Iron Bioavailability From Spirulina (Arthrospira Platensis) And Its Interactions With Other Dietary Factors In Vitro And In Vivo

Deficiency of iron is common worldwide. Various approaches have been used to improve iron intake and absorption. These include the use of spirulina, a microalage that is already popular in many Asian countries as a functional food supplement. The main objective of this study was to determine the iron bioavailability from spirulina and its interactions with other dietary factors both in vitro and in vivo. In vitro digestion/Caco-2 cell culture system accompanied by either centrifugation or dialysis step was used to assess the availability of iron from spirulina. Using the centrifugation method, the cultured and commercial spirulina yielded significantly higher results (P< 0.05) than then dialysis method, both in the form of iron available for uptake and the actual amount of iron being transported across the Caco-2 cells. The amount of available iron and iron being transported from ferrous sulphate (FeS04) did not differ significantly for both the dialysis and centrifugation method. The effects of different molar ratios of nutrients (calcium, ascorbic acid, zinc, tannic acid and caffeine) to iron on the availability of iron from cultured spirulina differs in comparison with FeS04. In the presence of lower concentrations of calcium (1:5, 1:10, 1:15 and 1:20 Fe:Ca molar ratios), iron from spirulina was not significantly inhibited compared to FeS04 but at higher concentrations (1 :37.34, 1:74.67 and 1:149.34 Fe:Ca molar ratios) iron from both spirulina and FeS04 was significantly inhibited. The availability of iron from spirulina in the presence of ascorbic acid were not significantly enhanced at all the molar ratios tested (1:0.5, 1:1, 1:1.5 and 1:2 Fe:AA molar ratios) whereas iron availability from FeS04 were significantly higher for all the molar ratios. Both zinc and tannic acid were more inhibiting on iron availability from spirulina in comparison to FeS04. As for caffeine, it did not show any significant inhibitory effects on both iron availability from spirulina and FeS04. Two iron pools could coexist in the spirulina, one containing organic iron and another comprising inorganic iron. Organic iron is known to be more bioavailable and less affected by the presence of other nutrients. This could be one of the explanations why the iron from this algae is highly available and its bioavailability is not significantly affected by other nutrients as in FeS04. Haemoglobin repletion assay was used to further investigate the effect of calcium on absorption of iron in spirulina and it comparison with FeS04. In this study, haemoglobin and haematocrit levels of male Sprague-Dawley rats fed both spirulina and FeS04 were found similar although the dose of FeS04 used had twice the amount of iron compared to that in spirulina. The presence of calcium did not significantly reduced the haematological value in rats fed spirulina and FeS04. The percentage of haemoglobin regeneration efficiency (HRE) obtained was significantly higher in rats fed spirulina compared with rats fed FeS04 indicated that the absorption efficiency were better from iron in spirulina compared to iron in FeS04. The distribution study of iron from spirulina and FeS04 in the presence of calcium was done using iron deficient and iron normal male ICR mice fed either spirulina or FeS04 tagged extrinsically with 59Fe. The amount of 59Fe being absorbed by the iron deficient mice fed spirulina was comparable with those fed FeS04 at 6 hand 24 h. However at 7 d, the FeS04 group showed better absorption than the spirulina group. In the iron normal mice, a significantly lower percentage of 59Fe was observed in mice fed spirulina compared to mice fed FeS04 at 6 hand 24 h indicating that iron from spirulina were not readily absorbed in iron normal states, which could prevent iron overload and toxicity. The presence of calcium did not significantly inhibit iron absorption in spirulina as shown in the in vitro study. This study indicated that spirulina is a concentrated source of iron for both supplementation and fortification. Iron from spirulina is highly bioavailable and easily absorbed by the body especially in the iron deficient state. Beside providing the necessary iron, it could also prevent iron overload and toxicity in normal iron status and thus making spirulina suitable for both the iron deficient and normal iron status

In vitro inhibitory potential of selected Malaysian plants against key enzymes involved in hyperglycemia and hypertension.

Introduction: This study was conducted to determine the inhibitory potential of selected Malaysian plants against key enzymes related to type 2 diabetes and hypertension. Methods: The samples investigated were pucuk ubi (Manihot esculenta), pucuk betik (Carica papaya), ulam raja (Cosmos caudatus), pegaga (Centella asiatica) and kacang botol (Psophocarpus tetragonolobus). The inhibitory potential of hexane and dichloromethane extracts against the enzymes were determined by using α-amylase, α-glucosidase and angiotensin I-converting enzyme (ACE) inhibition assay. Results: In α-amylase inhibition assay, the inhibitory potential was highest in pucuk ubi for both hexane (59.22%) and dichloromethane extract (54.15%). Hexane extract of pucuk ubi (95.01%) and dichloromethane extract of kacang botol (38.94%) showed the highest inhibitory potential against α- glucosidase,while in ACE inhibition assay, the inhibitory potential was highest in hexane extract of pegaga (48.45%) and dichloromethane extract of pucuk betik (59.77%). Conclusion: This study suggests a nutraceutical potential of some of these plants for hyperglycemia and hypertension prevention associated with type 2 diabetes

Effect of selected cereal grains on in vitro bioaccessibility of isoflavones in soymilk

