Processing Strawberries to Different Products Alters Contents of Vitamin C, Total Phenolics, Total Anthocyanins, and Antioxidant Capacity

Abstract

Strawberries were processed to juice, nectar, wine, and puree. For investigation of the antioxidant capacity as well as the contents of ascorbic acid, total phenolics and total anthocyanins, samples were taken after different stages of production to determine the effects of processing. The content of vitamin C was measured spectrophotometrically. The total phenolic content was analyzed by using the Folin-Ciocalteu method, and the amount of total anthocyanins was determined by using the pH-differential method. Two different methods-the trolox equivalent antioxidant capacity assay and the ferric reducing antioxidant power test-were used to determine the hydrophilic antioxidant capacity. This study showed the decrease of all investigated parameters within processing strawberries to different products. The content of ascorbic acid decreased with production time and processing steps, especially during heat treatment. The investigations on total phenolics in strawberry products proved fining to be a mild method to clarify berry juices and wines without removing high amounts of total phenolics. Fermentation did not lead to heavy losses of total phenolics, probably due to polymerization and condensation of monomer phenolics such as anthocyanins. Total anthocyanins and the hydrophilic antioxidant capacity decreased while using high temperatures. Anthocyanins also decreased considerably during the processing of wines, mainly caused by fermentation and pasteurization.

Effect of ingredients on oxidative stability of fish oil‐enriched drinking yoghurt

“…CA and pectin did not affect oxidation, even though they were added in concentrations expected to be high enough to inhibit oxidation [16,17]. When planning the experiment, we assumed that the concentration of sugar with 6 wt-% in total (2 wt-% added as sugar and 4 wt-% provided by the fruit preparation) was too low to retard lipid oxidation [18,19]. Our results did not indicate that sugar affected oxidation and thereby the results seemed to confirm our assumption.…”

“…The effect of pectin could thus be evaluated by comparing the emulsion with both acid and pectin, in addition to fish oil, with the emulsions with acid only. The concentration of sugar and the antioxidant content of the strawberry fruit preparation were considered to be too low to retard lipid oxidation [18,19]. Thus, in this study, sugar and fruit preparation were added simultaneously and their combined effect was evaluated.…”

The effects of pre-harvest and post-harvest factors on the nutritional quality of strawberry fruits: A review

“…The fruit juice redilution or concentration, the storage in tank farm, the production of strawberry jam by heating under vacuum, bottling, closing under vacuum and cooling are the main processes for strawberry derived products [63]. Several studies showed that strawberry products possess a decreased NQ compared to fresh fruits, and that the degree of reduction is strictly related to production time and processing steps, such as heat treatment.…”

The effects of the “green passive MAP” on the evolution of the gaseous and quality parameters in strawberries

“…The total polyphenols measured at the packing fruit were 203.72 25 mg GAE 100 -1 g according to previous works (Klopotek et al, 2005;Da Silva Pinto et al, 2008). Limited studies reported the changes in strawberry polyphenols in response to carbon dioxide treatments (Gil et al, 1997).…”