Antioxidant activity and quality of soy enriched apple bar

Antioxidant activity of a soy enriched apple bar (SEAB) prepared from the pulp of culled apples and soy protein isolate (3%) was determined using a ferric reducing antioxidant power (FRAP) assay. The antioxidant activity was 8500 muM g(-1) FRAP and phenol content was 175 mg 100 g(-1). The soy enriched apple bar had 20 fold protein and 1.6 fold higher antioxidant activity than the plain apple bar. No significant change in antioxidant activity and total phenols was recorded during storage at ambient (22-31C) or low (4 +/- 1) temperatures. The pectin, protein and ascorbic acid contents decreased while nonenzymatic browning and total sugars increased significantly with increase in storage periods. The product was organoleptically acceptable and microbiologically safe after 180 days of storage. A sheaf stable soy enriched apple bar with high antioxidant activity, phenol content and sensorial quality can be an ideal source of dietary antioxidants.