Many bioactive peptides have been described from marine sources and much marine biomass is still not explored or utilized in products. Marine peptides can be developed into a variety of products, and there is a significant interest in the use of bioactive peptides from marine sources for nutraceuticals or functional foods. We present here a mini-review collecting the knowledge about the value chain of bioactive peptides from marine sources used in nutraceuticals and functional foods. Many reports describe bioactive peptides from marine sources, but in order to make these available to the consumers in commercial products, it is important to connect the bioactivities associated with these peptides to commercial opportunities and possibilities. In this mini-review, we present challenges and opportunities for the commercial use of bioactive peptides in nutraceuticals and functional food products. We start the paper by introducing approaches for isolation and identification of bioactive peptides and candidates for functional foods. We further discuss market-driven innovation targeted to ensure that isolated peptides and suggested products are marketable and acceptable by targeted consumers. To increase the commercial potential and ensure the sustainability of the identified bioactive peptides and products, we discuss scalability, regulatory frameworks, production possibilities and the shift towards greener technologies. Finally, we discuss some commercial products from marine peptides within the functional food market. We discuss the placement of these products in the larger picture of the commercial sphere of functional food products from bioactive peptides.

This study generated bioactive hydrolysates using the enzyme Alcalase and autolysis from mesopelagic fish, including Maurolicus muelleri and Benthosema glaciale. Generated hydrolysates were investigated for their bioactivities using in vitro bioassays, and bioactive peptides were identified using mass spectrometry in active hydrolysates with cyclooxygenase, dipeptidyl peptidase IV and antioxidant activities. In silico analysis was employed to rank identified peptide sequences in terms of overall bioactivity using programmes including Peptide Ranker, PrepAIP, Umami-MRNN and AntiDMPpred. Seven peptides predicted to have anti-inflammatory, anti-type 2 diabetes or Umami potential using in silico strategies were chemically synthesised, and their anti-inflammatory activities were confirmed using in vitro bioassays with COX-1 and COX-2 enzymes. The peptide QCPLHRPWAL inhibited COX-1 and COX-2 by 82.90% (+/−0.54) and 53.84%, respectively, and had a selectivity index greater than 10. This peptide warrants further research as a novel anti-inflammatory/pain relief peptide. Other peptides with DPP-IV inhibitory and Umami flavours were identified. These offer potential for use as functional foods or topical agents to prevent pain and inflammation.

(1) Background: it is only the longer chain omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (20:5n-3, EPA), and docosahexaenoic acid (22:6n-3, DHA) and not the shorter chain α-linolenic acid (ALA, 18:3n-3) that have been linked to health benefits. (2) Methods: 45 dogs divided into three groups were first given premium dry food for 38 days (baseline). The O3I was then used as a diagnostic tool to provide a measure of the sum of EPA + DHA in red blood cell membranes given as a percentage of all fatty acids. The dogs were subsequently fed with either krill meal (krill), fishmeal/oil (fish) or flaxseed cake (flax) included in raw food providing daily 416 mg EPA + DHA (971 mg ALA), 513 mg EPA + DHA (1027 mg ALA) and 1465 mg ALA (122 mg EPA + DHA), respectively. (3) Results: the average baseline O3I level of all dogs was low (1.36%), warranting n-3 supplementation. After four weeks, O3I levels were significantly increased in the krill (from 1.36 ± 0.44 to 2.36 ± 0.39%) and fish (from 1.35 ± 0.22 to 1.9 ± 0.35%) groups (p < 0.001). No significant modification of the O3I was detected in the flax animals. (4) Conclusions: only marine n-3 PUFAs resulted in a significantly increased O3I, with dietary krill meal providing the highest increase.

