Chemical Composition, Antioxidative and Cholesterol Lowering Properties of Selected Malaysia Seaweeds

The objectives of this study were to evaluate in vitro antioxidant activity and total phenolic screenings of eight species of Malaysia seaweeds (Kappaphycus alvarezii, Eucheuma denticulatum, Halymenia durvillaei, Caulerpa lentillifera, Caulerpa racemosa, Dicyota dichotoma, Sargassum polycystum and Padina spp.), determine chemical composition of three selected edible seaweeds and investigate effects of these seaweeds on antioxidative, cholesterol-lowering, and their effects on biochemical, morphological and histological characteristics of selected tissues of rats fed on high-cholesterol/high-fat (HCF) diets. In vitro antioxidant activities of the eight species of seaweeds were evaluated using TEAC (trolox equivalent antioxidant capacity) and FRAP (ferric reducing antioxidant power) assays. Total phenolic contents of these seaweeds were determined using Folin-Ciocalteu assay. Red seaweed K. alvarezii, green seaweed C. lentillifera and brown seaweed S. polycystum were selected based on their high in vitro antioxidant activity, and further evaluated for their chemical composition, in vivo antioxidant activity and cholesterol-lowering effects in Sprague Dawley rats fed with HCF diet for 16 weeks. Chemical analysis of seaweeds comprised of proximate composition, dietary fiber, vitamin C, vitamin E (α-tocopherol), minerals, carotenoids, chlorophylls, fatty acids and amino acids. Animal experimental diets comprised of eight groups: normal diet (N, control group), HCF diet (HCF group), normal diet supplemented with 5% seaweeds (N+KA, N+CL and N+SP groups), and HCF diet supplemented with 5% seaweed (HCF+KA, HCF+CL and HCF+SP groups). Effects of seaweeds in preventing hypercholesterolaemia and peroxidation in rats were studied via assessing the plasma lipids and, plasma and organs malondialdehyde (MDA) concentrations. Likewise, activities of antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were accessed as indices of oxidative stress. Biochemical markers for liver, heart and kidney damage such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), creatinine kinase (CK), CK-MB isoenzyme, urea, creatinine and uric acid were measured. Somatic index and descriptive histological changes in the liver, heart, kidney, brain, spleen and eye of the experimental rats were also performed, while quantitative histology was restricted only to necrosis in the liver, kidney and brain. The results showed that administration of K. alvarezii and C. lentillifera reduced (PC. lentillifera>K. alvarezii. However, K. alvarezii and C. lentillifera were more effective than S. polycystum in improving the antioxidant status by reducing (P<0.05) lipid peroxidation and increasing (P<0.05) antioxidant enzymes in liver, heart and kidney of rats fed the HCF diet. Histological examinations demonstrated consumption of all three seaweeds did not exert any damage to the liver, heart, kidney, brain, spleen and eyes in normal rats. In conclusion, K. alvarezii and C. lentillifera showed hypolipidaemic effects, improve antioxidant status and exert a protective effect in mitigating the cardiac, hepatic, renal and brain abnormalities in rats fed HCF diet. The presence of high dietary fiber especially soluble fiber, omega-3 fatty acids such as eicosapentaenoic acid (C20:5ω3), and antioxidant compounds such as polyphenols, vitamin C, α-tocopherol, carotenoids and selenium may probably contributed to the cholesterol-lowering and antioxidant efficacy of these seaweeds

Antioxidant activities and phenolics content of eight species of seaweeds from north Borneo

The antioxidant activity of eight edible species of Malaysian North Borneo seaweeds obtained from Sabah waters (Kudat, Tanjung Aru and Semporna) consisting of three red seaweeds (Eucheuma cottonii, E. spinosum and Halymenia durvillaei), two green seaweeds (Caulerpa lentillifera and C. racemosa) and three brown seaweeds (Dictyota dichotoma, Sargassum polycystum and Padina sp.) were determined. Methanol and diethyl ether were used as extraction solvent. The antioxidant activities were determined by two methods, TEAC (trolox equivalent antioxidant capacity) and FRAP (ferric reducing antioxidant power) assays. The total phenolic content of the extract was determined according to the Folin–Ciocalteu method and results were expressed as phloroglucinol equivalents. The methanolic extracts of green seaweeds, C. lentillifera and C. racemosa, and the brown seaweed, S. polycystum showed better radical-scavenging and reducing power ability, and higher phenolic content than the other seaweeds. The TEAC and FRAP assays showed positive and significantly high correlation (R 2 = 0.89). There was a strong correlation (R 2 = 0.96) between the reducing power and the total phenolic content of the seaweeds methanolic dry extracts. These seaweeds could be potential rich sources of natural antioxidants

