The large amounts of organic waste thrown into the garbage without any productivity, and the increase in the demand for electrical energy worldwide, has led to the search for new eco-friendly ways of generating electricity. Because of this, microbial fuel cells have begun to be used as a technology to generate bioelectricity. The main objective of this research was to generate bioelectricity through banana waste using a low-cost laboratory-scale method, achieving the generation of maximum currents and voltages of 3.71667 ± 0.05304 mA and 1.01 ± 0.017 V, with an optimal pH of 4.023 ± 0.064 and a maximum electrical conductivity of the substrate of 182.333 ± 3.51 µS/cm. The FTIR spectra of the initial and final substrate show a decrease in the peaks belonging to phenolic compounds, alkanes, and alkenes, mainly. The maximum power density was 5736.112 ± 12.62 mW/cm² at a current density of 6.501 A/cm² with a peak voltage of 1006.95 mV. The molecular analysis of the biofilm formed on the anode electrode identified the species Pseudomonas aeruginosa (100%), and Paenalcaligenes suwonensis (99.09%), Klebsiella oxytoca (99.39%) and Raoultella terrigena (99.8%), as the main electricity generators for this type of substrate. This research gives a second use to the fruit with benefits for farmers and companies dedicated to exporting and importing because they can reduce their expenses by using their own waste.

Agricultural waste negatively impacts the environment and generates economic difficulties for agro-industrial companies and farmers. As a result, it is necessary for an eco-friendly and sustainable alternative to managing this type of waste. Therefore, the research aimed to investigate lettuce waste as an alternative substrate to generate bioelectricity in single-chamber microbial fuel cells (scMFCs). It was possible to report voltage and electric current peaks of 0.959 ± 0.026 V and 5.697 ± 0.065 mA on the fourteenth day, values that were attained with an optimum pH of 7.867 ± 0.147 and with an electrical conductivity of 118.964 ± 8.888 mS/cm. Moreover, as time passed the values began to decline slowly. The calculated value of maximum power density was 378.145 ± 5.417 mW/cm² whose current density was 5.965 A/cm², while the internal resistance reported using Ohm’s Law was 87.594 ± 6.226 Ω. Finally, it was possible to identify the Stenotrophomonas maltophilia bacterium (99.59%) on a molecular scale, as one of the microorganisms present in the anodic biofilm. The three microbial fuel cells were connected in series and demonstrated that they were capable of lighting an LED bulb, with a voltage of 2.18 V.

This research aimed to use kiwi waste as fuel to generate bioelectricity through microbial fuel cells. It was possible to generate an electrical current and voltage peaks of 3.807 ± 0.102 mA and 0.993 ± 0.061 V on day 11, showing an electrical conductivity of 189.82 ± 3.029 mS/cm and an optimum operating pH of 5.966 ± 0.121. The internal resistance of the cells was calculated using Ohm’s Law, resulting in a value of 14.957 ± 0.394 Ω, while the maximum power density was 212.68 ± 26.84 mW/m² at a current density of 4.506 A/cm². Through the analysis of the FTIR spectra carried out on the substrate, a decrease in the characteristic organic peaks was observed due to their decomposition during the electricity-generation process. In addition, it was possible to molecularly identify the bacteria Comamonas testosteroni, Sphingobacterium sp., and Stenotropho-monas maltophila adhered to the anodized biofilm. Finally, the capacity of this residue to generate bioelectricity was demonstrated by lighting an LED bulb with a voltage of 2.85 V.

The increase in the population and its need to produce food has caused the level of contamination by organic waste to increase exponentially in recent years. Innovative methods have been proposed for the use of this waste and thus to mitigate its impact. One of these is to use it as fuel in microbial fuel cells to generate electricity. This research aims to generate bioelectricity using coriander waste in microbial fuel cells. The maximum voltage and current observed were 0.882 ± 0.154 V and 2.287 ± 0.072 mA on the seventh and tenth day, respectively, these values were obtained working at an optimum operating pH of 3.9 ± 0.16 and with an electrical conductivity of 160.42 ± 4.54 mS/cm. The internal resistance observed in the cells was 75.581 ± 5.892 Ω, with a power density of 304.325 ± 16.51 mW/cm² at 5.06 A/cm² current density. While the intensity of the final FTIR (Fourier transform infrared spectroscopy) spectrum peaks decreased compared to the initial one, likewise, with a percentage of identity, it was possible to attribute 98.97, 99.39, and 100% to the species Alcaligenes faecalis, Alcaligenes faecali, and Pseudomonas aeruginosa. Finally, the cells were connected in series, managing to turn on an LED light (red) with the 2.61 V generated. This research provides an innovative and environmentally friendly way that companies and farmers can use to reuse their waste.

This research used tomato waste as a substrate (fuel) in Single Chamber-Microbial Fuel Cells (scMFC) on a small scale. The electrochemical properties were monitored, the functional groups of the substrate were analyzed by Fourier Transform Infrared Spectrophotometry (FTIR) and a microbiological analysis was performed on the electrodes in order to identify the microorganisms responsible for the electrochemical process. The results show voltage peaks and an electrical current of 3.647 ± 0.157 mA and 0.957 ± 0.246 V. A pH of 5.32 ± 0.26 was measured in the substrate with an electrical current conductivity of 148,701 ± 5849 mS/cm and an internal resistance (R_int) of 77. 517 ± 8.541 Ω. The maximum power density (PD) displayed was 264.72 ± 3.54 mW/cm² at a current density (CD) of 4.388 A/cm². On the other hand, the FTIR spectrum showed a more intense decrease in its peaks, with the compound belonging to the phenolic groups being the most affected at 3361 cm⁻¹. The micrographs show the formation of a porous biofilm where molecular identification allowed the identification of two bacteria (Proteus vulgaris and Proteus vulgaris) and a yeast (Yarrowia lipolytica) with 100% identity. The data found show the potential of this waste as a source of fuel for the generation of an electric current in a sustainable and environmentally friendly way, generating in the near future a mechanism for the reuse of waste in a beneficial way for farmers, communities and agro-industrial companies.

Nowadays, nutritional foods have a great impact on healthy diets. In particular, maca, oatmeal, broad bean, soybean, and algarrobo are widely used in different ways in the daily diets of many people due to their nutritional components. However, many of these foods share certain physical similarities with others of lower quality, making it difficult to identify them with certainty. Few studies have been conducted to find any differences using practical techniques with minimal preparation and in short durations. In this work, Principal Component Analysis (PCA) and Near Infrared Spectroscopy (NIR) were used to classify and distinguish samples based on their chemical properties. The spectral data were pretreated to further highlight the differences among the samples determined via PCA. The results indicate that the raw spectral data of all the samples had similar patterns, and their respective PCA analysis results could not be used to differentiate them. However, pretreated data differentiated the foods in separate clusters according to score plots. The main difference was a C-O band that corresponded to a vibration mode at 4644 cm⁻¹ associated with protein content. PCA combined with spectral analysis can be used to differentiate and classify foods using small samples through the chemical properties on their surfaces. This study contributes new knowledge toward the more precise identification of foods, even if they are combined.