쌀단백질 첨가와 펀칭시간이 호박인절미의 노화에 미치는 영향 = Effect of rice protein addition and punching time on the retrogradation of pumpkin injeolmi

다국어 초록 (Multilingual Abstract)

Purpose: This study examined the effects of rice protein (RP) addition on the retrogradation of pumpkin injeolmi during storage and the impact of punching time during injeolmi preparation on the rate of retrogradation. Methods: Pumpkin injeolmi was prepared by adding 0%, 1%, 3%, and 5% RP to wet glutinous rice flour containing dried pumpkin. After steaming, twelve types of samples were made by varying the punching time: No punching (NP), punching for 5 min (P5), and punching for 10 min (P10). The changes in the retrogradation characteristics of samples during storage were measured using a texture analyzer (TA), x-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Results: According to the hardness values measured using TA, retrogradation increased from the second day of storage for all samples. However, as the RP amount increased, lower hardness values were observed compared to the control group, most notably with RP 5% addition regardless of punching, indicating a pronounced anti-retrogradation effect. XRD of the NP samples showed that an increase in RP addition led to a decrease in relative crystallinity, indicating a delayed retrogradation of injeolmi. The DSC results showed that melting enthalpy values declined with RP addition, indicating diminished recrystallization relative to the control group. SEM indicated that pore size became more uniform than the control, and the walls of the mesh structure thickened as RP addition increased, forming a complete gel structure, corroborating the retrogradation inhibition. Conclusion: These results confirmed that RP can be used as a retrogradation inhibitor in injeolmi. In particular, adding 5% RP without punching could improve product quality during storage and extend shelf life, potentially serving as the optimal manufacturing condition for injeolmi production.