Determination of Macronutrient Compositions in Selected, Frequently Consumed Leafy Vegetables, Prepared According to Common Culinary Methods in Sri Lanka

Abstract

Information regarding realistic macronutrient gains by consuming cooked Sri Lankan leafy vegetables are rare. Some available information often overestimates available carbohydrate contents and under-estimates dietary fibre contents, as a result of not using in-vitro digestion models prior to proximate analysis. In aim to address this issue, nine most frequently consumed leafy vegetables types in Sri Lanka were cooked and analysed for their moisture, digestible carbohydrate, protein, fat, soluble fibre and insoluble fibre contents. All vegetables were prepared in most frequently practiced culinary methods by the local community such as salads, tempered with oils, or as curries/gravies. Dry weights of all macronutrients were determined using six replicates to maximize the accuracy of results.
Majority of the leafy vegetable types selected elicited substantial amounts of dietary fibre. The highest content of insoluble dietary fibre was present in Centella asiatica (centella) leaves salad (51.0±3.4%), whereas highest percentage of soluble dietary fibre was in Heracleum sphondylium (hogweed) leaves prepared as a curry (16.4±1.7%). H. sphondylium curry (20.7±1.3%) and Sesbania grandiflora (Hummingbird) leaves salad (20.7±0.9%) resulted in greatest amounts of digestible carbohydrates.The highest fat content (12.6±0.5%) was in Ipomoea aquatic (water spinach) since it was tempered with coconut oil as it is the mostly practiced local culinary method for Ipomoea. Spinacia oleracea (spinach) curry elicited the highest protein content (4.8±0.9%) among all leafy vegetables.

Keywords: Dietary fibre, leafy vegetables, digestible carbohydrates, Centella asiatica, Heracleum sphondylium, Sesbania grandiflora