Nata de Coco
Acetobacter xylinum bacteria are Gram-negative bacteria that can synthesize cellulose from fructose. Cellulose has a pore across on the mini glucan crystals which then coalitioned in microfibrils. Microfibril clusters that exist in the structure of the compounds formed as the ribbons that can directly observed using microscope.
Manufacturing Step of Nata De Coco
1. Preparation of starter media / Nata De Coco Seed
Microbial starter culture is the most important ingredient in the formation of nata. As a starter, used pure cultures of Acetobacter xylinum. These bacteria can be produced from pineapple pulp that has been incubated (brooded) for 2-3 weeks. Starter used in the manufacture of nata of 170 ml.
2. Filtering and boiling
To remove debris mixed in coconut water, coconut water been filtered by using a filter cloth. Then mix sugar (100 g /L coconut water) and 0.5% ammonium sulfate, boil and let cool.
3. Inoculation (Blending with starter)
Once cooled, pH adjusted by adding acetic acid or vinegar about 20 ml (99.8% acetic acid as much as 0.75%) to lower the pH to obtain the range of acidity (pH) 3-4 so it suitable for bacterial growth. Then inoculated by adding starter (Acetobacter xylinum) 170 ml.
4. Fermentation (curing)
Insert the mixture into the fermentation container (basin size : 34 x 25 x 5 cm). Container covered with filter cloth and put into place that is clean and safe. Carried out during 8-14 days of curing until the layer reaches a thickness of approximately 1.5 cm. Store at room temperature.
After curing is completed by forming a layer of nata, nata layer removed carefully with a fork or tongs are clean so that the liquid below the layer is not contaminated. Fluid under nata can be used as seed in the next process. Remove membrane attached to the bottom of the nata, then washed or soaked in fresh water to remove mucus and acid then do the cutting and washing again until the acid gone.
Nata has a clean and then given a syrup to be packed or for other consumption.
- The source of carbon is an important factor in the fermentation process. Bacteria to produce nata require a carbon source for metabolic processes. Glucose will enter the cell and used for supplying the energy required in the breeding. Fructose that there will be synthesized into cellulose. The amount of sugar that is added must be considered so that sufficient for metabolism and the formation of pelikel nata. Although the coconut water are sugars, but the sugars are not sufficient for the formation of pelikel that need to be added from outside.
- Besides sugars, nitrogen sources is an important factor as well. Nitrogen is required in the formation of proteins that are important in cell growth and enzyme formation. Lack of nitrogen causes the cells grow less well and inhibit the formation of enzymes necessary so that the fermentation process may have failed or are not perfect. Nitrogen is used for the manufacture of nata is generally ZA (Ammonium sulphate) which is relatively inexpensive and tend to be acidic than urea.
- pH of the medium was made approximately 3-4 using acetic acid and incubation temperature of about 28 - 30C or room temperature and protected from contaminants, such as with closed filter cloth or newspaper.