This study aimed to assess the variations in the nutritional attributes of thirteen Moringa oleifera cultivars. Leaves from six-month-old plants were harvested and tested for various nutritional attributes. There were significant (p ≤ 0.05) differences in the carbohydrates, energy, some of the sugars and fibre amongst the cultivars. The levels of moisture in the cultivars ranged from 7.10% to 8.20%. Additionally, there were significant (p ≤ 0.05) differences across the cultivars in microelements studied except for zinc (Zn). These data revealed that plants from different geographical provenances differed in their adapting to varied environments. In general, under the same cultivation, management and environmental conditions, the main reasons for these differences occurred in cultivars could be associated with the genetic background of each M. oleifera germplasm. However, the study cautions on the differences of nutritional properties, as some of the cultivars have been reported not to be pharmacological potent.

Organic Medium Enclosed Trough (OMET) is a new non-drainable growing technique. The study envisioned to investigate the interactive effects of OMET and Amaranth species vari-ation on some growth attributes, bioactive compounds and nutrients. Three Amaranth species: A. caudatus, A. cruentus and A. tricolor were grown in an OMET and non-OMET growing conditions. Growth attributes, irrigation water, bioactive compounds and nutri-ents were determined. Non-OMET and A. cruentus showed the highest total phenolics and flavonols followed by A. caudatus and A. tricolor, whilst tannins were predominant in A. caudatus followed by A. cruentus and A. tricolor. The use of unsupervised PCA showed major metabolic variation based on Amaranth species and the use of supervised OPLS-DA showed clear metabolic variation based on OMET and non-OMET. OMET and A. cruentus showed the highest plant height, stem diameter, biomass, and some nutrients (%protein, Ca, P, Cu, Se, Zn), followed by A. caudatus based only on growth and biomass, and A. tricol-or based only on some nutrients (Mg, K, Mn, and Fe). The use OMET system on A. cruentus and A. tricolor can be recommended to mitigate climate change effects on nutritional com-position using low irrigation water.

Melatonin is an important hormone with a methoxy-indole structure. It is secreted regularly by the pineal gland of mammals. It takes part in many chemical, biological, and physiological activities of the body. Melatonin, acts as a basic hormone, and is responsible for circadian rhythm regulation and sleep control. It has been shown to occur in the highest concentration in organisms during the night times. In living organisms, many activities that have physiological, biological, hormonal, and psychological characteristics follows a certain rhythm. Body temperature, hormone levels, sleep-wakefulness, and some other cognitive functions in humans also change with the circadian rhythm. Its synthesis and release begin with darkness and end with light. This review aims to explore the functions of melatonin such as its stimulating effects on antioxidant enzymes, reducing lipid peroxidation, and protecting brain tissue from oxidative damage. It also has properties that stop the proliferation of cancer cells and prevent tumor growth. Melatonin, which was previously known only as an animal hormone, has been found to also exist in plants. Research has shown that melatonin is present in almost all plant species analyzed to date and that it performs functions similar to those in animals. In plants, it plays a vital role in dealing with various abiotic and biotic stresses. Melatonin acts as an important antioxidant in post-harvest technology and extends the post-harvest life of fruits and vegetables. It also takes part in the regulation of stress-specific genes and the activation of pathogenesis-related proteins and antioxidant enzymes. The most prominent roles of melatonin in plants include regulating circadian rhythm, growth, and development, and increasing tolerance to a wide range of environmental stress factors. The review reveals the effects of melatonin as an extremely important secondary metabolite, on human, animal, and plant metabolism. The use of PRISMA guidelines was used for reporting, search, selection, and synthesis. Information up to 2024 was searched from search engines for the occurrence, nature and function of melatonin. Key words such as structural function, hormonal function, secretion and metabolism were used in the search of publications.

Cholesterol is a lipid-derived substance found in lipoproteins and cell membranes. It is also one of the main sources for the production of bile acids, vitamin D, and steroid hormones. Today, foods are evaluated by consumers not only according to their taste and nutritional content but also according to their effects on consumer health. For example, many consumers choose foods according to their cholesterol level. The cholesterol in the food can directly affect the blood cholesterol level when consumed, which can lead to cardiovascular diseases. High levels of cholesterol can lead to diet-related human diseases such as cardiac arrest, paralysis, type II diabetes cerebral hemorrhage. In societies with high living standards, interest in and consumption of foods that lower or have low cholesterol levels have increased recently. Accordingly, efforts to increase the variety of foods with reduced cholesterol levels are on the rise. This has indirectly insulted in accurate measurement of cholesterol levels in blood and food being of great importance. Classical chemical, enzymatic, colorimetric, polarographic, chromatographic, spectrophotometric methods, and enzymatic, nonenzymatic, and electrochemical sensors and biosensors are used for the determination of cholesterol in foods. The purpose of this review is to reveal and explore current and future trends in cholesterol detection methods in foods. The review will summarize the most appropriate and standard methods for measuring cholesterol in biological components and foods.