Low Temperature Storage Affects the Anthocyanins and Phenolic Compounds Accumulation in ‘Coreano' Garlic (Allium sativum), Poster Board #025

Garlic quality is determined by the size bulb, uniform shape and absence of defects, additionally also the bulb color is an important feature of marketing process especially where the purple or red bulbs are appreciated. Previous experiments have shown that storage of ‘seed’ cloves of ‘Coreano’ variety at 5 °C ahead the harvest time up to six weeks and increased the purple color of the bulb. The aim of the this work was to compare the anthocyanins contents and their profile as well as the total phenolic compounds of outer scale-leaves of garlic bulbs (Allium sativum) cv. 'Coreano' cultivated from 'seed' cloves stored at room temperature (RT) and 5 °C. Two sets of 'Coreano' garlic cloves were stored at those temperatures during 5 weeks. After the storage the bulbs were shelled and the selected cloves were planted at Cosio, Aguascalientes Mexico during the 2010–11 season. Periodically samples of five bulbs were taken and their outer scale-leaves were separated and the anthocyanins and total phenolic compounds were extracted with 5% acetic acid in methanol. Anthocyanins quantification was carried out by differential pH method and the total phenolic compounds were measured by Folin-Ciocalteu assay. Independent samples were used for the characterization of anthocyanins profile by HPLC-DAD-ESI-MS. The results were analyzed by analysis of variance and Tukey mean comparison test. The anthocyanins and phenolic compounds content were greater in samples whose ‘seed’ cloves were stored at 5 °C (0.3802 mg cyanidin 3-glucoside (C3G)/g and 1.8737 mg gallic acid equivalents (GAE)/g respectively), while the samples whose cloves were stored at RT, the anthocyanins and phenolic compounds content represented only one third of samples stored at 5 °C (0.1032 mg C3G/g and 0.6138 mg GAE/g, respectively). HPLC-DAD-ESI-MS analysis showed five anthocyanins in samples of outer scale-leaves which were identified as cyanidin 3-glucoside and its malonyl and acetoyl derivates, two of these compounds have not been reported previously in garlic. Results indicated that storage at low temperature induced the accumulation of anthocyanins and total phenolic compounds and their HPLC profile of anthocyanins were slightly different in both storage conditions.