Spectral biological mechanism of red wax-coated double-composite paper apple bag and its effect on apple coloring?

In modern fruit tree cultivation technology, bagging technology is widely used to improve fruit quality, especially the color, smoothness and commercial value of apples. The core of this bagging technology lies in its red inner layer design, which is based on the principle of spectral biology and optimizes the coloring process of apples by precisely regulating the light environment. Light is an important environmental factor for plant growth and development, and light of different wavelengths has a specific regulatory effect on the physiological processes of plants. In the visible spectrum, red light has a significant effect on the photomorphogenesis, photosynthesis and accumulation of secondary metabolites of plants. The inner layer of the red wax-coated double-composite paper apple bag uses a specific red dye or pigment, whose spectral characteristics enable it to selectively transmit red light, provide appropriate light signals for the fruit, filter blue-violet light, reduce excessive synthesis of chlorophyll, and adjust the proportion of far-red light, affecting the activity of photosensitive pigments, thereby regulating the ripening process of the fruit. This spectral screening effect creates an optimized light environment, allowing apples to accumulate anthocyanins more efficiently during development, while reducing chlorophyll residues, thereby promoting uniform coloring.

Anthocyanin is the key pigment that determines the red color of apples, and its synthesis is affected by multiple factors such as light, temperature and hormone levels. Red light can upregulate the activity of key enzymes such as phenylalanine ammonia lyase, chalcone synthase and anthocyanin synthase, thereby promoting the biosynthesis of anthocyanins. Studies have shown that under red light conditions, the anthocyanin content in apple peel can be significantly increased, making the fruit appear brighter red. Photosensitive pigments in plants are the main receptors for red light. After red light irradiation, photosensitive pigments are converted from inactive forms to active forms, thereby activating a series of downstream gene expressions, including transcription factors that regulate anthocyanin synthesis and enzymes that catalyze anthocyanin glycosylation. The activation of this signaling pathway significantly increases the accumulation rate of anthocyanins. Traditional white or transparent fruit bags allow blue-violet light to pass through, promote chlorophyll synthesis, and cause the peel to have a green background color, affecting the red color. The red inner layer filters the blue-violet light, reduces the chlorophyll content, and makes the color of anthocyanins more vivid.

The red inner layer can also improve the uniformity of apple coloring. The light scattering properties of the red inner layer make the light more evenly distributed in the bag, avoiding the problem of uneven coloring caused by local strong light or weak light. Combined with the humidity control function of the wax coating, the red inner layer can maintain a stable microenvironment, reduce the negative impact of adversity on anthocyanin synthesis, and ensure that the fruit can be well colored in different parts. Traditional transparent bags may cause sunburn of fruits under strong light, while the red inner layer can filter some ultraviolet rays and strong light, reduce the risk of physiological disorders, and increase the rate of high-quality fruit. The red inner layer does not work independently, but works in synergy with the wax coating and double-composite paper structure to improve the quality of apples. The wax coating provides a suitable humidity environment to prevent cracks on the fruit surface without affecting gas exchange; the outer layer of the double-composite paper is UV-resistant and waterproof, and the inner layer is soft and breathable to reduce mechanical damage; the red inner layer optimizes the light environment, promotes coloring, and improves the value of the product. This multi-level synergistic effect makes the red inner wax-coated double-composite paper apple bag an ideal choice for modern high-quality apple cultivation.