"Health from eating" series | Why does black wolfberry change color when soaked in water? Talk about the eating tips of black wolfberry

Black wolfberry, also known as black wolfberry or black wolfberry, is a plant variety that looks similar to ordinary wolfberry but is darker in color. The fruit of black wolfberry is usually dark purple or black, which is very different from the traditional red or orange wolfberry. Black wolfberry is rich in vitamins, minerals, antioxidants and polysaccharides, and contains a certain amount of unsaturated fatty acids, making it a natural food with high nutritional value.

Friends who have drunk black wolfberry soaked water must have observed a very interesting phenomenon: even if only a handful of black wolfberry is put into the water, the color of the water will change significantly. Moreover, different water quality and water temperature will also cause the color of the black wolfberry water to be different. So why is this? Is it that the wolfberry fruit is dyed? Do the different colors of water correspond to different types or dyeing processes of black wolfberry? In fact, the difference in the color of black wolfberry soaked water is mainly because black wolfberry is rich in anthocyanins. Anthocyanins are a water-soluble pigment that is particularly sensitive to acidity and alkalinity, and will change into different colors as the acidity and alkalinity of the environment change.

Anthocyanin is widely found in many plants in nature, such as purple cabbage, purple sweet potato, red amaranth, etc. It is a glycoside derivative with a variety of similar molecular structures. As a natural pigment in plants, anthocyanin often gives fruits, vegetables and flowers special colors such as red, purple, blue and orange.

As shown in the figure, anthocyanins will produce different color changes in different pH environments. This is because the anthocyanin molecular structure undergoes tautomerism between the phenolic structure and the quinone structure in different pH environments, causing color changes. This change will be reflected in the phenol oxidation process, and there are multiple phenolic hydroxyl groups in the anthocyanin molecule, so the color change is more complicated.

So will the nutritional value of black wolfberry be affected in different acid-base environments? How can we eat black wolfberry in a healthy way? In fact, in common drinking water environments, even if there are some differences in pH, it will not have a significant impact on the nutritional value of black wolfberry, so there is no need to deliberately select the type of drinking water used to brew black wolfberry. Common purified water, mineral water, and boiled tap water can be used to brew black wolfberry. But it should be noted that the water temperature should not be too high when brewing black wolfberry. The suitable brewing temperature is about 60°C, and the maximum should not exceed 80°C. Excessively high water temperature will destroy the vitamins contained in wolfberry to a certain extent, so try to avoid brewing directly with boiling water. Common ways to eat black wolfberry include brewing method, instant method, and complementary food method. The specific operation methods are as follows:

1. Brewing method: Brew with warm water below 80℃, wait for about 5 minutes and then drink. You can refill it two or three times.

2. Instant eating method: Take fresh black wolfberry or dried black wolfberry and chew it directly. The nutrients in black wolfberry will be absorbed more fully and the health benefits of black wolfberry will be more effectively exerted. It should be noted here that fresh black wolfberry or dried black wolfberry must be washed before eating, because they usually have dust on the surface and are not suitable for direct consumption.

3. Food supplement method: When making soup, wait until the soup is cooked, turn the heat to the lowest, add a handful of washed black wolfberries, and continue to cook on low heat for 2 minutes. When mixing dough or stuffing, you can crush the washed black wolfberries and add them to increase the flavor of the dough or stuffing. It should be noted that the acidity and alkalinity of the dough and stuffing will also affect the dyeing effect of the black wolfberries.

The above is the common knowledge and eating tips about black wolfberry. I wish you all a happy enjoyment and healthy diet.

Author: Du Kun, Luoyang Normal University

Review expert: Zhang Juanmei, associate professor of the School of Pharmacy, Henan University

Image source:

【1】Xiao Jing. Exploratory experimental design: extraction of anthocyanins from purple cabbage and its application as an acid-base indicator[J]. Guangdong Chemical Industry, 2019, v.46;No.392(06):97+112-113.

References:

【1】Xiao Jing. Exploratory experimental design: extraction of anthocyanins from purple cabbage and its application as an acid-base indicator[J]. Guangdong Chemical Industry, 2019, v.46;No.392(06):97+112-113.