Pistachio (Pistacia vera L.) is consumed in almost every part of the world enclosed in shells that are thrown out in baskets. Similarly, hulls separated from pistachio are discarded as waste in food processing industries. These waste materials contain functional constituents having immense industrial and nutraceutical applications. This review article summarizes the scientific investigations regarding the functional constituents and bioactive compounds in pistachio shells (PSs) and pistachio hulls (PHs). It also highlights the nutraceutical potential exhibited by functionally active compounds as well as their potential applications in various industries including nutraceutical, medicinal, and feed industries together with biosynthetic development of useful products and wastewater treatment. Pistachio waste (PW) comprising PS and PH is a rich source of various bioactive compounds. PS is full of lignin, cellulose, and hemicellulose. PH is an excellent source of carbohydrates (80.64 ± 0.98%) (including glucose, galactose, rhamnose, arabinose, xylose, mannose, galacturonic acid) as well as ash (6.32 ± 0.26%) and proteins (1.80 ± 0.28%) with small amounts of fats (0.04 ± 0.005%). Owing to its composition, PW can be beneficial in many nutraceuticals, including antioxidation, cytoprotection, anti-obesity, anti-diabetic, anti-melanogenesis, neuroprotection, anti-cancer, anti-mutagenesis, anti-inflammation, and anti-microbial. The waste materials have vast applications in the food industry, such as bio-preservation of oils and meat products, prevention of enzymatic browning in fruits, vegetables, and mushrooms, development of functional cereal and dairy products, production of food enzymes, emulsions, and manufacturing of biodegradable films for food packaging. The use of these waste products to develop and design novel functional foods with improved quality is important for both food industries and food sustainability. Graphical Abstract

Health-protective functional foods are gaining popularity in the world of nutrition because they promote excellent health while decreasing pharmaceutical burdens. Chia seeds (CS) (Salvia hispanica L.), the greatest vegetative source of α-linolenic acid, bioactive proteins, and fibers, are among the top unconventional oilseeds shown to have bounteous benefits against various non-communicable diseases. Purposely, this study was designed to integrate roasted CS powder into white-flour-based ordinary bakery goods to improve their nutritional and nutraceutical profiles. CS efficacy in normal and hyperlipidemic Sprague-Dawley rats resulted in mitigating blood glucose, triglycerides, total cholesterol, and low-density lipoprotein cholesterol while elevating high-density lipoprotein cholesterol, hematocrit, hemoglobin, red blood cell counts, and platelets. The nutritional profiling of chia-fortified muffins indicated significant increases of 47% in fat, 92% in fiber, 15% in protein, and 62% in minerals. The farinographic experiments of CS-blends revealed generally improved dough quality features with a significant rise in the degree of softening as fortification levels increased. A marketable recipe for CSF-muffins with several degrees of fortification demonstrated a significant rise in fat, 92% rise in fiber, 15% rise in protein, and 62% rise in minerals. Sensorial evaluation by trained taste panelists revealed a maximum appraisal of the 15% chia-fortified muffins due to aroma, appearance, and overall acceptability, and were forwarded for being acceptable for commercialization.