• Culinary science and hospitality research
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• v.20 no.6
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• pp.56-68
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• 2014

Yam Yackwa (YP) was made by addition of yam power (15%) into flour. Depending on extension of storage time, lightness and redness of YP were increased. Yellowness of YP was decreasing until 3 days and increased from 9 days of storage. However, the yellowness of Yackwa without Yam powder (Non-YP) was increasing until 3 days and decreased from 6 days of storage. Hardness, gumminess, and chewiness of YP were improved compared to Non-YP. It means that the addition of yam power makes Yackwa soft. Oil absorption of Non-YP was low. Acid value and peroxide value of YP were 1.57 and 19.04, respectively. Moisture contents, crude ash, crude fat, crude protein, and carbohydrate of YP were $2.55{\pm}0.08%$, $0.71{\pm}0.01%$, $6.11{\pm}0.06%$, $15.97{\pm}1.40%$, and $64.66{\pm}0.09%$, respectively.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.596-602
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• 1994

To separate and concentrate mucilage from yam(Dioscorea batatas DECNE), yam was dried, microparticulated using impact mill and air-classified at different air classifying wheel speed(ACWS) in classifier. As ACWS increased from 5,000 rpm to 22,500 rpm, the contents of dietary fiber, protein and lipid of air classified microparticles(ACM) increased remarkably. Especially the ACM with ACWS over 15,000 rpm showed 36.41% dietary fiber and 16.66% protein. The dietary fiber and protein components were concentrated to $2.5{\sim}9.0$ times as compared with whole yam powder. Concomitantly the non-fibrous carbohydrate decreased from 88.31% to 16.84. The damaged starch(%), WSI and WAI of ACM of ACWS over 15,000 rpm were $1.5{\sim}3.0$ times higher than those of ACM under ACWS 15,000 rpm. The apparent viscosity of ACM was 0.0800 Pa s over ACWS 15,000 rpm and 0.0080 Pa s under ACWS 15,000 rpm. Judging from viscosity of ACM, the mucilage component of yam was concentrated to 10 times. In conclusion, the optimum process to separate and concentrate the mucilage from yam consisted of the microparticulation to $5{\sim}30{\mu}m$ and the air-classification at ACWS over 15,000 rpm.