Natural Melanin Synthesized by Aureobasidium pullulans Using Food Wastes and its Characterization

It is known that food wastes occur in the entire food chain from farm to fork and pose a major problem worldwide. In Turkey, approximately 45 thousand tons of onion peel and 550 thousand tons of bread emerge as waste. On the other hand, the wastes of potato, apple, and pear in the field are approximately 455 thousand, 122 thousand, and 27 thousand tons per year, respectively. It is also known that the annual total kitchen waste generated only in Ankara is approximately 5.35 megatons. It is also obvious that traditional waste disposal methods cause environmental, economic, and social problems, and therefore, the conversion of food waste into biotechnological products with high added value is more sustainable, oriented to meet global needs, and is profitable. In this study, the potential use of onion, potato, apple, pear, and carrot peels, and bread residues for the production of melanin, a high-value-added pigment, by fermentation was investigated. In the fermentation studies, a native strain Aureobasidium pullulans AZ-6 and A. pullulans NBRC 100716 strain were used separately as inoculum. The highest total melanin production (3.71 g/L) from the food wastes in the study was achieved by A. pullulans NBRC 100716 with carrot peel extract, and a similar result (3.28 g/L) was obtained with apple peel extract. This study revealed that carrot and apple peels can be important substrate sources for melanin production.

Food waste is one of the biggest societal problems in the globe due to its detrimental consequences on the environment. According to estimates from the Food and Agriculture Organization, this comes to about 1.3 billion tonnes per year. The current study aims to produce sustainable food products with high nutritional value by incorporating food waste. For the extraction of economically relevant products such as dietary fibers, biopolymers, natural antioxidants, and food additives, potato and carrot peel represent an inexpensive, valuable, and conveniently available resource. Cheese is a functional dairy product that people eat for its high nutritional content, which aids in the treatment of conditions including diabetes, obesity, hypertension, and digestive problems in addition to giving them energy. Thus a control sample and 10 samples of melted cheese with various amounts of potato and carrot peelings were prepared. To explore the nutritional value of potato and carrot peels in melted cheese, an analysis was conducted on the fluctuation of physicochemical (acidity, pH, dry matter, water activity, and salt content) and enzymatic (L-lactic acid, lactose, D-glucose, and D-galactose) parameters. Consumer acceptability of the products was assessed by textural and sensory analysis. During the whole storage period, the samples of melted cheese with potato and carrot peels recorded higher values than the control sample, the results obtained for them being better. Samples with added potato or carrot wastes were more stable over time, as compared to control samples.

Urban food waste management with multi-agent participation: A combination of evolutionary game and system dynamics approach

Food waste is generated at several stages of the food chain. According to the European Waste Hierarchy, the creation of food waste should above all be prevented, meaning that waste materials with good microbial and nutritional quality should be directed to food use, either directly or through light processing. However, to be feasible, food waste utilisation solutions should be economically profitable, environmentally sustainable and scalable to provide a means to utilise a larger share of the raw materials. In this study, we propose a feasibility evaluation approach for food waste utilisation and prevention solutions. We use two case examples: (1) an artisan bar soap product based on carrot peels, and (2) the retail selling of 2nd class carrots. Both cases are evaluated with six feasibility indicators: edible food waste reduction potential, scalability, level at waste hierarchy, climate impact reduction potential, economic impact, and social impact. Case 2 performed better regarding all indicators other than economic impact. Critical aspects that need to be improved included climate reduction potential for both cases and food waste reduction potential for case 1. The results show that this kind of a holistic approach is useful in identifying the most feasible food waste prevention and utilisation measures.

This study aimed to compare the process of maturity and humus fraction evolution as well as bacterial community dynamics in composting from different domestic organic wastes (food waste (FW), and vegetable waste (VW)) and decipher the key biotic influencing factors of humic acid formation through correlation analysis and ecological network. The results showed that organic carbon components in FW with high ratio of soluble organic carbon and hemicellulose were more easily to be degraded in composting compared to VW. After 30days of composting, the content of HA-C generated by VW was 35.41%, higher than 29.01% of FW, and the growth rate of HA-C generated was 38.42% and 28.34%, respectively. PARAFAC analysis showed that the structure of HA generated in VW was more complex, and the proportion of humic acid-like components (C3 + C4) was 60.32%, while FW only accounted for 43.86%. However, the evolution growth rate of aromatic components in HA in FW was 26.88% in 30days of compost, which was higher than 15.17% in VW. High-throughput sequencing indicated that Lactobacillus was the initial dominated genera in composting from different domestic wastes. Thermobifida, Thermovum, and Pusillimas as well as Aeribacillus were core bacterial genera that promoted the humification process in FW and VW, respectively. Network analysis showed that there was higher bacterial interacted connection degree and complexity in FW compared to VW. This study was of great significance for optimizing organics conversion and humification efficiency of household waste composting.

