The Selection And Validation Of Fingerprint Information For Kiwi Fruit Geographical Origin Traceability

Food geographical origin traceability technologies are very important for assessing food geographicalprovenance and protecting specialty products. Mineral element fingerprinting, organic compoundfingerprinting and electronic nose have been attached much attention to the geographical originidentification and traceability of plant-derived agricultural products in recent years. The objective of thispaper was to determine the content differences of mineral elements, organic compounds and odorcompounds in kiwi fruit from different regions, and explore the feasibility and stability of thesefingerprint techniques for geographical origin traceability of kiwi fruit. A total of123kiwi fruit samplesand180soil samples (topsoil and subsoil) were collected from Shaanxi (Zhouzhi, Meixian), Sichuan(Muchuan) and Hunan (Yongshun) provinces of China during the2012and2013harvest time,respectively. The concentrations of Na, K, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo, Cd, Sb, Ba, La, Ce,Nd, Tl and Pb in kiwi fruit and soil were measured by inductively coupled plasma mass spectrometry(ICP-MS). The contents of VC, VE, soluble sugar, total acid, and total sugar were determined usingultraviolet–visible spectroscopy, handheld refractometer and some other instruments. The odorcompound compositions of kiwi fruit were analyzed by electronic nose coupled with pattern recognitiontechniques. Analysis of variance (ANOVA), multiple comparison analysis, correlation analysis andlinear discriminant analysis (LDA) were applied in data analysis. This study focused on thecharacteristics and differences of above determined indicators in kiwi fruit from different regions,discrimination power for origin, and the relationship of contents of mineral elements, organiccompounds and odor compounds in kiwi fruit with their growing environment, genotype and storagetime. The verification test was conducted to examine the origin discrimination effect of the selectedindicators to kiwi fruit samples from another year. Finally, the effective traceability index system andthe discriminant model were established. The main conclusions were as follows:(1) There were significant differences of mineral elements, organic compounds and odor compounds inkiwi fruit according to geographical origin. It was feasible to determine the geographical origin ofkiwi fruit using these fingerprint analysis technologies. The effectiveness order: organic compoundfingerprint> mineral element fingerprint> electronic nose.(2) The concentrations of Cr, Mo, Sb, La, Nd and Tl were significantly different both in kiwi fruit andsoil (topsoil, subsoil) from different regions. The effect of genotype on these elements were notobvious. These six elements could successfully identify the provenance of kiwi fruit and wereconsidered reliable for geographical origin traceability.(3) The contents of VCand VEin kiwi fruit had significant differences among regions. The effects ofgenotype and short-term storage were observed to be relatively small on these two variables. Theycould be used as potential traceability indicators for kiwi fruit.(4) The odor fingerprints in kiwi fruit were greatly influenced by storage condition. Electronic nose hasthe potential for tracing the geographical origin of kiwi fruit. But the stability of its discriminant model needs to be further enhanced.(5) The combination of mineral elements and organic compounds notablely improved the correctclassification rate and had a better traceability efficacy on kiwi fruit origin than those singlemethods.(6) The stability of different traceability techniques: mineral element fingerprint> organic compoundfingerprint> electronic nose. The geographical origin discriminant effect of Mo, Sb, La, Nd, Tl, VCand VEto kiwi fruit from different years was effective. These seven indicators as geographicalorigin fingerprint information of kiwi fruit were relatively stable.