Sensory, physicochemical, and cooking qualities of instant noodles fortified with red seaweed, eucheuma denticulatum

Instant noodles are widely consumed worldwide, but frequent consumption of instant noodles is unhealthy. Therefore, in the present study, instant noodles were produced with composite flour (blend of wheat flour and potato starch at weight ratios of 9:1, 8:2, and 7:3) incorporated with red seaweed powder, Eucheuma denticulatum in proportions of 0, 5, 7.5, 10, 12.5, and 15%. The cooking qualities, physicochemical (textural properties, pH, color, water activity), and sensory properties of the noodles were then determined. The incorporation of 7.5 - 15% of seaweed powder had significantly (p<0.05) increased the cooking yield and reduced the cooking loss but lengthened the optimum cooking time of noodles. The pH values and water activity of noodles had been significantly (p<0.05) reduced by adding 7.5 - 15% seaweed powder. The addition of seaweed powder had also weakened the tensile strength and softened the noodles. Seaweed noodles were darker, denser greenish, and less yellowish than control noodles. Among the three seaweed noodles (F2, F5, F12) selected through the ranking test, panelists preferred F2 and F5 (both scored 4.63 on a 7-point hedonic scale for overall acceptability) more than F12. Overall, noodles sample F5 (at a wheat flour: potato starch ratio of 9: 1; 15% seaweed powder) is the best-formulated seaweed noodles in this study, owing to its highest cooking yield and lowest cooking loss even with prolonged cooking, lowest water activity, and acceptable sensory qualities

ACE-Inhibitory and Antioxidant Activities of Hydrolysates from the By-Products of Hybrid Grouper (Epinephelus lanceolatus × Epinephelus fuscoguttatus)

Protein hydrolysates, generated from the by-products of fish, have received much attention over recent years, due to their antihypertensive and antioxidant activities. The potency of bioactive peptides, however, is affected by the type of enzyme selected and the duration of hydrolysis required to generate the protein hydrolysate. This study was aimed to investigate the effects of using four different enzymes (Alcalase, Proteinase K, Trypsin, and Pepsin) and hydrolysis time (1 - 48 h), on the ACE-inhibitory and antioxidant activities (hydroxyl radical scavenging activity and reducing power), of protein hydrolysates from the head and bones of hybrid grouper (Epinephelus lanceolatus × Epinephelus fuscoguttatus). Among the enzymes tested, Alcalase was the most effective enzyme hydrolysing the by-product of hybrid grouper, followed by Proteinase K, Trypsin, and Pepsin (p < 0.05). According to the results attained, enzyme with the higher degree of hydrolysis exhibited higher antioxidant activities, but not ACE-inhibitory activity. This indicates that the ACEinhibition potency of hydrolysate, from the by-product of hybrid grouper, is very much dependent on the type of enzyme, and the treatment duration during hydrolysis. The ACE-inhibitory activity of Alcalase and Trypsin hydrolysates was found to decrease in tandem with the increase in hydrolysis time. On the other hand, a longer hydrolysis time resulted in a higher ACE-inhibitory activity for Proteinase K and Pepsin hydrolysate (p < 0.05). The results attained suggest that the selection of an appropriate enzyme, together with an effective hydrolysis time, can enhance the bioactivities of the hydrolysate obtained from the by-product of hybrid grouper

Chemical composition and physicochemical properties of tropical red seaweed, Gracilaria changii

