Quality and safety attributes on shredded carrots by using Origanum majorana and ascorbic acid

Abstract

The increased need for consumption of raw vegetables has led to the production of minimally processed products like shredded carrots. There is a current trend towards the use of natural agents for the preservation of fresh produce quality, as alternatives to synthetic compounds such as chlorine. The purpose of this study was to evaluate the effects of different washing treatments with aqueous solutions of marjoram (Origanum majorana) essential oil (EO) (1:1500 v/v), marjoram hydrosol (Hyd) (1:15 v/v), ascorbic acid (AA) (1%) and their respective combinations on the quality of shredded carrot under storage at 4 °C for 9 d. The EO-treated carrots had acceptable aroma and AA-treated carrots obtained acceptable carrot-like aroma. The carrots’ orange color preserved with the AA application compared to the untreated control but marjoram Hyd application resulted to a final product with darker color and increased respiration after 6 and 9 d of storage at 4 °C and 90% RH. Furthermore, the application of AA increased total phenolic content and antioxidant activity of shredded carrots, while the combination of AA with EO and Hyd increased carotenoid content. Total soluble solids were increased following the application of marjoram Hyd. The application of AA increased total acidity and lowered pH values of shredded carrots at the 9th day of storage. Decay incidents, as observed by the total viable counts and yeast and filamentous fungi, were decreased by single or combined treatment during storage. Ascorbic acid alone or in combination with Hyd or EO maintained quality and preservation of processed carrots and in that way can be proposed as alternative sanitizers.