Published on International Journal of Food & Nutrition
Publication Date: June 26, 2019
Agustian Nurhaeni, Nur Hidayat & Rahmad Hadi Bawono
Pacific Monas Culinary Academy, Surabaya
Ubaya Politeknik, Surabaya
Journal Full Text PDF: Fermentation Kinetics “Slurry” Coconut Fruit Meat by Rhizopus oryzae L.16.
Fermentation kinetics studies are fundamental in understanding any fermentation process. Coconut oil processing research through fermentation kinetics studies can illustrate the growth rate of the cells, the use of substrate consumption and product formation. The purpose of this research is to study the kinetics of fermentation in a batch of basic materials coconut meat porridge by R. oryzae L.16 into coconut oil. Conditions that are controlled fermentation time and temperature of fermentation. Chemical analysis determined was the yield of palm oil, starch and the number of colonies. The research result coconut oil from the coconut fruit pulp fermentation by R. oryzae fermentation L.16 produce 34oC temperature conditions, the highest oil yield of 43.87%. Fermentation kinetics calculation results obtained specific growth rate values of 0.0649 h-1, the number of products based on the amount of substrate consumed (Y ) Of 7.1075 h-1, the number of microbial cells which grow based on the substrate consumed (Y) Of 5.4839 h-1, the specific rate of product formation (Qp) of 0.4613 h-1, the specific rate of substrate reduction (Qs) equal to 0.0118 h-1, the growth rate constants (KP1) of 0.0032 h-1.
Keywords: Fermentation, coconut & kinetics.
Vegetable oil is one of the important commodity in international trade are widely consumed worldwide in both developed and developing countries, Arsyad and Ghaffar . One of the important vegetable oil in the world is coconut oil. Indonesia is number two oil producer after the Philippines, the USDA .
Coconut oil research lately continued what is now known as Coconut Oil. One way that is likely to be applied to the palm oil industry is a small and large scale fermentation. However, the problem, at the time will be applied is very difficult to do, from lab scale to pilot scale plan and factories. For that matter, is necessary to study the kinetics to determine the optimal conditions, both quantitatively and qualitatively. Data kinetics obtained are expected to provide an overview of environmental factors are optimal, and this is very important, because it allows control of fermentation, engineering and design of bioreactors which is one of the foundations for the development of biotechnology processes, Judoamidjojo et al. .
Environmental conditions have a significant effect on the formation of the product (Cp) which is associated with the growth of microbes (Cx), this can be known through the study of batch fermentation kinetics that can be expressed by the following equation:
is a fermented coconut oil yield (gL-1); Cx is the growth of microbes, the value KP1 is coconut oil formation rate constants in the growth phase, and KP2 is a constant speed on the phase formation nonpertumbuhan coconut oil, Suharto  and said .
Kinetics of fermentation obtained can illustrate the relationship between mold growth with the number of oil produced and the substrate used for the growth of mold, . The research objective was to study 1) the effect of fermentation temperature and fermentation time coconut meat porridge by R. oryzae L.16, 2) fermentation kinetics of coconut meat slurry to the formation of oil by R. oryzae L.16.
2. MATERIALS AND METHODS
2.1 Materials and Equipment
The materials used in the experiment are coconuts Dwarf types, with harvesting age 12-13 months, from Parakan Muncang, Cicalengka. Inoculum used was inoculum powder , pure culture R. L.16 OBTAINED FROM THE COLLECTION OF THE LABORATORY OF PACIFIC MONAS CULINARY ACADEMY.
The tools used in the experiments is the Erlenmeyer flask, electrical balance, volumetric pipette, test tubes, petri dishes, beakers, incubators, autoclaves, needle ose, blenders, centrifuges, funnels, and shaker, Laminar Air Flow Cabinet.
The study consisted of the stages of preparation and research. At the stage of preparation of the inoculum carried out the manufacture of powder R. ORYZAE L.16, For the research phase conducted two phases involving two factors fermentation temperature and fermentation time. For the first study to analyze the stages oil yield calculation, the number of colonies, determined starch content several times an interval of 6 hours during the fermentation 48 hours. Fermentation kinetics assessed based on results of the first study phase.
2.3 Preparation of inoculum
Provision of R. oryzae culture L.16 done by: a total of 39 g PDA included in a beaker and diluted with 1000 ml of distilled water, then heated over a water bath. PDA liquid put into a test tube as much as approximately 5 ml, then covered with cotton. Then performed at a temperature strerilisasi 121oC for 15 minutes. In a still hot state test tubes tilted and left for some time. The test tube that has been chilled and frozen ready to be used as a medium for the growth of R. oryzae L.16.
2.4 Preparation of inoculum powder
250 g of rice included in the flask, then added distilled water in the ratio 1: 1. Erlenmeyer covered with cotton and paper and tied with a rubber band, then performed the sterilization at a temperature of 121oC for 15 minutes. Parboiled rice strerilisasi result is cooled to 27oC. Each 250 g rice plus 2.5 ml suspension of mold spores containing 3.2 x 106 cfu / ml to R. oryzae L.16.
Rice and the suspension was stirred until well blended, then poured into a sterile aluminum tray, and then leveled. Incubation was performed at 30 ° C for 3 days. After incubation is complete, the temperature was raised to 37 ° C – 40 ° C for 3 to 4 days until the inoculum to dry. Furthermore, the inoculum is milled with a blender until it becomes flour. Number of mold inoculum levels R. oryzae L.16 powder is 8 x 108cfu / g.
