Changes in amino acids content in tubers of jerusalem artichoke (Helianthus tuberosus L.) cultivars during storage

The objective of the three-year study was to determine the influence of postharvest storage on essential and nonessential amino acids content in tubers of different cultivars of Jerusalem artichoke (Helianthus tuberosus L.) – ‘Rubik’, ‘Albik’ and ‘Sauliai’. The experiment was performed in 2007–2009. The plants were grown in the experimental field of Lithuanian University of Agriculture in Kaunas (from 2011 August – Aleksandras Stulginskis university). The Jerusalem artichoke tubers were stored for 20 weeks at the temperature of 2°C (± 0.5°C) and RH 90–95 % in polypropylene (PP) perforated bags, capacity of 10 kg, in 4 replicates. Amino acids contents were determined immediately after harvest and during storage of the tubers in every 4 weeks by the method of ion-exchange chromatography and then detected photometrically. The data obtained were statistically analyzed with two-factor Anova (STATISTICA software). Standard deviation and the least significant difference at the 95% probability level were calculated with Fisher’s LSD test. Data presented in tables are mean values of the three years of the experiment. The results obtained showed that directly after harvest and during the storage the dominating amino acid in tubers of all cultivars was of essential amino acids – arginine, and of nonessential – asparagine, glutamine and alanine. Tubers of cv. ‘Sauliai’ after 20 week storage accumulated the highest amount of essential amino acids – treonine, valine, isoleucine, leucine, phenylalanine and nonessential – serine, glycine, alanine, tyrosine. Significant correlations between contents of some amino acids in the tubers were found.

Celem trzyletnich badań było określenie wpływu przechowywania pozbiorczego na zawartość egzogennych i endogennych aminokwasów w bulwach topinamburu (Helianthus tuberosus L.) trzech odmian uprawnych: ‘Rubik’, ‘Albik’ i ‘Sauliai’. Bulwy przechowywano przez okres do 20 tygodni w temperaturze 2 C (± 0,5 C) oraz warunkach wilgotności względnej (90–95%). Wyniki wskazują, że bezpośrednio po zbiorze oraz podczas przechowywania dominującym aminokwasem spośród amainokwasów egzogennych u wszystkich odmian była arginina, a spośród aminokwasów endogennych asparagina, glutamina i alanina. Bulwy odmiany ‘Sauliai’ po 20 tygodniach przechowywania akumulowały najwięcej egzogennych aminokwasów – treoniny, waliny, izoleucyny, leucyny, fenyloalaniny i endogennych – seryny, glicyny, alaniny i tyrozyny. Stwierdzono silne korelacje między zawartościami niektórych aminokwasów w bulwach.