ASETILASI TEPUNG TALAS (Colocasia esculenta)MENGGUNAKAN ASAM ASETAT GLASIAL: PENGARUH KONSISTENSI LULUHAN DAN PH PADA SWELLING POWER DAN KELARUTAN

Tepung talas (Colocasia esculenta) telah digunakan dalam pembuatan produk makanan walaupun masih dalam ragam yang terbatas karena memiliki kelemahan sifat fisikokimianya. Asetilasi merupakan salah satu cara yang dilakukan untuk meningkatkan nilai swelling power (SP) dan kelarutan (WS) tepung. Tujuan dari penelitian ini adalah untuk mengkaji pengaruh konsistensi luluhan dan pH reaksi asetilasi tepung talas dengan asam asetat glasial terhadap SP dan WS. Sejumlah tepung talas didispersikan pada 225 mL air suling untuk memperoleh konsistensi luluhan (30% atau 20% b/v) dan diaduk selama 1 jam pada suhu 30oC. Selanjutnya, pH luluhan dijaga (pada 8,0 atau 7,0) dengan menambahkan larutan NaOH 3%. Sejumlah asam asetat glasial ditambahkan secara bertetes-tetes ke dalam luluhan sambil terus diaduk dan dijaga pHnya dengan menambahkan larutan NaOH 3%. Reaksi dibiarkan berlangsung selama waktu tertentu (30-120 menit), terhitung sejak seluruh asam asetat glasial masuk ke dalam luluhan. Untuk menghentikan reaksi, pH luluhan diubah menjadi 4,5 dengan menambahkan larutan HCl 0,5 N. Luluhan diendapkan dan dicuci dua kali dengan air suling (1:3 b/v) dan dilanjutkan dengan mencuci sekali dengan etanol 95% hingga bebas asam. Tepung terasetilasi yang diperoleh selanjutnya dikeringkan dalam oven listrik pada suhu 40oC untuk dianalisis nilai SP dan WSnya. Hasil penelitian menunjukkan bahwa pada konsistensi dan pH yang tinggi, nilai SP meningkat seiring dengan waktu. Walaupun nilai WS juga meningkat dengan berjalannya waktu, namun nilainya hampir tidak dipengaruhi oleh konsistensi luluhan. Pada lingkungan basa, nilai WS terus meningkat seiring dengan waktu reaksi, sedangkan pada lingkungan yang netral, nilai WS tetap setelah reaksi berlangsung 30 menit. Pada semua pH, nilai SP meningkat seiring dengan waktu reaksi, dan menurun pada waktu reaksi lebih dari 90 menit. Secara umum, semua tepung talas terasetilasi yang diperoleh pada penelitian ini mempunyai SP dan WS yang lebih tinggi dari tepung asalnya

Anthocyanidins and anthocyanins: colored pigments as food, pharmaceutical ingredients, and the potential health benefits

Anthocyanins are colored water-soluble pigments belonging to the phenolic group. The pigments are in glycosylated forms. Anthocyanins responsible for the colors, red, purple, and blue, are in fruits and vegetables. Berries, currants, grapes, and some tropical fruits have high anthocyanins content. Red to purplish blue-colored leafy vegetables, grains, roots, and tubers are the edible vegetables that contain a high level of anthocyanins. Among the anthocyanin pigments, cyanidin-3-glucoside is the major anthocyanin found in most of the plants. The colored anthocyanin pigments have been traditionally used as a natural food colorant. The color and stability of these pigments are influenced by pH, light, temperature, and structure. In acidic condition, anthocyanins appear as red but turn blue when the pH increases. Chromatography has been largely applied in extraction, separation, and quantification of anthocyanins. Besides the use of anthocyanidins and anthocyanins as natural dyes, these colored pigments are potential pharmaceutical ingredients that give various beneficial health effects. Scientific studies, such as cell culture studies, animal models, and human clinical trials, show that anthocyanidins and anthocyanins possess antioxidative and antimicrobial activities, improve visual and neurological health, and protect against various non-communicable diseases. These studies confer the health effects of anthocyanidins and anthocyanins, which are due to their potent antioxidant properties. Different mechanisms and pathways are involved in the protective effects, including free-radical scavenging pathway, cyclooxygenase pathway, mitogen-activated protein kinase pathway, and inflammatory cytokines signaling. Therefore, this review focuses on the role of anthocyanidins and anthocyanins as natural food colorants and their nutraceutical properties for health. Abbreviations: CVD: Cardiovascular disease VEGF: Vascular endothelial growth factor

Effects of solvent properties on the Soxhlet extraction of diterpenoid lactones from Andrographis paniculata leaves

A solid-liquid extraction was performed for the leaves of Andrographis paniculata in order to obtain two bioactive components, andrographolide and deoxyandrographolide. The problem of hydrolysable components and solvent removal difficulties in the conventional extraction led us to study further the effects of solvent properties on the conventional extraction using Soxhlet method in order to determine the best solvent or solvent mixture for high extraction yield of A. paniculata. This solvent selection is very important prior to alternative extraction methods since it can be used as a preextraction solvent, main solvent, or co-solvent. Based on the yield of extract and andrographolide and deoxyandrographolide content, methanol was found to be the best solvent

Influence of Temperature and Solid Concentration on the Physical Properties of Noni (Morinda citrifolia L.) Juice

