/mg having a yield of 22%. Specific activity of α-amylase increased up to the level of 143 U/mg and had 1.5-fold purification factor having a yield of 6% after Sephadex gel filtration. Optimum value of α-amylase was obtained at 35°C and at pH 6 for the time duration of 72 h. The Km and Vmax values for α-amylase were 1.3 mg and 39 mg/min, respectively. Calcium chloride (CaCl2) was found to increase the activity of α-amylase while all other compounds seemed to have inhibitory action against α-amylase. Silver nitrate (AgNO3) was the strongest inhibitor and therefore would not be advised for use in future research against α-amylase production.Keywords: α-Amylase, purification, characterization, waste bread, Ganoderma tsuage

In this study, fuel properties of two bioethanol fuel, one produced from waste bread (E100b) and the other originated from sugar beet (E100) and base gasoline (E0) were treat as a subject. It was investigated that the properties of fuel blends formed by mixing both bioethanol with gasoline in the same proportions as 5, 10, 15, 85%. The evaluation was based on the fuel properties, which are thought to have the most influence on engine operation, such as density, purity, kinematic viscosity, octane number, heating value. Waste bread based- bioethanol has been found to cause an increasing effect on the density, kinematic viscosity, while decreasing the heating value to some extent. The results showed that differences in fuel properties among both bioethanol that are thought to be related to purity can be ignored for fuel blends with low bioethanol content.

Food-grade waste and side streams should be strictly kept in food use in order to achieve sustainable food systems. At present, the baking industry creates food-grade waste as excess and deformed products that are mainly utilized for non-food uses, such as bioethanol production. The purpose of this study was therefore to explore the potential of waste wheat bread recycling for fresh wheat bread production. Waste bread recycling was assessed without further processing or after tailored fermentation with lactic acid bacteria producing either dextran or β-glucan exopolysaccharides. When non-treated waste bread slurry was added to new bread dough, bread quality (specific volume and softness) decreased with increasing content of waste bread addition. In situ EPS-production (dextran and microbial β-glucan) significantly increased waste bread slurry viscosity and yielded residual fructose or glucose that could effectively replace the sugar added for yeast leavening. Furthermore, fermentation acidified waste bread matrix, thus improving the hygienic safety of the process. Bread containing dextran synthesized in situ by Weissella confusa A16 showed good technological quality. The produced dextran compensated the adverse effect of recycled bread on new bread quality attributes by 12% increase in bread specific volume and 37% decrease in crumb hardness. In this study, a positive technological outcome of the bread containing microbial β-glucan was not detected. The waste bread fermented by W. confusa A16 containing dextran appears to enable safe bread recycling with low acidity and minimal quality loss.

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.

Amongst the many forms of food waste, bread is a major contributor to the problem. Two aims of this research investigate waste breads potential of being a bioresource for the production of fermentable sugars which are precursor of valuable bioproducts by fermentation process: finding optimum substrate, water and enzyme ratio to produce the highest amount of fermentable sugars and investigating the rheological behavior of the system during hydrolysis. Two stage waste bread hydrolysis was performed with enzymes alpha-amylase and amyloglucosiades and response surface methodology was used to optimize substrate, water and enzyme ratio. Discovery Hybrid Rheometer-2 (TA Instruments) fitted with a parallel-plate geometry was used to investigate steady flow viscosity of the slurry during hydrolysis. 99 % of theoretical maximum glucose yield, a main fermentable sugar, is achieved by optimizing enzymatic hydrolysis conditions of waste bread at liquefaction and saccharification stages. Just after the addition of alpha-amylase enzyme, substantial decrease is observed in viscosity and Casson apparent yield stress of the slurry. During saccharification stage, glucose yield increases dramatically while viscosity of the slurries is very low and does not change considerably. The results imply that utilizing high concentrations of waste bread as a feedstock to produce fermentation products offers economic benefits without causing high power consumption, excessive wear on equipment, and reduced conversion which are generally expected consequences for high-solid processing.

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.

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 CO2 up to 3.5%.

