TOFU PRODUCTION BASED ON LOCAL VARIETY SOYBEAN

TOFU PRODUCTION BASED ON LOCAL VARIETY SOYBEAN Rifda Naufalin, Santi Dwi Astuti, Beny Ferdiansyah and Agus Rusdiana Fakultas Pertanian, Universitas Jenderal Soedirman. rifda_unsoed@yahoo.com ABSTRACT The local varieties of soybean can be used as an alternative of raw material in tofu production because it has high protein content. The textural properties and taste were determined by type of coagulant. The objectives of this research were to : 1) examine the influence of soybean varieties on the coagulant and protein content of tofu 2) examine the influence of coagulant type on the sensory properties of tofu; 3) determine the physical, chemical and sensory properties of selected tofu. The research used Randomized Completely Block Design (RCBD). Two factors examined were: 1) soybean varieties consist of Rajabasa, Tidar, Mitani, and Import; 2) types of coagulant consist of calcium sulfate, acetic acid, whey and citric acid. The analyzed physicochemical properties were protein content, coagulant, hardness level, water content and ash content. The analyzed sensory properties were color, aroma, tenderness, acid taste, bitter taste, and overall acceptability level. Data were analyzed by analysis of variance and followed by Duncan's Multiple Range Test. The results showed that: Local soybean varieties can be used as raw material alternative of tofu production because it had similar physic and chemical properties, ie 60.46 78.36% db protein; 157.31 216.07% wb coagulant; 0.1 0.12 mm/g/s hardness level; and 70.60 78.05% wb water content. The tofu selected was made from Rajabasa varieties and whey coagulant (V1G1). This product had 183.86% w.b. coagulant, 1.13 mm / g / s firmness level; 76.54% w.b. water; 65.73% d.b. protein; and 1.31% d.b. ash. The product was accepted by semi trained panelists (score 2.98; moderately like); gray whitish color (score 1.77); moderately tender texture (score 3.11); moderately strength aroma (score 2.51), slightly acid taste (score 2.13 ) and slightly bitter taste (score 1.63). Key word : local variety soybeans, tofu, coagulant type INTRODUCTION Soybean is one of protein which is used as food processing, such as tofu. Tofu is the preferred non fermentation soybean in Indonesia. The superiority of tofu based on nutricion is the highest food protein and contains of complete amino acid (Suprapti, 2005). Today, the import product of tofu still used by the tofu craftsman, besides its lower price it supply the more soybean. Kalisari Cilongok is one on tofu center in Banyumas. This inashry is preferred by the housewife scale. The craftsman in that village amount 313 groups with 2-4 employees and up to 8-9 tons/days for the soybean used. The matter is the used of import soybean is preferred than the local soybean, and the price is going to be increased today. The way to decrease these import food addiction which is released from Center of Isotop Technology Application and Nuclier Radiation (PATIR BATAN) using nuclier technique for mutation of soybean since 1980, PATIR BATAN displayed the highest variety of soybean, Rajabasa which is released on (2004) Galur Mutan No. 214 x 23 and Mitani on 2008 No. 13-D x 9 and Tidar on 1987 1

