It is widely believed that rosehips should be harvested before frost, because after low temperatures hit, they lose most of their useful substances and vitamins, especially vitamin C. It so happened that in the Autumn of 2021, one row of our first, small so-called “signal” harvest was not collected until late October and remained on the bushes until the spring of 2022.
In December 2021, the air temperature in Voznesensky district of Nikolaev region in general and on the plantation in particular, was between – 3 and – 12 degrees Celsius for about 15 days. In January 2022 before the sampling date (12.01.2022), the temperature also dropped to below zero, i.e. to – 8 degrees Celsius.
The study of “overwintered” rosehips showed unexpected results: the content of vitamin C has dropped from 5100 mg% to 5000 mg%, i.e. virtually remained unchanged, while all other main indicators, by which the properties of rosehips are evaluated, increased: sugar from 860 to 920 mg%, vitamin P from 3200 to 3500 mg%, fat content in the seeds also increased from 17200 to 18500, though slightly decreased in vitamin E from 54 to 49 mg% respectively.
Probably, we can cautiously assert that the opinion about essential reduction of vitamins and other biologically active substances in the berries of rosehips which have suffered frosting is not confirmed. These indicators do not decrease or decrease within the margin of error of devices, and for some indicators even increase.
In winter 2022-2023 we are definitely going to continue research in this field.
PS: The increase of fats in the seeds of rosehips that have survived the frost by more than 1000 mg% is also worth noting.