Physicochemical properties and phytochemical components of white mulberry (Morus alba L.) fruits with different density at harvest

Reducing waste and controlling fruit quality is a challenge for retailers and processors. The fresh fruit and processing industries are seeking a reliable method to comprehend fruit characteristics to meet consumer demands for high-quality fruit. The harvested white mulberry was divided into five density stages (D1–D5, 0.960–1.060 g/cm3) using a densimetric flotation method, and the effects of fruit density on its physicochemical properties, phenolics content, volatile compounds, and cellular structure were investigated. Low-density fruits (D1, D2) contain less glucose, fructose, and more citric acid, hexanal and methyl acetate. The highest contents of chlorogenic acid, caffeic acid, and syringic acid were found in fruits at the D3 stage, with 64.6 mg/100 g DW, 15.8 mg/100 g DW and 14.1 mg/100 g DW, respectively. They may better eliminate free radicals and promote the health of the body. Moreover, rapid loss of fruit firmness, damage to cell structure, and a decrease in phenolics content after the fruit density exceeded 1.020 g/cm3 (D4, D5) indicate that the fruit is overripe, unsuitable for further storage and should be processed immediately. The presented data demonstrate the effect of fruit density on white mulberry quality and will serve as a valuable resource for retailers and processors.