Chemical Characteristics of Results and Discussion

Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013 Palembang, South Sumatra -Indonesia, 24-25 October,2013 127 Figure 1 shows that the length, width and thickness of batik rice grain both rough and milled rice tend to be larger than ordinary rice. Ciherang rice variety was classified as long rice grain due to the ratio of length and width was more than 3. The ratio between length and width of both rough batik and ordinary rice were 4.09 and 4.00, respectively, while the ratio between length and width of milled batik and ordinary rice were 3.54 and 3.61, respectively. Color analysis was carried out by using the CIELAB system, and LCH color scale. CIELAB color space set in cube form shape of a cube. L axis starting from the top down top to bottom with a maximum value of 100 indicating perfect reflecting diffuser is indicated as a white, and a value of zero indicates the color black. Axes a and b have no numerical limits. Positive a indicates red, and negative a is green. Positive value of b is yellow and negative b is blue. In this study, the color of ordinary rice grain sample was considered as standard. The results of color intensity for milled batik and ordinary rice grains are presented in Table 1. Table 1. Colour intensity of milled batik and ordinary rice grains No. Colour components Milled ordinary rice Milled batik rice 1. L Lightness , 69.90 ± 1.87 72.23 ± 2.85 2. C Chroma , 12.00 ± 0.20 11.57 ± 0.67 3. h Hue , o 77.83 ± 0.49 79.27 ± 1.63 4. a 2.43 ± 0.15 2.23 ± 0.35 5. b 11.27 ± 0.67 11.77 ± 0.25 Lipase is the primary enzyme that resulted in hydrolysis of triglycerides into glycerol and fatty acids. Lipase significantly increased free fatty acids in brown rice due to lipid hydrolysis [10], wherein the lipase activity is affected by moisture, temperature, pH, time and water activity [11][12]. The activity of lipase enzyme increased at the temperature of 40 o C, then its activity would decrease after reaching the temperature of 60 o C [13]. The humidity in the stack of wet rough rice grains was high and its temperature might reach 40°C, and this condition could support the occurrence of such lipase activity. Texture analysis showed that the texture of cooked batik rice 29 gf was higher than that of cooked ordinary rice 20.67gf. It might be due to aleurone on the surface of milled batik rice disrupting water penetration into the rice endosperm during cooking, so it resulted in harder texture in cooked milled batik rice. Higher degree of milling resulted in easier water absorption into the rice endosperm when cooking rice [14]. Higher milling degree means more aleurones were brushed off during milling that could be indicated by whiter milled rice. In addition, it might result in softer texture in cooked rice [14].

3.2. Chemical Characteristics of

Batik Rice Chemical properties were analyzed on amylose, protein, amino acid, and thiamin content, as well as antioxidant activity. Protein contents of milled batik and ordinary rice were 6.64 and 6.94, respectively. The protein content in milled batik rice was lower than milled ordinary rice, which might be due to some proteins, especially the water-soluble proteins dissolved and leached out in water during the delay-drying process of batik rice grain. Amino acids contents in milled batik and ordinary rice are presented in Table 2. The results of thiamin content analysis showed that thiamin was not detected in both milled batik and ordinary rice. The antioxidant activity was calculated as IC50, which means the amount of material required to inhibit DPPH radical formation 1,1-Diphenyl-2-picryl-hydrazyl DPPH by 50. Analysis of antioxidant activity in milled batik rice at IC50 was 6.44 g100 mL, and in milled ordinary rice was 6.82 g100 mL. The difference in antioxidant activity between milled batik and ordinary rice was only 0.38 . It can be explained that only small amount of aleurone attached on the surface of milled batik rice during the delayed-drying rough rice grains. The slight amount of aleurone on the surface of milled batik rice was indicated by darker colour on batik rice. It could be speculated that only small amount of antioxidant compounds could migrate into rice endosperm during the delayed-drying process, therefore there was only slight increase of the antioxidant activity in milled batik rice. Compounds that can function as antioxidant in rice aleurone are tocopherol, tocotrienol and oryzanol [15][16][17][18]. Those compounds can inhibit the oxidation of fatty acids in the aleurones. Proceeding of 2013 International Seminar on Climate Change and Food Security ISCCFS 2013 Palembang, South Sumatra -Indonesia, 24-25 October,2013 128 Table 2. Amino acid content in rice No. Amino acids Percentage in Milled Batik Rice Milled Ordinary Rice 1 Aspartic acid 0.54 0.51 2 Glutamic acid 1.18 1.08 3 Serine 0.3 0.28 4 Histidine 0.11 0.10 5 Glycine 1.52 1.40 6 Threonine 0.16 0.15 7 Arginine 0.41 0.39 8 Alanine 0.34 0.31 9 Tyrosine 0.12 0.11 10 Methionine 0.18 0.17 11 Valine 0.34 0.32 12 Phenylalanine 0.37 0.34 13 Isoleucine 0.25 0.23 14 Leucine 0.47 0.43 15 Lysine 0.19 0.16

3.3. Sensory Analysis