Effects of high pressure processing on bioactive compounds in spinach and rosehip puree

High pressure processing (HPP) is a novel food processing technology that uses minimal heat and preservatives. It can inactivate a variety of pathogenic and spoilage bacteria to ensure safe foods and extend shelf life by maintaining nutritional and sensory attributes. The present investigation studied the effects of HPP (200, 400, 600 MPa; 5, 10 min; room temperature) on the following parameters: contents of carotenoids and vitamin E and antioxidant capacity (AOC) in spinach and rosehip puree; chlorophyll contents in spinach and in vitro bioaccessibility of carotenoids in rosehip puree. Contents of carotenoids, chlorophylls and vitamin E were determined by HPLC. AOC was analysed by several assays (total phenolics, TEAC, ORAC). In spinach, HPP led to a significant increase of the content of carotenoids, chlorophylls and vitamin E, probably due to an increased extractability. Total carotenoid content in rosehip puree was almost unchanged by HPP with single carotenoids behaving differently. The in vitro digestion model showed that 42.2 ± 7.4% of the total carotenoids of the rosehip puree was released and is potentially available for absorption. HPP had no significant effect on the bioaccessibility of total carotenoids. No distinct trend for the effects of HPP on the tocopherol contents in both food samples could be deduced. Mostly, no changes were induced by pressure. In both plant foods, the AOC was retained. The results provide further scientific evidence of the benefits of HPP in retaining micronutrients and phytochemical properties of plant foods.