Effect of Different Drying Method on the Nutritional Quality and Antioxidant Activity of Jiangyong Fragrant Ginger Based on Principal Component Analysis

To comprehensively evaluate the effects of drying methods on the nutritional quality and antioxidant activity of Jiangyong fragrant ginger, seven different drying methods including natural drying (ND), hot air drying (HAD), infrared drying (ID), microwave drying (MD), vacuum drying (VD), hot air-microwave combined drying (HAMCD), infrared-hot air combined drying (IHACD) were used to dry Jiangyong fragrant ginger. Thirteen indexes such as total phenols, total flavonoids, gingerols, curcumin, vitamin C, starch, cellulose, free amino acids, soluble protein, soluble sugar, DPPH free radical scavenging rate, hydroxyl radical scavenging rate and total reducing capacity of the dried samples were determined, and the core indexes were screened by principal component analysis. The comprehensive evaluation model of the quality of dried ginger was constructed for comprehensive scoring. The results showed that MD had the shortest drying time and the highest drying efficiency; The determination of quality indicators found that the total phenol content of ID was the highest; The total flavonoid content of ND was the highest; The gingerol, curcumin content and vitamin C content of MD were the highest; The starch content of HAD was the highest; The soluble sugar content of HAMCD was the highest; The soluble protein and free amino acid content of IHACD was the highest; The highest cellulose content and the best antioxidant activity were VD. Through principal component analysis, 13 quality indicators were summarized into four principal component factors, with contribution rates of 34.942%, 26.725%, 17.602%, and 12.016%, respectively, and the cumulative contribution rate was 91.285%. The quality evaluation model of Jiangyong fragrant ginger was established through principal component analysis, it was concluded that VD had the highest comprehensive score. The research results can provide a reference for the deep processing of Jiangyong fragrant ginger and the development of high-value products.