**Abstract**

Bioactive ingredients (BI) bestow various health-promoting outcomes on consumers, including treating or preventing diabetes, obesity, cancer, coronary heart diseases, and so on. Several BI have been found in nature, such as flavonoids, carotenoids, polyphenols, curcumin, phytosterols, probiotics, bioactive peptide, minerals, and nano-bio minerals, which can be incorporated into foodstuffs to improve their nutritional values. The foods containing BI are considered functional food. This review shed light on the health benefits of various BI for consumers. Due to the growing rate of population and surging demands for healthy foods in the future, it is pivotal to use affordable natural sources of BI to provide functional foods for a vast majority of people. Thus, in this review article, some potent by-products are addressed as alternative sources of BI.

**Keywords:** bioactive ingredients, functional food, nutrients