2.5 Determining the optimum fermentation time and temperature
Pieces of coconut meat that has been cleaned put into a blender with water added with a ratio of 1: 4. Furthermore, the destruction of over 10 minutes to make porridge coconut meat that is used as the substrate. Substrate put in a 100 ml Erlenmeyer flask, then covered with cotton and paper and tied with a rubber band. Furthermore sterilized in an autoclave at a temperature of 121oC for 15 minutes. Substrates that have been sterilized subsequently cooled to room temperature. each inoculated with R. oryzae inoculum L.16 powder.
Implementation of the above activities is done by using a shaker stirring speed of 150 rpm. The temperature of the fermentation is done in a variety of conditions, namely 30oC, 32oC and 34oC. The fermentation was carried out for 48 hours with an interval of 6 hours. Once fermentation is complete, the substrate is centrifuged at 4000 rpm for 10 minutes. Centrifugation will separate oil, water and sediment.
The data collected was analyzed tested by analysis of variance, while the difference was tested by Duncan’s multiple range.
2.6 Fermentation kinetics of coconut meat porridge byR. oryzae L.16 on palm oil produced
To determine the kinetics study in this study used the following equation:
(1) The specific rate of growth R. oryzae L.16. :
3. RESULTS AND DISCUSSION
3.1 The yield of coconut oil
The results showed that the fermentation time, fermentation temperature significant effect (P < 0.05) on the yield of palm oil produced. Based on the results of research show that at a temperature of 30 oC, 32 oC and 34 oC with a fermentation time of 0 hours to 30 hours saw increased the yield of oil produced, where the fermentation time to 30 hours the resulting oil yield 38.44% respectively; 40.93%; 43.87% significantly different (P < 0.05) higher than other fermentation time. But after 30 hours of fermentation, the resulting oil yield decline began at the time of fermentation to 36 hours to 48 hours. The highest oil yield is achieved at a temperature of 34oC fermentation as much as 43.87%. This shows that the coconut meat slurry fermentation is done at a temperature of 34 ° C is the most suitable conditions for the growth and metabolic activity of R. oryzae L.16 is the growth and development of the best mold, so that the decomposition of the substrate into a mass of cells more quickly. Figure 1. Coconut oil yield fermented “slurry” coconut meat by R. oryzae L.16 at different fermentation temperatures 3.2 The number of colonies The observations showed mold growth in fermented substrate. For more details R. oryzae L.16 growth can be seen in Figure 2. Based on the results shown in Figure 2, shows that the fermentation temperature of 34 ° C showed the highest growth rate and the number of colonies at most for R. oryzae L.16. The highest number of colonies as 187,5x108cfu / ml is produced at a temperature of 34oC, with a fermentation time to 30 hours was significantly different than the number of colonies on the fermentation temperature 30 ° C (166 x 108cfu / ml) and 32 ° C (171 x10 cfu / ml). This shows that at a temperature of 34oC with fermentation time on hour-30 is the best fermentation time and temperature as well as the most favorable conditions for the development and metabolic activity of R. oryzae L.16. Figure 2. The number of colonies of R. oryzae L.16 Determination of starch content during the fermentation process aims to determine the content of starch is used as an energy source for the growth of mold. The treatment time of fermentation, fermentation temperature significant effect (P < 0.05) levels of starch. But the interaction between fermentation with fermentation temperature, no significant effect (P < 0.05) levels of starch. Based on the results of research show that at a temperature of 30 oC, 32 oC and 34 oC with a fermentation time of 0 hours to 48 hours showed a decrease in starch content. This shows that during the fermentation of coconut meat porridge to the use of starch as an energy source for growth and metabolic activities of R. oryzae L.16. 3.3 The kinetics of coconut meat slurry fermentation by R. oryzae fermentation L.16 at a temperature of 34 ° C At a temperature of 34 oC, the measurement of mold growth quantitatively R. oryzae L.16 done at logarithmic phase or exponential phase. L.16 R. oryzae mold growth at exponential phase are on the clock to 9 to 24. In this phase, the specific rate of coconut oil formation (Qp) is 0.4613 h-1, with a specific rate of growth of R. oryzae L.16 Is 0.0469 h-1. This shows that the fermentation temperature of 34oC, the specific rate of mold growth Of 0.0469 h-1 to produce as much as 0.4613 h-1. While the specific rate of change of the starch content (Qs) is 0.0118 h-1, it is stated that for every growth amounted to 0.0469 R. oryzae L.16 need starches hour-1 hour-1 as much as 0.0118. Growth coconut oil product yield (Yp / s) is 5.4839 and the growth of cell biomass yield (Yx / s) is 7.1075. Coconut oil yield obtained maximum on hour 30 is 44.25%, With the number of colonies of R. oryzae L.16 maximum of 189×108 cfu / ml, While time critical fermentation took place at the 26th produce palm oil yield as much as 42.18% with the number of colonies of R. oryzae L.16 as 183×10 cfu/ ml. Coconut oil formation rate constants in the growth phase R. oryzae L.16 L.36 is 0.0032, and the constant speed of coconut oil in phase R. oryzae non growth L.16 L.36 is 0,0029. Figure 3. Fermentation yield curve “slurry” coconut meat on the kinetics of coconut oil products (Cp), the number of colonies R.oryzae L.16 (Cx), a decrease in starch content (Cs) at a temperature of 34oC fermentation. Overall results of kinetic calculations coconut meat slurry fermentation by R. oryzae L.16 presented in Table 1. Table 1. Kinetic parameters fermented palm oil production “slurry” coconut meat by R. oryzae L.16.
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