Effects of whole seaweed consumption on humans: current evidence from randomized-controlled intervention trials, knowledge gaps, and limitations.

Seaweed is often recognized for its potential health benefits, attributed to its abundance of dietary fibers, protein, and polyphenols. While human observational studies have shown promise, the collective evidence from human intervention trials remains limited. This narrative review aims to comprehensively analyze the effects of seaweed intake on humans, while critically assessing the methodology, including Cochrane risk-of-bias assessment. A search was conducted in online databases, including PubMed, Scopus, and Google Scholar, covering the period from 2000 to May 2023. The focus was on randomized controlled clinical trials (RCTs) evaluating the impact of whole seaweed, either consumed as capsules, integrated into food products or as part of meals. Various health outcomes were examined, including appetite, anthropometric measures, cardiometabolic risk factors, thyroid function, markers of oxidative stress, and blood mineral concentrations. Out of the 25 RCTs reviewed, the findings revealed limited yet encouraging evidence for effects of seaweed on blood glucose metabolism, blood pressure, anthropometric measures, and, to a lesser extent, blood lipids. Notably, these favorable effects were predominantly observed in populations with type-2 diabetes and hypertension. Despite most trials selecting a seaweed dose aligning with estimated consumption levels in Japan, considerable variability was observed in the pretreatment and delivery methods of seaweed across studies. Moreover, most studies exhibited a moderate-to-high risk of bias, posing challenges in drawing definitive conclusions. Overall, this review highlights the necessity for well-designed RCTs with transparent reporting of methods and results. Furthermore, there is a need for RCTs to explore seaweed species cultivated outside of Asia, with a specific emphasis on green and red species. Such studies will provide robust evidence-based support for the growing utilization of seaweed as a dietary component in regions with negligible seaweed consumption, e.g., Europe.

Mild blanching prior to pH-shift processing of Saccharina latissima retains protein extraction yields and amino acid levels of extracts while minimizing iodine content.

The seaweed Saccharina latissima is often blanched to lower iodine levels, however, it is not known how blanching affects protein extraction. We assessed the effect of blanching or soaking (80/45/12 °C, 2 min) on protein yield and protein extract characteristics after pH-shift processing of S. latissima. Average protein yields and extract amino acid levels ranked treatments as follows: blanching-45 °C âˆ¼ control > soaking âˆ¼ blanching-80 °C. Although blanching-45 °C decreased protein solubilization yield at pH 12, it increased isoelectric protein precipitation yield at pH 2 (p < 0.05). The former could be explained by a higher ratio of large peptides/proteins in the blanched biomass as shown by HP-SEC, whereas the latter by blanching-induced lowering of ionic strength, as verified by a dialysis model. Moreover, blanching-45 °C yielded a protein extract with 49 % less iodine compared with the control extract. We recommend blanching-45 °C since it is effective at removing iodine and does not compromise total protein extraction yield.

Pilot-Scale Ensilaging of Herring Filleting Co-Products and Subsequent Separation of Fish Oil and Protein Hydrolysates.

In this study, ensilaging of herring (Clupea harengus) filleting co-products was taken from lab-scale to pilot scale (1500 L) while monitoring the protein degree of hydrolysis (DH) and lipid oxidation. Subsequently, the possibility of recovering fish oil and protein hydrolysates using batch centrifugation at different g-forces/times was investigated. Around 38% DH was recorded after 2-day pilot-scale ensilaging of herring co-products at ambient temperature (i.e., ~ 22 °C), which was similar to the DH found in lab-scale (40% after 2 days; 22 °C). The lipid oxidation marker 2-thiobarbituric acid reactive substances (TBARS) reached 20 µmole TBARS/kg silage after 2-day ensilaging. Centrifugation of the silage at 3000-8500 × g for 2-20 min revealed successful separation into fish oil and protein hydrolysates. Heat-treating the silage (85 °C; 30 min) prior to centrifugation resulted in significantly higher oil and hydrolysates recoveries; the same being true for increased g-force. At 8500 × g, the recovery of oil and hydrolysates were 9.7 and 53.0% w/w, respectively, from heat-treated silage, while recoveries were 4.1 and 48.1% w/w, respectively, from non-heat treated silage. At 4500 × g, being a more scalable approach, corresponding numbers were 8.2 and 47.1% (w/w) as well as 2.0 and 40.2% (w/w). The recovered fish oil contained 8% EPA and 11% DHA of total fatty acids. Free fatty acids (FFA), peroxide value (PV), p-anisidine value (p-AV), and total oxidation (TOTOX) values of oils were in the range of 4-7% (FFA), 3.6-3.7 meq/kg oil (PV), 2.5-4.0 (p-AV), and 9.9-11.1 (TOTOX), respectively, which were within the acceptable limits for human consumption specified by the GOED voluntary monograph. The recovered protein hydrolysates contained peptides in the molecular weight range 0.3-6 kDa (~ 37%) and 11-34 kDa (~ 63%). Also, the remaining solids contained 15-17% (w/w) protein, having 44-45% essential amino acids. Overall, the results suggest that herring co-product silage is a valuable source of fish oil and protein hydrolysates, paving the way for ensilaging based-biorefining of herring co-products into multiple products. Supplementary Information: The online version contains supplementary material available at 10.1007/s11947-022-02870-9.

