Influence of steam treatment and drying on carrots composition and concentration of phenolics, organic acids and carotenoids

Funding Information: This research was supported by the National Research Programme “Agricultural Resources for Sustainable Production of Qualitative and Healthy Foods in Latvia AgroBioRes” (2014–2017), Project No. 4 “Sustainable Use of Local Agricultural Resources for Qualitative and Healthy Food Product Development (FOOD)”. Publisher Copyright: © 2018 Sciendo. All rights reserved.Carrot (Daucus carota L.) is a globally used vegetable from the Apiacea family. It contains macro and micro elements, as well as various phytochemicals. The aim of the study was to determine concentration of carotenoids and organic acids, phenolic composition and antiradical scavenging activity, and colour changes during steam-blanching (for 1.5 and 3.0 min) and in dried carrots in convective and microwave-vacuum driers. Gravimetric, spectrophotometric, and high performance liquid chromatography (HPLC) methods were used for analysis. Carotenoids in fresh carrots were detected in high amounts, which decreased during thermal treatment and drying. The main organic acids in fresh carrots detected in highest amounts were oxalic, tartaric, quinic, malonic, and citric acids. Ascorbic acid concentration decreased minimally with steam processing, but significantly during drying. Fresh carrots contain minimal amounts of total phenolics, which increased during the thermal and drying processes used, while flavonoid, flavonol, flavan-3-ol and phenolic acid concentration decreased. The compound found in highest amounts by HPLC methods were 3.4-dihydroxybenzoic and 3.5-dihydroxybenzoic acids, catechin, 4-hydroxybenzoic acid, epicatechin and sinapic acid.publishersversionPeer reviewe

FOODBALT 2014 DETERMINATION OF MAJOR SUGARS IN FRESH AND DRIED SPICES AND VEGETABLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Abstract Carbohydrates are one of the most important energy sources in plants synthesized during photosynthesis. They are important for plants to grown and produce. Polysaccharide content changes depending on plant type, growing location and weather conditions. The highest content differs in roots and leaves-photosynthesis starts in leaves, but to grow and produce mostly carbohydrates are localized in roots. It is important to follow up in differences between sugars changes in vegetable and spices. There are many researches focusing on sugar changes mostly in fruits and cereals, less in vegetables, herbs, and spices. The aim of this research was to determine major sugars in nine spices and vegetables-celery (Apium graveolens var dulce), parsley (Petroselinum crispum), dill (Anethum graveolens), leek (Allium ampeloprasum L.), garlic (Allium sativum L.), onion (Allium cepa), celery root (Apium graveolens var. rapaceum), pumpkin (Curcubica maxima), carrot (Daucus carota) grown in Latvia in 2013. Analyses were made using high performance liquid chromatography (HPLC) in the laboratories of Latvia University of Agriculture, Faculty of Food Technology for fresh samples and samples dried in convective dryer at 45±1 °C temperature. Fructose, glucose, sucrose and maltose content was determined using HPLC method, and moisture content in each sample was established by drying samples till constant weight. Results were expressed as grams per 100 grams of dry weight (DW). Analysing obtained results the highest total sugar content was found in vegetable roots (carrot), lowest-in spices' leaves. Convective drying at 45±1 °C process takes from 12 till 48 hours to reduce moisture content. After drying process in most cases individual sugar content increased significantly. During drying process water is removed from samples, sugars are changing, which may indicate possible Maillard reaction