Producción Científica, Food waste is a current global problem. The aim of this work was to investigate the possibility of reintroducing bread discarded by retailers in the preparation of sugar-snap cookies. Bread flours were obtained from stale breads (white and whole wheat) milled with 200, 500 and 1000 μm sieves. Cookies were elaborated using 100% bread flours and combinations of 50% of bread flour and wheat flour. The rheology of the doughs, the dimensions of the cookies, their texture and colour were evaluated. Bread flour doughs presented higher G’ (elastic modulus), G” (viscous modulus) values than the control, especially with increased particle size. Bread flour cookies had a smaller diameter and a harder texture than the control, but in the case of whole bread flours of larger particle sizes, those differences were reduced. Cookies made with bread flour had a darker colour and higher a* values. The 50% mixtures did not present significant differences with respect to the control in terms of dough rheology, hardness, or lightness. Although the spreading factor was reduced, it was more similar to the control than to 100% bread flour cookies. Wasted bread flour can thus be used to replace wheat flour in cookie formulations., Junta de Castilla y León - (VA177P20), TRANSCOLAB FEDER-Interreg España-Portugal - (project 0612_TRANS_CO_LAB_2_P)

In this paper yields of bioethanol from seven samples of bread were compared. Samples of bread were produced and prepared in a laboratory by mixing wheat and buckwheat flour in amounts of 0, 20, 40, 50, 60, 80 and 100%. At first, the analysis of all seven samples of bread was done (dry matter, starch content and pH value of bread sample suspensions). Then the waste bread suspensions were hydrolyzed by applying commercial hydrolytic enzymes, Termamyl® SC and SAN Extra® L. The fermentation process was carried out with dry instant yeast, Saccharomyces cerevisiae, after which distillation of all fermented suspensions was performed. The ethanol contents in the distillates of all seven samples were determined. The highest yield of bioethanol was detected in the bread sample made of pure wheat flour. The ethanol yield gradually decreased with increasing content of buckwheat flour in bread. These results could be useful when considering the possibility of utilization of waste bread from different sources as a feedstock for bioe­thanol production.

The aim of this study was to optimise airflow rate for glucoamylase and protease production from waste bread via solid state fermentation by Aspergillus awamori in packed bed bioreactors. Airflow rates, between 0.40 and 3.00 vvm, were tested. In all experiments, the fungal growth was almost uniform throughout the solids. Fungi grew both on and within the substrate and fungal cakes were formed. The highest glucoamylase and protease activities were recorded as 130.8 U/g bread (db) and 80.3 U/g bread (db) in the experiments with 1.50 vvm airflow rate, respectively. These values are 27.2% and 32.3% higher than the glucoamylase and protease activities obtained in petri dish experiments with static air. At 1.50 vvm airflow rate, the dry weight of the solids had decreased to 46% of the initial value at the end of the fermentation. The temperature of the solids increased up to 37.5 ??C with high axial temperature gradients due to high metabolic activity. The average moisture content of the solids first decreased to 150% (db) and then increased to 275% (db) by the end of the fermentation. Both above and below 1.50 vvm airflow rate, enzyme production and fungal growth were affected significantly. Also, a Gaussian-based mathematical model was developed to model the effects of airflow rate on enzyme production. The model fitted almost seamlessly to the experimental data. Thus, this study clearly showed the effects of aeration on glucoamylase and protease production from waste bread under solid state fermentations. ?? 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

According to the significant role of sugar alcohols (Polyols) in food industries, in the present study the possibility of microbial production of mannitol from bread waste was studied. Microbial growth and amylase production were investigated by five Iranian native strains of Bacillus spp in starch agar and broth. The best strain was selected, and its growth curve was determined. Leuconostoc mesentroides PTCC 1059 was used as a control strain to convert fructose to mannitol. In order to determine the ability of selected strains in converting waste breads into mannitol sugar, a culture medium was prepared from waste of Lavash and Baguette breads. Afterward, the ability to convert starch into fructose by Chemical analysis glucose test was used, and then bio-conversion analysis of fructose to mannitol by HPLC analysis was investigated. HPLC results showed that the Bacillus subtilis and Leuconostoc mesentroides PTCC 1059 had the ability of producing mannitol at a rate of 4.8g/L from fructose 5%, 0.15 g/L from Lavash bread 5%, and 0.2g/L from Baguette bread.

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%.

