The fruit of goji berry is ripe in 6~11 months. The fruit can be picked when the fruit turns from green to red and the flesh is slightly spongy. If premature pick, the fruit is not full, dry color is darker; if too late picking, sugar is too large and easy to fall off, after drying the color is darker, affecting the appearance. Picking fruits should be carried out after 10 in the morning. Don`t pick them after rain. Take them lightly when you pick them, and pick them together with the fruit handles. Otherwise, the juice will affect the quality of the outflow.
The drying process of goji berry is divided into three stages
The first stage is the rising speed drying stage. Dry room temperature up to 35 DEG -40 DEG, circulating wind speed 2.3 m / s, air fresh water evaporation to make the diffusion free state quickly, especially the pericarp water loss reached 50%, skin wrinkles, structure of water pulp began to slowly seeping from the cortex of stomata, fruit sugar concentration increased, the inhibition of enzyme activation the activity of protection the main components of polysaccharide, vitamins, amino acids, especially the protection of the red pigment is good. Dry fruit has a beautiful color.
The second stage is the constant speed drying stage. Due to water leakage in the fresh fruit, non binding water gathered sufficient peel, this is because the surface of the water vapor pressure and temperature pressure is basically the same, the internal moisture quickly moved to the surface of the fruit compression in order to meet the needs of skin moisture vaporization. When the water loss rate of fruit reached nearly 50%, the indoor temperature rose to 50 -55, and the cycling speed decreased. The less water contained, the shorter the dehydration time. A large number of dehydration, so that the shape of the fruit shrink, half dry state, this period weighing, measuring water, fruit containing about 30% of water.
The third stage is slow down drying stage. When the fruit is cut down to about 30%, the thermal conductivity of fruit becomes small, inside and outside temperature increases, when the indoor hot air to reach 55 degrees -60 degrees, because the fruit in less moisture, moisture migration rate of evaporation decreased, water exudation is slow, so the need for a time to slow discharge.
A common phenomenon is the fruit of Goji berry fruit drying the moisture diffusion surface is greater than the internal diffusion rate, fruit containing free water leakage rate is greater than the structure of water leakage rate, this is because the Goji berry fresh high fructose dehydration leads to difficulties. If the temperature is too high, the surface water of fresh loss too fast, and water and fruit extravasation for not up, then the skin will bubble, blocking the drain holes, but the fruit in water can not discharge, the decoloration, decrease the quality of cortex has. So the first fruit surface grease maceration, suitable temperature and wind speed plus in dehydrated skin at the same time through holes penetrate fruit temperature inside the fruit, to discharge the water, so as to speed up the drying speed and drying quality assurance.