Peaches are rich in nutrients as one of the fruits favored by consumers. However, peaches are subject to damage during growth, picking and storage, causing a decline in the quality and seriously impairing the economic value of peaches. Therefore, detection techniques for peach quality are of paramount importance in ensuring the commercial value of fruits. However, traditional detection methods have the disadvantages of destroying samples, being time-consuming, and high cost. Nondestructive detection methods such as those basevd on acoustic, mechanical, dielectric or optical characteristics as well as electronic nose, especially the detection methods based on optical characteristics, have been developed rapidly due to their nondestructiveness, rapidity and accuracy. At present, they have been widely used in the internal and external quality detection of peach fruit. However, there is a lack of systematic summary on their advantages, disadvantages and future prospects. This paper summarizes the latest progress in the application of the nondestructive techniques to evaluate the external quality (size, shape, color, aroma, and surface defects) and internal quality (variety, sugar content, titratable acid, hardness, chilling damage, and insect damage) of peach fruit. In addition, the problems of using the nondestructive techniques to detect peach quality and future directions in this field are discussed. It is expected that this review will provide reference for research on nondestructive detection techniques for peach quality.

Surface-enhanced Raman spectroscopy (SERS) is an emerging ultrasensitive analytical technology with potential applications in many fields, such as food safety detection, environmental monitoring and clinical diagnosis. However, traditional SERS detection mainly relies on Au or Ag nanomaterials as substrates, resulting in poor signal uniformity, poor stability and high cost. Benefitting from the combination of SERS and photocatalysis, the signal uniformity, batchto-batch consistency and cost effectiveness can be significantly improved by using semiconductor-noble metal composite nanomaterials as SERS substrates. Moreover, the elimination of hazardous analytes and the recyclable SERS detection can be achieved via photocatalyzed degradation. The current review mainly focuses on new developments in photocatalysis-SERS for the recyclable detection of food contaminants. The design and fabrication procedures of recyclable SERS substrates made of inorganic/organic semiconductor photocatalysts and noble metal nanomaterial composites are introduced along with their advantages and shortcomings, and their potential applications in the detection and elimination of typical food contaminants including pesticides, banned additives and antibiotics are discussed in detail. Finally, the current challenges and future trends in this field are also summarized.