Efficient sophorolipids production using food waste

Food loss and waste have a negative environmental impact due to the water, land, energy and other natural resources used to produce the wasted food, along with post-consumption disposal costs. Reducing food waste will thus help improve sustainability and decrease the environmental impact of the food system. Using food waste for animal feed is of growing importance in terms of the policies targeted at tackling food waste but the current legal framework in the European Union (EU) strongly restricts the possibility of using food waste for this purpose. The aim of this work is to evaluate the feasibility of innovative measures for feed production in the EU and to identify the best strategies to implement them. First, a technical evaluation of a case study is presented, which is a process developed in the United States for urban food waste transformation into animal feed. Second, there is an analysis of the potential application of this process in the European Union within the current legal framework. The results reveal that the feed product derived from food waste is compliant with EU safety requirements and is nutritionally valuable. This work also suggests that the implementation of this kind of process in the European Union has great potential, provided that food surplus is recovered and treated before it turns into waste and that the different types of food surplus identified are used as feed for the right animal type in accordance with European legislation (i.e., livestock, aquarium fish, pets). On these terms, pet food can be the most concrete strategy for using food waste within the European context. In general, the implementation of feed-from-food measures to reduce food waste in Europe is already possible and does not need to wait for further policy interventions.

This paper introduces a new approach for domestic food waste management and pretreatment through the dehydration of food waste separated at source. An innovative domestic waste dryer was used in order to carry out the research performed. This work presents the methodology and the results of the first pilot scale demonstration of a new technique for the separation and dehydration of food waste separated at source. The system was installed in 25 selected households in Papagos-Cholargos Municipality in Athens, Greece, and operated on a daily basis for a total period of 8 months. The hygienic dehydration of food waste at source resulted to its significant mass reduction, about 70 % w/w, due to the removal of its moisture content during the drying process, while the energy requirements are sustained at economically viable levels. The low water content of the produced biomass prevents the biological decomposition, restricts odor emissions, and thus reduces the frequency at which domestic waste needs to be collected. Additionally, the dried biomass can be handled much easier compared to wet food waste. Also, the examined physicochemical characteristics of the dried waste show that it has the potential to be used in alternative and environmental friendly ways to produce high value-added products such as bioethanol, biogas, thermal energy, and compost.

Black soldier fly larvae (BSFL), Hermetia illucens, have shown remarkable potential for food waste bioconversion, contributing to sustainability and waste management efforts. This study evaluated the effects of different food waste compositions (three types of diets: egg pasta in milk, rice with peas, and couscous mixture with egg, spinach, and carrot peels) and their microbial quality (fresh vs. spoiled) on BSFL bioconversion efficiency, microbiology, and nutritional value. Microbiological analyzes of the larvae were performed using the plate dilution method and MALDI-TOF mass spectrometer. All test variants spotted successful bioconversion. However, bioconversion efficiency (BE) and waste reduction rate (WR) were highest for couscous-based diets, with fresh couscous yielding a highest BE of 27.41% and WR of 81.34%. Nutritionally, larvae reared on mixture of couscous, egg, spinach, and carrot peels displayed the highest protein content (up to 35.5%). Microbial analysis indicated increased microbial counts, particularly Enterobacteriaceae and spore-forming bacteria, in larvae fed spoiled diets. Potentially pathogenic microorganisms such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii were detected, underscoring the need for microbial safety measures in BSFL-based applications. This study highlights the critical role of feed composition and quality in determining the efficiency and safety of BSFL bioconversion, providing valuable insights for optimizing their use in sustainable food waste management and as a resource in feed or food production.

