Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

고령지농업연구소에서 육성된 '자심' 감자(Solanum tuberosum L.) 괴경의 자주색 육색은 안토시아닌 색소의 축적에 기인한다. 본 연구는 이러한 '자심' 감자의 괴경 조직에 안토시아닌이 축적될 때 결정적으로 관여하는 기상 환경요인을 분석하고 색소 함량 증대를 위한 질소시비 기준을 설정하기 위하여 수행되었다. 기상 환경요인이 뚜렷하게 다른 3개 지역에서 파종시기 또는 재배 작형을 달리하여 '자심' 감자를 재배하고 수확된 괴경의 안토시아닌 함량을 분석한 결과, 수확일을 기준으로 수확전 30일 동안의 야간온도가 낮을수록 괴경내 안토시아닌 축적이 왕성한 것으로 나타났다. 안토시아닌 축적에 영향을 미치는 질소시비 수준의 효과를 분석한 결과 고랭지인 대관령에서는 권장시비량 처리구에 비해 감량시비 혹은 증량시비 처리구에서 안토시아닌 함량이 낮은 결과를 보였다. 그러나 평난지인 강릉에서는 시비수준간 뚜렷한 차이를 보이지 않았다. 이러한 결과로 볼 때 안토시아닌이 고농도로 축적된 자주색 육색의 '자심' 감자를 생산하기 위해서는 적절한 재배지대 및 작형의 선택과 시비관리가 매우 중요할 것으로 생각된다.

자색고구마 색소 농축액의 유동특성을 원뿔형 회전점도계를 사용하여 가용성 고형분의 농도 25-65% 및 온도 20-6의 범위에서 조사하였다. 자색고구마 색소 농축액은 뉴톤성유체의 특성을 나타냈다. 자색고구마 색소 농축액의 점도의 온도에 대한 영향은 Arrhenius 식을 따랐으며, 활성화에너지는 14.23-43.00 kJ/mol로서 농도가 증가함에 따라 직선적으로 증가하였다. 자색고구마 색소 농축액의 점도와 온도 및 농도에 대한 관계를 조사한 바,