from the selection of mutan B 1682 (Mulyana et.al, 2010). These varieties are planted in Kalisari Cilngok Banyumas in the yard test amount 426 m 2. Mitani soybean (medium seed), Rajabasa (big seed), and Tidar (small seed). Among these varieties, Rajabasa has the highest productivity, 100 seeds of Rajabasa have 24,36 g while Mitani has the weight 12,01 g/100 seeds and Tidar 7,3 g/100 seeds. Physically, Rajabasa is bright yellow, Mitani is yellow-green, and Tidar is sulfur colour. Tofu is theprotein gell, then the quality of its rendement and texture is based on the total protein extracted in soybean essense before coagulant (Poysa dan Woodrow, 2002). Soybean varieties and processing technique used are the prior factor of these varieties (Mujoo et al., 2003). Tofu processing needs the coagulant protein in the essense (Suprapti, 2005). And the used of coagulant is very essential in this processing because it depends on the quality of tofu. The coagulant used are whey, citrid acid, calsium sulfate and acetate acid. According to Widayanti (1992), the difference koagulan will deffer taste, aroma, constitential, and water compound. The different coagulant will state the texture and taste of tofu (Poysa dan Woodrow, 2002). Both are kind of acid coagulant, but they have different cloding. Acid solvent such as whey and citrid acid are used to clod the protein in point of isoelectrical. The research result of Yulistiani and Nuryati (2006), shown that coagulant tofu with citrid acid concentrate 15% found the coagulant of ph closer into isoelectrical point of 4,52. The purposes of the research are: 1). To study the effect of soybean varieties into its rendements and total protein of tofu; 2). To study the effect of coagulant substance into sensory characteristic of tofu; 3). To study physicochemical and sensory characteristic from the best treatment. RESEARCH METHODOLOGY Materials and Tools The materials used were local soybean and import soybean. The local varieties are Rajabasa, Tidar, and Mitani which is achieved from the plantation in Kalisari Cilongok. The import soybean is achieved from Wage traditional market Purwokerto. The coagulant used are citrid acid, calcium sulfate, acetate acid and whey. The chemical material is PA (pro analysis grade) they are K 2 S 2 O 4, HgO, H 2 SO 4, K 2 S, NaOH, HCl, Aquades. The tools were thermometer, ph meter, oven, tanur, destilat tool, penetrometer. Process of Tofu production Steps of tofu production are sortation of soybean to separate the broken and dirty soybean, weighing the dried soybean amount 200 g.submersion or soaking with the volume of water 3 more from the dried soybean (b/v) for 8 12 hours, paring and cleaning to separate the epidermis of soybean, 2

weighing the wet soybean, grinding with blender by adding hot water 1:5 from wet weight in the temperature 70 80 o C for 7 minutes to decrease rotten smell, boiling the soybean puree, filtering with the mori fabric to separate the milk and the waste of soybean, additioning the coagulant in temperature 70 80 o C, stirring, separating curd and whey using fabric, pressuring and forming, and boiling in hot water blanching for about 5 minutes in boiling water. Treatment This research used the experiment with randomize completely block design which consists of 16 combination treatments and 3 times replication and found 48 trials unit. There are 2 trial factors in this research, they are: 1) soybean varieties (V) consist of Rajabasa (V1); Tidar (V2); Mitani (V3); and Impor (V4) and also coagulant substances (G) consist of calsium sulfate (G1), acatic acid (G2), whey (G3), and citrid acid (G4). RESULT AND DISCUSSION Physicochemical characteristic 1. Rendement Rendement of tofu is counted based on the weight of tofu production devided the weight of used tofu. The result analysis is shown that the use of soybean variety (V) and the use of coagulant (g) give the real effects into rendement and both interactions (VxG) did not give the real effect. The medium value of rendement of the use of the soybean varieties Rajabasa (V1), Tidar (V2), Mitani (V3) and import (V4) are 196,53 % (bb); 169,74 % (bb); 182,31 % (bb); and 168,53 % (bb). The effect of soybean varieties into rendement of tofu is shown in figure 1. Figure 1.The effect of soybean variety into rendement of tofu 3

According to figure1, it is shown that rajabasa has the highest rendement 196,53 % (bb). This matter guessed from the variety of rajabasa has the highest protein 35,76% (bk) compared with the protein value of import soybean 33,93% (bk). Tofu is one of dregging of soy protein, and then the rendement is affected by the more soybean protein. According to Antarlina et al. (2002), seed protein is correlated with the rendement of tofu. Figure 2. the effect of coagulant into rendement of tofu The mean of rendement using sulfate calcium (G1), acetate acid (G2), whey (G4), and citrid acid (G4) are 195,45; 185,715; 170,94; 165,01. The use of sulfate calcium and acetate acid give the highest rendement 195,45 and 185,715 from the use of whey and citrid acid. 2. Total Protein The result is shown that the treatment of soybean variety (V) gives the real affetct into the degree, while the coagulant subtancial (G) and both interaction (VxG) did not give any affection into total protein of tofu. 4

