Abstract:

Significance The quality of cotton fibers is closely related to the quality of downstream textiles. At present, Problems exist in the cotton market such as shoddy goods and confusion of production areas, which infringe on the legitimate rights and interests of consumers and undermine the fairness and justice of national cotton storage. Therefore, research on the geographic origin traceability of cotton fibers is an important issue. The conventional methods for identifying the geographic origin of cotton fibers are based on manual experience identification and by reviewing cotton import documents. The manual experience appraisal method is easily influenced by human subjective consciousness and cannot fully and accurately distinguish the geographic origin and quality of cotton fibers, and cotton import documents are easy to forge. Therefore, it is necessary to develop a scientific and accurate method for tracing the geographic origin of cotton fibers, which will not rely on product packaging and product documents but rather on testing the cotton fibers, in order to quickly determine the geographic origin of cotton fibers, standardize the order of cotton trading markets, and ensure the quality of downstream textiles.

Progress In recent years, some emerging technologies have developed in the field of biological origin traceability, such as near infrared spectroscopy, DNA molecular markers technology, and stable isotope technology. The determination of the origin and traceability of cotton fibers using near-infrared spectroscopy technology is based on the slight differences in the absorption intensity of hydrogen containing chemical functional groups of cotton fibers from different origins in the near-infrared region, which can be combined with other analysis methods to detect and trace cotton fibers from unknown origins. The DNA molecular marker technology is adopted to identify the origin of cotton fibers by analyzing genetic markers between individual cotton fibers to determine biological differences. DNA molecular markers of cotton fibers are detected using DNA detection techniques such as polymerase chain reaction to obtain their DNA fingerprints, thereby achieving variety identification and origin traceability. Cotton usually grows in fixed areas, and the isotope "fingerprints" of cotton fibers in the same area are extremely similar, which can fully reflect the growth environment of cotton and its interaction with environmental changes. Therefore, the source of cotton fibers can be distinguished by common stable isotope ratios. These technologies have been preliminarily studied in the field of cotton fiber origin traceability, and have more advantages than other traditional identification methods.

Conclusion and Prospect The near infrared spectroscopy technology can utilize appropriate mathematical models for large-scale detection of cotton samples, but further exploration is needed in terms of modeling accuracy and automation. In the future, computer simulation technology can be combined to achieve real-time monitoring of cotton quality and production areas. The DNA molecular marker technology can directly detect differences on molecular chains of cotton fibers, without being limited by cotton fiber maturity, growth environment, and gene expression, and has extremely high accuracy. However, it is difficult to extract complete DNA molecular chains from mature cotton fibers, and no complete gene database can be provided yet. In the future, it is necessary to improve cotton fiber DNA purification technology and improve purification efficiency. The detection results of stable isotope technology are not affected by human and environmental factors, but many factors that affect the abundance of various isotopes in cotton fibers exist, such as latitude and longitude, climate, and human intervention. In future research, more factors that affect cotton growth should be considered, and research on other stable isotopes should be added, not limited to elements C, H, O, and N. Next, based on existing detection methods, multiple technology fusion traceability methods can be developed to overcome the drawbacks of a single technology, achieving complementary advantages, and increasing the applicability of detection. By collecting a large number of samples and expanding the sample range, the cotton fiber origin database will be enriched, and the efficiency and accuracy of cotton fiber origin traceability will be improved.

Key words: cotton fiber, geographic origin, near infrared spectroscopy, DNA molecular marker, stable isotope analysis