Effect of Different Drying Methods on the Nutritional Value of Hibiscus sabdariffa Calyces as Revealed by NMR Metabolomics.

Red mature calyces of Hibiscus sabdariffa were collected from 16 different locations in Meghalaya, India. Samples were processed using shade drying (SD) and tray drying (TD). NMR spectroscopy was used to assess the metabolic composition of the calyces. In this study, 18 polar metabolites were assigned using 1D and 2D NMR spectra, and 10 of them were quantified. Proximate analysis showed that the TD method is more efficient at reducing moisture and maintaining the ash content of the Hibiscus biomass. NMR metabolomics indicates that the metabolite composition significantly differs between SD and TD samples and is more stable in TD plant processing. The differences in post-harvest drying has a greater impact on the metabolite composition of Hibiscus than the plant location.

Inhibitory effects of kiwifruit extract on human platelet aggregation and plasma angiotensin-converting enzyme activity.

Previous human studies suggest that supplementation with kiwifruits lowers several cardiovascular risk factors such as platelet hyperactivity, blood pressure and plasma lipids. The cardiovascular health benefit of fruit and vegetables is usually attributed to the complex mixture of phytochemicals therein; however, kiwifruit's cardioprotective factors are not well studied. In this study, we investigated the effects of kiwifruit extract on human blood platelet aggregation and plasma angiotensin-converting enzyme (ACE) activity. A sugar-free, heat-stable aqueous extract with molecular mass less than 1000 Da was prepared from kiwifruits. Typically, 100 g kiwifruits produced 66.3 ± 5.8 mg (1.2 ± 0.1 mg CE) of sugar-free kiwifruit extract (KFE). KFE inhibited both human platelet aggregation and plasma ACE activity in a dose-dependent manner. KFE inhibited platelet aggregation in response to ADP, collagen and arachidonic acid, and inhibitory action was mediated in part by reducing TxA2 synthesis. The IC50 for ADP-induced platelet aggregation was 1.6 ± 0.2 mg/ml (29.0 ± 3.0 µg CE/ml), whereas IC50 for serum ACE was 0.6 ± 0.1 mg/ml (11.0 ± 1.2 µg CE/ml). Consuming 500 mg of KFE (9.0 mg CE) in 10 g margarine inhibited ex vivo platelet aggregation by 12.7%, 2 h after consumption by healthy volunteers (n = 9). All these data indicate that kiwifruit contains very potent antiplatelet and anti-ACE components. Consuming kiwifruits might be beneficial as both preventive and therapeutic regime in cardiovascular disease.

Comparative study on composition and functional properties of brewer's spent grain proteins precipitated by citric acid and hydrochloric acid.

Brewer's spent grain (BSG) is an abundant agro-industrial residue and a sustainable low-cost source for extracting proteins. The composition and functionality of BSG protein concentrates are affected by extraction conditions. This study examined the use of citric acid (CA) and HCl to precipitate BSG proteins. The resultant protein concentrates were compared in terms of their composition and functional properties. The BSG protein concentrate precipitated by CA had 10% lower protein content, 5.8% higher carbohydrate, and 5.4% higher lipid content than the sample precipitated by HCl. Hydrophilic/hydrophobic protein and saturated/unsaturated fatty acid ratios increased by 16.9% and 26.5% respectively, in the sample precipitated by CA. The formation of CA-cross-linkages was verified using shotgun proteomics and Fourier transform infrared spectroscopy. Precipitation by CA adversely affected protein solubility and emulsifying properties, while improving foaming properties. This study provides insights into the role of precipitants in modulating the properties of protein concentrates.

Exploring the Potential of Atlantic Mesopelagic Species Processed on Board Commercial Fishing Vessels as a Source of Dietary Lipids.

This study investigates the use of untapped mesopelagic species as a source of long-chain polyunsaturated omega-3 fatty acids (LC n-3 PUFAs) to meet the growing demand. The challenges faced by commercial fishing vessels, such as varying catch rates and species distribution affecting lipid levels, are addressed. Marine oils were produced post-catch using thermal separation and enzymatic hydrolysis during four commercial cruises, screening approximately 20,000 kg of mixed mesopelagic species. Maurolicus muelleri and Benthosema glaciale were the dominant species in the catch, while krill was the primary bycatch. The lipid composition varied, with B. glaciale having a higher prevalence of wax esters, while triacylglycerols and phospholipids were more predominant in the other species. LC n-3 PUFAs ranged from 19% to 44% of lipids, with an average EPA + DHA content of 202 mg/g of oil. Both processing methods achieved oil recoveries of over 90%. Estimates indicate that the mesopelagic biomass in the Northeast Atlantic could supply annual recommended levels of EPA + DHA to 1.5 million people, promoting healthy heart and brain functions. These findings offer valuable insights for considering mesopelagic species as a potential source of dietary marine lipids, laying the groundwork for further research and innovation in processing and obtaining valuable compounds from such species.

