Abstract

The effect of freezing, frozen storage (–18 °C for 6 months), thawing, juice extraction, and hot-air drying on the anthocyanin profile of haskap berry (Lonicera caerulea L.) was investigated using RP-HPLC. Five anthocyanins (ANCs) were quantified: cyanidin 3,5-di-glucoside (4.27 % of the total ANCs), cyanidin 3-glucoside (89.39 %), cyanidin 3-rutinoside (2.07 %), pelargonidin 3-glucoside (0.83 %), and peonidin 3-O-glucoside (3.44 %). Freezing did not significantly affect the content of individual ANCs, while frozen storage resulted in significant reductions (16.00-24.50 %). Thawing the frozen berries in the microwave oven retained the highest content of different ANCs. The highest degradation, however, occurred while thawing at room temperature. Extracting juice from the berries significantly reduced the content of individual ANCs. Drying the berries to 25 % moisture content at 60, 100, and 140 ºC reduced the individual ANCs by 73.85-76.19, 78.46-80.95 and 90.77-95.40 %, respectively. The overall stability of the five ANCs during storage and processing is summarized by the following trend (from most to least stable): peonidin 3-O-glucoside > pelargonidin 3-glucoside > cyanidin 3,5-diglucoside > cyanidin 3-rutinoside > cyanidin 3-glucoside.

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