Drying method capable of keeping color, aroma and taste quality of fresh momordica grosvenori

Abstract

The invention discloses a drying method capable of keeping color, aroma and taste quality of fresh momordica grosvenori. The method comprises the following steps: placing the harvested fresh momordica grosvenori at normal temperature for 3-7 days, and turning once per day; punching a small through hole with the diameter of 1.5-2.0mm from the pedicel to fruit stem; and arranging in a vacuum freezer dryer, and drying under the conditions of the vacuum degree of 70+ / -10Pa and the temperature of 40-50 DEG C for 10-20 hours. Active substances in the momordica grosvenori are prevented from reacting with oxygen under the vacuum conditions, and the evaporation speed of moisture in the materials is increased; a certain temperature is given during drying, so that the moisture in the momordica grosvenori can be reduced from about 80 percent to 8 percent or below within 20 hours; because the temperature is low, and the preservation can be performed under anoxic conditions, the color and inherent quality of the momordica grosvenori can be well preserved; and the vacuum degree and temperature are controlled in the vacuum freezer dryer, the drying time is shortened, and the production practicability of the technology is improved. The problem that the momordica grosvenori has a burnt flavor can be solved, and the product quality is stabilized.

Description

technical field [0001] The invention relates to the drying of Luo Han Guo, in particular to a drying method capable of maintaining the color, fragrance and quality of fresh Luo Han Guo. Background technique [0002] Luo Han Guo is a special product of our country and is known as the "Oriental God Fruit". However, the water content of the fruit is more than 80%, which is not resistant to storage and transportation. It must be reduced to less than 8% to facilitate long-term storage and transportation. At present, the drying methods of Luo Han Guo are: [0003] 1. Hot air drying is the most commonly used method at present. This method uses equipment such as drying rooms and ovens to increase the temperature of Luo Han Guo with wood or electric heating air to remove the moisture of Luo Han Guo and achieve the purpose of drying; this method uses heat The surface of the object is heated first by radiation or hot air convection, and then transferred to the interior of the obje...

AI Technical Summary

Problems solved by technology

[0003] 1. Hot air drying is the most commonly used method at present. This method uses equipment such as drying rooms and ovens to increase the temperature of Luo Han Guo with wood or electric heating air to remove the moisture of Luo Han Guo and achieve the purpose of drying; this method uses heat The surface of the object is heated first by radiation or hot air convection, and then transferred to the interior of the object through heat conduction. The whole process generally takes 5~7 days, the drying time is long, the temperature control stability is poor, and the drying process is very easy to make the Luo Han Guo The sugar is burnt, which affects the quality, that is, the color and taste. At the same time, the drying time is too long, and the output is greatly limited.

[0004] 2. The method of freeze-drying Luo Han Guo. Chinese patent application numbers are 201110124239.6 and 201010556027.0. The flow process of this type of method is: fresh Luo Han Guo→washing→finishing→clean water cooling→punching→prefreezing→vacuum freeze-drying; this method has the following defects : First, after pre-freezing, the cells of Luo Han Guo are broken. During the vacuum freeze-drying process, the sugar contained in the fruit will leak out along the skin of the fruit, making the surface sticky with sugar foam; this seriously affects the appearance quality of Luo Han Guo; The second is to use this method first to invest in pre-freezing facilities, which increases the energy consumption of pre-freezing, and the drying time is also longer. The whole process needs at least 50 hours, and the practicality of the technology is limited.

However, because the moisture content of each Luo Han Guo is different, the same batch enters the microwave dryer, and the drying time control becomes difficult: if the drying time is long, the fruit with low moisture will have a burnt smell; The effect of drying cannot be achieved, that is, this method still cannot guarantee the stability of quality