Eni Harmayani

Characterization of glucomannan from Amorphophallus oncophyllus and its prebiotic activity in vivo.

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.

Immunomodulatory Activity of Octenyl Succinic Anhydride Modified Porang (Amorphophallus oncophyllus) Glucomannan on Mouse Macrophage-Like J774.1 Cells and Mouse Primary Peritoneal Macrophages

Porang is a local plant of Indonesia, which has a high content of glucomannan. In this study, porang glucomannan (PG) was esterified with octenyl succinic anhydride (OSA) to enhance emulsion properties to be widely used in food industry. OSA-modified PG (OSA-PG) enhanced the phagocytosis activity of macrophage-like J774.1 cells and mouse peritoneal macrophages. In addition, OSA-PG increased the production of IL-6 and TNF-α by enhancing their gene expression. Immunoblot analysis displayed that OSA-PG tended to activate both nuclear factor-κB and mitogen-activated protein kinase cascades. Treatment of OSA-PG with polymyxin B revealed that cytokine production induced by OSA-PG was not caused by endotoxin contamination. Our findings also indicated that OSA-PG activates macrophages through not only Toll-like receptor (TLR) 4, but another receptor. Overall findings suggested that OSA-PG has a potential as an immunomodulatory food factor by stimulating macrophages.

Characteristics of glucomannan isolated from fresh tuber of Porang (Amorphophallus muelleri Blume)

Porang is a potential source of glucomannan. This research objective was to find a direct glucomannan isolation method from fresh porang corm to produce high purity glucomannan. Two isolation methods were performed. In first method, sample was water dissolved using Al2(SO4)3 as flocculant for 15 (AA15) or 30 (AA30) minutes with purification. In second method, sample was repeatedly milled using ethanol as solvent and filtered for 5 (EtOH5) or 7 (EtOH7) times without purification. The characteristics of obtained glucomannan were compared to those of commercial porang flour (CPF) and purified konjac glucomannan (PKG). High purity (90.98%), viscosity (27,940 cps) and transparency (57.74%) of amorphous glucomannan were isolated by EtOH7. Ash and protein level significantly reduced to 0.57% and 0.31%, respectively, with no starch content. Water holding capacity (WHC) of EtOH7 glucomannan significantly enhanced, whereas its solubility was lower than those of PKG due to its ungrounded native granular form.

Immunostimulatory activity of snake fruit (Salacca edulis Reinw.) cultivar Pondoh Hitam extract on the activation of macrophages in vitro

Snake fruit (Salacca edulis Reinw) cultivar Pondoh Hitam is a tropical fruit produced in Indonesia. It is consumed freshly or processed and believed as the most delicious snake fruit cultivar. Snake fruit flesh contains high polisaccharides such as pectin and dietary fiber. Therefore, snake fruit is a potential immunostimulator candidates but the immunological effect of snake fruit flesh has not been reported. In the present study, immunostimulatory activity of snake fruit flesh extract (SFFE) on macrophages activation was evaluated.SFFE was prepared by extracting from snake fruit flesh with water, methanol 70%, and ethanol 70% for 15 h at 4°C. Then obtained SFFE was used to stimulated cytokine production in vitro using J774.1 cell line. The extract giving strongest stimulation was sellected for in vivo assay to stimulate cytokines production and gene expression using peritoneal macrophage (P-mac) of BALB/c mice.The results showed that SFFE exhibited immunostimulatory activities. Immunostimulatory activit...

Kinetic oxidation of protein and fat in snapper (Lutjanus sp) fillet during storage

Fillet of snapper (Lutjanus sp) contains oil and proteins that are easily oxidized during storage. The kinetic model can determine oxidation reaction rate. The objective of this research was to evaluate kinetic oxidation reaction of both oil and protein in fillet of snapper. Fillet of snapper was stored at 0, 10, 20, 30 and 40 °C. The reaction rate constant (k) and activation energy were further determined. Results showed that the value of k increased from 0.28 mg/kg per day to 10.27 mg/kg per day at temperatures from 0 to 40 °C for the peroxide value. For the acid value, TBA value and carbonyl value were rate constants 0.05 mg/kg per day becomes 3.56, mg/kg per day, 0.29 mg/kg per day to 8.91 mg/kg per day, and 0.38 nmol/gr per day becomes 12.06 nmol/gr per day, respectively. The activation energy (Ea) of oxidation reaction peroxide value 65.69 kJ/ mol.K, while the acid value, the TBA value and carbonyl value, 84.80 K/mol.K, 62.99 K/mol.K and 63.64 K/mol.K, respectively. Fish fillet started to deteriorat...