The aim of this study was kinetic analysis of the multi-enzyme solution produced from waste bread via solid state fermentation by Aspergillus awamori. It was found that at normal temperature for hydrolysis reactions, 60 °C, the activation energies for denaturation of A. awamori glucoamylase, 176.2 kJ/mol, and protease, 149.9 kJ/mol, are much higher than those for catalysis of bread starch, 46.3 kJ/mol, and protein, 36.8 kJ/mol. Kinetic studies showed that glucoamylase and protease in the multi-enzyme solution should have at least two conformations under the two temperature ranges: 30–55 °C and 60–70 °C. Thermodynamic analysis showed that, deactivation of glucoamylase and protease in the multi-enzyme solution can be reversible between 30 °C and 55 °C, since ΔS is negative and ΔH is positive. On the other hand, for glucoamylase and protease, both ΔS and ΔH are positive between 60 °C and 70 °C. This means that the deactivation of both enzymes in the multi-enzyme solution is spontaneous in this temperature range. It was also found that the glucoamylase produced in the solid state fermentation of waste bread is more thermally stable than the protease in the mixture. Consequently, the protease had little or no effect on the stability of the glucoamylase. Furthermore, the half-life of the glucoamylase produced from waste bread pieces was much higher than that produced from wheat flour. This is an important finding because the mode of production, via solid state fermentation, appears to have increased the thermostability of the enzyme significantly.

When it is not consumed, bread presents a major source of food waste, both in terms of the amount and its economic value. However, bread also possesses the characteristics of an ideal substrate for solid state fermentation. Yet nearly all wasted bread ends up in landfill sites, where it is converted into methane by anaerobic digestion. Governments are finally taking action and, according to the EU Landfill Directive, for example, biodegradable municipal waste disposed into landfills must be decreased to 35% of 1995 levels, by 2020. Solid state fermentation of waste bread for the production of value added products is a novel idea, which could help with the achievement of this target. In this study, glucoamylase and protease production from waste bread pieces, via solid state fermentation, was investigated in detail. The optimum fermentation conditions for enzyme production were evaluated as, 20 mm particle size, 1.8 (w/w, db) initial moisture ratio, and duration of 144 h. Under these conditions, glucoamylase and protease activities reached up to 114.0 and 83.2 U/g bread (db), respectively. This study confirms that waste bread could be successfully utilised as a primary raw material in cereal based biorefineries.

Bu çalışmada atık ekmek, kavun ve karpuzun biyoetanol üretimineuygunluğu araştırılmıştır. Bayat ekmek tozu, üç farklı enzim dozu ile (0.25, 0.38 ve0.5 mL kg-1) termostabil α-amilaz ve glikoamilaz kullanılarak sıvılaştırıldı vesakkarize edildi. En yüksek şeker 125.35 g L-1, 69.3 DE ve %76.02 nişasta-şekerdönüşüm oranı ile 0.5 mL kg-1 enzim dozajında elde edildi. 1 gram bayat ekmektenen yüksek 0.226 gram şeker elde edildi. Etanol fermantasyonunu optimize etmekamacıyla, denemeler iki farklı sıcaklıkta (25°C ve 30 °C), pepton ilaveli ve ilavesizolmak üzere pH 5.5 ve 150 rpm'de Saccharomyces cerevisiae aktif kuru mayasıkullanarak gerçekleştirildi. Tek yönlü ANOVA, üç hammadde arasında etanolverimi bakımından istatistiksel olarak önemli bir fark olmadığını göstermiştir (p =0.38). Benzer şekilde azot ilavesinin de etanol verimine etkisi istatistiksel olarakönemli bulunmamıştır. Azot ilave edilmeyen atık ekmek hidrozilatı, kavun karpuzsuyu fermantasyonlarında elde edilen etanol verimleri sırasıyla, 0.490, 0.451 ve0.475 g/g şeker olarak bulunmuştur. Aynı hammaddelere azot ilavesi ile elde edilenetanol verimleri sırasıyla 0.497, 0.471 and 0.509 g/g şeker şeklinde olmuştur. In this study waste bread, watermelon, and muskmelon feedstocks wereinvestigated for bioethanol production. Waste bread was liquefied and saccharifiedby thermostable α-amylase and glucoamylase using 0.25, 0.38, and 0.5 mL kg-1enzyme doses. 0.5 mL kg-1 enzyme dose yielded maximum DE 69.3, and 76.02%starch to sugars conversion efficiency, and per gram of waste bread yielded 0.226gram of sugars on a dry mass basis. Bioethanol fermentations were performed attwo different temperatures (25 and 30°C) and with and without nitrogensupplementation at pH 5.5, by Saccharomyces cerevisiae. One-way ANOVAamong all three feedstocks resulted in statistically non-significant differences onethanol yield (p = 0.38). Similarly, there were no significant differences betweenthe groups with respect to nitrogen supplementation. The ethanol yields on wastebread hydrolysate, watermelon and muskmelon without nitrogen supplementationat 30°C were found to be 0.490, 0.451 and 0.475 g/g sugar, respectively. Thosewith nitrogen supplementation were 0.497, 0.471 and 0.509 g/g sugar, respectively.Fermentation at 30°C yielded higher ethanol yield than at 25°C. 97

