This issue is jointly completed by Nandu Appraisal, Food Science Popularization Group &CEC Consumer Experience Center
The copyright of this article belongs to southern metropolis newspaper. Reproduction without permission is prohibited.
During the Spring Festival, every household must have a "New Year's goods" - a variety of green juice drinks, and has become a common drink on the table.
However, every time at this time, a seemingly scientific video will be popular in the circle of friends. In the online video, netizens used a white "paper towel" to stir in a cup full of orange juice, and the orange juice became transparent. Correspondingly, the white "paper towel" becomes orange-yellow. In the video, netizens solemnly told everyone that orange juice drinks are full of pigments, "or drink less is better." Is the experiment in this video real? An ordinary paper towel can make the orange juice fade? Is colorful juice really harmful to health?
Nandu Appraisal, together with the "Food Science Popularization" team of South China Agricultural University, walked into the Guangzhou CEC Food Safety Testing Consumer Experience Center to explore the truth behind juice and pigments.
The experimenters of the "Food Science Popularization" of the Food College of South China Agricultural University show the freshly squeezed orange juice in the beaker.
Identification by head
Small video brush screen circle of friends "paper towel" makes Fanta become "Sprite"
The appraiser Jun found that such a video is not the first time it has appeared in the circle of friends. But every once in a while, there will be similar videos on the Internet, and each time they appear, they will be turned around by netizens. Why is such a video retweet rate so high? The appraiser randomly interviewed several Guangzhou citizens who forwarded the small video in the circle of friends. They said they retweeted the video mainly because they were very worried about the pigment content of juice drinks. "We forwarded it to the circle of friends in the hope that our children and families would see this video, be vigilant, and stop drinking carbonated juice."
The appraiser also interviewed several elementary school students at random. They all said that they preferred drinks to boiled water. Yu, a first-grade student, said that he likes to drink Fanta and Coke the most, "The drink is very sweet, and the color is very good, and when you see different flavors, you want to try what it tastes." ”
After stirring in Fanta and washing with water, the masterbatches that have adsorbed artificial pigments still appear orange.
Identification transcripts
Different colors of juice will be stirred by "paper towels"?
●Date: December 22, 2016
●Location: Guangzhou CEC Food Safety Testing Consumer Experience Center
●Target: Fanta orange juice flavored drink, Fanta apple flavored beverage, Gatorade blueberry flavor, Sunkist grape juice, so-called 100% orange juice beverage and pure artificial freshly squeezed orange juice
●Instruments: beakers, masterbatches, glass rods, paper towels, etc
●Purpose: Whether the color in the drink can be absorbed by the masterbatches, and how much energy the masterbatches absorb.
Pre-live lab discussion
Live
A Adsorption identification
Freshly squeezed orange juice is also "absorbed."
In the online video, netizens used a "white paper" to absorb all the "orange" in the orange juice. The expert jun understands that in fact, this "white paper" is not an ordinary white paper. "This white paper is actually a masterbatche, not ordinary paper." As soon as the testers came up, they revealed that the masterbatches are actually a high-tech nano-adsorption material, which is more often used in the laundry process. "When washing clothes, put the masterbatches in the water, and the masterbatches can quickly absorb the dye pigments that are free in the water, so that the clothes will not be dyed." Therefore, being able to "absorb color" is the most important function of masterbatches.
The adsorption experiment made a direct comparison between the adsorption capacity of masterbatches and wet paper towels. The experimenters first poured three different orange juices into a beaker of 100ml each, which are Fanta orange flavored carbonated drinks, a brand of juice known as "100% pure juice", and freshly squeezed pure orange juice. Next, the testers put a masterbatche in each of the three beakers and stirred with a glass rod for 3 minutes.
In the process of stirring, the expert Jun found that the masterbatches in Fanta soda were colored very quickly, and within a minute and a half, the soda color in the beaker basically faded and became "Sprite", and the masterbatches were dyed bright orange. The color of the masterbatches in a brand of juice known as "100% pure juice" is also very obvious, but the color is lighter than the masterbatche in Fanta soda, and the color of the orange juice in the beaker has hardly changed. Among the fresh orange juice squeezed by the experts and testers on the spot, the mixed masterbatches were also dyed pale yellow, but the orange juice retained in the beaker was the most intense. "It can be seen that even pure natural juices also contain pigmented ingredients, but this is a natural pigment." The experimenter said.
