Fruit-vegetable Waste Research Articles

Linking microbial population dynamics in anaerobic bioreactors to food waste type and decomposition stage

A key question in anaerobic microbial ecology is how microbial communities develop over different stages of waste decomposition and whether these changes are specific to waste types. We destructively sampled over time 26 replicate bioreactors cultivated on fruit/vegetable waste (FVW) and meat waste (MW) based on pre-defined waste components and composition. To characterize community shifts, we examined 16S rRNA genes from both the leachate and solid fractions of the waste. Waste decomposition occurred faster in FVW than MW, as accumulation of ammonia in MW reactors led to inhibition of methanogenesis. We identified population succession during different stages of waste decomposition and linked specific populations to different waste types. Community analyses revealed underrepresentation of methanogens in the leachate fractions, emphasizing the importance of consistent and representative sampling when characterizing microbial communities in solid waste.

Valorization of fruit vegetable waste for semi-synthetic leather

Valorization of fruit vegetable waste for semi-synthetic leather

Anaerobic Biodegradability and Biomethanation Potential of Fruit-Vegetable Wastes at Sindh, Pakistan

The urban environment of every city of Pakistan has been degraded because of open dumping and burning of organic wastes along with other wastes. The focus of this study was to evaluate the fruit and vegetable wastes for methane generation through biomethanation process. After collection, various parameters such as alkalinity, volatile fatty acids, pH, lignin content, moisture content, total solids, volatile solids, fixed carbon, and elements (C, H, N, O, S) of waste samples were determined by using standard methodology. Anaerobic biodegradability of fruit and vegetable wastes was observed from 54 to 77% and from 59 to 87% along with their methane generation potential in the range of 258-367 NmL /gmVS and 274-407 NmL/gmVS, respectively. Further, the effect of feedstock to inoculum ratio was studied. The result of that showed that lower methane potential at a higher ratio and vice versa was observed. It was concluded that at a lower feedstock to inoculum ratio, fruit as well as vegetable wastes become more feasible for the biomethanation process. The study recommends that the conversion of fruit and vegetable wastes into methane gas by anaerobic digestion plays a significant role to save urban environment of the country.

Use of a Highly Specialized Biocatalyst to Produce Lactate or Biohydrogen and Butyrate from Agro-Industrial Resources in a Dual-Phase Dark Fermentation

This study aimed at investigating the feasibility of using a highly specialized bacterial inoculum harboring lactic acid bacteria (LAB) and lactate-oxidizing, hydrogen-producing bacteria (LO-HPB) to produce either lactate or biohydrogen and butyrate from several agro-industrial resources via dual-phase dark fermentation. The feedstocks were fruit–vegetable waste, cheese whey, coffee wastewater, tequila vinasse, and maize processing wastewater, and were tested in both mono- and co-fermentation. The results obtained indicated that the biocatalyst used was able to perform a dual-phase lactate fermentation, producing high lactate (13.1–36.4 g/L), biohydrogen (0.2–7.5 NL H2/Lfeedstock, equivalent to 0.3–1.7 mol H2/mol hexose), and butyrate (3.3–13.9 g/L) with all the tested feedstocks. A series of self-fermentation tests were also performed with crude cheese whey and fruit–vegetable waste for comparison purposes. Compared to inoculum-aided fermentations, the self-fermentation exhibited a reduced bioconversion efficiency. Short-length 16S rRNA gene sequencing analysis showed that LO-HPB was the dominant microbial group (86.0%) in the biocatalyst, followed by acetic acid bacteria (5.8%) and LAB (5.7%). As expected, the molecular analysis also showed significant differences in the microbial community structure of the biocatalyst and those that evolved from self-fermentation. Besides lactate fermentation and oxidation, the biocatalyst also assisted the bi-phasic lactate fermentation via oxygen consumption, and apparently, via substrate hydrolysis. Overall, this study can lay the foundation for robust inoculum development, which is of special significance in the field of dark fermentation, and proposes an innovative bioprocess for agro-industrial valorization through a trade-off approach, tailoring the metabolic pathway to the target product(s).

