Texture of steamed rice cake prepared via soy residue and hydroxypropyl methylcellulose supplementation

Abstract

Background and objectives: Okara and hydroxypropyl methylcellulose (HPMC) were added to jeungpyun, a steamed rice cake, as fermentation enhancers. Three types of jeungpyun were prepared: containing only rice (C), with okara added (O), and okara treated with HPMC (OH). Findings: During fermentation, the OH batter had the highest volume, followed by O and C; particularly OH maintained its volume without batter collapse after 2 hrs. The viscosity (C: 446, O: 575, OH: 991 cP) and water-holding capacity (C: 2.9, O: 8.7, OH: 17.2%) of batter also showed the same tendency with volume. After steaming, the volume of OH jeungpyun was the highest (1.7 cm3/g), followed by O (1.5 cm3/g) and C (1.4 cm3/g). The sensory panel scores of the okara treated samples were 1.8 (OH)–2.4 (O) fold lower in hardness than C. Addition of okara decreased the hardness and the rate of hardening of jeungpyun during storage, particularly in OH. Conclusions: Okara improved the fermentation of batter, and improved the hardness and volume of jeungpyun. HPMC stabilized the batter and maintained the volume. Significance and novelty: This study suggests the application of okara as a fermentation source and its impact on quality effect.