Biohydrogen production from waste bread in a continuous stirred tank reactor (CSTR) was techno-economically assessed. The treating capacity of the H2-producing plant was assumed to be 2 ton waste bread per day with lifetime of 10years. 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/m3 H2 (or USD14.89/kg H2). The payback period and net present value (NPV) of the plant were 4.8years 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.

A novel biorefinery concept of utilising waste bread as a sole nutrient source for the production of a nutrient rich feedstock for the fermentative succinic acid production by Actinobacillus succinogenes has been developed. Waste bread was used in the solid-state fermentations of Aspergillus awamori and Aspergillus oryzae that produce enzyme complexes rich in amylolytic and proteolytic enzymes, respectively. The resulting fermentation solids were added directly to a bread suspension to generate a hydrolysate containing over 100 g/L glucose and 490 mg/L free amino nitrogen (FAN). A first-order kinetic model was used to describe the effect of initial bread mass ratio on glucose and FAN profiles. The bread hydrolysate was used as the sole feedstock for A. succinogenes fermentations, which led to the production of 47.3 g/L succinic acid with a yield and productivity of 1.16 g SA/g glucose and 1.12 g/L h. This corresponds to an overall yield of 0.55 g succinic acid per g bread. This is the highest succinic acid yield compared from other food waste-derived media reported to date. The proposed process could be potentially utilised to transform no-value food waste into succinic acid, one of the future platform chemicals of a sustainable chemical industry.

The present study is the first of its kind to use industrial waste bread for ethanol and food-grade filamentous fungal biomass production, with an ‘integrated-biorefinery’ approach for the existing wheat-based ethanol facilities. Four different food-grade fungi such as Neurospora intermedia, Aspergillus oryzae, belonging to ascomycetes and Mucor indicus, Rhizopus oryzae, belonging to zygomycetes, were screened. Initial screening for fungal cultures (without external enzyme saccharification) showed an ethanol yield maximum of 47.8 ±1.1 to 67.3 ±2.1, and 38.7 ±1.1 to 67.7±1.8 mg per g dry substrate loading from whole-grain bread and white-bread respectively, post the enzymatic liquefaction. Scale-up of the N. intermedia fermentation achieved using bench scale airlift reactor showed an ethanol yield maximum of 91.6 ±2.1 and 87.5 ±1.9 mg per g dry substrate loading for whole-grain bread and white-bread respectively.

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 49.78g/L glucose and 284.12mg/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 7.4L/(Ld) was achieved at chemical oxygen demand (COD) of 6000mg/L. According to the results obtained from this study, 1g waste bread could generate 0.332g glucose which could be further utilized to produce 109.5mL hydrogen. This is the first study which reports continuous biohydrogen production from waste bread by anaerobic sludge.

