Amaranth Seeds and Sprouts as Functional Ingredients for the Development of Dietary Fiber, Betalains, and Polyphenol-Enriched Minced Tilapia Meat Gels.

There is an increasing interest in the development of meat processed products enriched with antioxidant dietary fiber to augment the consumption of these health beneficial compounds. This study aimed to evaluate the nutritional, nutraceutical, and antioxidant potential, as well as the physicochemical properties of minced tilapia fillets (meat) gels with added amaranth seed or sprout flours (0%, 2%, 4%, 8%, and 10% w/w). Dietary fiber content was significantly increased with the addition of amaranth seed (1.25-1.75-fold) and sprout flours (1.99-3.21-fold). Tilapia gels with added 10% amaranth seed flour showed a high content of extractable dihydroxybenzoic acid and cinnamic acid, whereas the addition of 10% amaranth sprout flour provided a high and wide variety of bioactive compounds, mainly amaranthine and bound ferulic acid. The addition of amaranth seed and sprout flours increased hardness (1.01-1.73-fold) without affecting springiness, decreased luminosity (1.05-1.15-fold), and increased redness and yellowness. Therefore, amaranth seed and sprout flours could be used as functional ingredients for the development of fish products rich in bioactive compounds.

Citrus decoction by-product represents a rich source of carotenoid, phytosterol, extractable and non-extractable polyphenols.

This study aimed to carry out an exhaustive chemical characterization of citrus (orange, mandarin, and grapefruit) decoctions as well as the residues obtained during the decoction process (by-products). The citrus decoctions were rich in hesperidin, naringin, and narirutin, but carotenoids and phytosterols were not detected. Interestingly, these flavanones were found in a higher concentration in the extractable polyphenol fraction of the citrus decoction by-products. Moreover, the greatest content of hesperidin and naringin was found bound to the food matrix by ether/ester bonds. Violaxanthin and ß-cryptoxanthin were found as major carotenoids in the orange and mandarin decoction by-products, respectively, whereas the grapefruit decoction by-product showed a low content of carotenoids. All citrus by-products showed ß-sitosterol as the major phytosterol, followed by ß-campesterol. Therefore, the by-products obtained during the elaboration of citrus decoctions are rich sources of bioactive compounds that can be used for the development of functional foods or dietary supplements.