Change of Texture of Back-pyun as affected by glutinous-rice

찹쌀첨가량에 따른 백편의 조직감 특성의 변화

Back-pyun is a kind of rice cake made by steaming rice flour added sugar, water and salt and garnished with shredded chestnuts, dates, mushrooms and pinenuts. The Back-pyun has been widely used in Korean celebrations. This study aimed to compare and determine the effects on sensory characteristics and texture of Back-pyun 1) when the proportion of glutinous rice, added i.1 making Back-pyun, is 0%, 5%, 10%, 15%, 20%, 25% and 30% 2) then it reheated after storage for 0,24, 48 and 72 hours. Evaluation was conducted through sensory evaluation and objective evaluation. The results are as follows : 1. In sensory evaluation, color of Back-pyun turned yellow as the addition level of glutinous rice increased and then by reheating after storage for 24, 48 and 73 hours. Coarseness was not significantly different as the addition level of glutinous rice increased before storage. But Back-pyun reheated after storage for 24,48 and 72 hours were significantly different by the addition level of glutinous rice. Softness, dryness and crumblyness tended to decrease as the addition level of glutinous rice increased and by reheating after storage for 24, 48 and 72 hours. The most favorite tendency on the appearance was at the addition level of glutinous rice of 5%. Texture and overall preference were better at the addition level from 10% to 20% than any other levels. 2. Rheometer measurement indicated that compression force, gumminess ana chewiness tended to increase as the addition level of glutinous rice increased and decrease by the storage conditions. But work ratio and recovered height did not have much effect the addition level of glutinous rice and the storage conditions. Compression force of Back-pyun (not reheated) tended to increase by the storage time and the addition level of glutious rice. Especially it showed remakably increasing tendency during 24 hours storage (at $4^{\circ}C$) 3. Moisture content tended to increase by the addition level of glutinous rice and decrease by the storage time. But moisture content of Back-pyun reheated after storage for 24 hours stowed the increasing tendency. 4. Softness of Back-pyun had significant relationship with compression force and work ratio. Dryness and crumblyness had significant relationship with work ratio. Therefore compression force and work ratio represented the texture of Back-pyun.

백편을 만들때 멥쌀가루 100에 찹쌀가루를 총중량의 0%, 5%, 10%, 15%, 20%, 25%, 30% 첨가하고 저장시간 0시간, 24시간, 48시간, 72시간 저장한 후($4^{\circ}C$ 에서) reheating한 백편의 기호성과 조직감(Textur) 에 어떠한 영향을 끼치는 가를 관능검사와 기계적 검사에 의해 측정한 결과를 다음과 같이 요약할 수 있다. 1. 관능검사 결과 백편의 Color는 찹쌀의 첨가량이 증가할수륵 누런색이 짙어졌으며, 24,48,72시간 저장 한 후 reheating한 백편도 누런색이 짙어지는 경향을 나타냈다. Coarseness는 찹쌀의 첨가량이 증가할수록 증가하는 경향이었으나 저장전의 백편은 유의적인 경향을 나타내지 않았다. 찹쌀의 첨가량이 증가할수륵 Softness, Dryness, Crumblyness는 감소경향을 나타냈으며 24,48,72시간 저장한 후 reheating한 백편도 유의적인 감소청향을 나타냈다. 외관의 기호도는 찹쌀의 첨가율이 5%인 백편을 가장 좋아했고, 조직감 및 종합적인 기호도는 찹쌀의 첨가율이 $10{\sim}20%$인 백편을 좋아했다. 2. Rheometer에 의한 백편의 Texture는 찹쌀의 첨가량이 증가할수록 Compression force, Gumminess, Chewiness가 증가하는 경향을 나타냈다. 24,48,72시간 저장한 후 reheating한 백편은 저장전보다 점점 감소경향을 나타했다가 72시간 저장한 후 reheating하면 다시 증가경향을 나타했다. Work ratio 및 Recovered height는 찹쌀의 첨가량과 저장근간의 변화에 크게 영향을 미치지 않았다. Reheating하지 않고 0,24,48,72시간 저장한 백편의 Compression force는 찹쌀의 첨가량이 증가할수륵 증가경향이 켰고 저장시간이 경과함에 따라 Compression force가 증가하였는데 특히 24시간 저장하는 동안 급격히 증가하였다. 3. 찹쌀 첨가량이 증가할수록 수분함량은 증가하였고, 저장시간이 경과함에 따라 수분함량은 감소경향을 나타냈으나 24시간 저장한 후 reheating한 백편만이 수분함량의 증가경향을 나타했다. 4. 백편의 Softness는 Compression force 및 Work ratio와 유의적인 상관관계를 나타내었으며, Dryness와 Crumblyness는Work ratio와 유의적인 상관관계를 나타내고 있어 백편의 조직감은 Compression force 와 Work ratio로 대치할 수 있을 것이라고 사료된다. 수분함량은 기계적 검사보다 관능검사와 더욱 높은 상관관계를 나타냈다.