Gunnlaug Røthe(1), Terje Vasskog(2), Inger Martinussen(1)1and Kåre Rapp(1) (1) Norwegian Crop Research Institute, Holt Research Centre, Box 6232, N-9292 Tromsø, (2) Norway2Institute of Pharmacy, University of Tromsø, N-9000 Tromsø, Norway
I like this study because it addresses antioxidant activities of crowberries, but also a question all berry pickers have– do I hand harvest or use one of those berry pickers? The researchers harvested productive and not-so-productive plots in open and forested areas in northern Norway. They harvested berries for 6 years which is pretty amazing in this era of publish-as-soon-as-you-have-a-smidgen-of-data even after one season. Good scientists know that it takes at least 3 years of data to get any reliable data on field plots. The string pickers they mention are the small plastic harvesters with metal times that are so common in berry picking areas in Alaska.
They found that hand harvesting beat out berry pickers in nearly every year. The researchers, however, did not report on how long it took to harvest these plots with the two methods. For commercial harvest, that might be important. However, look at the yields in each year. 1995 was an extremely good year, but then yields plummeted in 1997, a phenomenon that is common to wild harvested berries. A rollercoaster of yields can be expected.
Another possible reason not to use pickers is uneven ripening. At any one time, there are overripe, full ripe and unripe berries on the plants. The authors showed that the highest levels of antioxidants occurred at full ripe. On either side of that, the levels of antioxidants decreased significantly. For instance levels of phenols in fruit were 364 mg/100 g unripe, 423 mg/100g ripe and 272.3 mg.100 g overripe. No doubt, the berry pickers will ensure greater numbers of berries in the unripe and overripe categories.
The authors also found that the amounts of antioxidants are dramatically reduced during the processing -from raw material to product (juice, jelly, wine). The flavonoids quercetin, for instance showed 268.4 and 798.0 ug/g in unprocessed berries and skins, respectively. Levels in processed products ranged from 1.7 to 25.6 ug/g, a huge drop.