Fruit and vegetable products-Determination of mineral impurities

This standard specifies the method for determining mineral impurities in fruit and vegetable products. This standard is applicable to the determination of mineral impurities in fruit and vegetable products, such as sand mixed with raw materials and mixed into products during processing, high-density metals, glass, etc. GB/T 12294-1990 Determination of mineral impurities in fruit and vegetable products GB/T12294-1990 Standard download decompression password: www.bzxz.net
This standard specifies the method for determining mineral impurities in fruit and vegetable products. This standard is applicable to the determination of mineral impurities in fruit and vegetable products, such as sand mixed with raw materials and mixed into products during processing, high-density metals, glass, etc.

National Standard of the People's Republic of China bzxZ.net
Determination of mineral impurities in fruit and vegetable products
Fruit and vegetable products--Determination of mineral impurities
This standard adopts the international standard ISO762--1982 "Fruit and vegetable products-Subject content and scope of application". This standard specifies the method for determining mineral impurities in fruit and vegetable products. GB 12294---90
-Determination of mineral impurities".
This standard is applicable to the determination of mineral impurities such as mud, sand, high-density metal, glass, etc. mixed into the products from raw materials and processing in fruit and vegetable products.
2 Principle
The sample is rinsed and organic matter is removed, and the residue is ashed at high temperature and weighed. The ashed product obtained is the mineral impurities. 3 Instruments and equipment
Stand-mounted balance: sensitivity 0.1g.
High-speed tissue crusher: 10000~12000r/min. High-temperature electric furnace. :
Analytical balance: sensitivity 0.0001g.
Crock: porcelain or quartz products, 40mL9
Dryer: put effective 1 desiccant inside.
Beaker: 800, 2000mL.
Funnel: diameter 9cm.
Ash-free filter paper: diameter 7cm.
Measurement steps
Sample preparation
General products: such as jam, jelly, quick-frozen fruits, vegetables, etc., mix the sample thoroughly, weigh 500g, accurate to 0.5g, 4.1.1
Put it into the high-speed tissue crusher and pound it into a homogenous slurry (quick-frozen products must be placed in a plastic bag in advance and immersed in hot water to melt), and transfer all of them into a 2000mL beaker.
4.1.2+Products: After the sample is carefully mixed, weigh 100g, accurate to 0.1g, put it in an 800mL beaker, add 400mL distilled water, and heat to boiling. Leave it at room temperature overnight to rehydrate it, then crush it with a high-speed tissue crusher, and then transfer it to a 2000mL beaker. 4.2 Weighing
Put the cleaned crucible in a high-temperature electric furnace and burn it at 600±10℃ for 1h. When the furnace temperature drops below 200℃, take out the crucible, cool it in a desiccator for 30min, and weigh it to an accuracy of 0.0002g. 4.3 Rinsing
Add distilled water to the 2000mL beaker containing the sample to nearly fill the cup, stir evenly with a glass rod, tilt the beaker slightly, and let it stand for 10 minutes. After that, pour most of the upper clear liquid and slurry into the second 2000mL beaker, add distilled water to the two beakers to nearly fill the cup, stir evenly, let it stand for 10 minutes, then pour the upper slurry in the second beaker into the third 2000mL beaker, and pour the upper slurry in the first beaker into the second beaker. Continue the operation and pour the slurry in the third beaker into the sink until all the floating slurry in each beaker is completely removed.
Transfer the residues in the second and third beakers to the first beaker without damage. If there is a small amount of pulp and seeds in the residue, continue to rinse with a small amount of water, pour the upper rinsing liquid into another 2000mL beaker, and repeat the above operation until all seeds and pulp are rinsed off. Collect the residue in the first beaker, then wash it into a funnel with ash-free filter paper and filter it dry. 4.4 Ashing and weighing
Take out the filter paper and residue, put them into a weighed crucible, place them on an electric furnace or gas lamp to carbonize until no smoke is generated, then put them into a high-temperature electric furnace, burn them at 600±10℃ for 1h, cool them to below 200℃, take them out, cool them in a dryer for 30min, and weigh them to an accuracy of 0.0002g.
5 Calculation of determination results
5.1 Calculation formula
Mineral impurity content is expressed in grams of mineral impurities per 100g sample, and the calculation formula is as follows: Mineral impurities (g: 100g)
Weight of one crucible, g,
Weight of one crucible and ash, g,
Weight of one sample, g.
5.2 Result expression
(m2 -m,)
Two parallel samples are taken from the same sample for determination, and the arithmetic mean is taken as the determination result, retaining two decimal places. 5.3 Allowable difference
The maximum allowable difference of the mineral impurity determination values ​​of two parallel samples is that when the content is less than 0.3g/100g, the absolute difference between the two shall not exceed 0.01g/100g; when the content is higher than 0.3g/100g, the relative difference shall not exceed 3%. Additional remarks:
This standard is proposed by the Ministry of Agriculture of the People's Republic of China. This standard was drafted by the Vegetable and Flower Research Institute of the Chinese Academy of Agricultural Sciences. The main drafters of this standard are Yang Hongfu, Huang Wanchun and Huang Qiaohua. This standard was first issued in 1989.
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