Physico-Chemical Properties and Nutrition of Marine Lipids.

Marine lipids, especially long-chain polyunsaturated omega-3 fatty acids, play important roles in human nutrition and health [...].

Upgrading Marine Oils from Cod (Gadus morhua) On-Board the Deep-Sea Vessels-From Waste to Value.

Significant amounts of marine raw material are lost on-board the deep-sea vessels due to fast quality degradation. Optimal on-board handling and processing strategies can upgrade these resources from waste to food ingredients rich in nutrients such as omega-3 fatty acids. The objective of this study was to investigate the effect of raw material freshness and sorting on the quality, composition and yield of oil produced thermally from cod (Gadus morhua) residuals on-board a commercial trawler. Oil was produced from whole viscera fractions with liver or out-sorted livers right after a catch and after chilled storage for up to 6 days. The results showed that significantly higher oil yields could be obtained if the raw materials were stored for 1 day or longer. However, an undesired emulsion was formed when viscera were stored for 4 days. All oils were rich in health beneficial omega-3 fatty acids, but viscera oils had generally lower quality with higher levels of free fatty acids and oxidation products. However, out-sorting of the liver was not necessary to meet guidelines for high-quality fish oil. Both viscera and liver could be stored for up to 2 days at 4 °C prior to oil production and still meet quality criteria for food applications. These results demonstrate a large potential in upgrading currently wasted marine raw materials into high-quality food ingredients.

Enzymatic Hydrolysis of Orange-Footed Sea Cucumber (Cucumaria frondosa)-Effect of Different Enzymes on Protein Yield and Bioactivity.

While sea cucumber is a food delicacy in Asia, these food resources are less exploited in Europe. The aim of this study was to determine the chemical composition and potential food applications of the less exploited orange-footed sea cucumber (Cucumaria frondosa). In particular, the antioxidative capacity and free amino acids associated with the umami flavor released by enzymatic hydrolyses by either Bromelain + Papain (0.36%, 1:1) or Alcalase (0.36%) were studied. Fresh C. frondosa contained approximately 86% water, and low levels of ash (<1%) and lipids (<0.5%). The protein content was 5%, with a high proportion of essential amino acids (43%) and thus comparable to the FAO reference protein. The high concentration of free amino acids associated with umami, sour, sweet, and bitter may contribute to flavor enhancement. Hydrolysis by Bromelain + Papain resulted in the highest protein yield, and the greatest concentration of free amino acids associated with umami and sour taste. All samples showed promising antioxidant capacity measured by FRAP, ABTS, DPPH and ORAC compared to previous reports. The inorganic arsenic concentration of fresh C. frondosa ranged from 2 to 8 mg/kg wet weight and was not affected by processing. This is comparable to other seafood and may exceed regulatory limits of consumption.

Silage for upcycling oil from saithe (Pollachius virens) viscera - Effect of raw material freshness on the oil quality.

The main objective of this study was to investigate how the freshness of saithe (Pollachius virens) viscera affected the quality, composition and yield of oil obtained by silaging. Minced viscera with and without liver were stored separately for up to 3 days at 4 °C before silaging at pH 3.8 for 6 days at 10 °C. An antioxidant mixture was added to evaluate the effect on the lipid oxidation. Oil was extracted thermally from untreated raw material during storage (day 0-3) and after silaging. For oil obtained after silaging of viscera with liver, the oil yields increased significantly when the raw material was stored for more than one day prior to the treatment. Use of fresh raw material (collected at day 0) led to significantly lower oxidation compared to longer raw material storage. After one day of storage, the oxidation was less dependent on the freshness. Silaging with antioxidants resulted in significantly lower formation of oxidation products compared to acid without antioxidants and the most significant differences were observed after one day of storage. Contents of docosahexaenoic acid (DHA) and total omega-3 fatty acids decreased significantly when the raw material was stored for 1-3 days prior to silaging compared to fresh raw material. Results obtained by high resolution nuclear magnetic resonance (NMR) spectroscopy indicated that oxidation of esterified DHA might explain the DHA decrease. The free fatty acid content was highest when fresh raw material was used and was most likely affected by the formation of cholesteryl esters observed in NMR spectra after longer storage. The study shows that although the oil quality is reduced during silaging, processing shortly after catch and use of antioxidants can optimize the quality resulting in less oxidized oil richer in omega-3 fatty acids.

Effects of similar intakes of marine n-3 fatty acids from enriched food products and fish oil on cardiovascular risk markers in healthy human subjects.