As the increasing accessibility of ready-to-eat and packaged foods, rapid consumption habits have intensified the negative environmental impact of food waste, highlighting the need for sustainable recycling methods. The utilization and recycling of food waste represent a crucial approach to promoting environmental sustainability. In this context, the utilization of food waste is crucial for combating microorganisms surrounding infected wounds or tissue, ranging from minor scratches to deep tissue injuries. Since the resistance mechanisms of microorganisms against active agents used in conventional treatment methods contribute to delayed wound healing, there is a growing need for novel, sustainable, and cost-effective alternative approaches. This study focuses on the use of organic waste, specifically carrot peels, in the synthesis of nanoparticles via an environmentally friendly “Green Synthesis” method, providing a sustainable biotechnological solution such as use chitosan and silver nanoparticle. Chitosan, a natural biopolymer, is known for its biocompatibility, biodegradability, and wound-healing properties. Additionally, it supports cell proliferation, accelerates tissue regeneration, and maintains moisture balance, thereby contributing positively to the wound healing process. Silver nanoparticles (AgNPs), on the other hand, exhibit antibacterial, antifungal, and anti-inflammatory properties, making them valuable biomaterials for the treatment of infected wounds. In this study, AgNPs derived from carrot peels (C) were combined with chitosan to synthesize Ch/AgNP-C, and their potential as antimicrobial wound-healing materials was investigated. To evaluate the interaction of nanoparticles with microorganisms around deep wounds or infected tissues using nuclear methods, Ch/AgNP-C were labelled with Iodine-131 ([131I]I) and analysed using a radioiodination method to determine labelling efficiency. The microbial uptake of the radiolabelled nanoparticles was examined using a Cd(Te) detector. The characterization of Ch/AgNP-C synthesized was performed using High-Performance Liquid Chromatography (HPLC), Dynamic Light Scattering (DLS), Zeta Potential Measurement. The hydrodynamic diameter of Ch/AgNP-C was determined to be 223.8 nm, with a zeta potential of -30.9 mV. Antimicrobial activity was evaluated in methicillin resistant Staphylococcus aureus (MRSA), S. aureus, E. coli and Candida sp. strains. The radiolabelling quality control of [131I-I]-Ch/AgNP-C was conducted using Thin-Layer Radiochromatography (TLRC), with labelling efficiency calculated to exceed 95% (n=3). This study presents a model for repurposing food waste for biotechnological and healthcare applications. The findings support the antimicrobial efficacy and wound-healing potential of Ch/AgNP-C. Furthermore, by investigating the distribution of radiolabelled nanoparticles on microorganisms, an innovative approach to the diagnosis and treatment of infectious diseases has been proposed. Sustainable approaches based on food waste recycling, such as this, can significantly contribute to combating climate change and advancing innovative biomaterial applications in healthcare. Keyword: Green synthesis, food waste, antimicrobial activity, iodine-131

Purpose Hydrothermal pretreatment stands out for its efficiency and simplicity yet offers economic and environmental benefits. Its application on non-fibrous organic waste such as kitchen and fruit waste are deemed efficient and does not require extreme working parameters. This study evaluated the effect of predetermined parameters on the hydrothermal pretreatment of various food waste. We aimed to establish a set of parameters for the hydrothermal pretreatment, to promote the utilisation of waste for fermentation into value-added products. Methods The kitchen and fruit wastes were homogenized and treated at varying temperatures, incubation times, and water ratios. Reducing sugar, protein, and lipid content was analysed pre- and post-treatment. The treated waste was used as a medium for bacterial cellulose fermentation and the yield was compared to chemical medium. Results The models identified the optimum parameters for maximizing glucose production were at incubation temperature of 115 °C for 75 min and 1:2 waste-to-water ratio, achieving 449.031 mg/mL (kitchen waste), 382.033 mg/mL (guava waste), and 358.840 mg/mL (watermelon waste), with satisfactory desirability and model fit for kitchen waste and guava waste. Attempts to produce bacterial cellulose (BC) from the treated waste recorded promising results. While kitchen waste had higher glucose content post-hydrothermal pretreatment, guava waste and watermelon waste produced more BC due to lower oil content, which did not interfere with the oxygen transfer. Conclusion The conducted hydrothermal pretreatment at the pre-optimized conditions increased the potential of the food waste tested as a media substitute for BC production.

