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THE EFFECT OF DIFFERENT FRYING CONDITIONS ON THE COLOR PARAMETERS OF PURPLE SWEET POTATO (Ipomoea batatas Poiret) SLICES Rahmat Fadhil1*, Diswandi Nurba2, Kiki Ikhwanto2 1 Department of Agricultural Engineering, Syiah Kuala University, Jalan Teungku Hasan Krueng Kalee No.3 Darussalam 23111, Banda Aceh, Indonesia 2 Laboratory of Postharvest Technology, Syiah Kuala University, Darussalam 23111, Banda Aceh, Indonesia *
[email protected] Article history: Received : 26 April 2016 Accepted : 6 June 2017 Keywords: Color; Purple sweet potato; L*a*b* model; Frying; Adobe Photoshop CS5.
ABSTRACT The aim of the research was to analyze of the surface color measurement to the pre-frying and post-frying purple sweet potato (Ipomea batatas Poiret) slices by using a combining device i.e. the digital camera and the graphic software. It is believe that such analysis method able to observe colors and an average in a value of L*a*b* units of food ingredient surfaces. The digital images of purple sweet potato slices could be displayed on the computer screen or printed on a certain piece of paper their colors and structures can be analyzed. To do so, the method of digital image application is used, namely a digital camera Canon Ixus 145 without using the camera light and with the distance focus of 10 cm from the object. Following that, the resulted images, were plotted against colors on the Adobe Photoshop CS5. The results show that the use of the Adobe Photoshop CS5 software is extremely helpful in measuring colors of purple sweet potato chips due to the fact that it could bring a consistency when defining colors of pre-frying and post-frying slices with the system model of L*a*b* units. Overall, this study found that there is no difference in colors between pre-frying purple sweet potatoes and the post-frying ones in various treatments by the variance analysis and continued to the Duncan Multiple Range Test (DMRT) at a confidence level of 95 percent (p0.05)
Descriptions: K1S1 = the NaHCO3 concentration of 1 gram and the thickness of 1 mm K2S1 = the NaHCO3 concentration of 3 grams and the thickness of 1 mm K3S1 = the NaHCO3 concentration of 5 grams and the thickness of 1 mm K1S2 = the NaHCO3 concentration of 1 gram and the thickness of 2 mm K2S2 = the NaHCO3 concentration of 3 grams and the thickness of 2 mm K3S2 = the NaHCO3 concentration of 5 grams and the thickness of 2 mm K1S3 = the NaHCO3 concentration of 1 gram and the thickness of 3 mm K2S3 = the NaHCO3 concentration of 3 grams and the thickness of 3 mm K3S3 = the NaHCO3 concentration of 5 grams and the thickness of 3 mm
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Fadhil et al. Carpathian Journal of Food Science and Technology 2017, 9(2), 35-42
Figure 2. The graph of Pre-frying L*a*b values (Adopted from Konicaminolta, 2003)
Figure 3. The graph of Post-frying L*a*b values (Adopted from Konicaminolta, 2003)
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Fadhil et al. Carpathian Journal of Food Science and Technology 2017, 9(2), 35-42
Hoever, several other treatments show a significant difference between those of prefrying and post-frying (L*: K1S2, K2S2, K3S2; a*: K3S1; b*: K3S1, K1S2) (Table 1). Figure 2 and Figure 3 also show the different L*a*b* values gained. Apparently, it is due to the inhomogeneous color of those purple sweet potato slices resulting in the different L*a*b* values of each thickness and NaHCO3 concentration.
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4.Conclusions The use of the Adobe Photoshop CS5 software is very helpful in analyzing colors of purple sweet potatoes as it could provide a consistency in defining colors of pre-frying and post-frying slices with the system model of L*a*b* units. Overall, there is no significant difference among several treatments of prefrying and post-frying purple sweet potatoes by the Duncan Multiple Range Test (DMRT) at the confidence level of 95 percent (P
