Flavor characterization of Citri Reticulatae Pericarpium (Citrus reticulata 'Chachiensis') with different aging years via sensory and metabolomic approaches.

Guangchenpi (GCP), which is the peel of Citrus reticulata 'Chachiensis', is widely used as an herbal medicine, tea and food ingredient in southeast Asia. Prolonging its aging process results in a more pleasant flavor and increases its profitability. Through the integration of sensory evaluation with flavoromic analysis approaches, we evaluated the correlation between the flavor attributes and the profiles of the volatiles and flavonoids of GCP with various aging years. Notably, d-limonene, γ-terpinene, dimethyl anthranilate and α-phellandrene were the characteristic aroma compounds of GCP. Besides, α-phellandrene and nonanal were decisive for consumers' perception of GCP aging time due to changes of their odor activity values (OAVs). The flavor attributes of GCP tea liquid enhanced with the extension of aging time, and limonene-1,2-diol was identified as an important flavor enhancer. Combined with machine learning models, key flavor-related metabolites could be developed as efficient biomarkers for aging years to prevent GCP adulteration.

Multiomics integrated with sensory evaluations to identify characteristic aromas and key genes in a novel brown navel orange (Citrus sinensis).

'Zong Cheng' navel orange (ZC) is a brown mutant of Lane Late navel orange (LL) and emits a more pleasant odor than that of LL. However, the key volatile compound of this aroma and underlying mechanism remains unclear. In this study, sensory evaluations and volatile profiling were performed throughout fruit development to identify significant differences in sensory perception and metabolites between LL and ZC. It revealed that the sesquiterpene content varied significantly between ZC and LL. Based on aroma extract dilution and gas chromatography-olfactometry analyses, the volatile compound leading to the background aroma of LL and ZC is d-limonene, the orange note in LL was mainly attributed to octanal, whilst valencene, ß-myrcene, and (E)-ß-ocimene presented balsamic, sweet, and herb notes in ZC. Furthermore, Cs5g12900 and six potential transcription factors were identified as responsible for valencene accumulation in ZC, which is important for enhancing the aroma of ZC.