The aim of this study was to optimise airflow rate for glucoamylase and protease production from waste bread via solid state fermentation by Aspergillus awamori in packed bed bioreactors. Airflow rates, between 0.40 and 3.00 vvm, were tested. In all experiments, the fungal growth was almost uniform throughout the solids. Fungi grew both on and within the substrate and fungal cakes were formed. The highest glucoamylase and protease activities were recorded as 130.8 U/g bread (db) and 80.3 U/g bread (db) in the experiments with 1.50 vvm airflow rate, respectively. These values are 27.2% and 32.3% higher than the glucoamylase and protease activities obtained in petri dish experiments with static air. At 1.50 vvm airflow rate, the dry weight of the solids had decreased to 46% of the initial value at the end of the fermentation. The temperature of the solids increased up to 37.5 degrees C with high axial temperature gradients due to high metabolic activity. The average moisture content of the solids first decreased to 150% (db) and then increased to 275% (db) by the end of the fermentation. Both above and below 1.50 vvm airflow rate, enzyme production and fungal growth were affected significantly. Also, a Gaussian-based mathematical model was developed to model the effects of airflow rate on enzyme production. The model fitted almost seamlessly to the experimental data. Thus, this study clearly showed the effects of aeration on glucoamylase and protease production from waste bread under solid state fermentations. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Besides increasingly important issues with regard to quantity and availability of raw materials together with their properties and quality the feedstock costs are very important for the production of bulk chemicals. Especially for biotechnological processes, in which the carbon of various substrates should be converted into microbial products (e.g. lactic acid), there is an increasing interest in the use of biogenic residues and waste materials. Carbohydrates like starch, which is the main constituent of the bakery waste, are preferably used as substrates/nutrients for several fermentation processes. As part of a European project (BREAD4PLA) we have been carried out different analytical methods for the estimation of parameters which are basically characteristic in terms of the further use as main substrate for lactic acid fermentation processes. The main objective of this research is to show the production of polylactic acid from residual bread in a pre-industrial continuous process. In the sense of a closed loop (organic waste from the bakery industry, fermentative production of lactic acid from remaining bread, polymerization of lactic acid to polylactic acid, PLA modification by compounding and film production as well as final testing and evaluation of these films for packaging), the 100% biodegradable PLA film can subsequently be used for the packaging of fresh baking goods. First results about the potential of waste bread as an alternative substrate source for lactic acid fermentation are presented and discussed.

After selection from eight yeast commercial or type strains based on their aromatic potential to valorize bread by-products, Geotrichum candidum ATCC 62217 formed fruity aroma compounds (pineapple-like) on fermented waste bread (35% white bread crumb and 65% water). Fatty acids esters were identified, including ethyl esters of acetic acid, propionic acid, butyric acid and isobutyric acid. Their production corresponded to the stationary growth phase of the strain and, after 48 h, it was improved by agitation and, to a lesser extent, at 30°C compared to 25 or 20°C. Aromatic properties of the strain were linked to its ability to metabolize organic acids.

When it is not consumed, bread presents a major source of food waste, both in terms of the amount and its economic value. However, bread also possesses the characteristics of an ideal substrate for solid state fermentation. Yet nearly all wasted bread ends up in landfill sites, where it is converted into methane by anaerobic digestion. Governments are finally taking action and, according to the EU Landfill Directive, for example, biodegradable municipal waste disposed into landfills must be decreased to 35% of 1995 levels, by 2020. Solid state fermentation of waste bread for the production of value added products is a novel idea, which could help with the achievement of this target. In this study, glucoamylase and protease production from waste bread pieces, via solid state fermentation, was investigated in detail. The optimum fermentation conditions for enzyme production were evaluated as, 20 mm particle size, 1.8 (w/w, db) initial moisture ratio, and duration of 144h. Under these conditions, glucoamylase and protease activities reached up to 114.0 and 83.2 U/g bread (db), respectively. This study confirms that waste bread could be successfully utilised as a primary raw material in cereal based biorefineries. (C) 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Optimal conditions for sourdough production from waste bread containing sugar were studied. Using a dough prepared with 50% white bread crumb in water instead of 35% crumb, high levels of acidity were formed at 35°C with a commercial lyophilized starter containing Lactobacillus plantarum . The effect of temperature (25 or 35°C) on titratable acidity development was equivalent to crumb concentration (35 or 50%). Cell growth stopped after 12–24 h but acid production continued for more than 48 h. Best results were obtained with whole wheat bread crumb followed by sweet-type crumb (about 8% sugar, dry basis) and white bread crumb. Two commercial sources of Lactobacillus plantarum , one meat starter and one bread starter, were screened based on acid production in fermented bread crumb.

Bread, the staple of the west and, increasingly, the rest of the world, is also one of the most heavily wasted of all food products. Currently, much of this waste is disposed of in landfill sites where it decomposes to methane and carbon dioxide. Yet it is a potentially valuable, renewable resource for the production of chemicals. This chapter explores the opportunities for enhancing the value of this cereal-based waste food through the use of fermentation. Following a review of the literature concerning bread waste utilization, potential process systems are proposed and examined. As bread is a solid raw material, solid state fermentation is preferred as the most efficient means of delivering bioprocesses, and some preliminary optimization studies are presented.