Carbonated beverage pigments are absorbed most thoroughly
However, the testers reminded the appraiser to note that the colors adsorbed on the masterbatches are not necessarily pigments, but may also be the juice in the juice, or the components of the pulp. Therefore, in order to identify how much pigment the masterbatches have absorbed, the testers clean the masterbatches with water.
"Masterbatches have a fixing effect, and the pigment adsorbed on it cannot be washed off, but the juice can be washed off."
After some cleaning, the expert jun saw that the color of the masterbatches in the Fanta soda was very fixed, the cleaned masterbatches were still yellow and clear, and there was almost no washed color in the clean water used for cleaning, "Which shows that the masterbatches are all pigments." ”
After the masterbatches in a certain brand of juice known as "100% pure juice" are cleaned, a lot of juice and pulp are precipitated in the water, and the color of the masterbatches is faded. The masterbatches in freshly squeezed orange juice were washed and the color was the lightest of the three samples.
Fanta is the most easily absorbed, is Fanta the most unhealthy? Not really. The tester told the appraiser that Fanta's formula was clearly written that it was a carbonated drink, made only of "orange juice flavor", and did not list the ingredients containing "orange juice" in the ingredient label. "It is written very clearly, it contains sunset yellow, which is the artificial pigment, which is the reason why Fanta is orange-yellow." The testers stressed that edible pigments can be eaten within the scope of national standards, and the current qualified beverages and pigments will not exceed the standard.
Three colored drinks were tested, with apple soda in green, grape juice in purple, and functional drinks in blue. Compare the effect of mixing into the masterbatches.
The adsorption effect of wet paper towels is far inferior to that of masterbatches
In the same experimental procedure, the tester replaced the masterbatche with a wet paper towel and performed it again. The appraiser found that the adsorption effect of wet paper towels was far worse than that of masterbatches. Especially in the comparison of the tests in Fanta soda, the effect is very obvious. In previous experiments, masterbatches sucked orange juice into "Sprite." With wet paper towels, it is only dyed with a faint layer of orange, and the color change of the soda in the beaker is not obvious.
"Ordinary paper towels cannot perform this experiment at all, because ordinary paper towels will rot when stirred in juice. So, the pigment is actually not as scary as the video shows. The experimenters concluded that in terms of the color of the masterbatches, the pigment content in Fanta was the highest. A brand of orange juice, known as "100% pure fruit juice," also contains pigments. Freshly squeezed orange juice has the least pigment content and is the healthiest.
In addition to orange juice drinks, the trialists also tested Gatorade Blueberry-flavored Sport Functional Drinks, Sunkis Grape Juice and Fanta Apple Juice Carbonated Drinks. After three minutes of stirring, the masterbatches in the sports functional drink turned blue, and the color of the drink in the beaker became significantly lighter; the masterbatches in the grape juice became purple-black, but the color of the grape juice itself did not change much; and the masterbatches in the Fanta apple juice carbonated drink became bright green, and the drinks in the beaker also faded into "water".
B Concentration identification
If the pigment content is higher than the national standard, 3 masterbatches cannot be fully adsorbed
For beverages with different concentrations of artificial edible coloring, can masterbatches also be absorbed? The testers prepared the artificial pigment Sunset Yellow as the main body of the test. "Sunset yellow is the orange of orange juice, which is used in many juice drinks." According to China's "Sanitary Standards for the Use of Food Additives" (GB2760-1996), sunset yellow can be used for fruity beverages (liquid, solid), juice drinks, soda, prepared wine, and concentrated juice The maximum use amount is 0.1g/kg.
According to the proportional conversion, in the test, since the amount of water added in each beaker is a fixed 250 ml, the engineer set the standard value of sunset yellow to 0.025 g. The experimenters first poured 250 ml of water into each of the 5 beakers, and then added different doses of sunset yellow to the beakers. From right to left, shimizu, add 0.0125g (1/2 of the national standard), add 0.025g (national standard), add 0.05g (2 times the national standard), and add 0.1g (4 times the national standard). The appraiser saw that even if a little powder of sunset yellow dissolved, a cup of water quickly turned yellow color. Depending on the amount added, the color of the water also shows a gradient from light to dark.
