Efri Mardawati

Non-starch contents affect the susceptibility of banana starch and flour to ozonation

AbstractThe properties of native flour and starch were compared and the changes in their properties were evaluated following ozonation at 100 and 200xa0ppm. X-ray diffraction analysis indicated that crystallinity index of both ozonated banana flour and starch decreased by 1.6%, B-type pattern of native banana flour and starch did not change following ozonation. The presence of higher amounts of non-starch components decreased the sensitivity of flour to the oxidation, as indicated by the lower carboxyl content compared to that of starch. The flour also required higher ozone concentration than starch to alter its properties, particularly pasting properties. Ozonation tended to increase peak, hold and final viscosity of both. A prominent change in the freeze thaw stability of both flour and starch following ozonation was the most encouraging result. Ozonation also improved the solubility of flour which was important to reduce cooking loss when applied in a range of food products. The solubility improvement in the flour might be linked to the formation of new binding following ozonation presumably involving protein present in the granule surface.n

KINETIC STUDY OF OIL PALM EMPTY FRUIT BUNCH ENZYMATIC HYDROLYSIS

Asxa0 lignocellulosic biomass, Oil Palm Empty Fruit Bunch (OPEFB) can be used as the source of xylose that can be further utilized as the raw material for xylitol production. The processing of OPEFB to xylose comprises of pretreatment and hydrolysis that can be performed enzymatically. This process offers the advantages of moderate operation conditions and more environment ally friendly. This article describes the kinetic study of enzymatic hydrolysis process of OPEFB for producing xylose using self-prepared and commercial xylanase enzymes. Despite the possible mass transfer limitation, the Michaelis Menten kinetics was hypothesized. The results indicated that the reaction at pH 5 and 60°C followed the Michaelis Menten kinetics, xa0with V m of 0.84 g/L-h and K m of 48.5 g/L xa0for the commercial enzyme, and V m of 0,38 g/L-h and K m of 0,37 g/L for the self-prepared enzyme. The reaction is affected by temperature, with E a of 8.6 kcal/gmol. The performance of self-prepared xylanase enzyme was not yet as good as the commercial enzyme, Cellic Htec 2. Keywords: enzymatic hydrolysis; kinetics parameter; OPEFB ; xylanase; xylose

The studies of Leaf extract of Ficus lyrata Warb on antimicrobial activities

The extract of leaf Ficus lyrata Warb has potential as antimicrobial agents, because it contains bioactive components such as polyphenols, tannin and triterpenoid that can inhibit the growth of microbials. The maceration extraction method was used in this study using water as solvent agents, to extract secunder metabolit. The aim of reaserch is to compare the antimicrobial activity between fresh and encapsulation leaf extract. The activity were tested to 2 of bacterias, i.e.; Eschericia coli, dan Bacillus Subtilis. Experimental design of descriptive analysis was used in this research. The results indicated that formation of inhibited zone in the tested media which proved by KirbyBauer testing method are different between fresh and encapsulation leaf extract. Antimicrobial effectiveness of Fresh extract of F. lyrata Warb leaf of Bacillus Subtilis is 6.66 mm and Escherichia Coli is 4.33, on the other hand for encapsulated extract of Bacillus Subtilis is 2,03 mm and Escherichia Coli 3,44 mm. This extract has a potential as natural antimicrobials agent for animals

