Analytical Methods Applied to Characterization of Actinidia arguta, Actinidia deliciosa, and Actinidia eriantha Kiwi Fruit Cultivars

In this research, eight kiwi fruit genotypes (six har- dy kiwis (Actinidia arguta and their hybrids), one of Actinidia deliciosa 'Hayward,' and one of Actinidia eriantha 'Bidan' were examined and compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared (FT-IR) spectra, and nuclear magnetic res- onance (NMR) spectroscopy. Proteins were extracted from lyophilized fruits, flesh with seeds, grinded seeds, and singu- lar seeds and then separated by SDS-PAGE. Matrix similarity and dendrogram was generated using Nei coefficient and Un- weighted Pair Group Method with Arithmetic mean (UPGMA) algorithm. Based on protein patterns, Actinidia species were clearly distinguishable, whereas differences be- tween hardy kiwi fruit cultivars were minor or nondetectable. The electrophoretical separations were able to distinguish a half of hardy kiwi fruit cultivars, so cluster analysis revealed a limited number of cultivar groups. Intervarietal polymor- phism was low and this affected the results of similarity anal- ysis. One distinct cluster, composed of two pairs of cultivars and identical by protein patterns, was obtained. Cultivars 'Ananasnaya' and 'Weiki,' according to the morphological description, were similar. Oppositely, 'M1' cultivar signifi- cantly differed from other hardy kiwi cultivars by densitometrical bands intensity. All examined singular seeds of 'Ananasnaya' cultivar possessed identical protein patterns. The protein patterns of 'Bingo' and 'Ananasnaya' hardy kiwi fruits harvested in 2011 and 2013 were identical. Three weeks storage after harvest did not affect the protein composition of these cultivars. FT-IR and NMR spectrum of hardy kiwi fruits were presented and compared with 'Hayward' and 'Bidan' and showed slight differences in comparison with the protein profiles. SDS-PAGE is more applicable than FT-IR and NMR for comparison of different kiwi fruit cultivars. The used ana- lytical methods can be applied to any food analysis in order to distinguish the main compounds and to present fingerprints of different cultivars.