Enhanced methane production from the anaerobic co-digestion of food waste plus fruit and vegetable waste.

Food waste (FW) and fruit, vegetable waste (FVW) are important components of municipal solid waste, yet the performance and related mechanisms of anaerobic co-digestion of FW and FVW for methane production have been rarely investigated. In order to get a deeper understanding of the mechanisms involved, the mesophilic FW and FVW anaerobic co-digestion in different proportions was investigated. The experimental results showed that when the ratio of FW and FVW was 1/1 (in terms of volatile suspended solid), the maximum biomethane yield of 269.9 mL/g TCOD from the codigested substrate is significantly higher than that in FW or FVW anaerobic digestion alone. FW and FVW co-digestion promoted the dissolution and biotransformation of organic matter. When the recommended mixing ratio was applied, the maximum concentration of dissolved chemical oxygen demand (COD) was high as 11971 mg/L. FW and FVW co-digestion reduced the accumulation of volatile fatty acids (VFA) in the digestive system, thus reducing its negative impact on the methanogenesis process. FW and FVW co-digestion process synergistically enhanced microbial activity. The analysis of microbial population structure showed that when FW and FVW were co-digested at the recommended ratio, the relative abundance of Proteiniphilum increased to 26.5%, and the relative abundances of Methanosaeta and Candidatus Methanofastidiosum were also significantly increased. The results of this work provide a certain amount of theoretical basis and technical support for the co-digestion of FW and FVW.

Unlocking the high-rate continuous performance of fermentative hydrogen bioproduction from fruit and vegetable residues by modulating hydraulic retention time

Harnessing fruit-vegetable waste (FVW) as a resource to produce hydrogen via dark fermentation (DF) embraces the circular economy concept. However, there is still a need to upgrade continuous FVW-DF bioprocessing to enhance hydrogen production rates (HPR). This study aims to investigate the influence of the hydraulic retention time (HRT) on the DF of FVW by mixed culture. A stirred tank reactor under continuous mesophilic conditions was operated for 47 days with HRT stepwise reductions from 24 to 6 h, leading to organic loading rates between 47 and 188 g volatile solids (VS)/L-d. The optimum HRT of 9 h resulted in an unprecedented HPR from FVW of 11.8 NL/L-d, with a hydrogen yield of 95.6 NmL/g VS fed. Based on an overarching inspection of hydrogen production in conjunction with organic acids and carbohydrates analyses, it was hypothesized that the high FVW-to-biohydrogen conversion rate achieved was powered by lactate metabolism.

Infusion of fruit-vegetable waste biomass into bakery sludge to enhance nutrient availability and vermicompost maturity using Eisenia fetida

Infusion of fruit-vegetable waste biomass into bakery sludge to enhance nutrient availability and vermicompost maturity using Eisenia fetida

Anti-Inflammatory and Chondroprotective Effects Induced by Phenolic Compounds from Onion Waste Extracts in ATDC-5 Chondrogenic Cell Line.

Osteoarthritis is a prevalent degenerative condition that is closely related to the destruction and inflammation of cartilage. The high prevalence of this pathology exhorts researchers to search for novel therapeutic approaches. Vegetable-fruit wastes have emerged as a promising origin of anti-inflammatory and antioxidant compounds that, in some cases, may also exert chondroprotective effects. This study aims to decipher the potential of onion waste products in the inhibition of molecular events involved in osteoarthritis. Onion extracts showed a high content of phenolic compounds and antioxidant properties. Cytocompatibility was demonstrated in the chondrogenic cell line ATDC-5, exerting viability percentages higher than 90% and a slight increase in the S phase cycle cell. The induction of inflammation mediated by the lipopolysaccharide and onion extracts' treatment substantially inhibited molecular markers related to inflammation and cartilage degradation, highlighting the promising application of onion extracts in biomedical approaches. The in silico analyses suggested that the results could be attributed to protocatechuic, ellagic, and vanillic acids' greater cell membrane permeability. Our work provides distinctive information about the possible application of waste onion extracts as functional components with anti-inflammatory and chondroprotective characteristics in osteoarthritis.

