• Korean journal of food and cookery science
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• v.27 no.4
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• pp.1-16
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• 2011

The purpose of this study was to investigate the physicochemical and sensory properties of various breads prepared with purple-fleshed sweet potatoes and their powders. As the amount of purple-fleshed sweet potato and its powder increased, pH of the dough and bread, volume, dough yield, baking loss rate, and fermentation power of the dough decreased, whereas acidity of the bread increased. The lightness and yellowness of the breads decreased significantly, but redness increased with increasing content of purple-fleshed sweet potato and its powder. The textural properties, such as hardness, chewiness, springiness, and brittleness were significantly higher in groups with added purple-fleshed sweet potato and its powder compared to those in the control. The anthocyanin content and DPPH radical scavenging of dough and bread were higher in groups with purple-fleshed sweet potato and its powder than those in the control group. The groups with 5% and 10% purple-fleshed sweet potatoes and their powders had significantly higher scores for overall acceptability as compared to the control group.

• Journal of the Korean Dietetic Association
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• v.16 no.4
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• pp.341-352
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• 2010

The aim of this study was to use purple sweet potato powder to develop a recipe for a nutritional cookie with an optimal composition of ingredients and texture, in order to acquire strong preference responses by all age groups in sensory tests. Wheat flour was partially substituted with purple sweet potato powder to reduce the wheat flour content of the cookies. Measurements were made and analyzed according to the Response Surface Methodology technique, which showed 16 experimental points including 3 replicates for the purple sweet potato powder, sugar, and butter. The compositional and functional properties of the sample were measured, and the values obtained were applied to a mathematical model. A canonical form and perturbation plot showed the influence of each ingredient on the final product mixture. The results of sensory evaluations showed very significant values for flavor (P<0.0071), texture (P<0.0306), taste (P<0.0190), and overall quality (P<0.0142). Instrumental analysis showed significant values for hardness (P<0.0027), yellowness (P<0.0061) and spread ratio (P<0.0001). The optimal compositional ratios were determined to be 21.75 g for the purple sweet potato powder, 37.05 g for the sugar, and 60.59 g for the butter.

• Culinary science and hospitality research
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• v.18 no.5
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• pp.279-292
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• 2012

This study was performed to investigate the quality characteristics and antioxidant activity of noodle added freeze-dried purple sweet potato powder. For Hunter's color resulted, as the amount of purple sweet potato powder increased, L-value and b-value decreased, the a-value increased. Anthocyanin contents of purple sweet potato powder at concentration of (mg/100 g) were 99.62%. DPPH radical scavenging activities of purple swe et potato powder at concentration of $1,000{\mu}L/mL$ were 84.60%. The texture of cooked noodles appeared no significant differences in cohesiveness, Springiness, Hardness, Gumminess and Chewiness decreased as the am ount of purple sweet potato powder increased. The weight, volume, moisture contents of noodles were not significantly. Sensory evaluation of acceptability including color, aroma, taste, chewiness and overall-acceptabi lity appeared the 6% added group was the best for higher. According to the positively evaluated anthocyanin content, DPPH radical scavenging activities, quality characteristics and sensory evaluation, a purple sweet pota to powder content 6% appears to be most appropriate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.896-903
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• 2015

The objective of this study was to investigate the effect of nitrite substitution of sausage with purple sweet potato by examining the quality characteristics of sausage. Four sausage samples were prepared as follows: F1 (0.15% sodium nitrite), F2 (0.2% pigment), F3 (0.2% pigment and 5% powder), and F4 (0.2% pigment and 10% powder). A substitution of sodium nitrite with 0.2% purple sweet potato pigment reduced redness while increased yellowness. However, the addition of 5% purple sweet potato powder to 0.2% purple sweet potato pigment increased redness while reduced yellowness, which was similar to those of sausage with 0.15% addition of sodium nitrite. Further, color change increased as the content of purple sweet potato increased. As the amount of purple sweet potato increased, the contents of Ca, K, and Mg increased but hardness, gumminess, and chewiness decreased. In the sensory evaluation, the addition of purple sweet potato did not influence on appearance, color, or flavor. However, the addition of 10% purple sweet potato decreased the taste and texture of sausage. Correlation coefficients between overall acceptability, texture, appearance, color, taste, and flavor were 0.901, 0.895, 0.877, 0.844, and 0.688, respectively. Therefore, proper content of purple sweet potato powder and purple sweet potato pigment were determined to be 5% and 0.2%, respectively, for the substitution of sodium nitrite.

• Food Engineering Progress
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• v.15 no.1
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• pp.34-40
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• 2011

As an attempt to develop a value-added food product, purple sweet potato powder was added in a model system of steamed bread as a healthy food ingredient and physicochemical properties such as moisture content, specific volume, spread ratio, color, texture as well as consumer preferences on the attributes such as uniformity, color, flavor, elasticity, chewiness, taste, and overall preference were evaluated. Moisture content ranged from 44.16 to 44.55% (wet basis) and appeared independent on the level of purple sweet potato (PSP) powder incorporation. As a result of the addition of PSP powder, the specific volume of steamed bread decreased from 3.22 to 2.55 mL/g, and value of 4.5% sample was significantly lower than other samples (p<0.05). On the other hand, spread ratio ranged from 2.01 to 2.53, and appeared to decrease as the PSP powder concentration increased (p<0.05), indicating a significant improvement. Lightness $(L^*)$ decreased significantly as the PSP powder content increased (p<0.05) for both dough and skin of the steamed bread. In addition, an increasing trend in redness ($a^*$-value) and a decreasing trend in yellowness ($b^*$-value) were noticed. Firmness increased significantly with the addition of PSP powder regardless of concentration (p <0.05); however, firmness was not significantly different among samples containing 1.5-4.5% PSP powder (p>0.05). Consumer acceptance test indicated that incorporation of 3% PSP powder in the formulation of steamed breads would be recommended.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1329-1337
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• 2012

