Influence of microwave bag vs. conventional microwave cooking on phytochemicals of industrially and domestically processed broccoli

Impact of thermal processing on polyphenols, carotenoids, glucosinolates, and ascorbic acid in fruit and vegetables and their cardiovascular benefits

Bioactive compounds in fruit and vegetables have a positive impact on human health by reducing oxidative stress, inflammation, and the risk of chronic diseases such as cancer, cardiovascular (CV) diseases, and metabolic disorders. However, some fruit and vegetables must be heated before consumption and thermal processes can modify the amount of nutraceuticals, that is, polyphenols, carotenoids, glucosinolates, and ascorbic acid, that can increase or decrease in relation to different factors such as type of processing, temperature, and time but also the plant part (e.g., flower, leaf, tuber, and root) utilized as food. Another important aspect is related to the bioaccessibility and bioavailability of nutraceuticals. Indeed, the key stage of nutraceutical bioefficiency is oral bioavailability, which involves the release of nutraceuticals from fruit and vegetables in gastrointestinal fluids, the solubilization of nutraceuticals and their interaction with other components of gastrointestinal fluids, the absorption of nutraceuticals by the epithelial layer, and the chemical and biochemical transformations into epithelial cells. Several studies have shown that thermal processing can enhance the absorption of nutraceuticals from fruit and vegetable. Once absorbed, they reach the blood vessels and promote multiple biological effects (e.g., antioxidant, anti-inflammatory, antihypertensive, vasoprotective, and cardioprotective). In this review, we described the impact of different thermal processes (such as boiling, steaming and superheated steaming, blanching, and microwaving) on the retention/degradation of bioactive compounds and their health-promoting effects after the intake. We then summarized the impact of heating on the absorption of nutraceuticals and the biological effects promoted by natural compounds in the CV system to provide a comprehensive overview of the potential impact of thermal processing on the CV benefits of fruit and vegetables.

Microwave bag cooking affects the quality, glucosinolates content and hydrolysate production of broccoli florets

Appropriate processing and cooking technologies can effectively improve the content of bioactive compounds in vegetables. The effects of microwave bag cooking on broccoli floret quality attributes, glucosinolates (GLSs) content and hydrolysate production were investigated in this study. Microwave bag cooking not only preserved the color of the florets, but also enhanced the total phenolic and flavonoid content, as well as total chlorophyll and ascorbic acid content. Furthermore, the majority of the microorganisms were inactivated, and the structure of the florets was greatly destroyed, thereby increasing antioxidant capacity and promoting the release of GLSs and myrosinase activity in the florets. Moreover, microwave bag cooking significantly enriched the sulforaphane (SFN) and indole-3-carbinol (I3C) production of broccoli florets in the meantime, demonstrating that it was a convenient and quick cooking option to satisfy the requirements of modern consumers.