Seafood is consumed all around the world. It is considered a high-quality food and
an excellent source of vitamins, minerals, proteins, essential amino acids, and fatty
acids (1–3). Seafood consumption have been associated with the reduction of inflammatory
diseases, stroke, arthritis, hypertension, attention deficit hyperactivity disorder,
and reduced risk of Alzheimer's disease, cardiovascular disease, cancer, and depression
(1, 4).
Contamination of coastal areas and oceans, originating from human activities, disturbs
marine ecosystems, thus causing seafood to be also a potential source of pollutants
such as microplastics, pesticides, synthetic musks, persistent organic pollutants,
metals, and pharmaceuticals (3–6). There is also the threat of potential biological
hazards such as the production and accumulation of natural toxins and allergens (e.g.,
tetrodotoxin, histamine, ciguatera), as well as parasites and various infectious pathogens,
including bacteria and viruses. The consumption of contaminated seafood may, therefore,
represent a major hazard to human health (4). Owing to this, the risk-benefit scale
for seafood consumption has always been a discussion issue. Nonetheless, the quality
decline of the aquatic environment over the years may have toppled toward the risk
portion, with several protection agencies issuing policy statements and/or guidance
on this conundrum. Overall, it is vital to monitor the aquatic environment and produce
more research about new developments and understanding on the safe production, value,
and risks of seafood for human consumption. The articles included in this Research
Topic are from experts in the fields of food quality, food safety, risk assessment,
health hazard, toxicology, and nutritional research.
Fish is highly consumed around the world, representing 17% of the total animal protein
consumed by humans (7). The reducing of production costs while maintaining the flesh
quality and flavor of aquaculture fish is a challenge. An alternative is the inclusion
of plant protein in fish meals. On this aspect, Li et al. combined molecular biology
and metabolomics techniques to thoroughly investigate the molecular mechanisms by
which different plant proteins affect the proliferation and degradation of muscle
proteins of yellow catfish. The authors found soybean meal, peanut meal, cottonseed
meal, sesame meal and corn gluten meal regulated the biosynthesis and degradation
of muscle protein by affecting the content of vitamin B6, proline, glutamic acid,
and phenylalanine (tyrosine) in muscle. The plant proteins improved the flesh quality
and texture, despite significantly reducing the growth performance. The authors observed
that inhibition of myocyte proliferation-related genes in cottonseed, sesame and corn
gluten groups might additionally be regulated by the increase of glutamic acid and
the decrease of tyrosine contents (Li et al.). The work provides a needed theoretical
basis for further understanding the mechanism of plant proteins regulating flesh quality.
Still related to alternative protein sources, Alvanou et al. evaluated for the first
time the incorporation of larvae of black soldier flies (Hermetia illucens) in the
feeds of aquaculture crayfish. Crustaceans have long been considered a delicacy. The
demand for crustaceans, on the one hand, has been increasing worldwide, which can
lead to overexploitation of wild species. On the other hand, the aquaculture farming
of these species is costly due to the substantial amount of fishmeal required in the
feeds (Alvanou et al.). Insects are high in protein and fat, and an alternative of
low environmental footprint. The investigation of Alvanou et al. found that 98 days
fishmeal replacements of 50 and 100% in juvenile diets increased crayfish survival
but negatively affected its growth performance and feed utilization. The inclusion
of the fly larvae in the diet also altered the fatty acid levels and profiles of crayfish.
The study shed some light on contradictory results available in the literature for
other species.
On another relevant topic and with a different approach, Quaresma et al. studied the
protein quality of dried salted cod fish, the 3rd highest consumed fish in the European
Union. Due to high demand and capture, Atlantic cod is considered a vulnerable species
by the International Union for the Conservation of Nature. In comparison, Pacific
cod is captured in lower amounts. Considering this, Quaresma et al. evaluated and
classified the nutritional quality in relation to the cod species (Gadus morhua and
Gadus macrocephalus) and harvesting areas (Norway and Iceland Exclusive Economic Zones)
using an essential amino acid index. They found the amino acid profiles and the index
produced full accurate discrimination of the cod species. Discrimination of the location
was above 85%. Furthermore, Norwegian cod protein was classified as of high quality,
while that of Iceland cod was of useful quality protein. The same five limiting amino
acids were found in both species.
By contrast, Gao et al. approached seafood from the innovative perspective of marine
bioactive peptides. They studied the potential of peptides from tilapia skin for the
treatment of ulcerative colitis, which is a main type of Inflammatory Bowel Disease.
Tilapia peptides display anti-inflammatory, antioxidant, antihypertensive, and immunomodulatory
properties amongst others (8). The authors employed cell culture assays (CT-26 and
HT-29 cell lines) and an induced mouse model of colitis (Dextran sulfate sodium-induced)
to evaluate the effects of the peptides. These peptides seemed to inhibit inflammation
and apoptosis directly in the colon epithelium, emerging as a potential alternative
treatment for inflammatory bowel disease (Gao et al.). The mechanistic investigation
points out a role of such bioactive peptides in the protection against external stimuli,
which passes through enhancing the barrier function of the colon epithelium, reducing
the release of inflammatory cytokines, and suppressing apoptosis.
In sum, the contributing articles address either the benefits of seafood consumption,
potential health usages, or alternatives to improve seafood safety and quality. These
bring new information on relevant aspects of the topic, opening questions and challenges
for future research related to alternative protein sources, the nutrient sensing signaling
pathways, quality evaluation and species discrimination based on essential and non-essential
amino acid profiles, and the role of fish bioactive peptides in health and disease.
Author contributions
SS and MM wrote the original draft of the article. LG and VD reviewed and edited the
article. All authors contributed to the article and approved the submitted version.