PRODUCTION OF SINGLE CELL PROTEIN FROM ORANGE PEELS USING SACCHAROMYCES CEREVISIAE

ABSTRACT The global population increase has intensified demand for sustainable protein sources, as traditional protein production requires extensive resources, prompting exploration of alternatives. Single Cell Protein from microorganisms offers rapid production cycles and high protein content, while orange peels constituting 50–60% of citrus processing waste globally create disposal challenges despite being rich in carbohydrates suitable for microbial fermentation. Abundant discarded orange peels pose environmental problems, yet established protocols for efficiently producing Single Cell Protein from them using Saccharomyces cerevisiae remain limited, necessitating investigation for sustainable waste-to-protein conversion. This study aimed to investigate the production of single-cell protein from orange peels using baker's yeast (S. cerevisiae). Fresh orange peels were collected, dried, ground, and fermented with S. cerevisiae for seven days under controlled conditions. Protein content was determined using the Kjeldahl method, while reducing sugar utilization was measured using the DNS method. Results showed that the initial protein content of orange peel substrate (6.8%) increased to 19.7% after fermentation, while reducing sugar concentration decreased by 22% during the seven-day fermentation period. The final protein content was comparable to other agricultural waste substrates, being higher than groundnut shell (11.56%) and rice straw (18.3%) but slightly lower than bambara nut shell (21.88%). In conclusion, orange peels serve as viable substrates for Single Cell Protein production, achieving competitive protein enrichment while supporting waste-to-value conversion strategies for environmental sustainability. Scale-up studies and detailed nutritional profiling of the produced Single Cell Protein are recommended