Influence of the Thermal Processing on the Physico‐Chemical Properties and the Antioxidant Activity of A Solanaceae Vegetable: Eggplant

Abstract

Physico‐chemical parameters, antioxidants and antioxidant activity were evaluated in eggplant fruit (Solanum melongena) before and after domestic cooking methods (frying, griddling and baking). The results showed large differences among the three treatments. After the cooking process, total phenolics and flavonols increased significantly, whereas vitamin C, carotenoid, lycopene and anthocynin contents decreased significantly. The thermal treated samples showed significant increase in their chemical composition (pH, total soluble solids, ash and non enzymatic browning) along with a significant loss in their water and total sugar contents. Results showed that eggplant improved its antioxidant capacity in all cooking methods. Taken together, our results suggest that the various thermal treatments can increase some phytonutrients and antioxidant activity of eggplant. Practical Applications Eggplant (Solanum melongena L.) is an important source of phytochemicals in the Algerian diet, which can be consumed after three cooking processes: frying, griddling and baking. However, few data are available on the effect of these domestic cooking methods on its nutritional quality. The purpose of this study is to offer to the consumers the best cooking way that enhances phytonutrients and antioxidant activity of eggplant fruit.

Effect of Domestic Cooking on Physicochemical Parameters, Phytochemicals and Antioxidant Properties of Algerian Tomato (Solanum Lycopersicum L. Var. Marmande)

“…It rises with the rate of 6.53 %, 3.71 % and 2.35 % in grilled, fried and baked tomatoes, respectively. A similar result were found in our study on the effect of the three cooking methods tested on eggplant (Arkoub-Djermoune et al, 2016) which may be attributed to the extraction organic acids after softening of the cell walls in cooked samples and/or to their degradation during cooking, which induced a proton release. Furthermore, the increase of pH in cooked tomatoes could be ascribed to the reduction of available carboxylic groups of proteins (Ergezer and Gokce, 2011 et al (2018) this loss is the result of heat treatment (Sahlin et al, 2004).…”

Optimization of mucilage extraction from chia seeds (Salvia hispanica L.) using response surface methodology

“…This behavior can be attributed to the Maillard products produced during heating, with a higher roasting temperature resulting in a greater browning index. Thus, there are two reactions that could result in the caramelization browning: sugar–sugar reactions when heated at high temperatures, and the Maillard reaction, which results from reactions between reducing sugars and proteins and their derivatives (amino acids and amides) . On the other hand, the change of color may be due to the passage of some impurities, such as natural pigments, tannins, coat, tegument, and germ, favored by high temperature …”

“…Thus, there are two reactions that could result in the caramelization browning: sugar-sugar reactions when heated at high temperatures, and the Maillard reaction, which results from reactions between reducing sugars and proteins and their derivatives (amino acids and amides). 28 On the other hand, the change of color may be due to the passage of some impurities, such as natural pigments, tannins, coat, tegument, and germ, favored by high temperature. [29][30][31] The experimental data were fitted to a second-order polynomial model for predicting the variation in extraction yield Y (% (d.b.))…”

Hydrogen peroxide scavenging activity of grape (Vitis vinifera) methanolic extract

“…Antioxidant capacity is widely used as a parameter for medicinal bioactive components. Different artificial species have been used such as 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) (Brand-williams et al, 1995;Mariutti et al, 2008), 1,1 diphenyl-2-picrylhydrazyl (DPPH) (Sharma et al, 2013;Arkoub-Djermone et al, 2015), OH radicals scavenging activity (Mathew and Abraham, 2006), hydrogen peroxide scavenging activity (H 2 O 2 ) (Baydar et al, 2007), Ferric reducingantioxidant power (FRAP) (Derradji-Benmeziane et al, 2014), superoxide anion radical scavenging activity (O.2-) (Gulcin et al, 2010) and many others methods. In this study, the antioxidant activity of the grape extract has been evaluated in vitro tests namely: hydrogen peroxide scavenging activity.…”