This study was conducted to evaluate the effects of adding purple-fleshed sweet potato (PFP) powder on the texture properties and sensory characteristics of cooked pork sausage. Sodium nitrite alone and sodium nitrite in combination with PFP were added to five different treatments sausages (CON (control) = 0.01% sodium nitrite, SP25 = 0.005% sodium nitrite and 0.25% purple-fleshed sweet potato powder combination, SP50 = 0.005% sodium nitrite and 0.5% purple-fleshed sweet potato powder combination, PP25 = 0.25% purple-fleshed sweet potato powder, PP50 = 0.5% purple-fleshed sweet potato powder). The sausages were cooked to $74^{\circ}C$, stored at $4^{\circ}C$ for 6 wks, and used for chemical analysis, textural properties, and a sensory evaluation on 0, 2, 4 and 6 wks of storage, respectively. Similar CIE $a^*$ and $b^*$ values were determined in sausages from CON, SP25 and SP50 at the end of storage, and they were higher in CIE $a^*$ but lower in CIE $b^*$ than that of the PP25 and PP50 sausages. Significant differences were observed for brittleness and hardness when PFP was added to the sausages but were not confirmed after 4 wks of storage. The objective color score was influenced by adding PFP; however, the effect was not dose dependent. In overall acceptability, panelists favored the CON, SP25, SP50, and PP50 sausages but did not prefer PP25 sausages at the end of storage. Therefore, adding PFP to cooked pork sausages improved color and texture properties and sensory characteristics, but further study is needed to determine the proper ratio of sodium nitrite and PFP.

• Journal of the Korean Society of Food Culture
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• v.24 no.6
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• pp.756-761
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• 2009

The objective of this study was to assess the quality characteristics of almond Dasik prepared with the addition of purple sweet potato powder (PSPP). Five different levels (0, 5, 10, 15, and 20%) of PSPP were added and the physicochemical properties of the Dasik were examined. Crude protein and crude fat contents decreased as the level of PSPP increased (p<0.05). The Hunter L-value decreased while the a-value increased as the PSPP level increased. Texture measurements showed that the addition of PSPP increased hardness, cohesiveness, and brittleness. Total polyphenol content and antioxidant activity were assessed in terms of estimating the functionality of the Dasik. The results showed that incorporating PSPP into the Dasik provided higher polyphenol content and antioxidant activity compared to the control Dasik (p<0.05). The results of a consumer acceptance test revealed that the Dasik sample made with 15% PSPP was most preferred and the 20% sample was the least preferred. Therefore, it is suggested that purple sweet potato powder can be incorporated into Dasik up to 15% without reducing its quality.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.458-461
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• 1997

Yogurts were prepared by the fermentation of milk containing purple sweet potato powder(PSPP). The effect of PSPP addition on quality and sensory evaluation were as follow ; acidity, brix and viable cell count of PSPP yogurt was higher than the control. As the level of PSPP lightness and yellowness decreased. Redness increased significantly wit increases in viscosity. In consideration with the sensory evaluation of the PSPP yogurt, texture and color was better than the control, and taste was similar to the control. The sensory test of yogurt ranked highest at 3%~40% PSPP.

• Korean journal of food and cookery science
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• v.27 no.2
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• pp.19-29
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• 2011

Sweet potato powders made from eight Korean varieties, including purple-fleshed, orange-fleshed, and commercial dry type sweet potatoes, were investigated for physicochemical and pasting properties to develop processed food. Crude protein and lipid contents of Shinjami and Borami were higher than those of other varieties. The lightness value of raw sweet potato flesh was the highest value in Shinchunmi, and the lowest in Shinjami. Using the color difference (${\Delta}E$), color similarities compared to the white plate occurred in the following order; purple-fleshed > orange-fleshed > commercial dry type sweet potatoes. Total and damaged starch contents were significantly different (p<0.05). Total starch content of sweet potatoes was higher in commercial dry sweet potatoes (61.89-70.46%), particularly Shinchunmi (70.46%) but lower in orange-fleshed sweet potato (48.87 and 49.53%, respectively). Water binding capacity of Yeonwhangmi, swelling power and solubility of Shinyulmi were the highest values (174.70, 25.54 and 87.49%, respectively) among them (p<0.05). But oil absorptions of Shinyulmi and Shinchunmi showed lower values (97.08 and 97.54%, respectively). All sweet potato powders had an A type x-ray diffraction pattern. The initial pasting temperatures of sweet potato powders ranged from 69.50 to $75.95^{\circ}C$ and the amylolytic enzyme in sweet potato powder lowered pasting viscosity.

• Journal of the Korean Society of Food Culture
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• v.18 no.3
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• pp.202-210
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• 2003

The purpose of this study was to investigate the effects of dietary purple sweet potato(Ipomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C), induced hepatotoxicity rats fed control diet(EC), normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachlolide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(AST/GOT) of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G6Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.