ABSTRAK Pati garut, sebagaimana jenis pati alami lainnya diketahui memiliki kelemahan sifat fisik dan kimia yang menyebabkan penggunaan pati garut pada industri pangan relatif terbatas. Untuk itu maka perlu dilakukan perbaikan sifat fisik dan kimianya dengan cara melakukan modifikasi pati garut. Selain itu modifikasi pati juga dapat memberikan efek fisiologis yang menyehatkan bagi tubuh. Penelitian ini dilakukan dengan tujuan untuk mendapatkan metode sintesis pati-garut butirat. Penelitian dilakukan dengan menggunakan Rancangan Acak Lengkap sederhana dengan faktor teknik pencucian pati-garut butirat yang meliputi pencucian dengan menggunakan aquades, dengan mengggunakan aquades dan diikuti dengan penggunaan etanol dan dengan menggunakan aquades dan etanol dan kemudian diakhiri dengan proses sentrifuse. Parameter analisis meliputi aroma pati-garut butirat, % butiril, derajat substitusi dan profil FTIR pati-garut butirat Hasil penelitian menunjukkan bahwa proses pencucian dengan menggunakan aquades sebanyak dua kali dan dilanjutkan pencucian dengan menggunakan etanol yang diikuti dengan proses sentrifuse pada 3000 rpm selama 15 menit diketahui cukup efektif untuk menghilangkan aroma butirat pada pati-garut butirat, akan tetapi tidak berpengaruh terhadap % butiril dan derajat substitusi pati-garut butirat. Hasil analisis dengan menggunakan Fourier transform infrared spectrophotometer FTIR menunjukkan bahwa pada pati-garut butirat terbentuk lembah baru pada panjang gelombang 1740 cm-1 dan berbeda dengan pati alami. Keyword pati-garut butirat, gugus butiril, derajat substitusi, FTIR PENDAHULUAN Umbi garut Marantha arundinacea Linn yang tumbuh di wilayah iklim tropis, memiliki potensi yang besar sebagai bahan pangan. Produksi umbi garut Discover the world's research25+ million members160+ million publication billion citationsJoin for free A preview of the PDF is not available ResearchGate has not been able to resolve any citations for this Chem. 816735-740 Acetylation of high-amylose 70% maize starch to high degree of substitution DS was studied by reacting starch with acetic anhydride using 50% aqueous NaOH as the catalyst. DS increased with increasing reaction times and increasing ratios of acetic anhydride to starch. Reac- tion efficiency RE increased with longer reaction times and decreased with increases in the ratios of acetic anhydride to starch for extended reaction times. Increasing the amount of NaOH increased both DS and RE. A series of starch acetates with DS values of were prepared and their crystalline structures, chemical structures, thermal stability, and morphological properties were investigated. After acetylation, and as DS increased from to the crystalline structures of starch steadily disappeared. The carbonyl group's peak at 1,740 cm-1 appeared in the FTIR spectra. The intensity of this peak increased with a decrease in the peak intensity of the hydroxyl groups at 3,000-3,600 cm-1, indicating that the hydroxyl groups on starch were replaced by the acetyl groups. Thermal stability of starch acetates increased. The smooth surface of the starch granules became rough with acetylation. Further acetylation led to the loss of the starch granules and the formation of beehive- and fibrous- like Santayanon Jatuphorn WootthikanokkhanChemical modification of the cassava starch was conducted through acylation by using propionic anhydride as an esterifying reagent. The reaction was carried out in the presence of a pyridine catalyst and the effects of reaction variables such as the anhydride content, reaction time and reaction temperature on the degree of acylation were investigated. Results from Fourier transform infrared spectroscopy suggested that the hydroxyl groups in the starch molecules were converted into ester groups, accompanied by an increase in water stability of the starch. The propionyl content was found to be non-linearly dependent with the reaction variables. Scanning electron micrographs of the modified starch-blended polyurethane showed a better interfacial adhesion than the normal starch-blended polyurethane. However, results from the soil burial test showed that the modified starch experienced a slower biodegradation than the normal Betancur Luis Chel GuerreroThe physicochemical and functional properties of Canavalia ensiformis starch hydrolyzed with HCl were studied. The factors analyzed were HCl concentration temperature 45−55°C, and reaction time 3−6 h. Alkali number and viscosity were the response variables. A 23 factorial design with five replicates of the central trial was used. Hydrolyzed starch with HCl at 55 °C for 6 h reached an alkali number of The hydrolysis reaction did not present important changes on the starch chemical composition except for an ash content reduction. A comparison between these hydrolyzed starches and the native starches showed a viscosity cP, swelling power g of water/g of starch, and retrogradation reduction. A solubility increment was found. Gelatinization temperature did not vary 76−82 °C. Keywords Canavalia; starch; acid hydrolysis; functional propertiesGranular and crystalline structure of starch citrates from normal, high amylose and waxy corn starch were characterized using scanning electron microscopy SEM, optical microscopy, X-ray diffraction and Fourier transform infrared spectroscopy FT-IR in this study. SEM showed that citric acid treatment induced changes in the morphology of starch granules. The granule structure of starch citrates was not collapsed or destroyed even after heating. Normal and high amylose corn starch citrates maintained birefringence but lost it upon heating at 100 °C for 30 min. However, waxy corn starch citrate showed no birefringence, even before heating. Starch citrates showed different X-ray