Purpose: Unripe apples have a higher organic acid and polyphenol content than ripe apples, but a significant amount of unripe apples are discarded during the apple harvest. In this study, we investigated the potential of utilizing unripe apples as a food ingredient. Methods: Unripe apple powder (0%, 1.5%, 3%, 4.5%, 6%) was added to Allulose Jeungpyun (a traditional Korean rice cake) and evaluated for quality characteristics, antioxidant activity, and acceptability. Results: Increasing the amount of unripe apple powder decreased the pH, lowered brightness, hardness, chewiness, and gumminess, and increased the sugar content, moisture content, cohesiveness, and antioxidant activity. Sensory evaluation showed that the allulose Jeungpyun sample with 4.5% unripe apple powder was the most palatable. Conclusion: The addition of unripe apple powder to allulose Jeungpyun could improve its palatability and functionality. Thus, unripe apple powder showed promise as an additive for a variety of foods.