The effect of temperature on the physical properties of fresh noni (Morinda citrifolia L.) juice with three different solid concentrations (5, 10, and 15°Brix) was investigated. The flow behaviour index (n) and thermal conductivity (k) were found to increase with the increase in temperature. On the other hand, the juice density (ρ) and consistency coefficient (K) were found to decrease with increasing temperature. The increase in solid concentration leads to increase juice density and consistency coefficient, but reduce flow behaviour index and thermal conductivity. The experimental data were then correlated with temperature and solid concentration using nonlinear regression equations or empirical models. It was found that the physical properties calculated using proposed equations agree well with the experimental data with coefficient of determinations (R2) ranged from 0.9897 to 0.9998

Comparison of sludge drying performance between microwave and convective drying

Drying of the sludge which reduces its volume and mass is an important aspect for sludge management. Experiments were carried out to compare the efficiency between microwave and convective drying. The results showed that microwave drying is more efficient than convective drying up to about 30 times. This is mainly caused by the different drying mechanisms. Microwave penetrate into total mass of sludge and cause water molecules to vibrate rapidly. Vibration of water molecules creates frictional heat and sludge heated volumetrically that avoids limitation of the poor heat conductivity of the material. It was clearly indicated by the core temperature profiles during drying. In microwave drying, the core temperature achieved 85C in less than one minute, while convective drying took about 500 minutes to achieve the same temperature. Higher power level of microwave gave higher drying rate. Hence the energy and time required for the drying process were reduced significantly

Potensi Jus Jeruk Nipis (Citrus Aurantifolia) Sebagai Bahan Pengkelat Dalam Proses Pemurnian Minyak Nilam (Patchouli Oil) Dengan Metode Kompleksometri

Lime Juice Potential as Chelating Agent in Patchouli Oil Purification Using Complexometry MethodPatchouli oil is one of the export commodities that have high economical value for Indonesia. In general, patchouli oil obtained from the hydrodistillation of patchouli leaves. Most industries are still using patchouli oil refiners made of ferrous metal. As this process takes place at high temperatures, water vapor will contain a lot of dissolved oxygen that is corrosive and causes iron to rust easily. The rust will dissolve in patchouli oil obtained and led to the resulting of dark oil and patchouli aroma becomes weaker. This situation led to a lower market price of patchouli oil. One method that can be used to purify is complexometry method with citric acid as the chelating agent. This certainly not familiar to farmers, therefore this study tried to simplify this process by finding a material that easily found by the common people. Orange juice contains citric acid which is enough to be used as a chelating agent, other than that lemon is a fruit that are easy to obtain in the community at abundant and the price is cheap. Therefore lemon juice was chosen as an alternative chelating material. The purpose of this study was to determine the influence of operating temperature, concentration of the chelating agent and the stirring time in the chelating process and find out the extent to which lemon juice can be used as a chelating agent. The treatments tested consisted of (1) the concentrations of citric acid, which are 0.5%, 1%, 2% and 4%; (2) Temperatures operation of the refinery. That are 30oC, 50 oC, and 75 oC, (3) agitation times, namely 15, 30, 45, 60, 75, and 90 minutes. Assessment of the results of purification is based on clarity, levels of Fe2+, and the content of the main components in patchouli oil refining results. Purification results showed that the increase in temperature causes the formation of complex ions faster to achieve equilibrium. The increase in the concentration of the citric acid led to complex ion formation process more quickly to achieve phase equilibrium. The best concentration was 1% combined with the use of temperature of 75 oC. Refined patchouli oil results have Fe2+ levels as low as 22.731 ppm. Based on the physical traits, the main constituent component content, and the Fe2+ content, refined patchouli oil meets the requirements of the Indonesian National Standards

Penentuan Jenis Solven Dan Ph Optimum Pada Analisis Senyawa Delphinidin Dalam Kelopak Bunga Rosela Dengan Metode Spektrofotometri Uv-vis

Rosela merupakan tanaman yang telah diketahui banyak mengandung senyawa antosianin sebagai antioksidan. Antioksidan merupakan senyawa penting dalam menjaga kesehatan tubuh karena berfungsi sebagai penangkap radikal bebas yang banyak terbentuk dalam tubuh. Antosianin pada kelopak bunga rosela berada dalam bentuk glukosida yang salah satunya adalah senyawa delphinidin. Kandungan senyawa delphinidin yang terkandung dalam kelopak bunga rosela dapat dianalisis kadarnya menggunakan metode Spektrofotometri UV-Vis. Prinsip dasar Spektrofotometri UV-Vis adalah analisis yang didasarkan pada pengukuran serapan sinar monokromatis oleh suatu laju larutan berwarna pada panjang gelombang spesifik dengan menggunakan monokromator prisma atau kisi difraksi dengan detektor fototube. Kelarutan dari delphinidin antara lain larut dalam akuades, metanol dan etanol pada berbagai suhu berkisar antara (298 sampai 343) K di bawah tekanan atmosfer. Tujuan dari penelitian ini adalah untuk mengetahui jenis solven yang paling sesuai sebagai pelarut delphinidin dan pH yang paling optimum. Pada penelitian ini digunakan variabel tetap yaitu bunga rosela dan suhu percobaan : 30oC. Sedangkan variabel berubahnya yaitu jenis solven (akuades, metanol, dan etanol) serta pH dengan variasi pH 4; 4,5; 5; 5,5; 6. Hasil percobaan, menunjukkan bahwa metanol merupakan solven yang paling sesuai untuk melarutkan senyawa delphinidin, sedangkan pH yang paling optimum untuk analisis senyawa delphinidin dengan metode Spektrofotometri UV-Vis adalah 4,5