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

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

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 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

Physical properties and cooking quality of noodles incorporated with green seaweed, caulerpa lentillifera

Caulerpa lentillifera consumption as fresh vegetables has long been practiced by those living in coastal areas, particularly during the lean season where income and food sources are scarce. They are typically consumed fresh due to their appetising taste and nutritional properties. Although, C. lentillifera has gained popularity over the recent years among consumers, not many food products derived from it has been made. In this study, the effects of incorporation of C. lentillifera powder (CLP) on its physical properties (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, and resilience) and cooking quality (optimum cooking time, cooking yield, and cooking loss) were investigated. Five noodle formulations with different levels of percentages of C. lentillifera powder, F1 (CLP 0%) as the control, F2 (CLP 2.5%), F3 (CLP 5.0%), F4 (CLP 7.5%), and F5 (CLP 9.0%) were prepared. As the percentage of CLP added to the noodles increased, the optimum cooking time of the noodles was longer as compared to the control noodle, F1. The cooking loss of the noodles was seen to increase with a higher amount of CLP added as well. In terms of its texture profile, the results showed a decreasing trend. This trend could be due to the negative effects that the CLP has on the gluten development which obstructed the protein-starch matrix of the noodles. In conclusion, the noodles added with higher CLP have poor physical and cooking characteristics compared to control noodles

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

The effect of fortification of wood ear mushroom powder (auricularia sp.) in instant noodles on the postprandial blood glucose level in human subjects

The aim of this study was to evaluate the effect of instant noodles fortified with wood ear mushroom (Auricularia sp.) on the postprandial blood glucose level in human subjects. A total of 21 participants had volunteered but only 10 female respondents aged range 23–31years old and have a normal body mass index with a median of 21.04 kg/m2 were selected to participate in the glycaemic analysis study. They were served with control instant noodles, fortified instant noodles with wood ear mushroom powder, and three glucose solutions which all contained a total of 50 g of available carbohydrates in 5 different sessions randomly. The postprandial blood glucose level within two hours indicated a significant difference (P<0.05) between the mean of control and fortified instant noodles at 30 minutes (the peak) and 120 minutes. The mean of incremental area under the curve (IAUC) of reference food was the highest at 269.83 mmol.min/L while the mean of IAUC of the test food was 196.43 mmol.min/L and 179.78 mmol.min/L for control and fortified noodles respectively. There was a significant difference (P<0.05) in the mean of IAUC between reference and test food. The value of glycaemic index value of the control instant noodles was 75.84 (high) while the fortified instant noodles was 68.91 (medium). In conclusion, the instant noodles fortified with wood ear mushroom (Auricularia sp.) powder is effective and could be used as a potential functional ingredient for glycaemic contr