Effects of steeping variables and substrate mesh size on starch yield extracted from oil palm trunk

Abstract

Large area of oil palm plantation in Malaysia generated significant amount of oil palm biomass such as oil palm trunk. This material is assumed to possess multipurpose utilization, including a starch-producing raw material. This work is aimed to determine the total extractable starch from oil palm trunk (OPT) using commercial steeping methods. The extraction methods used in this study include steeping the OPT in sodium metabisulphite (Na2S2O5) alone and with the addition of lactic acid (C3H6O3). The effect of process parameters: incubation temperature (IT) (room temperature at 26 °C, 40 °C, 50 °C), incubation period (IP) (24 h, 36 h, 48 h) and substrate mesh size (MS) (20 mesh, 40 mesh, 60 mesh) were evaluated for their effect on starch yield. The experimental results indicated that with the addition of lactic acid during steeping improved the starch yield (3.61%) as compared to that of steeping using sodium metabisulphite alone (0.92%). The effect of substrate mesh size is more significant than process parameters: incubation temperature and incubation period on the starch yield. The contour plot was derived from the equation and applied to determine the interactive effects of IT × IP, IT × MS and IP × MS. Among the interactions, IT × MS is more significant than IT × IP, and IP × MS on the starch yield. A second-order regression equation was developed for the response as a function of independent coded parameters (R2 = 0.91). Conclusively, starch recovery increased with increase of OPT mesh size and steeping incubation temperature.

Effects of various grated sago sizes, steeping periods and trunk sections on sago starch recovery (Metroxylon spp.)

“…The steeping method used water as solvent in order to extract the native starch. Dried grated material (sago trunk) of 2 g according to the grade sizes (2.80 mm, 2.00 mm, 1.00 mm, 0.85 mm, 0.45 mm, 0.30 mm and <0.30 mm) were steeped in 0.2% sodium metabisulphite (Na 2 S 2 O 5 ) (Tay et al, 2013) which was dissolved in water (H 2 O) at room temperature as shown in Figure 2. The steeping period was set at 5 mins, 24 hrs, 48 hrs and 72 hrs.…”

“…The extracted liquids were centrifuged at 2000 rpm for 10 mins and analyzed to determine the value of starch content using VIS spectrophotometer (Lambda 35, Perkin Elmer, USA) at 650 nm wavelength. An iodine solution was added into the solution as a starch indicator (Tay et al, 2013). The experiments were repeated six times.…”

“…The losses occur due to the inefficiency of the extraction process. One of the factors that influence the extraction efficiency is the proportion of the sago trunk structure that ruptured which is producing various of grated sago size (Tay et al, 2013). The native sago starch extraction is different from roots and cereals as it is more complicated.…”

Agricultural Biomass Based Potential Materials

“…The EFB is believed to have the potential for converting carbohydrates into different biochemical with the high content of cellulose and hemicelluloses (about 75 %). Biochemical conversion uses biocatalysts, such as enzymes, in addition to heat and other chemicals, to convert the carbohydrate portion of the biomass (hemicellulose and cellulose) into an intermediate sugar stream (Tay et al 2013). These sugars are intermediate building blocks that can then be fermented or chemically catalyzed into a range of advanced biofuels and value-added chemicals.…”

Enhancement of technical value of oil palm (Elaeis guineensis Jacq.) waste trunk through modification with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU)

“…In 2012, total area of oil palm plantations located in Malaysia and Indonesia exceeded 10 million hectares. Since during harvesting each hectare yields over 70 tones of dry waste trunk biomass (Chin et al 2012), the resource seems to be cheap, abundant and promising prospective raw material for chemical processing to sugars, alcohols and other derivatives (Akmar and Kennedy 2001; Tay et al 2013;Chin et al 2010;Wanrosli et al 2004). Alternatively, palm trunk can be used as a source of lignocellulosic material for wood technology in particleboard (Baskaran et al 2013), plywood (Hoong et al 2013), furniture (Suhaily et al 2012) or laminated veneer lumber (Sarmin et al 2013).…”