There is convincing evidence that consumption of fish and fish oil rich in long-chain (LC) n-3 PUFA (n-3 LCPUFA), EPA (20 : 5n-3) and DHA (22 : 6n-3) reduce the risk of CHD. The aim of the present study was to investigate whether n-3 LCPUFA-enriched food products provide similar beneficial effects as fish oil with regard to incorporation into plasma lipids and effects on cardiovascular risk markers. A parallel 7-week intervention trial was performed where 159 healthy men and women were randomised to consume either 34 g fish pâté (n 44), 500 ml fruit juice (n 38) or three capsules of concentrated fish oil (n 40), all contributing to a daily intake of approximately 1 g EPA and DHA. A fourth group did not receive any supplementation or food product and served as controls (n 37). Plasma fatty acid composition, serum lipids, and markers of inflammation and oxidative stress were measured. Compared with the control group, plasma n-3 LCPUFA and EPA:arachidonic acid ratio increased equally in all intervention groups. However, no significant changes in blood lipids and markers of inflammation and oxidative stress were observed. In conclusion, enriched fish pâté and fruit juice represent suitable delivery systems for n-3 LCPUFA. However, although the dose given is known to reduce the risk of CVD, no significant changes were observed on cardiovascular risk markers in this healthy population.

Nutritionally Enriched Muffins from Roselle Calyx Extract Using Response Surface Methodology.

Hibiscus sabdariffa, often called Roselle, is a flowering plant with a variety of traditional medicinal uses. Its calyx, with a bright and attractive red color, produces a tart and pleasant acidic taste. The purpose of this study was to develop a Roselle muffin and assess the acceptability, nutrition, and shelf life of the muffin using its ingredients. The muffin was developed using different formulations in different proportions resulting from Response Surface Methodology (RSM). Sensory parameters were used to assess the muffin's acceptability. According to the findings, the combination of extract volume 45.37 mL, citric acid 1.11 g, and sodium bicarbonate 1.67 g produces the best muffin, with the panelist's sensory scores reaching up to 84%. The outcome of the study suggests muffins baked with the Roselle calyx extract have high antioxidant (12.53 ± 0.13)%, anthocyanin (126.63 ± 1.96) mg Cyn-3-glu/100 g, phenolic (12.91 ± 0.69) mg GAE/100 g, and ascorbic acid (12.10 ± 0.89) mg/100 g contents. The microbial shelf life of the developed muffin is estimated to be 6 days at room temperature. The study findings can therefore be utilized in the development of foods containing Roselle calyx extract.

High resolution NMR for studying lipid hydrolysis and esterification in cod (Gadus morhua) gonads.

High resolution NMR was applied to study biochemical changes of lipids in cod (Gadus morhua) gonads during 7 days storage at 4 degrees C. Changes were observed in the (13)C and (1)H resonances of cholesterol which were due to esterification of fatty acids at the hydroxyl position in roe and milt. Furthermore, the (13)C NMR spectra showed that the lipolytic changes in milt and roe where different. New resonances appeared during storage, due to formation of specific free fatty acids, with the corresponding changes in resonances of the esterified carbonyls and glycerols. The highly unsaturated n-3 fatty acids were hydrolysed from the sn-1 and sn-2 position of both phosphatidylcholine and phosphatidylethanolamine in milt. The lipolytical changes in roe were less prominent compared to the changes in milt, however significant levels of sn-1-lysophospholipids was detected both in roe and milt. The current data demonstrate that high resolution NMR may be a suitable method to non-destructively study hydrolysis and esterification reactions occurring in heterogeneous marine lipids in a one step procedure.

Fatty acid and lipid class composition in eyes and brain from teleosts and elasmobranchs.

The fatty acid and lipid class composition of the eyes and brain were determined for the following species: Atlantic cod (Gadus morhua), saithe (Pollachius virens), redfish (Sebastes marinus), Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), Portuguese dogfish (Centroscymnus coelolepis), black dogfish (Centroscyllium fabricii), and leafscale gulper shark (Centrophorus squamosus). Fatty acid analyses of eyes from teleosts in the present study indicated that the lean species contained high ratios of docosahexaenoic acid (DHA) versus eicosapentaenoic acid (EPA), and high ratios of n-3 fatty acids versus n-6 fatty acids, while these ratios were significantly lower for the fatty fish species. The lipid class analyses revealed that among both elasmobranchs and teleosts, phospholipid was the dominant class of lipids in the eyes of lean species, while triacylglycerol was the dominant class of lipids in fatty species. Analyses of the fatty acid composition of brains revealed that the deep-sea elasmobranchs, Portuguese dogfish, black dogfish, and leafscale gulper shark, contained a level of arachidonic acid (AA) that was higher than their level of EPA and about fivefold higher than what was found in the brains of teleosts. Such high levels of AA are not normally observed in fish brains; rather, they are generally observed in brains of higher vertebrates.