Setyaningsih, W., Saputro, I. E., Palma, M., Barroso, C. G.

A new microwave-assisted extraction (MAE) method has been investigated for the extraction of phenolic compounds from rice grains. The experimental conditions studied included temperature (125-175 °C), microwave power (500-1000 W), time (5-15 min), solvent (10-90% EtOAc in MeOH) and solvent-to-sample ratio (10:1 to 20:1). The extraction variables were optimised by the response surface methodology. Extraction temperature and solvent were found to have a highly significant effect on the response value (p < 0.0005) and the extraction time also had a significant effect (p < 0.05). The optimised MAE conditions were as follows: extraction temperature 185 °C, microwave power 1000 W, extraction time 20 min, solvent 100% MeOH, and solvent-to-sample ratio 10:1. The developed method had a high precision (in terms of CV: 5.3% for repeatability and 5.5% for intermediate precision). Finally, the new method was applied to real samples in order to investigate the presence of phenolic compounds in a wide variety of rice grains. read more

Millati, R., Isroi, Ishola, M. M., Syamsiah, S., Cahyanto, M. N., Niklasson, C., Taherzadeh, M. J. 

Oil palm empty fruit bunch (OPEFB) was pretreated using white-rot fungus Pleurotus floridanus, phosphoric acid or their combination, and the results were evaluated based on the biomass components, and its structural and morphological changes. The carbohydrate losses after fungal, phosphoric acid, and fungal followed by phosphoric acid pretreatments were 7.89%, 35.65%, and 33.77%, respectively. The pretreatments changed the hydrogen bonds of cellulose and linkages between lignin and carbohydrate, which is associated with crystallinity of cellulose of OPEFB. Lateral Order Index (LOI) of OPEFB with no pretreatment, with fungal, phosphoric acid, and fungal followed by phosphoric acid pretreatments were 2.77, 1.42, 0.67, and 0.60, respectively. Phosphoric acid pretreatment showed morphological changes of OPEFB, indicated by the damage of fibre structure into smaller particle size. The fungal-, phosphoric acid-, and fungal followed by phosphoric acid pretreatments have improved the digestibility of OPEFB’s cellulose by 4, 6.3, and 7.4 folds, respectively. read more

Cahyanto, M. N., Isroi, Millati, R.,  Syamsiah, S., Niklasson, C., Lundquist, K., Taherzadeh, M. J.

Lignocellulosic carbohydrates, i.e. cellulose and hemicellulose, have abundant potential as feedstock for production of biofuels and chemicals. However, these carbohydrates are generally infiltrated by lignin. Breakdown of the lignin barrier will alter lignocelluloses structures and make the carbohydrates accessible for more efficient bioconversion. White-rot fungi produce ligninolytic enzymes (lignin peroxidase, manganese peroxidase, and laccase) and efficiently mineralise lignin into CO ₂ and H ₂O. Biological pretreatment of lignocelluloses using white-rot fungi has been used for decades for ruminant feed, enzymatic hydrolysis, and biopulping. Application of white-rot fungi capabilities can offer environmentally friendly processes for utilising lignocelluloses over physical or chemical pretreatment. This paper reviews white-rot fungi, ligninolytic enzymes, the effect of biological pretreatment on biomass characteristics, and factors affecting biological pretreatment. Application of biological pretreatment for enzymatic hydrolysis, biofuels (bioethanol, biogas and pyrolysis), biopulping, biobleaching, animal feed, and enzymes production are also discussed. read more

Harmayani, E., Aprilia, V., Marsono, Y.

Porang (Amorphophallus oncophyllus) is local perennial plant rich in glucomannan. The aim of this study was to extract and characterize glucomannan from porang tuber and to evaluate its potency as prebiotic in vivo. The research consisted of the following steps, i.e. extraction of glucomannan, evaluation of its physico-chemical properties, and in vivo study. Extraction was done by immersing porang fluor with water at 55 °C followed by coagulating glucomannan using ethanol. Solubility, water holding capacity, viscosity, degree of acetylation, degree of polymerization (DP), and purity of the glucomannan were evaluated. In vivo study was done using thirty-two Wistar rats which were divided into four groups. Each group was treated for 14 days with standard AIN 93 (standard), porang glucomannan, commercial konjac glucomannan, and inulin diet as source of fiber. Bacterial population and chemical properties of digesta were analyzed after intervention. The results of the study indicated that the yield of glucomannan from porang flour was 18.05% with 92.69% purity. Compared to commercial glucomannan, porang glucomannan showed higher solubility (86.4%) and degree of acetylation (13.7%), but lower viscosity (5400 cps), WHC (34.5 g/g), and DP (9.4). Diet supplemented with porang glucomannan inhibited the growth of Escherichia coli, enhanced the production of total SCFA, and reduced pH value of cecal content. The study indicated that glucomannan from porang may be used as functional food. read more

