Research Progress on Detection of Apple Watercore Based on Visible and Near-Infrared Spectroscopy

Apples are one of the most widely produced fruits globally, recognized for their crisp texture, juiciness, and nutritional value. Apples affected by watercore are particularly favored by consumers for their high sugar content and unique flavor. However, during prolonged storage, watercore apples often experience metabolic disorders, making it necessary to develop a rapid, high-throughput, and effective nondestructive testing method to monitor this condition. Near-infrared (NIR) spectroscopy has gained extensive application in apple quality assessment due to its speed, low cost, and ability to measure multiple indices simultaneously. This paper reviews physiological diseases affecting apples, particularly watercore, and discusses various nondestructive testing methods. It emphasizes the current application of visible/near-infrared (Vis/NIR) spectroscopy in detecting watercore in apples. Additionally, this paper addresses the challenges and prospects of using Vis/NIR spectroscopy for watercore detection. This review is aimed at providing insights into more effective ways to manage physiological changes in apples, such as watercore.