Potato ranks as the fourth most extensively cultivated staple crop worldwide, with significant quantities subjected to processing. The processing operations produce substantial solid and liquid waste, necessitating sustainable and efficient management strategies. This study investigates the compositional properties and valorization potential of potato processing residues by employing an integrated biorefinery approach. Solid waste, predominantly potato peels, and liquid effluent samples were collected from a local chips manufacturing plant. The solid fraction was oven-dried at 60 °C for 48 hours before proximate analysis for starch, protein, fat, minerals, cellulose, hemicellulose, and lignin content. Liquid waste was analyzed for starch and protein. Polyphenols were extracted using ethanol and quantified spectrophotometrically as gallic acid equivalents. High-resolution LC-MS was employed to profile polyphenols and other bioactives. The protein was further extracted and characterized for its compositional and nutritional properties via Protein Efficiency Ratio (PER) and Essential Amino Acid Index (EAAI). Data were integrated to design a scalable biorefinery process suitable for major potato processing industries in India. Peel waste contained 12-16% starch and 9-14% protein, with lignocellulosic fractions comprising cellulose (18-20%), hemicellulose (28-30%), and lignin (9-11%). Mineral analysis revealed significant calcium, magnesium, and potassium levels. Peels exhibited high polyphenol content (900-1000 mg GAE/100g). The liquid waste primarily comprised starch (70-75%) and protein (4-6%). SDS-PAGE confirmed Patatin as the dominant protein. High fractions of leucine, lysine, aspartic and glutamic acid, and hydroxyproline were found in the protein extracts. Protein quality metrics showed promising PER (2-2.5) and EAAI (1.03) values. LC-MS analyses revealed the presence of high-value bioactives in peels, including chlorogenic acid, gallic acid, vanillic acid, glycoalkaloids, surfactants, and choline. The biorefinery model developed based on these findings was optimized to maximize nutrient recovery and enhance economic returns in the Indian processing sector. Potato processing wastes are nutrient-dense and contain valuable bioactives ideal for integrated valorization via a biorefinery approach. This waste utilization model demonstrates significant potential for mitigating greenhouse gas emissions from waste disposal, establishing novel revenue streams, creating employment opportunities, and fostering a circular economy, thereby contributing to multiple Sustainable Development Goals (SDG 3, 12, 13 & 15).
