Meat proteins and associated by-products can be used as a source of bioactive hydrolysates and peptides with potential for use as functional food ingredients. Functional foods are foods that have a potentially positive effect on health, beyond basic nutrition. Numerous bioactive peptides, including angiotensin-I-converting enzyme (ACE-I, EC 3.4.15.1) and dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) inhibitors, have been generated from meat by-product proteins to date. However, in order to use and commercialize bioactive hydrolysates and peptides as food ingredients, a number of significant challenges must first be overcome. This article gives an overview of the current state-of-the-art of meat-derived bioactive hydrolysate and peptide uses in the food industry. It also reviews frequent challenges faced when developing biologically active hydrolysates and peptides as food ingredients. These challenges include, but are not limited to, high production costs, negative sensory attributes in end products, taste modifications of carrier food products and compliance with, for example, the European Food Safety Authority (EFSA), the Food and Drug Administration (FDA), and other regulatory bodies in China, or Japan, as well as potential toxicity or allergenicity. We suggest strategies that may assist in overcoming these challenges, focusing on those that may be used to improve the taste attributes of the end products.

Astaxanthin is a high-value carotenoid currently being produced by chemical synthesis and by extraction from the biomass of the microalga Haematococcus pluvialis. Other microalgae, such as Chlorella zofingiensis, have the potential for being used as sources of astaxanthin. The differences between the synthetic and the microalgae derived astaxanthin are notorious: not only their production and price but also their uses and bioactivity. Microalgae derived astaxanthin is being used as a pigment in food and feed or aquafeed production and also in cosmetic and pharmaceutical products. Several health-promoting properties have been attributed to astaxanthin, and these were summarized in the current review paper. Most of these properties are attributed to the high antioxidant capacity of this molecule, much higher than that of other known natural compounds. The aim of this review is to consider the main challenges and opportunities of microalgae derived products, such as astaxanthin as food. Moreover, the current study includes a bibliometric analysis that summarizes the current research trends related to astaxanthin. Moreover, the potential utilization of microalgae other than H. pluvialis as sources of astaxanthin as well as the health-promoting properties of this valuable compound will be discussed.