Effects of thermal treatments on ascorbic acid content of leafy vegetables: An in vitro analysis

Abstract

The green leafy vegetables are packaged with nutritional and medicinal benefits for holistic wellbeing which ca n be contributed to presence of phytochemicals and micronutrients. Processing of food, affects the nutritional value, concentration, and biological activities of all components to different extent. In this perspective, the content of antioxidant activity in unprocessed food in relation to that in processed foods requires attention and has emerged as an important parameter to assess product quality. Further, most vegetables are consumed post cooking, though a few like green leafy ones are consumed raw, as in salads. This study aims to evaluate the effect of cooking on the vitamin C in commonly used greens as spinach (Spinacia oleracea L.), radish (Raphanus sativus L.), fenugreek (Trigo nella foe nu m-g rae cum L.), coriander (Co ria ndrum sativum L.) a nd shepu (An eth um graveolens L.). Domestic heating methods used were blanching, steaming, and microwaving. Vitamin C was estimated through titrimetry and the results of the study revealed that cooking causes a significant reduction in ascorbic content of all five leafy vegetables with microwaving cooking accounting to maximum loss for all five samples. Highest vitamin C loss on blanching was in fenugreek (51.04 %), followed by shepu leaves (45.35%), coriander (44.64%), radish leaves (16.67%) and spinach (15.68%) while on steaming, highest loss of vitamin C amongst selected vegetable occurred in fenugreek leaves (35.77%), followed by radish leaves (33.34%), coriander leaves (25.67%), shepu (22.74%), spinach leaves (17.58 %). In view of this, it could be concluded that cooking by boiling with microwaving, steaming and blanching decreases the vitamin C contents in green leafy vegetables, and needs to be considered, so as to make available ascorbic acid, maximally.

Assessment of the effect of heat processing on vitamin composition of selectedstaple green leafy vegetables in Nigeria

“…Nevertheless, these leafy vegetables are commonly exposed to various cooking processes in order to increase their palatability [3]. They are extremely vulnerable to vitamins loss during processing [4], hence the contents of water-soluble vitamins can be altered by most of these processing methods, particularly the thermolabile components, thereby reducing the amount of the water-soluble vitamins required for daily body metabolism [5]. Therefore, this study evaluates and compares the vitamin content and retention in six regularly consumed vegetable species, both fresh and processed.…”

Effect of Heat Processing on Vitamin Composition of Selected Staple Green Leafy Vegetables in Nigeria

“…Nevertheless, these leafy vegetables are commonly exposed to various cooking processes in order to increase their palatability [3]. They are extremely vulnerable to vitamins loss during processing [4], hence the contents of watersoluble vitamins can be altered by most of these processing methods, particularly the thermolabile components, thereby reducing the amount of the water-soluble vitamins required for daily body metabolism [5]. Therefore, this study evaluates and compares the vitamin content and retention in six regularly consumed vegetable species, namely, Amaranthus hybridus, Corchorus olitorius, Ocimum gratissimum, Talinum triangulare, Telfaria occidentalis and Vernonia amygdalina, both fresh and processed, in order to acquire the necessary vitamins, like, ascorbic acid (vitamin C), thiamin (vitamin B1), riboflavin (vitamin B2) and niacin (vitamin B3) that are important for human metabolism and protection of human body against diseases.…”

Screening of in vivo anti-inflammatory and analgesic potential of methanolic extract of roots of Glycyrrhiza glabra L. in rats

“…0.93 billion Indians, who make up 17.84 % of the world's population, still rely on traditional remedies to maintain their essential health (Usha et al, 2018;Cordell, 2002). For their primary healthcare, both urban inhabitants in wealthy countries and rural communities in developing countries use these drugs, which are widely used today (Mehrotra, 2021;Das, 2021). The foundation of the ancient Indian medical system known as Ayurveda is made up of medicinal herbs (Bhatt, et al, 2021;Palai and Patra, 2021;Sumathi, et al, 2021).…”