Introduction

Historically, chili is one of the oldest domesticated crops in the world  Since they contain impressively beneficial chemical compounds such as capsaicinoids, carotenoids (provitamin A), flavonoids, vitamins (Vitamins C and E), minerals, essential oils, and aromas, they are consumed by a large section of the population throughout the world. In addition to their color, aroma, and characteristic pungency, they are widely used throughout the world as a flavoring and spice. Worldwide, chili is cultivated for its nutritional, medicinal, and economic properties. A good source of antioxidants and potent compounds with biological activities, including capsaicinoids and phenolic acids, is chilies (Chapa-Oliver et al 2016; Manju et al 2002).

History of chilli

Prehistoric humans used chili as a food source. Chilis are grown almost everywhere, regardless of the climate or environment. They are relatively easy to cultivate in nearly any climate or environment. From the terai to the mid-hills of Nepal, chilies are widely cultivated, varying in color, flavor, and pungency. As a spice crop, it occupies the fourth position with a productivity of 3.45 t/ha. Nepalese kitchens are incomplete without it. Both green and dried chilies are commonly used for various purposes (Thapa et al., 2009).

Chili in the food industry

From ancient times, chilies have been one of the most important spices or savory food additives. Besides serving as a vegetable, spice, and value-added processed product, chili has become the most important commercial crop in the world (Ochoa-Alejo & Ramirez-Malagon 2001). However, chilies are not consumed as stand-alone dishes; instead, they are processed into spice powders, oils, sauces, pastes, etc. for flavor and color. Chili is popular worldwide due to the combination of color, flavor, and nutritional value In contrast to synthetic food preservatives, spices are gaining popularity among consumers (Loizzo et al 2017).

Chilies medicinal properties

For centuries, chili powder has been used as a medicine in Ayurvedic preparations as oil extracts and as a major ingredient in therapeutic remedies (Thapa et al 2009). It has been reported that chilies contain compounds that can exert multiple physiological and pharmacological effects, such as analgesia, anticancer activity, anti-inflammatory activity, antioxidant activity, and anti-obesity potential (Abdurahman, 2016; Caporaso et al. 2013). Pain can be relieved with capsaicin topical ointments, nasal sprays, and dermal patches (Ashwini et al. 2015; Prakash et al. 2017). In addition to treating asthma, coughs, sore throats, toothaches, and shingles, chili is used to relieve pain in rheumatoid arthritis, nerve damage, and diabetic neuropathy. (Goci et al., 2014). Studies have shown that chili reduces the likelihood of developing atherosclerosis by reducing blood cholesterol, triglyceride levels, and platelet aggregation as well as increasing fibrinolytic activity (Chopan & Littenberg 2017).

Chilies anti-oxidant properties

Capsaicinoids, carotenoids, and phenolic compounds in chili give the fruit an antioxidant property (Leonor et al 2016). Chili shows antioxidant activities because of the presence of the groups in the phenolic ring (a methoxy group in ortho position to OH) of capsaicinoids and ferulic acid ester, which influenced the antioxidant properties (Viktorija et al 2014). 

Chili and its antimicrobial properties

Chili contains bioactive compounds that have been known to act as a defense mechanism in them. It has been proven to show antimicrobial activity against Staphylococcus aureus, Salmonella typhimurium, Listeria monocytogene, Helicobacter pylori, Pseudomonas aeruginosa, and Bacillus cereus, (Grande-Villanueva et al 2015; Marini et al 2015).

Nutrients in chilies and their health benefits

Chili consists of an equally rich mix of phytonutrients which are the products of secondary metabolism that tend to exhibit ecological functions like plant defense against microbial and fungal pathogens and insect pests(Blanco-Rios et al 2017). Certain studies have proved that the consumption of these phytonutrients confers health benefits such as protection against oxidative damage to cells, preventing the development of common degenerative diseases and risk of coronary heart disease, stroke, and ocular diseases, cardio-protective, anti-microbial, anti-inflammatory, anti-mutagenic agents and possess the ability to scavenge singlet oxygen, inhibit free radicals, decompose peroxide and chelate metals (Salehi et al 2018). They also prevent the oxidation of essential fats within the cells of the brain that are considered necessary for its optimal functioning (Blanco-Ríos et al 2013).

Active constituents present include carotenoids, phenolic compounds, vitamins A, B, and C, volatile oils, flavonoids like β-carotene, α-carotene, lutein, zeaxanthin, and cryptoxanthin, minerals like potassium, manganese, iron and magnesium and other bioactive compounds such as sinapic acid, ferulic acid, violaxanthin, etc. (Baenas et al  2019).

Both sweet and hot varieties of capsicum are rich in vitamin C, and able to satisfy the RDI (Recommended Daily Dose) of 90 mg/100 g (FDA, 2020) in a single cup serving. Vitamin A is found in the form of β-Carotene. Chilis also find their use in the production of synthetic drugs for pain because of the neuroprotective activity of some phenolic compounds. Most forms of chili are rich in many minerals, vitamins, and amino acids essential for human health and growth. They are very high in potassium, magnesium, manganese, and iron, rich in calcium and phosphorus, and are good sources of vitamins K and B in addition to lycopene, flavonoids, and trace metals. A combination of these rich nutrients and antioxidant properties of the phytochemicals inherent in the C(Oǧuzkan 2019).

Their attractive colors are due to the presence of carotenoid and flavonoid pigments. β-carotene with pro-vitamin A activity and oxygenated carotenoids such as capsantine, capsorubin, and cryptocapsin are exclusive to chili. They also contain large quantities of neutral phenolic compounds or flavonoids called quercetin and luteolin(Lu et al., 2017).