Next, the testers put three masterbatches into each beaker and stirred. In this way, it is obvious that the ability of the masterbatches to absorb color is also limited, "reaching a certain level, the masterbatches will be saturated and can no longer continue to adsorb." The amount of pigment within the national standard can be adsorbed by three masterbatches. The identification jun found that the masterbatches in the beaker whose amount of pigment was lower than the national standard adsorbed all the pigments as quickly as possible, and the water in the original beaker was "restored". The masterbatches in the beaker that add the national standard pigment amount will also absorb the pigment cleanly, but the masterbatches are darker in color. The water in the other two beakers with a higher amount of pigment than the national standard still retains color, and the masterbatches are already absorbed very "saturated", showing a very bright orange color.
Add different doses of sunset yellow (from right to left, water, 1/2 national standard, national standard, 2 times national standard, 4 times national standard) to the beaker, and then use 3 masterbatches to stir the color contrast.
The appraiser said
Use within the national limit standard
Food coloring is harmless to the human body
The juice drinks sold on the market contain artificial color components, is it impossible to drink these drinks? "Artificial colors can only cause harm to the body if they are consumed for a long time and in large quantities." The experimenters explained that artificial pigments refer to organic pigments prepared by artificial chemical synthesis methods, which usually only have the effect of color development. "China's food additive hygiene standards have very strict restrictions on the type and dosage of artificial pigments to ensure food safety and protect people's health." It can be said that the edible pigments used within the national limit standard are harmless to the human body. Therefore, everyone does not have to be afraid of every beverage that uses artificial colors, as long as it is a qualified product, you can drink it with confidence. ”
Are pigments all harmful? Not quite. The experimenters said that the adsorption of pigments in the masterbatches in the video does not mean that the pigments in the beverage will threaten health, and it is unscientific to judge without dose. "For example, many drinks based on grape juice have a pigment called 'grape skin red' added. This pigment is a natural pigment extracted from the grape skin, which can promote people's appetite and increase the secretion of digestive juices, which is conducive to digestion and absorption. "Pigments also have certain bacteriostatic functions, and adding them to food can inhibit the growth of microorganisms. Objectively speaking, pigments have made great contributions to the development of the modern food industry, greatly increasing the variety and pattern of food, prospering the food market, making people's tables richer, making food more attractive, and satisfying people's pursuit of food.
Identification supplements
Long-term intake of pigments is harmful
Do not drink carbonated drinks as water
However, the testers also admitted that although the content of pigment in the juice we drink on weekdays is within the national standard, people should still reduce the intake of pigments in an appropriate amount. "Pigments have a greater impact on adolescents and young children than on adults. Long-term consumption of juice or carbonated drinks will cause genetic mutations in adolescents, which will also affect the intellectual development of adolescents, and may also lead to some excessive behaviors in adolescents in their daily lives. ”
In any case, these carbonated drinks are certainly not as safe and healthy as all-natural freshly squeezed juices. Therefore, the experimenters also repeatedly advocated in the process of experimentation that teenagers should not drink functional drinks, carbonated drinks, etc. as water. Even if the pigment content in the beverage is within the limited standard, long-term consumption of large quantities can be harmful to health.
Yang Jingge, deputy chief physician of the Department of Gastrointestinal Surgery of the First Affiliated Hospital of Jinan University, said that instead of worrying about the pigment content of these juices, it is better to worry about the sugar contained in the drink. "Many drinks, especially carbonated drinks, do not help absorb other nutrients except for sugar intake." Yang Jingge said that the intake of simple sugar, and then through the action of the liver, will be converted into the deposition of fat, which can easily lead to obesity in adolescents. "In addition to sugar, carbonated drinks also have carbonic acid, phosphoric acid, and especially cola, and this acidic substance is also very corrosive to tooth enamel. Excessive intake of phosphoric acid can also lead to calcium deficiency, resulting in adolescents prone to calcium deficiency. ”
Producer: Southern Metropolis Daily Science News Studio
Moderator: Chen Yangkai Coordinator: Nandu reporter Yin Lai
Written by: Nandu reporter Yin Lai Intern Wei Wei Na Correspondent Chen Yang
Photo: Nandu reporter Tan Qingju
Technical support: Guangdong Province (Guangzhou) product quality consumption education base, Guangzhou food science popularization group, CEC consumer experience center
Experimenters: Li Yilin Zhou Qianwen Kwong Xiaoqing Xu Jiahui Xu Shiqi Ye Minyi