In vitro digestibility and Caco-2 cell bioavailability of sea lettuce (Ulva fenestrata) proteins extracted using pH-shift processing.

Seaweed is a promising sustainable source of vegan protein as its farming does not require arable land, pesticides/insecticides, nor freshwater supply. However, to be explored as a novel protein source the content and nutritional quality of protein in seaweed need to be improved. We assessed the influence of pH-shift processing on protein degree of hydrolysis (%DH), protein/peptide size distribution, accessibility, and cell bioavailability of Ulva fenestrata proteins after in vitro gastrointestinal digestion. pH-shift processing of Ulva, which concentrated its proteins 3.5-times, significantly improved the %DH from 27.7±2.6% to 35.7±2.1% and the amino acid accessibility from 56.9±4.1% to 72.7±0.6%. Due to the higher amino acid accessibility, the amount of most amino acids transported across the cell monolayers was higher in the protein extracts. Regarding bioavailability, both Ulva and protein extracts were as bioavailable as casein. The protein/peptide molecular size distribution after digestion did not disclose a clear association with bioavailability.

Study of viability of high pressure extract from pomegranate peel to improve carrot juice characteristics.

Extracts from fruit processing by-products usually present high amounts of bioactive compounds with several important activities such as antioxidant and antimicrobial capacities. In this work we studied (i) the cytotoxicity profile of pomegranate peel extract and (ii) safety and quality aspects after incorporating this extract in carrot juice - a beverage with low antioxidant potential and highly prone to microbial growth. The extract was obtained by high-pressure extraction and was non-cytotoxic towards the Caco-2 cell line after in vitro digestion. The non-cytotoxic pomegranate peel extract was added to carrot juice in a concentration of 5 mg mL-1. Fortified juices were processed by high-pressure and conventional heat and stored under refrigeration. On the 28th day of storage, microbial counts in PPE-fortified juices were reduced by 1.0 log10 CFU mL-1 and the pressurized juices showed significantly fewer counts than the thermal-treated ones. Just after processing, phenolic and flavonoid contents, as well as ABTS and FRAP antioxidant capacities, increased 3.6, 3.5, 8.2, and 9.4-fold, respectively in the fortified juices. The extract addition did not affect any colour parameter and all studied physicochemical parameters i.e. total soluble solids, pH, colour, total phenolics, flavonoids, hydrolysable tannins, and antioxidant capacity remained constant throughout storage. These findings could pave the way towards the development of safe beverages with improved bioactive properties.

High value-added compounds from fruit and vegetable by-products - Characterization, bioactivities, and application in the development of novel food products.

Fruit and vegetable processing industry is one of the relevant generators of food by-products, which display limited commercial exploitation entailing economic and environmental problems. However, these by-products present a considerable amount of dietary fiber as well as bioactive compounds with important biological activities such as antioxidant and antimicrobial properties. Therefore, the international scientific community has considered the incorporation of their extracts or powders to preserve or fortify food products an area of interest, mainly because nowadays consumers demand the production of safer and health-promoting foods. In the present review, several statistical and other relevant data concerning the increasing generation of fruit and vegetable by-products (FVB) are critically analyzed and presented. Next, a special focus is given to the chemical characterization and bioactivities (namely antioxidant and antimicrobial properties) of several FVB. Lastly, an in-depth review with recent studies (briefly compiled) about the incorporation of fruit and vegetable processing wastes in animal, dairy, beverages, and bakery products, among others is provided.