A study on the proximate composition, minerals, vitamins, carotenoids, amino acids, fatty acids profiles and some physicochemical properties of freeze dried Gracilaria changii was conducted. It was discovered that this seaweed was high in dietary fiber (64.74 ± 0.82%), low in fat (0.30 ± 0.02%) and Na/K ratio (0.12 ± 0.02). The total amino acid content was 91.90 ± 7.70% mainly essential amino acids (55.87 ± 2.15 mg g1) which were comparable to FAO/WHO requirements. The fatty acid profiles were dominated by the polyunsaturated fatty acids particularly docosahexaenoic (48.36 ± 6.76%) which led to low x6/x3, atherogenic, and thrombogenic index. The physicochemical properties of this seaweed namely the water holding and the swelling capacity were comparable to some commercial fiber rich products. This study suggested that G. changii could be potentially used as ingredients to improve nutritive value and texture of functional foods for human consumption.and some physicochemical properties of freeze dried Gracilaria changii was conducted. It was discovered that this seaweed was high in dietary fibre (64.74 ± 0.82%), low in fat (0.30 ± 0.02%) and Na/K ratio (0.12 ± 0.02). The total amino acid content was 91.90 ± 7.70% mainly essential amino acids (55.87 ± 2.15 mg g1) which were comparable to FAO/WHO requirements. The fatty acid profiles were dominated by the polyunsaturated fatty acids particularly docosahexaenoic (48.36 ± 6.76%) which led to low x6/x3, atherogenic, and thrombogenic index. The physicochemical properties of this seaweed namely the water holding and the swelling capacity were comparable to some commercial fibre rich products. This study suggested that G. changii could be potentially used as ingredients to improve nutritive value and texture of functional foods for human consumption

ACE-inhibitory and antioxidant activities of hydrolysates from the by-products of hybrid grouper (Epinephelus lanceolatus × Epinephelus fuscoguttatus)

Protein hydrolysates, generated from the by-products of fish, have received much attention over recent years, due to their antihypertensive and antioxidant activities. The potency of bioactive peptides, however, is affected by the type of enzyme selected and the duration of hydrolysis required to generate the protein hydrolysate. This study was aimed to investigate the effects of using four different enzymes (Alcalase, Proteinase K, Trypsin, and Pepsin) and hydrolysis time (1 - 48 h), on the ACE-inhibitory and antioxidant activities (hydroxyl radical scavenging activity and reducing power), of protein hydrolysates from the head and bones of hybrid grouper (Epinephelus lanceolatus × Epinephelus fuscoguttatus). Among the enzymes tested, Alcalase was the most effective enzyme hydrolysing the by-product of hybrid grouper, followed by Proteinase K, Trypsin, and Pepsin (p < 0.05). According to the results attained, enzyme with the higher degree of hydrolysis exhibited higher antioxidant activities, but not ACE-inhibitory activity. This indicates that the ACE-inhibition potency of hydrolysate, from the by-product of hybrid grouper, is very much dependent on the type of enzyme, and the treatment duration during hydrolysis. The ACE-inhibitory activity of Alcalase and Trypsin hydrolysates was found to decrease in tandem with the increase in hydrolysis time. On the other hand, a longer hydrolysis time resulted in a higher ACE-inhibitory activity for Proteinase K and Pepsin hydrolysate (p < 0.05). The results attained suggest that the selection of an appropriate enzyme, together with an effective hydrolysis time, can enhance the bioactivities of the hydrolysate obtained from the by-product of hybrid grouper

Soy crisps incorporated with red seaweed, Kappaphycus alvarezii

Kappaphycus alvarezii (KA), an underutilized seaweed with potential benefits, is particularly used to extract kappa-carrageenan in the food industry. There is a notable absence of commercially available snacks that incorporate KA. This study aimed to develop soy crisps incorporating different concentrations of KA powder (0%, 2.5%, 5%, 7.5%, and 10%) and to determine the best formulation for addressing the gap. KA-incorporated crisps showed darker colour with more redness and yellowness and ideal texture. The crisps with 5% KA (F3) received significantly highest sensory scores for texture, taste, and overall acceptance (p<0.05). F3 crisps had higher ash, protein, fibre, and carbohydrates, and lower fat compared to control (F1), while providing more energy. In conclusion, these findings highlight the potential of KA-incorporated crisps as a nutritious and palatable snack option