Figure 3. The effect of soybean varieties into total protein of tofu The mean of total protein into Rajabasa (V1); Tidar (V2); Mitani (V3); Impor (V4) are 65,85% (bk); 70,98% (bk); 73,54% (bk); and 66,12% (bk). Mitani coagulant the highest means of protein 73,54% (bk), while the means of protein is achieved from import soybean 66,12% (bk). This is because of the protein of tofu is affected by protein of soybean as the raw material. Based on the analysis, a range of protein for Mitani = 37,08% (bk); Rajabasa = 35,76% (bk); Tidar = 34,76% (bk); import = 33,93% (bk). According to Schafer and Love (1992), soybean variety which is contain the highest protein is usually coagulant the highest protein. 3. Hardness level The measure of hardness level is to know how hard level of tofu. It is using penetrometer. The result is shown that the treatment of variety (V), coagulant substancial (G) and both interactions (VxG) did not affect anything into the texture of tofu. The means of hardness level on the treatment of Rajabasa (V1), Tidar (V2), Mitani (V3) and import (4) are 0,111mm/g; 0,103 mm/g; 0,106 mm/g; 0,105 mm/g. 4. Water content The result is shown that coagulant treatment (G) give the real effect on the water content of tofu, while soybean variety (V) and both interactions (VxG) did not give any effect into water content of tofu. the effect of coagulant into water content is shown at figure 4. Figure 4. the effect of coagulant into water content of tofu 5

The means of water content on the treatment of soybean are 74,91% - 77,23%. The use of sulfate calcium found the means of the highest water content 77,23% while the lowest level is using citrid acid 74,91%. The use of coagulant sulfate calcium produce the highest water content amount 15-20% than the use of other salt, because it chains more water in tofu (Subardjo et al., 1987). 5. Ash content Ash is the residue of mineral organic burn on 550 0 C (Sudarmaji, 1997). The statement of ash content is used to know anorganc or mineral compound which is produced on tofu (Winarno, 2002). The result is shown that treatment of soybean variety of (V) and coagulant (G) give the real effect into ash content of tofu, and both interactions (VxG) give the real affect. It is shown in figure 5. Figure 5. the affect of soybean variety ito ash content of tofu The means value of ash content from Rajabasa, Tidar, Mitani and Import are 2,52; 2,60; 2,50; 2,10. Tidar has the highest ash content while the import has the lowest one. This is occurred based on the soaking of the protein then the mineral soaking is more in protein (Cahyadi, 2007). The other one the ash content is used as raw material. The result of analysis raw material, ash content of Mitani = 5.46% (bk); Tidar = 5.17% (bk); Rajabasa = 5,03% (bk); import = 3,79% (bk). 6

Figure 6. the affect of coagulant into ash content of tofu The coagulant of calcium sulfate on the soybean (Rajabasa, Tidar, Mitani dan Impor) give the highest ash content than acetate acid acid, whey and citrid acid. This because of sulfate calcium is the anorganics compound which are increase the ash content of tofu. Sensory characteristic 1. colour The result of analysis of the treatment from soybean varieties (V) coagulant (G), and both interactions (VxG) affected into the colour of tofu. the means of colour from treatment of Rajabasa (V1), Tidar (V2), Mitani (V3) and import (V4) are 2,04 (white gray); 2,63 (gray whitten); 2,47 (whitish gray); dan 2,3 (whitish gray). The means of tofu colour because of soybean variety is shown at figure 7. Figure 7. the means colour of soybean varieties 7

