Different effects of heating and freezing treatments on the antioxidant properties of broccoli, cauliflower, garlic and onion. An experimental in vitro study

Abstract

Consumption of fruits and vegetables is associated with reduced risks of hypertension, stroke, coronary heart disease, cancer, dementia and type 2 diabetes mellitus. 1 The beneficial effects of vegetables and fruits are attributed to presence of certain bioactive compounds, like polyphenols. Flavonoids, phenolic acids, lignins and stilbenes are polyphenols that exhibit antioxidant effects. 2 Broccoli (Brassica oleracea var. italica) is a member of the Cruciferous family. 3 Glucosinolates, flavonoids, cinnamic acid derivatives, carotenoids, ascorbic acid, xanthophylls and minerals are among the substances that broccoli contains. The anticarcinogenic, antimutagenic and antioxidant properties of these compounds contribute to the health benefits from broccoli. 4 Cauliflower (Brassica oleracea var. botrytis L.) is also included in the Cruciferous family. The components of cauliflower include glucosinolates, ascorbic acid, carotenoids, phenolic compounds and vitamin E. 3 It has anticarcinogenic and antioxidant effects, like other cruciferous vegetables. 5,6 Garlic (Allium sativum) has been consumed as a vegetable and natural remedy for centuries. 7 In addition to organosulfur compounds, garlic contains high amounts of vitamins, minerals and phenolic compounds. So far, garlic has been reported to have anticancer, antimicrobial, antioxidant, anti-inflammatory, immunomodulatory and cardioprotective properties. 8 Onion (Allium cepa L.) is cultivated in many parts of the world, given its adaptable nature. Flavonoids and alk(en)yl cysteine sulfoxides are the main bioactive groups in onion, and these compounds are responsible for antithrombotic, antiasthmatic, anticarcinogenic, antioxidant, antifungal and antibacterial effects. 9

Recent Advances in Bioactive Compounds, Health Functions, and Safety Concerns of Onion (Allium cepa L.)

“…The influences of food processing on antioxidant capacities of onions were investigated as well, including drying (143,144), freezing (145), heating (41, 145), sautéing (38), and high-pressure processing (36). For instance, heating and freezing were found to reduce antioxidant activity of onion ( 145), while sautéing did not significantly change it (38).…”

Effects of different sterilization methods of herbal formula on phytochemical compounds and antibacterial activity against mastitis-causing bacteria

“…[ 25 ] demonstrated that phytochemical compounds in herbal plants were decreased in quantity with thermal processing, and the reduction increased with increasing heating time. Likewise, a recent study illustrated that heat treatment had deleterious effects on phenolic concentrations of cauliflower and onion extracts [ 26 ]. Conversely, this study demonstrated that autoclave sterilization exerted a less negative impact on phenolic and flavonoid compounds, compared with the microfiltration method.…”

Phytotherapy and food applications from Brassica genus

“…Rheumatic pains (Tuttolomondo et al, 2014) In this sense, several works demonstrated the antioxidant activi- In vitro studies to elucidate the convenient cooking and storage patterns for conservation of the best antioxidant potential of Brassica species have been performed (Çubukçu, Kılıçaslan, & Durak, 2019).…”

“…It could be explained that type of solvent is directly related with the content and quality of the extracted compounds. In vitro studies to elucidate the convenient cooking and storage patterns for conservation of the best antioxidant potential of Brassica species have been performed (Çubukçu, Kılıçaslan, & Durak, 2019).…”