COMPARATIVE STUDY OF GLUCOSE AND XYLOSE PRODUCTION IN ENZYMATIC HYDROLYSIS RESULT BY BATCH AND FED BATCH METHOD

Xylose is a five carbon chain monosaccharide that can be used as a substrate in the fermentation of low-calorie xylitol. While glucose is a six carbon chain monosaccharide that can be processed into glucose syrup as a more stable natural sweetener in the food processing industry. Xylose is xylan monomer produced from hydrolysis of hemicellulose from plants or biomass woody waste.xa0 While glucose is the result which is also produced in xylan hydrolysis by xylanase enzymatic hydrolysys. In the search for the source of hemicellulose, oil palm empty fruit bunch (OPEFB) as a solid waste from crude palm oil processing is a source that can be utilized in this research. OPEFB waste is abundant by the increasing world demand for vegetable oil. Considering the OPEFB enzymatic hydrolysis was a hetrogenous solid-liquid reaction, fed batch feeding of substrate was thought to improve the reaction performance. Hydrolysis experiments were performed at temperature 500C, pH 5 and for 96 hours hydrolysys time with substrate concentration at 15% and enzyme dose of 1%. The result showed that the feed-batch hydrolysis configuration provided higher yield of xylose and glucose than batch configuration but unsignificant. Keywords : Enzymatic Hydrolysis, Fed-batch, glucose, Xylan, Xylanase, Xylose.

Fractal Dimension Analysis of Texture Formation of Whey Protein-Based Foods

Whey protein in the form of isolate or concentrate is widely used in food industries due to its functionality to form gel under certain condition and its nutritive value. Controlling or manipulating the formation of gel aggregates is used often to evaluate food texture. Many researchers made use of fractal analysis that provides the quantitative data (i.e., fractal dimension) for fundamentally and rationally analyzing and designing whey protein-based food texture. This quantitative analysis is also done to better understand how the texture of whey protein-based food is formed. Two methods for fractal analysis were discussed in this review: image analysis (microscopy) and rheology. These methods, however, have several limitations which greatly affect the accuracy of both fractal dimension values and types of aggregation obtained. This review therefore also discussed problem encountered and ways to reduce the potential errors during fractal analysis of each method.

Pengaruh Konsentrasi Sel Awal dan pH Medium pada Fermentasi Xilitol dari Hidrolisat Tandan Kosong Kelapa Sawit

Abstrak Limbah tandan kosong kelapa sawit (TKKS) dapat dimanfaatkan secara optimal. Kandungan yang cukup besar dari TKKS adalah hemiselulosa. Hemiselulosa dapat dihidrolisis menjadi xilosa, dan xilosa dapat difermentasi menjadi xilitol. Tujuan dari penelitian ini adalah mengetahui pengaruh konsentrasi sel khamir awal dan pH medium pada proses fermentasi xilitol dari hidrolisat TKKS. Metode penelitian yang digunakan adalah metode eksperimental dan dianalisis secara deskriptif terhadap variasi konsentrasi sel khamir awal dan pH. Analisis dilakukan dalam 9 perlakuan dengan 2 kali ulangan. Hasil penelitian menunjukkan bahwa xilitol hanya terbentuk pada perlakuan pH 5 dengan konsentrasi sel awal 10 8 sel/mL pada jam ke 24 dan ke 96. Pada jam ke 24 dihasilkan xilitol sebesar 0,047 g/L dan perolehan xilitol terhadap xilosa 0,045 g/g. Pada jam ke 96 sebesar 0,138 g/L dan perolehan xilitol terhadap xilosa 0,094 g/g. Kata kunci: konsentrasi sel, pH, tandan kosong kelapa sawit, xilitol Abstract Waste of oil palm empty fruit bunches (OPEFB) can utilize optimally. The essential content of OPEFB was hemicellulose. Hemicellulose can be hydrolyzed into xylose, and the xylose fermented into xylitol. The purpose of this study is to determine the effect of yeast initial cell concentration and medium pH on xylitol fermentation process from OPEFB hydrolysate. The research method used was an experimental method and analyzed descriptively to the variation of yeast initial cell concentration and pH. The analysis was performed in 9 treatments with two replications. The results showed that xylitol was only formed at the treatment with pH 5 and an initial cell concentration of 10 8 cells/mL. At 24 hours xylitol was produced by 0.0474 g/L, and xylitol result to the xylose was 0.454 g/g. At 96 hours xylitol was produced 0.1381 g/L and xylitol yield to the xylose was 0.0938 g/g. Keywords: cell concentrations, pH, oil palm empty fruit bunches, xylitol