Rachma Wikandari, Ria Millati, Patrik Lennartsson, Eni Harmayani, Mohammad J. Taherzadeh

Mixed fungal cultures used for making tempe, a fermented soy bean food, were screened for biomass conversion. Thirty-two zygomycetes strains from two tempe cultures were isolated and identified as Rhizopus, Mucor, Rhizomucor, and Absidia species based upon morphology. The dry weight biomass of these strains contained 49% to 63% protein and 10-24% chitosan. The strains with the best growth performance were selected and registered at Culture Collection of Gothenburg University as Rhizomucor CCUG 61146 and Rhizomucor CCUG 61147. These strains were able to grow both aerobically and microaerobically. Their ethanol yields were 0.38-0.47, 0.19-0.22, and 0.31-0.38 g/g on glucose, xylose, and a mix sugars consisting of cellobiose, glucose, xylose, arabinose, galactose, and mannose, respectively. The biomass yield of the strains varied between 65 and 140 mg dry weight/g glucose read more

Umumnya, masyarakat masa kini hanya familiar dengan minuman fermentasi berupa yogurt, maupun kefir saja. Padahal, ada beberapa alternatif minuman fermentasi yang dapat menjadi pilihan untuk konsumsi sehari-hari, salah satunya adalah kombucha tea. Kombucha tea sendiri merupakan produk minuman fermentasi larutan teh, serta gula dengan menggunakan starter mikroba kombucha, yaitu Acetobacter xylinum, serta beberapa jenis khamir […]

Roti merupakan salah satu alternatif pengganti nasi. Pada umumnya roti dibuat dari tepung terigu, air, ragi, garam, gula, lemak, susu bubuk dan pengemulsi. Ada banyak faktor penentu kualitas roti salah satunya proses fermentasi. Proses fermentasi terjadi karena adanya penambahan ragi/yeast pada roti. Ragi sendiri merupakan mikro-organisme yang berperan dalam pengembangan roti seperti Saccharomyces cereviciae. Pada pembuatan […]

Dadih merupakan produk susu fermentasi yang berasal dari Minangkabau, Sumatra Barat. Umumnya dadih dapat dikonsumsi secara langsung maupun bersama nasi. Sekilas makanan ini tampak asing bagi beberapa masyarakat Indonesia. Dadih sendiri berasal dari susu kerbau yang dimasukkan ke dalam tabung bambu dan ditutup menggunakan daun pisang. Kemudian didiamkan selama satu hari dengan suhu ruang hingga […]

Makanan fermentasi terus mengalami perkembangan hingga menjadikannya sebagai trend gaya hidup sehat masa kini. Tak heran jika makanan ini digemari oleh masyarakat diberbagai belahan dunia. Setiap negara tentunya memiliki jenis makanan fermentasi dengai ciri khasnya tersendiri. Perbedaan tersebut biasanya bergantung pada bahan pangan yang ada di masing-masing negara. Berikut ini merupakan beberapa makanan fermentasai di […]

Tempe sudah tidak asing bagi masyarakat Indonesia. Makanan tradisional ini sudah dikenal sejak berabad-abad lalu, terutama oleh masyarakat Jawa. Teknik pembuatan tempe lalu menyebar ke seluruh Indonesia, seiring dengan penyebaran masyarakat Jawa yang bermigrasi ke seluruh penjuru Tanah Air. Tempe sendiri dibuat dari biji kedelai yang difermentasi menggunakan beberapa jenis kapang Rhizopus, seperti Rhizopus oligosporus, Rh. oryzae, Rh. stolonifer atau Rh. arrhizus. Kapang yang tumbuh pada kedelai akan […]