A comparative study on fibrinolytic enzymes extracted from six Bacillus spp. isolated from fruit-vegetable waste biomass

Fibrinolytic enzymes are considered as a significant therapeutic agent for thrombosis. Keeping the quest for identification of effective fibrinolytic enzyme(s) from microbial source, a comparative study was done on six Bacillus spp. isolated from fruit and vegetable waste. The fibrinolytic activities of the isolates were confirmed by a fibrin plate assay. Six potential isolates were identified by 16s rRNA sequencing as Bacillus altitudinus HEM05, Bacillus halotolerance ARKH1, Bacillus safensis CO05, Bacillus subtilis subsp. inaquorum BE1, Bacillus tequilensis SAS23 and Bacillus siamensis BHO27. Extracellular fibrinolytic enzymes were purified to homogeneity from all six isolates by acetone precipitation, anion exchange chromatography and gel filtration chromatography. Purified fibrinolytic enzymes showed fibrinolytic specific activity ranging from 60.92 U mg-1 to 220.19 U mg-1. Molecular weight (SDS PAGE) of purified enzymes ranged from 30,200 kDa to 69,500 kDa. Enzymes were effective over wide range of pH from 5 to 10, with optimum pH between 7 and 10. The enzymes were active between 37 °C to 60 °C. Effect of inhibitory activity of metal ions, protease inhibitors and amidolytic activity on purified enzymes indicated fibrinolytic enzymes from Bacillus altitudinus HEM05, Bacillus halotolerance ARKH1, Bacillus safensis CO05 as plasmin serine protease, from Bacillus subtilis subsp. inaquorum BE1, Bacillus tequilensis SAS23 as subtilin chymotrypsin like metalloprotease and from Bacillus siamensis BHO27 as subtilin chymotrypsin. In vitro assays for the purified enzyme preparations from all six isolates confirmed enzymes could activate plasminogen and significantly degraded the fibrin net of blood clot.

Influence of key operational parameters on biohydrogen production from fruit and vegetable waste via lactate-driven dark fermentation

This study aims at investigating the influence of operational parameters on biohydrogen production from fruit-vegetable waste (FVW) via lactate-driven dark fermentation. Mesophilic batch fermentations were conducted at different pH (5.5, 6.0, 6.5, 7.0, and non-controlled), total solids (TS) contents (5, 7, and 9%) and initial cell biomass concentrations (18, 180, and 1800 mg VSS/L). Higher hydrogen yields and rates were attained with more neutral pH values and low TS concentrations, whereas higher biomass densities enabled higher production rates and avoided wide variations in hydrogen production. A marked lactate accumulation (still at neutral pH) in the fermentation broth was closely associated with hydrogen inhibition. In contrast, enhanced hydrogen productions matched with much lower lactate accumulations (even it was negligible in some fermentations) along with the acetate and butyrate co-production but not with carbohydrates removal. At pH 7, 5% TS, and 1800 mg VSS/L, 49.5 NmL-H2/g VSfed and 976.4 NmL-H2/L-h were attained.

Enzymatic Pretreatment of Sugarcane Bagasse and Fruit-Vegetable Waste for Energy Conversion by Co-digestion

Enzymatic Pretreatment of Sugarcane Bagasse and Fruit-Vegetable Waste for Energy Conversion by Co-digestion

Compost Based on Pulp and Paper Mill Sludge, Fruit-Vegetable Waste, Mushroom Spent Substrate and Rye Straw Improves Yield and Nutritional Value of Tomato

Plant biomass in the form of waste materials and by-products from various industries can be a valuable material for the production of composts and growing media for urban gardening. In this study, pulp and paper mill sludge, fruit-vegetable waste, mushroom spent substrate and rye straw were used to produce compost that was further used as a medium component in container cultivation of tomato. The plants were grown in containers with a capacity of 3 dm3 filled with three types of compost-based growing media supplemented with high peat, fen peat, pine bark and wood fiber. The tomato plants grown in 100% peat substrate served as controls. The plants grown in the compost-enriched media had a higher leaf greening index and percentage of ripe fruit, and exhibited an increased content of total polyphenols and flavonoids, potassium, calcium, magnesium and copper in fruit as compared with the control. The tomatoes grown in a medium consisting of 25% compost, 30% high peat, 15% low peat, 20% pine bark and 10% wood fiber reached the highest fresh fruit weight, total polyphenol content and L-ascorbic acid levels. This study demonstrated that the compost produced from natural materials from various sources was a valuable potting medium supplement with positive effects on tomato yield and nutritional value.

