ARS | Publication request: Effects of post-harvest handling techniques on the retention of phytochemicals in wild blueberries

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 10, 2011
Publication Date: June 28, 2011
Citation: Gustafson, S.J., Grusak, M.A., Lila, M.A. 2011. Effects of post-harvest handling techniques on the retention of phytochemicals in wild blueberries [abstract]. Berry Health Benefits Symposium, June 27-29, 2011, Westlake Village, California. p. 61.

Technical Abstract: Wild blueberries (WBB) are known to have a unique phytochemical profile that boasts antioxidant and anti-inflammatory potential. Polyphenolic compounds in WBB conclusively demonstrate human health benefits ranging from decreases in cardiovascular risk factors and improving insulin sensitivity to battling oxidative stress in the central nervous system and even helping to promote a healthy gut microflora. The concentration of phytochemicals in WBB, however, may vary depending on their post-harvest handling and storage conditions. To better understand the effects of post-harvest handling and storage on phytochemical concentrations in WBB, we measured polyphenolic compounds in WBB subjected to a series of common storage conditions relevant to the berry industry or to consumers. Experiments were conducted to evaluate specific handling and storage treatments on the retention of anthocyanins (ANC), chlorogenic acid (CA), and proanthocyanidins (PAC). Using HPLC methods, polyphenolic concentrations were measured in extracts of WBB that were individually quick frozen (IQF), prior to storage at -80 or -20 degrees Celsius, or freeze dried (FD). Note that IQF (-20) WBB may have experienced freeze thaw conditions during transportation to the distributing source and again when relocated to our laboratory whereas IQF (-80) WBB had minimal exposure to temperature variation. Results indicated that FD and IQF (-80) WBB have similar profiles, with both exhibiting higher concentrations of phytochemicals than IQF (-20) WBB. In addition, IQF (-80) WBB were subjected to a series of freeze-thaw conditions and to refrigeration and room temperature storage for up to 10 days. These treatments exhibited decreased ANC, CA, and PAC concentrations. In conclusion, post-harvest handling, along with specific storage techniques, resulted in changes to the phytochemical profiles of WBB. These changes may ultimately influence the bioactivity of WBB when consumed. Further investigations, designed to help provide a better understanding of the processing and storage effects on WBB available to consumers, will be discussed.