This study investigatesthe potential of various agro-industrialand food wastes as alternative carbon sources for cost-effective andsustainable pullulan production by a domestic, melanin-free strainof Aureobasidium pullulans AZ-6. Ninenatural substrates, including cheese whey, molasses, grape pomace,sugar beet pulp, melon rind, watermelon rind, onion waste, carrotpeels, and sweet potato, were pretreated and used in supplementedfermentation media. Batch fermentations were carried out under optimizedconditions (pH 6.48; 24.2 °C; 100 strokes per minute), and biomass,extracellular polysaccharides (EPS), pullulan yields, and sugar consumptionkinetics were evaluated. Among the tested substrates, molasses exhibitedthe highest EPS (17.12 g/L) and pullulan titers (14.55 g/L), as wellas the greatest specific growth rate (0.104 h–1).Although cheese whey supported the highest biomass (13.03 g/L), itspullulan productivity was relatively low (4.98 g/L). Other substrates,such as sweet potato, onion waste, and carrot peels, also showed promisingpullulan yields (8.24–8.70 g/L) and substrate utilization rates.This study evaluates the potential of several waste-derived substratesfor pullulan biosynthesis and contributes to the circular bioeconomyby valorizing underutilized resources. To the best of our knowledge,sugar beet pulp, melon rind, watermelon rind, onion peel, and carrotpeel have been investigated as substrates for pullulan productionfor the first time in the literature.

Food waste is a major contributor to various environmental problems and food wasted at the household level makes up a significant proportion of the overall estimated totals. Fundamental questions remain about this waste as an aspect of domestic consumption and the appropriate policy response. Deficiencies in household food planning have been posited as a potential factor related to food waste production in the home, but this has not been developed in a way which connects clearly to existing sociological studies of meal planning. This paper therefore engages with feminist literature on domestic meal planning and material culture approaches to food waste. It moves the concept of anticipatory practice to the domestic space, to address forms of domestic meal planning and other food-related practices as anticipatory practices which are inherently oriented to the future. The paper draws on a number of semi-structured interviews, research diaries, and images completed and submitted by participants to highlight the establish meal planning practices as anticipatory, and to identify other forms of anticipatory practices around food. As part of this, the association of additional food in the home with food waste is also questioned and practices such as batch cooking are reassessed along with related practices. Meal planning is ultimately described as an anticipatory practice, a broader designation of organisational practices involved in food consumption which may be relevant for policy and research concerning food waste reduction.

Excessive food purchases, improper storage, incorrect food preparation, and the disposal of non-expired products contribute significantly to household food waste. Food and nutritional literacy can, therefore, be linked to household food waste and not just to diet quality. Consumers with high food literacy appear to better organize their food shopping and waste less than people with low food literacy. Different studies have demonstrated the association between high nutritional literacy, healthy eating habits, and a high amount of food waste, represented by highly perishable products. The relationship between a high-quality diet and food waste is mainly attributable to the consumption of fruit and vegetables, while an unhealthy diet is associated with fewer leftovers due to the high consumption of ultra-processed foods with a long shelf life. Social and economic conditions influence the effects of literacy on the production of domestic food waste. Many studies have reported that low-income individuals rarely waste food, while richer ones tend to produce more leftovers. The challenge for the scientific, educational, and health policy sectors is to promote the consumption of fresh, healthy, and inexpensive foods, especially in the most disadvantaged segments of the population, and at the same time, provide the knowledge necessary to limit the production of household waste.

Food wastes have a large number of functional ingredients that have potential for valorization. Melon peels are increasingly produced as waste in food industries in Thailand. This study aimed to optimize pectin extraction conditions from melon peel for its prebiotic potential. Optimization was conducted using a response surface methodology and Box-Behnken experimental design. An analysis of variance indicated a significant interaction between the extraction conditions on extraction yield and degree of esterification (DE). These include pH and solvent-to-sample ratio. The conditions for the extraction of pectin with low DE (LDP), medium DE (MDP) and high DE (HDP) were optimized. Pectin hydrolysate from LDP, MDP and HDP was prepared by enzymatic hydrolysis into LPEH, MPEH and HPEH, respectively. LDP, MDP, HDP, LPEH, MPEH and HPEH were compared for their efficiency in terms of the growth of three probiotic strains, namely Lactobacillus plantarum TISTR 877, Lactobacillus casei TISTR 390 and Enterococcus faecium TISTR 1027. Among the samples tested, HPEH showed the highest ability as a carbon source to promote the growth and prebiotic activity score for these three probiotic strains. This study suggests that melon peel waste from agro-industry can be a novel source for prebiotic production.