Effect of external heat source on temperature and moisture variation for composting of food waste

This paper investigates the outcome of having an external heat source on temperature and moisture variations in the food waste composting process. Food waste accumulation is a growing concern in many countries. Converting food waste into usable compost is a more desirable tactic than dumping to crowded landfill sites. Closed composting was applied in this work, which relies on a controlled but uninterrupted airflow during the organic material degradation process. However, undesirable odour released at low aeration rate due to low temperature and high moisture content found in the compost. Finding the ideal aeration rate with the least possible loss of moisture is needed, which was discussed in this paper. The vegetable-fruit waste used in the experiment was given an aeration rate of 0.3 L/min at a moisture setting of 60% and 70%. For 15 mins/day, the forced aeration was carried out at 3-day intervals. Results showed that 0.3 L/min with 60% and 70% moisture content attained best temperature peaks of 32.4°C and 31.6°C, respectively at day 13 for 28 days composting. A strong odour continued to exist with the compost and was mitigated by using an external additional heat source (light bulb). The light bulb also helped to provide a higher temperature for the compost of 41.5°C by day 1 for 10 days composting.

Enhanced biomethane production by 2-stage anaerobic co-digestion of animal manure with pretreated organic waste

Anaerobic co-digestion (AD) of different organic wastes is a promising technique to enhance clean energy (bioenergy) and manure (slurry) production, reducing stress on the environment. This is an experimental study aimed to investigate 2-stage co-digestion of pretreated organic wastes mixed with fresh animal manure (BD) and digester’s operation conditions (digester temperature and pH) to enhance biomethane production. To increase lignocellulose digestibility and biomethane (BM) production, fruit + vegetable waste (FVW) and corn stalks + wheat straw (CR) in ratio (1:1), respectively, were pretreated with inoculum taken from an anaerobic digester of poultry manure at 35 °C. This AD experiment was performed in a fixed dome biodigester with volumetric capacity of 2.3 m3. Biomethane potential (BMP) tests were conducted for biomass treatments and inoculum used (T1, T2, Ti) at 35 °C. In this study, the temperature of biodigester material was measured in mesophilic (30–40°C) and thermophilic (40–50°C) ranges and pH of fresh feed and slurry feed digesters was in optimum methane production range (7.01–7.52). The total daily methane productions from T1 and T2 were 125.13 ml/g VS and 104.89 ml/g VS in mesophilic range (30–40°C) while these values were 148.41 ml/g VS and 132.74 ml/g VS in mesophilic range (40–50°C), respectively. The 2nd stage digestion of slurry from fresh feed digester added 39–45% and 35–38% more methane production in T1 and T2 respectively. On calibration with BMP tests, experimental data have shown the synergetic effect on methane production and its thermal characteristics promoted by co-digestion of pretreated organic waste and BD. The economic and feasibility analysis proved the biomass co-digestion project viable and adoptable with positive (5.39 $) net return value (NRV), 2.92 years payback time (PBT), and 1.34 benefit cost ratio (BCR).