The lowest is produced from the tofu on Rajabasa (V1) 2,04 (white gray),while the highest is from Tidar (V2) 2,63 (whitish gray). The seed colour is affected the production of tofu. According to Antarlina et al (2002), it based on the used raw material, the seed by the bright yellow will produce the bright tofu and its preferred by consumers. Based on physhical of soybean variety of Rajabasa, Mitani has the yellow-green and Tidar has the sulfure colour. The means of the treatment soybean and the coagulant are shown in figure 8. Figure 8. the means of tofu colour using coagulant The means of colour of tofu is 2,25 (white-gray) 2,65 (whitish gray), the highest means of colour of tofu from calcium sulfate, while tofu colour with coagulant acetic acid, whey, and ctrid acid did not give any different. 2. Tenderness Tenderness of tofu sensory characteristic is produced in synergy interaction between water and protein. The result of analysis is shown that the treatment of soybean (V) and interaction of soybean variety and kind of coagulant did not affect the tofu tenderness, while the coagulant (G) is affected on the tenderness of tofu. the means of tofu tenderness on the soybean variety 3,05 ( low tenderness) until 3,38 (low tenderness). The means is because of the coagulant is shown in figure 9. 8

Figure 9.the means of tenderness of tofu using coagulant Tofu with coagulant calcium sulfate produces the highest means of tenderness. And the used of acetic acid will give the lowest tenderness level. It is caused by the interaction of protein and water in gell system. The highest level is achieved from import soybean 63,74% and water content 74,70%, it assumed from the difference protein and water content on the tenderness level. Calcium sulfate produces tofu 15-205 more than the other salt, because it chains more water in tofu (Subardjo et al., 1987). The highest water content will produce less tenderness, and the highest protein will produce the hard tofu because it has the complete texture (Obatulu, 2007). 3. Soybean Aroma Aroma is one of parameter which used to measure the preference of tofu. the result shown that the the coagulant (G) and both interactions (VxG) did not affect anything. The means of soybean aroma on treatment using calcium (G1), acetic acid (G2), whey (G3) and citrid acid (G2) are 3,24 (strong); 3,08 (strong); 2,53 (less strong) and 2,34 (less strong). The means of soybean aroma of tofu because of ield is shown on figure 10. 9

Figure 10. the means of soybean aroma using coagulant The means of soybean aroma is produced from coagulant calcium sulfate (G1) is 3,24 (strong) highest than citrid acid (G4) is 2,34 (less strong). It is caused by the amino aromatics acid which contributes on soybean aroma. Prolin amino acid, tryptophan are amino aromatics acid hold on the protein(kusnandar 2010). According to Subardjo et al. (1987), the use of calcium sulfate from producing tofu with sulfure smell if the heatinf os soybean milk is over done. Tofu which consist from acetic acid has the acid smell (Shurtleff and Aoyagi, 1979). 4. Sour taste The deviation into the taste will affect the acceptable value, after sour taste on tofu. The result is shown that the treatment of coagulant (G) is affected to sour acid, while soybean variety and both interactions did not give any affection. The means of sour taste from the coagulant of CaSO 4 (G1), acetic acid (G2), whey (G3) and citrid acid (G4) are 1,46; 1,99; 1,84; 2,24 (less sour). The means s shown in figure 11. Figure 11. the means of sour taste on the coagulant The means of sour taste is produced is produced from calcium sulfate (G1) is1,46 (less sour) lowest than citrid acid coagulant (G2) on 2,24 (less sour) and acetic acid (G2) on 1,99 (less sour). It is caused by citrid acid and acetic acid produced more sour on tofu than using whey. Ion H + on acetic acid (CH 3 COOH) contributes to the producing of acid sour. Acetic acid is included on weak acid with value of pka 4,8 and has the lowest acid level compared wih citrid acid with the value of pka 3,15 (deman, 1997). 10

