ABSTRACT The objective of this study was to determine the effects of dip wash treatments with 2% citric acid (CA), 0.2% benzoic acid (BA), 0.2% sorbic acid (SA) and acidic electrolyzed water (AEW) followed by 2 kJ·m–2 ultraviolet (UV) irradiation on the postharvest decay and quality of strawberry fruit cultivar ‘Malvina’, as compared to control, and UV alone treated samples. Weight loss, firmness, soluble solids content, titratable acidity, total phenolics content, total anthocyanins content, antioxidant activity and decay incidence of control and treated strawberry fruits were investigated during cold storage at 8 °C for 21 days. The result showed that UV-treated fruits had a lower weight loss, higher titratable acidity, phenolic and anthocyanin content and were firmer than the untreated fruits. Dip wash in AEW before UVC treatment reduced weight loss and increased firmness of strawberry fruits but did not significantly affect total phenolic content, total anthocyanins content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity and fruit decay. Dip wash treatment with organic acids followed by UVC irradiation was significantly more effective than UV treatment alone in reducing fruit decay and weight loss and in maintaining at higher levels titratable acidity, total anthocyanins content, total phenolic content and antioxidant activity of strawberries during refrigerated storage. The present findings demonstrate that dip wash treatment with 0.2% SA, 0.2% BA or 2% CA followed by UV treatment can be an effective method for maintaining the phytochemical content and delaying the decay of strawberry fruit during cold storage.

En este trabajo, un método sensible RPHPLC fue desarrollado para la determinación simultánea del ácido clorogénico, del ácido cafeico, del ácido vanílico y de la cafeína en las pruebas de café. El método fue aplicado para analizar ocho tipos de café disponibles en el mercado de Rumania, que fueron analizados también en cuanto al contenido total de polifenoles y la capacidad antioxidante. La reducción del radical DPPH fue utilizada para determinar la capacidad antioxidante de los extractos de café mientras que el contenido total de polifenoles fue determinado por la espectrofotometría (método Folin Ciocalteu). El contenido total de polifenoles se situó entre 1,98 g GAE/100 g y 4.19 g GAE/100 g mientras que el contenido de cafeína se situó entre 1.89 g/100 g y 3.05 g/100 g. Una gran variabilidad se observó con respecto al contenido de ácido clorogénico en las pruebas de café analizadas, contenido que se situó entre 0.6 y 2.32 g/100 g.

In the present study a simple and highly sensitive RP-HPLC method has been established for simultaneous determination of chlorogenic acid, caffeic acid, vanillic acid and caffeine in coffee samples. The method has been applied to eight different coffees available on the Romanian market which were previously analysed concerning the total polyphenols content and antioxidant capacity. Reduction of the DPPH radical was used to determine the antioxidant capacity of the coffee extracts while the total polyphenols content was determined by spectrophotometry (Folin Ciocalteu's method). The total polyphenols content ranged from 1.98 g GAE/100 g to 4.19 g GAE/100 g while the caffeine content ranged from 1.89 g/100 g to 3.05 g/100 g. A large variability was observed in chlorogenic acid content of the investigated coffee samples which ranged between 0.6 and 2.32 g/100 g.