Powdered activated carbon facilitates methane productivity of anaerobic co-digestion via acidification alleviating: Microbial and metabolic insights

Low methanogenic efficiency caused by excess acidification is a challenge during anaerobic digestion. This study indicated that both granular activated carbon (GAC) and powdered activated carbon (PAC) promoted the start-up of methanogenesis and methane output in anaerobic co-digestion of food waste and fruit-vegetable waste. Moreover, PAC performed better than GAC. Specifically, the highest cumulative methane yield and shortest lag phase were observed in 5 g/L PAC and 10 g/L PAC group, 22.0% higher and 62.5% shorter than that without activated carbon supplementation, respectively. PAC facilitated the methane productivity by effectively accelerating volatile fatty acids (VFAs) consumption and thereby alleviating acidification. Syntrophic VFAs oxidizing bacteria (Gelria and Syntrophomonas) and direct interspecies electron transfer related microorganisms (Geobacter and Methanosarcina) were remarkably enriched by PAC. Furthermore, metagenomic analysis showed that both PAC and GAC might facilitate the electron transfer between microbes by acting as the electrical bridge and enhance both hydrogenotrophic and aceticlastic pathways.

Effect of biochemical composition on odor emission potential of biowaste during aerobic biodegradation

This study aimed to identify the individual effect of biochemical composition on odor emission potential of biowaste during aerobic biodegradation. Three kinds of typical mixed wastes, including vegetable-fruit waste, garden waste, and protein-rich waste, were tested for emission quantity of seven common odorous families within 21 days of biodegradation under aerobic conditions. The cumulative odor yields (COY) were as follows: protein-rich waste (2408 μg g−1 DM) > vegetable-fruit waste (1169 μg g−1 DM) > garden waste (62 μg g−1 DM), and their cumulative odor intensity were 16,701, 1888, and 212 g−1 DM, respectively. The odor emission of vegetable-fruit waste mainly occurred in the first 3 days, accounting for 91.7% COY, and the predominant contributor to odor intensity (PCOI) were terpenes and sulfur compounds. With regard to garden waste, the odor emission rate was the highest on day 1 (22.4 μg g−1 DM d−1) and then rapidly decreased, and the PCOI were aldehydes. The odor emission rate of protein-rich waste increased gradually in the initial stage and reached the peak value on day 10 (661.9 μg g−1 DM d−1), and its PCOI were sulfur compounds. This study revealed for the first time the relationship between the odor emission potential of biowaste and its characteristic of biochemical composition, then proposed potential application for odor pollution control during aerobic composting.

Requirements of Solid Waste Management System in Savina Vegetable Market at Smart City Udaipur in Rajasthan

Awareness of Solid Waste Management is main requirement in India. Environmental deprivation, hygiene and health problems are raising due to increasing quantity of solid waste and improper execution of this service. It is need of hour to conduct detail surveys of different areas and identify the solutions to manage the solid waste. The main object of this study was to educate people about Solid Waste Management, benefits of separation at source and to estimate the quantity of separated wastes for design of processing centre for Savina Vegetable Market. Processing centers in campus of market can reduce transportation cost and also problems associated with landfills. After conducting 5 days workshop it was estimated that an average per day 3464 kg fruit-vegetable waste, 504 kg paper waste, 111 kg plastic wastes are generated in this market. Vegetable and fruit waste is generated in very high amount which can be converted into compost. It can be converted in to revenue for this market because farmers are the customers for compost and they visiting everyday in this market for selling the vegetables and fruits. As per calculation based on this study Rs 15, 60,000 revenue and 5, 59,200 profits per year can be generated after expenditure for maintenance of processing centre.

Pengolahan Sampah Buah dan Sayur dari Pasar Induk Mandalika Kota Mataram Nusa Tenggara Barat Sebagai Media Tumbuh Fusarium sp Inokulan Gaharu

The purpose of this research is to process fruit waste and vegetable waste from Mandalika Market at Mataram City as growth medium for Fusarium Sp agarwood inoculant. Collected fruit waste and vegetable waste were processed by grinding and filtrating into filtrate part and residue part. Filtrate part and residue part were formulated as combination growth media including: Fruit waste filtrate, vegetable waste filtrate, mix fruit-vegetable waste filtrate, fruit waste residue, vegetable waste residue and mix fruit-vegetable residue. Fusarium Sp. were sub-cultured into PDA before cultured on combination growth media. Colony diameter of Fusarium isolates were measured every day for seven days incubation period. Fusarium Sp. growth on media from fruit waste was better than its growth on media from vegetable waste. Fusarium Sp. has higher colony diameter on residue growth media compare to its colony diameter on filtrate growth media. On the other hand, filtrate growth media could support Fusarium Sp. to produce several pigmentations. This pigmentation could be an important key character for further taxonomical study. It could be concluded that fruit waste and vegetable waste from residue part could support maximum diameter colony of Fusarium Sp. while filtrate part of this waste could support Fusarium Sp. to produce pigmentation for taxonomical purpose.