Optimization of moistening solution concentration on xylanase activity in solid state fermentation from oil palm empty fruit bunches

Xylanase is an enzyme used in the industrial world, including food industry. Xylanase can be utilized as a 1,4-β-xylosidic endo-hydrolysis catalyst of xylanase, a hemicellulose component for obtaining a xylose monomer. This study aims to determine the optimum concentration of the fermentation medium using Response Surface Method (RSM) in the production of xylanase enzyme from oil palm empty fruit bunches (OPEFB) through solid state fermentation process. The variables varied in this study used factor A (ammonium sulphate concentration 1.0-2.0 g/L), B (concentration of potassium dihydrogen phosphate 1.5-2.5 g/L) and C (urea concentration 0.2 – 0.5 g/L). The data was analysed by using Design Expert version 10.0.1.0 especially CCD with total 17 running including 3 times replicated of canter point. Trichoderma viride was used for the process production of xylanase enzyme. The ratio between substrate and moistening solution used was 0.63 g / mL with temperature of 32.80C, 60 h incubation time. The analysis of enzyme activity was done by DNS method with 1% xylan as substrate. Analysis of protein content in enzyme was done by Bradford method. The optimum of moistening solution concentration in this fermentation was obtained. They are, the ammonium sulphate concentration of 1.5 g/L, potassium dihydrogen phosphate 2.0 g/L and urea 0.35 g/L with activity of 684.70 U/mL, specific activity enzyme xylanase 6261.58 U/mg, protein content 0.1093 U/mg, the model was validated using experiment design with perfect reliability value 0.96.

Production of xylitol from corn cob hydrolysate through acid and enzymatic hydrolysis by yeast

The abundance of corn production in Indonesia offers the potential for its application as the raw material for biorefinery process. The hemicellulose content in corn cobs can be considered to be used as a raw material for xylitol production. The purpose of this research was to study the effect of hydrolysis methods for xylitol production and the effect of the hydrolyzed corn cobs to produce xylitol through fermentation. Hydrolysis methods that would be evaluated were acid and enzymatic hydrolysis. The result showed that the xylitol yield of fermented solution using enzymatic hydrolysates was 0.216 g-xylitol/g-xylose, which was higher than the one that used acid hydrolysates, which was 0.100 g-xylitol/g-xylose. Moreover, the specific growth rate of biomass in fermentation using enzymatic hydrolysates was also higher than the one that used acid hydrolysates, 0.039/h compared to 0.0056/h.

The Effect of Freeze Dried Lactobacillus acidophilus Culture Concentration an Microbiological and Organoleptic Characteristics of Synbiotic Biscuits Made From Sorghum Flour and Soybean Flour

Sorghum flour and soybean flour can be processed as the main raw material in the manufacture of functional food product, namely synbiotic biscuits with addition of freeze dried Lactobacillus acidophilus culture. The purpose of study was to determine the concentration of freeze dried L. acidophilus culture on synbiotic biscuits made from sorghum flour and soybean flour with the best microbiological and organoleptic characteristics. The research method used was randomized block design with 4 treatments and 3 replications. The treatments were the freeze dried L. acidophilus concentration 8%, 10%, 12%, and 14%. The results of study showed that the addition of freeze dried culture of L. acidophilus to the synbiotic biscuits made from sorghum flour and soybean flour gave a significant different effect on total L. acidophilus probiotic bacteria, aroma and yield, but did not give a significant effect on the color, taste and texture preferences. Synbiotic biscuits made from sorghum flour and soybean flour with the addition of freeze dried L. acidophilus concentration of 14% (w/w) were selected as the synbiotic biscuit with the best characteristic with total bacterial content of probiotics 10,67 Log CFU g-1, were perceived a bit like to like by the panelist and the obtained yield was 92,14%.