Bioactive peptides are sequences of amino acids, cut from the parent protein with en-zymes or high pressure processing that can impart a tertiary health benefit to the con-sumer that goes beyond basic human nutrition. This study explores mesopelagic fish in-cluding Maurolicus muelleri and Benthosema glaciale as sources of peptides with an-ti-inflammatory, heart health beneficial, antioxidant and other bioactivities. Bioactive peptides were generated post-catch using different enzymatic hydrolysis processes ap-plied to mesopelagic species caught from experimental cruises targeting these fish. Maurolicus muelleri and Benthosema glaciale were the dominant species processed. Bi-oactive hydrolysates included a Maurolicus muelleri Alcalase hydrolysate and a Maurolicus muelleri autolysis. Hundreds of peptide sequences were identified using mass spectrome-try from active hydrolysates. In silico analysis was used to rank identified peptide se-quences in terms of overall bioactivity using Peptide Ranker, anti-inflammatory activity using PrepAIP, ability to impart Umami flavours with Umami-MRNN and dipeptidyl peptidase IV inhibitory potential using AntiDMPpred . Thirty peptides were selected fol-lowing in silico analysis. Several of the selected peptides had sequence homology with peptides derived from other fish proteins including Atlantic salmon (peptide QCPLHR-PWAL) and thin-lipped mullet (peptide FDAFLPM). Seven peptides predicted to have an-ti-inflammatory, anti-type 2 diabetes or Umami potential using in silico strategies were chemically synthesized and their anti-inflammatory activities confirmed using in vitro bioassays with COX-1 and COX-2 enzymes. The peptide QCPLHRPWAL inhibited COX-1 and COX-2 by 82.90% (+/-0.54) and 53.84% respectively and had a selectivity index greater than 10. This peptide warrant further research as a novel anti-inflammatory/pain relief peptide. Other bioactivities associated with DPP-IV inhibition and Umami flavours de-velopment are discussed. Identified peptides offer potential for use in functional foods or topical agents to prevent pain and inflammation associated with diseases like psoriasis, arthritis and inflammatory bowel disease, however further research in vivo is required.

Shrimp feeds depend on high levels of digestible protein and essential amino acids, which can be sourced from various commercially available feed ingredients. Marine proteins can be used to partially fulfill the requirements of these and other important nutrients. Their utilization is further influenced by their palatability and growth-promoting effect. However, marine ingredients can significantly drive costs in feed formulation depending on the type and dietary inclusion level. This study aimed to determine the minimum dietary level of fish meal (FML) and krill meal (KRM) and their mix ratio to elicit feed intake and growth performance in juvenile Penaeus vannamei. Ten diets were formulated with graded FML (90, 60, 30 g kg⁻¹) in combination with 15, 30, and 45 g kg⁻¹ KRM and a control diet with 120 g kg⁻¹ FML. Shrimp (1.28 ± 0.08 g body weight, BW) were stocked in seventy 1-m³ tanks (135 animals m⁻²), and after 88 days, their growth performance was determined. Feed preference was assessed through two-by-two comparisons in twenty 0.5 m³ tanks over four weeks. No significant differences in survival (93.9 ± 4.5%), gained yield (1235 ± 92 g m⁻²), and feed conversion ratio (1.47 ± 0.09) were observed. Diets with 60 g kg⁻¹ FML led to faster growth and higher feed intake than 30, 90, and 120 g kg⁻¹ FML. Shrimp on 30 g kg⁻¹ FML diets had the lowest BW, especially with 30–15 (FML-KRM) and 30–30 diets. Diets with 90 g kg⁻¹ FML outperformed 30 g kg⁻¹ FML. The control diet delivered a higher shrimp BW than diets 30–15 and 30–30, showing similar results to other diets except 60–15. Feed preference was influenced by KRM inclusion, with 15 g kg⁻¹ KRM resulting in higher apparent feed intake than 30 and 45 g kg⁻¹. The findings indicate that FML can be effectively reduced by up to 75% when combined with lower levels of KRM. This corresponds with the industry’s ongoing trend to achieve greater sustainability and cost efficiency through the reduced utilization of critical resources.