Sour taste is correlated to ph coagulant, whey has 4,8 for coagulant while citrid acid has 4,5. The additioning of acid means decreasing ph followed by increasing naiknya ion concentration (H + ), the more lowest of ph means ion H + concentration the mour sour of taste (Trenggono dan Sutardi, 1989). 5. Bitter taste The result is shown that the soybean variety (V), coagulant (G) and both interactions did not give any affection on bitter taste of tofu. the means of bitterness of Rajabasa (V1), Tidar (V2), Mitani (V3) and import (V4) are 1,721; 1,746; 1,742; 1,892 (quite bitter). Bitter taste comes because of hidrolisis of protein reaction into amino acids which caused the bitter taste. According to Winarno (2002), proteins can hydolice into acid and alkali. Hydrolisis protein on food product will produce peptide which contains acids on hydrofobics characteristics, and peptide which produce the bitter taste. (Fitzgerald and Cunin 2006). The bitter taste on hydrolisate of soybean is based on peptide, the peptide molecule about 2400 3500 Da from hydrolics 11S glisin caused the bitter taste (Kim et al. 2003). Amino acid which contributes on bitter taste, is L-tyrosine, L-tryptophan, L-leucine, L-threonine, and L-phenylalanine. 6. Preference Preference level of product is based on sensory quality such as colour, aroma and tenderness. The prefer tofu is the good smell tofu (without rotten smell), not bitter, delicious and elastic texture. The result is shown that the treatment with the coagulant (G) is give real affection fro the preference, while the treatment soybean coagulant (V) and both interactions (VxG) didnot affect anything. The means of preference for coagulant CaSO 4 (G1), acetic acid (G2), whey (G3) and citrid acid (G4) are 2,77; 2,62; 3,09; dan 2,62 (quite prefer). The means of preference is shown on Figure 12. 11

Figure 12. the means of preference level on two coagulants The highest means of preference of whey coagulant (G1) is 3,09 (quite prefer), while the lowest means of coagulant of acetic acid (G2) and citrid acid (G3) are 2,62 (quite prefer). The tofu preference is caused by whey coagulant based on quality of sensory. Tofu with whey coagulant has the highest tenderness 3,30 (quite tender) if compared with citrid acid coagulant and acetic acid and has the bitter taste intensity, soybean aroma, and cour acid lower than calcium sulfate coagulant, citrid acid, and acetic acid and tofu which is produced with whey coagulant is preferred. The means of bitter taste, soybean aroma and sour taste for tofu with whey coagulant are 1,72 (less bitter), 2,53 (quite strong), and 1,84 (quite sour). CONCLUSSION 1. Rajabasa variety produce tofu with the highest rendement 196,53% (bb). Protein level from all variety about 65,85% (bk) into 73,54% (bk). Its mean that the local soybean variety used in this research could be the alternative raw material substituted of import soybean in producing tofu. 2. Tofu with whey clodding is preferred (with the score 3,09 = quite prefer) compared with citrid acid coagulant (with the score 2,62= quite prefer). Tofu preference whith whey coagulant supported with sensory quality quite tender (3,03), quite strong soybean aroma (score 2,53), quite sour taste (score 1,84) and quite bitter taste (skor 1,71) 3. The best Tofu is from the combination of Rajabasa and whey coagulant (V1G1). Tofu has the rendement 196,53% (bb), total protein (65,85% bk); hardness level (1,13 mm/g/s); ash (1,31% bk); water content (76,54%). Based on sensory, the white-gray (score 1,77); quite bitter taste (score 1,63); and quite sour taste (score 2,13),quite strong soybean aroma (score 2,51), quite tender texture (score 3,11) and quite prefer (score 2,98). REFERENCES Antarlina, S.S., J. S. Utomo, E. Ginting, and S. Nikkuni. 2002. Evaluation of Indonesian Soybean Varieties for Food Processing. J. Food Sci. 58 68 pp. Deman, J.M. 1997. Kimia Makanan. Institut Teknologi Bandung, Bandung. 550 hal. Kim MR, Kawamura Y, and C. H. Lee. 2003. Isolation and identification of bitter peptides of typtic hydrolysate of soybean 11S glycinin by reverse-phase high performance liquid chromatography. J Food Sci 68: 24162-422. 12

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