diffraction patterns before and after heating. A new peak at 1724 cm−1 ester bond was observed in FT-IR for all starch citrates before and after heating, indicating starch citrates were heat-stable. After the deconvolution of spectra, the intensity ratio of 1016 cm−1/1045 cm−1 was used to calculate the ratio of amorphous to crystalline phase in the starch citrates. The ratio of 1016 cm−1/1045 cm−1 increased with an increase in the degree of substitution. Olayide LawalStarch was isolated from finger millet Eleusine coracana and it was etherified with propylene oxide to produce hydroxypropylated derivative. The specific specie used in this study is African finger millet known as jeero. The yield of starch obtained from finger millet on dry weight basis was Progressive increases in molar substitution MS were observed as the volume of propylene oxide added to the reaction medium increased. The X-ray pattern of native finger millet starch conforms to the A’ diffraction pattern characteristics of cereal starches. Prominent peaks were observed at around 2θ=15°, 17°, 18° and 23° and weaker peaks at around 2θ=20° and 26°. No pronounced differences were observed between the diffractograms of native starch and the hydroxypropyl derivatives. Hydroxypropylation improved the free swelling capacities of the native starch at all temperatures studied 30–90 °C. Turbidity of unmodified finger millet starch paste increased progressively as the days of storage increased. Turbidity reduced remarkably after hydroxypropylation and reduction in turbidity was observed as the MS of the modified starches increased. Hydroxypropylation reduced pasting temperature, increased peak viscosity but reduced setback value. In addition, hydroxypropylation reduced percentage syneresis of the unmodified starch. Retrogradation properties monitored with differential scanning calorimetry reveals that starch retrogradation reduced reasonably after hydroxypropylation. Carbon 13 NMR spectroscopy reveals that hydroxypropylation took place predominantly on carbon 6 on the anhydroglucose unit AGU.The physicochemical, morphological, thermal and rheological properties of acetylated corn and potato starches, prepared using acetic anhydride at different levels 4–12 g, were compared. Corn starch showed lower acetyl % and degree of substitution DS than potato starches under similar experimental conditions. The acetylated corn and potato starches showed slightly higher amylose contents than their counterpart native starches. Acetylated starches showed higher swelling power, solubility and light transmittance than native starches, which subsequently increased with the increase in acetic anhydride concentration in the reaction medium. The extent of change in these properties, as a function of acetic anhydride concentration, was significantly higher in potato than corn starches. Both potato and corn starches were fused after conversion to acetylated starches; however, this effect was more pronounced in the former under similar reaction conditions. The syneresis % of both acetylated and native starches increased during storage at 4 °C; however, the increase was less pronounced in acetylated physical properties of octenyl succinic anhydride OSA starches prepared from rice, wheat, and potato starches were studied. Rice and wheat OSA starches had significantly higher peak viscosity PV, hot paste viscosity HPV, and cool paste viscosity CPV, but potato OSA starch had only significantly higher CPV, relative to the native starch. The gel hardness was higher with lower degree of substitution DS but lower with higher DS OSA compared to native starch. The swelling volumes SV of rice and wheat OSA starches were significantly higher compared to native starch, but the SV of potato OSA starch was slightly lower at high DS. The gelatinization temperature GT of rice OSA starches was sharply lower at low DS; for wheat OSA starch it was slightly lower even at high DS, but potato OSA starches had higher GT than the native starch. The enthalpy of all the OSA starches decreased gradually with increased DS. This study showed that the magnitude of changes in physical properties of OSA-modified starches depends not only on their DS but also on the botanical origin of the native ditunjukkan pada Gambar 2 dan 3. Berdasarkan gambar tersebut diketahui bahwa profil FT-IR pada rentangan panjang gelombang antaraFt-Ir ProfilPatiProfil FT-IR pati garut dan pati-garut butirat dengan DS 0,053; 0,120 dan 0,187 ditunjukkan pada Gambar 2 dan 3. Berdasarkan gambar tersebut diketahui bahwa profil FT-IR pada rentangan panjang gelombang antara 4000-500 cm -1Lembah baru pada profil FT-IR pati-garut butirat adalah pada panjang gelombang 1740,64 cm -1 dan berkurangnya lembah pada panjang gelombang 1640,29 cm -1 , yang menunjukkan keberadaan ikatan C═O dari gugus butirilR SantayanonJ Wootthikanokkhandiketahui bahwa pada pati alami terdapat 14 tujuh lembah, sedangkan pada patigarut butirat terdapat 18 lembah. Profil tersebut menunjukkan pola yang serupa dengan jenis pati alami dan pati asetat dari beberapa jenis pati seperti dari pati jagung, pati kentang dan pati beras Santayanon, R. and J. Wootthikanokkhan, 2002. Lembah baru pada profil FT-IR pati-garut butirat adalah pada panjang gelombang 1740,64 cm -1 dan berkurangnya lembah pada panjang gelombang 1640,29 cm -1, yang menunjukkan keberadaan ikatan C═O dari gugus butiril. Gambar 2. Profil FTIR pati garut alamiAcetylated, propionylated or butyrylated starches raise large bowel short-chain fatty acids preferentially when fed to ratsG AnnisonR J IllmanD L TopingAnnison, G., Illman and Toping. 2003. Acetylated, propionylated or butyrylated starches raise large bowel short-chain fatty acids preferentially when fed to rats. J. Nutr. 1333523-3528.