Natural food coloring refers to pigments extracted or prepared from plants, animals, microorganisms or other natural sources for coloring food. These pigments are naturally produced due to biochemical reactions in living organisms and do not contain synthetic chemical components. Natural Food Colorants,Natural Food Pigments, natural food color Xi'an Day Natural Inc. , https://herb.dayqc.com
what is natural food color?
Natural food colors can be divided into the following categories according to their source:
1. Plant pigments: This is the most common source of natural food pigments, including pigments derived from a variety of fruits, vegetables, flowers, and plant roots. For example, red beets can provide red pigments, carrots can provide orange pigments, turmeric can provide yellow pigments, and blueberries and purple potatoes can provide purple and blue pigments.
2. Animal pigments: These pigments are rare and usually come from the tissues or excretions of certain animals. For example, cochineal is a red pigment derived from the cochineal insects that live on certain cacti.
3. Microbial pigments: Some microorganisms, such as monascus, can produce specific pigments, such as monascus red pigments.
4. Mineral pigments: Although less used, certain inorganic minerals can also be used as natural food pigments, such as titanium dioxide (white) and iron oxide (red, yellow and black). However, due to possible toxicity issues with some mineral pigments, their use is often severely restricted or banned.
Natural food colors are generally considered safer and healthier than synthetic colors due to their nature. However, their color stability, heat resistance, light resistance, and interaction with other food ingredients may not be as good as synthetic pigments, so their application in the food industry sometimes presents some challenges. At the same time, the extraction and processing of natural pigments can also affect their cost and sustainability. Nevertheless, as consumer concerns about food safety and health increase, the demand for natural food coloring is growing.
Rice black sorghum
Scotinophara lurida (Burmeister), a member of the Hemiptera order and Aphididae family, is commonly found in southern Hebei, Shandong, northern Jiangsu, and regions south of the Yangtze River. This pest primarily targets rice but also affects wheat, millet, corn, sugarcane, beans, potatoes, and citrus crops.
The nymphs feed by sucking sap from rice stems, leaves, and panicles, causing yellow spots on the affected areas. Severe infestations can lead to stunted growth and even plant withering. In recent years, changes in farmland ecosystems and crop distribution have led to an increase in pest populations, making it a growing concern for farmers.
Morphologically, adult S. lurida measures 8.5–10 mm in length and 4.5–5 mm in width, with a long oval shape and dark brown to black coloration. The head and lateral margins are similar in length, while the compound eyes are prominent. The front corner of the thoracodorsal plate extends laterally, and the small scutellum is slightly concave or truncated at the end. Eggs are nearly barrel-shaped, reddish-brown, measuring approximately 0.9 × 0.8 mm, with 40–50 breathing pores around the eggshell. The surface features a reticular pattern with small engraved dots and a white powdery coating.
First-instar nymphs have a brown head and belly, with red markings and red spots on the ventral side, reaching a body length of about 1.3 mm. Third-instar nymphs are dark brown to grayish brown, with a small reddish-brown spot on the abdomen and slightly visible wing buds, measuring 3.3 mm. Fifth-instar nymphs have a light black head and thorax, a slightly green abdomen, and well-developed hind wing buds, with a body length of 7.5–8.5 mm.
In terms of life habits, S. lurida has one generation in Jiangsu and Zhejiang, two generations in Jiangxi, and two to three generations in Guangdong. Adults and some older nymphs overwinter in soil cracks, under stones, in weed rhizospheres, between rice stalks, or within bark crevices, at depths of 5–10 cm. During early summer, they attack rice plants. Nymphs hide in sunny areas at the base of rice fields during the day, while feeding on leaves or panicles in the evening or on cloudy days. Eggs are laid on leaf sheaths 6–9 cm above the rice surface, usually in groups of more than 14 eggs arranged in two rows. Each female lays around 75 eggs. Fields with early sowing and lush green foliage tend to suffer more damage, especially in hilly areas.
Natural enemies of S. lurida include rice blast black bees, Beauveria bassiana, spiders, frogs, and birds. Control methods include using spores to submerge eggs in water for 24 hours to prevent hatching. During the egg-laying period, draining water to a depth of 10–13 cm can reduce egg deposition. Repeating this process every 3–4 days for 4–5 times can effectively kill many egg masses. In the early nymph stage, spraying solutions such as 2.5% emulsifiable concentrate at 1500 times dilution, 20% fenvalerate at 2000 times, or 19% trichlorfon crystals at 800 times is recommended. A second application after 15 days helps maintain control. Using 10% imidacloprid WP at 2000 times dilution may be slower in action, but its effect lasts up to 25–30 days, making it a long-term solution for pest management.