摘要
Vibrational spectroscopy analysis of full-ripened fig fruits(Ficus carica L.)was acquired using Fourier-transformed infrared(FTIR)spectroscopy by attenuated total reflectance(ATR).The objective of this study was to investigate accurate discrimination of 25 fig cultivars using chemometric analysis of both ATR-FTIR fingerprinting and in-vitro antioxidant activity along with chromatic coordinates color.In-vitro antioxidant activity was assessed through three methods and displayed statistically significant differences across cultivars and between the fruit parts,with promising antioxidant potency.Infrared spectra were measured separately on both peels and pulp to better know which fruit part provides high discrimination throughput between cultivars.The results showed vibration intensities of five fingerprint regions displaying statically significant differences.The highest vibration intensity occurred in the region of 1175-940 cm^(-1)including the phenols fingerprint.Principal components analysis based on integrated intensities corresponding to fingerprint regions,revealed two main groups in pulp samples,while five groups in peels samples.The pulp extracts of’Nabout’showed a typical vibration in 3000-2800 cm^(-1)and 1775-1725 cm^(-1)regions and,therefore was classified as single subset in cultivars scatterplot.This cultivar had a lightcolored fig and exhibited the highest antioxidant potency for all essays particularly in peel extracts.The biochemical assessment and FTIR fingerprinting data were involved in PCA analysis,and that displayed some dissimilarities in the classification patterns,given the fact that antioxidant activities and chromaticity together could not totally explain the classification based on FTIR fingerprinting between peel and pulp.Application of FTIR-ATR spectroscopy to discriminate fig cultivars seems to be a rapid,accurate and cost-effective alternative to laborious measurement techniques,in fig quality screening and preselection,such as chromatography analysis.This study suggests the use of fig peels for a high-level discrimination while using ATR-FTIR spectroscopy,since it provides high-throughput screening framework.
