Optimal stimulation of Citrus reticulate for bioenergy extraction in MFCs and antioxidant activity via traditional Chinese medicine processing methods

Background: Value added production of polyphenolic rich citrus peels in the form of agricultural waste valorization and as a medicinal herb holds exceptional practicality. Potential applications as natural electron shuttles for bioenergy production further valorizes citrus peels in a bid to promote sustainable energy generation. This first-attempt study thus tended to decipher the stimulating effects of traditional medicinal processing methods to augment the electron mediating capabilities of Citrus reticulate peels.Methods: Dried C. reticulate peels were subjected to stir-frying with individual adjuvants (e.g., vinegar, honey, soil, and bran) and analyzed via phytochemical analysis, antioxidant activity, and anti-inflammatory activity. Moreover, microbial fuel cells were used to evaluate the electron shuttling characteristics of the processed C. reticulate for bioenergy extraction. Significant findings: It was indicated that solid adjuvants (e.g., bran and soil) coupled with stir-frying were found to increase the phytochemical content (e.g., total phenols, flavonoids, and condensed tannins) of C. reticulate peels. Consequently, according to comparative analysis, bran stir-fried extracts with optimal processing methods further stimulate the ES characteristics of C. reticulate for bioenergy extraction. Enhanced power generation capacity was attributed to the chemical and physical changes of the bioactive compounds as a result of the processing methods. Furthermore, principal component analysis reveals that FRAP assay and total flavonoid content serve as a preliminary investigation for revealing the electron transport characteristics of C. reticulate.