Comparison of nutritional composition, bioactivities, and FTIR- ATR microstructural properties of commercially grown four mushroom species in Sri Lanka; Agaricus bisporus, Pleurotus ostreatus, Calocybe sp. (MK-white), Ganoderma lucidum

Abstract Mushrooms have been consumed as delicacies since ancient times; however, little knowledge is available on the nutritional and bioactive properties of commercially grown mushroom species in Sri Lanka; button (Agaricus bisporus), oyster (Pleurotus ostreatus), Makandura white (Calocybe sp.), and Reishi (Ganoderma lucidum). Samples from four mushroom species were analysed for proximate composition, mineral and fatty acid content, and antioxidant, antidiabetic, and microstructural properties. Carbohydrate, protein, fat, ash, and dietary fibre content in mushroom species ranged from 64.83–79.97%, 10.53–23.29%, 0.57–4.37%, 2.80–11.00%, and 33.04 to 75.33%, respectively. The highest (P ≤ 0.05) protein and ash content were observed in A. bisporus, and G. lucidum had the highest (P ≤ 0.05) fat and dietary fibre content. When considering the micronutrients, G. lucidum comprised higher (P ≤ 0.05) Ca, Mg, Mn, and Cu, while A. bisporus had higher (P ≤ 0.05) Fe and Zn contents than other species. Essential omega-6 fatty acid, linoleic (18:2n-6) content was in the range of 37- 81% in studied mushroom samples. Results obtained from FTIR (Fourier transform infrared spectroscopy) in conjunction with ATR (Attenuated total reflectance) revealed the presence of functional groups associated with fat (̴1740 cm−1), protein (̴1560 cm−1), polysaccharides (1500–750 cm−1) and moisture (̴3300 cm−1) in mushroom samples. According to the results, P. ostreatus showed the highest (P ≤ 0.05) polysaccharide content, while G. lucidum showed the lowest (P ≤ 0.05). The highest (P ≤ 0.05) total phenolic content (TPC) (3.95 ± 0.05 mg GAE/g DW) and total flavonoid content (TFC) (2.17 ± 0.06 mg CE/g DW) were observed in P. ostreatus. Antioxidant activity measured by DPPH, ABTS, and FRAP methods was higher (P ≤ 0.05) in P. ostreatus and A. bisporus compared to the other two species. Among all the studied mushroom species, G. lucidum showed the highest (P ≤ 0.05) α-amylase (IC50 = 77.51 ± 6.80 µg/mL) and α-glucosidase (IC50 = 0.4113 ± 0.08 µg/mL) inhibition activities. This study reveals the potential of using A. bisporus, G. lucidum, and P. ostreatus for nutritional, functional, and therapeutic uses. Graphical Abstrac

Cowpea : an overview on its nutritional facts and health benefits

Cowpea (Vigna unguiculata) is a legume consumed as a high‐quality plant protein source in many parts of the world. High protein and carbohydrate contents with relatively low fat content and complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet. Cowpea has gained more attention recently from consumers and researchers worldwide due to its exerted health beneficial properties including anti‐diabetic, anti‐cancer, anti‐hyperlipidemic, anti‐inflammatory and anti‐hypertensive properties. Among the mechanisms that have been proposed in the prevention of chronic diseases, the most proven are attributed to the presence of compounds such as soluble and insoluble dietary fiber, phytochemicals and proteins and peptides in cowpea. However, studies on the anticancer and anti‐inflammatory properties of cowpea have produced conflicting results. Some studies support a protective effect of cowpea on the progression of cancer and inflammation, while other studies demonstrate no effect. Since there are only a few studies carried on this regard, further studies in this area are suggested. In addition, despite the so far reported favorable effects of cowpea on diabetes, hyperlipidemia and hypertension, a long‐term epidemiological study investigating the association between cowpea consumption and diabetes, cardiovascular disease and cancer is also recommended

Chemical composition and health benefits of coconut oil : an overview

Coconut oil is an integral part of Sri Lankan and many South Asian diets. Initially, coconut oil was classified along with saturated fatty acid food items and criticized for its negative impact on health. However, research studies have shown that coconut oil is a rich source of medium-chain fatty acids. Thus, this has opened new prospects for its use in many fields. Beyond its usage in cooking, coconut oil has attracted attention due to its hypocholesterolemic, anticancer, antihepatosteatotic, antidiabetic, antioxidant, anti-inflammatory, antimicrobial and skin moisturizing properties. Despite all the health benefits, consumption of coconut oil is still underrated due to a lack of supportive scientific evidence. Even though studies done in Asian countries claim a favorable impact on cardiac health and serum lipid profile, the limitations in the number of studies conducted among Western countries impede the endorsement of the real value of coconut oil. Hence, long-term extensive studies with proper methodologies are suggested to clear all the controversies and misconceptions of coconut oil consumption. This review discusses the composition and functional properties of coconut oils extracted using various processing methods