Mangoes were depulped. The kernels were removed from water, cut into small pieces (about 1 cm3), and immersed into sodium metabisulfite 0.2 wt% (kernel: solution ratio, 1:2, wt/vol) for 48 h at 4oC, again to avoid browning. The kernels were then divided into three batches for further processing. The kernels were drained and ground in distilled water (kernel:water weight ratio, 1:1) for 3 min at 1750 rpm, the resulting suspension was filtered in a 60 mesh sieve stirred (200 rpm) for 10 min. The retentate was again ground in water in the cutter and filtered, and the procedure was repeated until there was no retentate. The starch slurry was allowed to settle for 40 min, separated, added with a 0.05 M NaOH solution (at a 1:2 slurry/solution weight ratio) in order to remove soluble fiber, and stirred at 200 rpm for 2 h at 25°C. The suspension was then centrifuged (20,000 g, 4°C, 20 min). The starch precipitate was collected, repeatedly washed in distilled water (at a 1:2 precipitate/water weight ratio), stirred (200 rpm, 5 min), and centrifuged, until the starch suspension reached pH 7. Absolute ethanol was added to the suspension (2:1 ethanol/suspension volume ratio), which was stirred (200 rpm, 1 h), then allowed to settle for 2 h at 25°C. The decanted starch was washed with distilled water, vacuum filtered through 28 µm filter paper, allowed to dry (40°C, 24 h), ground, and stored in sealed glass flasks. The starch yield was expressed as extracted starch to initial raw kernels (wt%, on a dry basis), as an average value of the three batches.
(pls create a flowchart. calculate its material and energy balance if there's any)
Mangoes were depulped. The kernels were removed from water, cut into small pieces (about 1 cm3), and immersed into sodium metabisulfite 0.2 wt% (kernel: solution ratio, 1:2, wt/vol) for 48 h at 4oC, again to avoid browning.
The kernels were then divided into three batches for further processing. The kernels were drained and ground in distilled water (kernel:water weight ratio, 1:1) for 3 min at 1750 rpm, the resulting suspension was filtered in a 60 mesh sieve stirred (200 rpm) for 10 min. The retentate was again ground in water in the cutter and filtered, and the procedure was repeated until there was no retentate. The starch slurry was allowed to settle for 40 min, separated, added with a 0.05 M NaOH solution (at a 1:2 slurry/solution weight ratio) in order to remove soluble fiber, and stirred at 200 rpm for 2 h at 25°C. The suspension was then centrifuged (20,000 g, 4°C, 20 min). The starch precipitate was collected, repeatedly washed in distilled water (at a 1:2 precipitate/water weight ratio), stirred (200 rpm, 5 min), and centrifuged, until the starch suspension reached pH 7. Absolute ethanol was added to the suspension (2:1 ethanol/suspension volume ratio), which was stirred (200 rpm, 1 h), then allowed to settle for 2 h at 25°C. The decanted starch was washed with distilled water, vacuum filtered through 28 µm filter paper, allowed to dry (40°C, 24 h), ground, and stored in sealed glass flasks. The starch yield was expressed as extracted starch to initial raw kernels (wt%, on a dry basis), as an average value of the three batches.
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