Effect of substrate ratio on biogas yield for anaerobic co-digestion of fruit vegetable waste & sugarcane bagasse

Abstract The present study investigates the influence of mixture of waste activated sludge (WAS) as inoculum (I) to the ratio of sugarcane bagasse (SB) and fruit-vegetable waste (FVW) as substrate (S) on biogas yield during anaerobic co-digestion. The lignin content of SB is very high, limiting its application for anaerobic digestion; therefore, FVW was used at varied ratio as substrate. Batch studies were conducted under ambient conditions in 500 mL glass bottles for 30 d at five different mixtures ratio of SB: FVW (100:0, 70:30, 50:50, 30:70 and 0:100) at different organic loading rate (OLR) varied from 0.85–2.4 g VS L−1 d−1 and at fixed Inoculum/Substrate (I/S) ratio of 1. Results demonstrate that the maximum biogas yield of 2600 mL d − 1 was observed at substrate (SB: FVW) ratio of 30:70 with I/S ratio ≈ 1.0. An increment of 79, 58 and 56% in biogas generation at 70:30, 50:50 and 30:70 mixture ratio of SB: FVW was observed compared to the mono anaerobic digestion of SB. The experimental data was validated with modified Gompertz equation and first order model and fits well. The kinetic coefficients determined at optimum ratio of 70:30 from Gompertz model were well supported the experimental data.

Process kinetic studies of biohydrogen production by co-fermentation of fruit-vegetable wastes and cottage cheese whey

Hydrogen (H2) is considered as fuel for future and its biological production from renewable feedstocks is very promising. Dark fermentation of fruit-vegetable waste (FVW) and cottage cheese whey (CCW) for the production of H2 constitutes a promising way for combining energy generation and lignocellulosic waste management. In this work, process kinetics of biohydrogen production via dark fermentation of FVW and CCW by pretreated anaerobic sludge inocula were investigated. To inhibit H2 consuming methanogens, the effects of various inoculum pretreatment, viz., 2-bromoethanesulfonate, heat-shock, acid, alkali, UV, and ultrasonication on H2-production were investigated which revealed 2-bromoethanesulfonate, heat-shock and acid-treated inoculum resulted in maximum bioH2 production and yield of 118.12 ± 1.05, 93.37 ± 1.3, 96.32 mMol/L and 1.66, 1.22 ± 0.01, 1.39 ± 0.02 mMol/gCODinitial, respectively. The effects of system initial pH, substrate to inoculum (S0/X0) and carbon to nitrogen (C/N) ratio on H2-production were evaluated which revealed maximum H2 production and yield could be achieved at pH 7, S0/X0 of 10.6 gCOD/gVS, and C/N 26.8. Modified Gompertz model and Modified Logistic model were used to define various kinetic parameters pertaining to cumulative H2-production which showed high R2 values (≥0.98). The influence of pH on H2 and ethanol/volatile fatty acids production kinetics were evaluated using Andrew's and Ratkowsky's model showing relatively good R2 values (≥0.62). Remarkably high production of ethanol (2.43 ± 0.28 mg/L) was noticed alongside H2 production at pH 7 suggesting that bioethanol can be recovered at the end of fermentative H2 production. Terminal Restriction Fragment Length Polymorphism and 16s rDNA sequencing revealed dominance of 9 bacterial species such as Escherichia coli, Clostridium butyricum, Streptococcus henryi, and 6 others uncultured bacteroides. This research determined different kinetic parameters for an enhanced H2 production strategy by co-fermentation of FVW and CCW providing an understanding of process behavior which will in turn help in the upscaling of the H2-production processes.