Nutritional evaluation and antioxidant activity of the exocarp, mesocarp, and endocarp from Parkia timoriana (DC.) Merr. pods for sustainable animal and human nutrition

Recycling food waste and agricultural byproducts into the food production cycle is essential for minimizing waste, consequently promoting sustainable global agricultural and food systems. This study aimed to support the goals of sustainable nutrition for both animals and humans by evaluating the nutritional composition, energy potential, and antioxidant properties of different anatomical components of the Parkia timoriana pod —namely, the exocarp, mesocarp, and endocarp. The analysis revealed that the mesocarp exhibited the highest levels of total amino acids, moisture, crude protein, ether extract, crude ash, nitrogen-free extract, non-structural carbohydrates, digestible energy, metabolizable energy, net energy for maintenance, gain, and lactation, as well as relative feeding values. It also contained the highest contents of phosphorus, potassium, iron, manganese, magnesium, copper, and zinc. In contrast, the exocarp had the highest levels of acid detergent fiber, acid detergent lignin, gross energy, calcium, total phenolic content, and DPPH radical scavenging activity, indicating strong antioxidant potential. The endocarp demonstrated the highest levels of dry matter, organic matter, total carbonhydrate, crude fiber, neutral detergent fiber, hemicellulose, cellulose, and the highest calcium-to-phosphorus ratio. Based on the nutritional classification for animals, all pod wall components were categorized as roughage and energy-rich feedstuffs. Forage quality grading classified the mesocarp as “Prime,” the exocarp as “Poor,” and the endocarp as “Reject,” reflecting their respective suitability in feed formulations. This is the first study to systematically characterize the internal anatomical components of P. timoriana pods, offering new insights into their heterogeneous nutritional and functional potential and supporting their targeted use as sustainable feed and functional ingredient resources.