Soymilk, which can be called as plant based “milk” is a favourite traditional beverage in Asian with various beneficial health protective effects due to the presence of isoflavones. Mixing cereal grains into soymilk to make a wholesome beverage for breakfast becomes popular. However, dietary factors may affect the bioaccessibility of isoflavones. The aim of this current work was to evaluate changes in the bioaccessibility of isoflavones in soymilk after mixing with selected cereal grains following in vitro gastrointestinal digestion. The samples were subjected to in vitro gastrointestinal digestion with its isoflavones content determined before and after simulated gastric digestion and intestinal digestion with dialysis membrane. Soymilk contained 1.80 ± 0.03 mg daidzein and 2.12 ± 0.08 mg genistein in 100 ml, while bioaccessibility of soymilk daidzein and genistein were 11.24 ± 0.46% and 5.09 ± 0.25% respectively. The addition of cereal grains except barley in soymilk showed significant reduction (p<0.05) in bioaccessibility of isoflavones. Dietary fiber content, especially the insoluble fiber of cereal grains was related to the reduction of bioaccessibility of isoflavones by its entrapping affinity of isoflavones and viscosity effect in the gut. The higher the dietary fiber added into the soymilk, the lower the bioaccessibility of isoflavones in soymilk

In vitro bioaccessibility of calcium, iron and zinc from breads and bread spreads

The in vitro bioaccessibility of calcium, iron and zinc of breads added with different bread spreads was determined. The mineral contents were assessed by flame atomic absorption spectrophotometer and expressed in fresh weight (mg/100 g). For the mineral bioaccessibility determination, in vitro gastrointestinal digestion was applied. Among the bread samples, calcium content of wholemeal bread with chocolate hazelnut spread ranked the highest (159.96±0.869 mg/100 g). For iron, white bread with chocolate hazelnut spread (6.92±0.411 mg/100 g) showed highest iron content while for zinc, white bread with peanut butter was the highest (1.82±0.015 mg/100 g). For calcium bioaccessibility, white bread with orange marmalade ranked the highest (39.33±4.865%) while wholemeal bread with peanut butter (14.70±0.265%) showed the lowest. The application of orange marmalade spread onto wholemeal bread increased the iron bioaccessibility significantly (9.73±1.387%). The acidic properties attributed by organic acids found in orange marmalade may favour both calcium and iron absorption. The zinc bioaccessibility of white bread alone remained the highest (20.63±3.536%) while wholemeal bread added with peanut butter (5.90±1.137%) showed the lowest. Overall, the addition of bread spreads particularly peanut butter and chocolate hazelnut spread had increased mineral contents of the bread samples. However, the presence of mineral enhancers (organic acids) and inhibitors (phytate and polyphenols) played some significant role in influencing the mineral bioaccessibility

The effect of extraction methods on fatty acid and carotenoid compositions of marine microalgae Nannochloropsis oculata and Chaetoceros gracilis

This study was conducted to assess three extraction methods for the determination of fatty acid compositions and carotenoids (lutein, zeaxanthin, ß-carotene, and a-carotene) from marine microalgae, Nannochloropsis oculata (NO) and Chaetoceros gracilis (CG). For this purpose, three different extraction methods for the determination of fatty acids (dichloromethane:methanol, water:propan-2-ol:hexane and direct saponification-ethanol KOH) and carotenoids (hexane:ethanol:acetone:toluene, methanol:chloroform and methanol:tetrahydrofulran) were used. Two derivatization methods using different types of catalyst (acetyl chloride and boron trifluoride) were also used for the transmethylation of the fatty acids into corresponding methyl esters. The results of the fatty acid compositions showed that NO had a higher amount of n-3 and n-6 polyunsaturated fatty acid (PUFA), particularly eicosapentaenoic acid (EPA) (C20:5). CG was predominantly high in palmitic acid (C16:0) and palmitoleic acid (C16:1). The extraction method 1 (dichloromethane:methanol) and extraction method 2 (water: propan-2-ol: hexane) with acetyl chloride-catalyzed transmethylation were found to be the best methods for the determination of fatty acid compositions in NO and CG, respectively. A significantly higher (P<0.05) amount of carotenoids was found in NO as compared to CG using different extraction methods. Extraction method 1 (involving saponification procedure) yielded the best result for NO while extraction method 3 (methanol: tetrahydrofuran with no saponification procedure) generated higher amounts of carotenoids in CG. Overall, this study has shown that significantly high amounts of fatty acids and carotenoids could be obtained from these microalgae using these methods

Iron intake and iron deficiency anaemia among young women in Kuala Lumpur

Objective: To assess the prevalence of iron deficiency, anaemia and iron deficiency anaemia (IDA) in women aged 20-40 years and its association with iron intake. Methods: A total of 388 women were recruited from universities and work sites in Kuala Lumpur and its suburbs. The subjects comprised 135 Malays, 130 Chinese and 123 Indians. Dietary intake was estimated using a single 24-hour food recall and a semi-quantitative food frequency questionnaire. Haemoglobin (Hb), haematocrit (hct), mean corpuscular volume (MCV) and serum ferritin were determined. Results: The prevalence of anaemia (Hb <12g/dL) was 20.9%, being highest among the Indians (26.4%) and lowest among the Malays (16.4%). About 10.3% of the women showed iron deficiency anaemia (IDA) (Hb <12g/dL + serum ferritin < 15μg/L + MCV <80fl/). The prevalence of IDA was highest in Indians (18.0%) followed by Chinese (9.9%) and Malays (4.3%). The mean (95%CI) intake of total iron was at 14.4 mg/day (95% CI 13.4, 15.5), amounting to 49.7% of the Malaysian recommended nutrient intake (RNI). Intake of iron was the highest for the Indians (16.0 mg/d) and the lowest for the Chinese (11.3 mg/d). Conclusions: The overall prevalence of IDA was lower compared to prevalence of anaemia. Nonetheless, the markedly higher prevalence of IDA among the Indians, despite relatively higher intake levels of iron-rich foods warrants further investigations, including the bioavailability of iron in the context of cultural practices that may influence food preferences and meal preparation

In vitro antioxidant capacities and antidiabetic properties of phenolic extracts from selected citrus peels

This study aims to determine the antioxidant capacities (AC) and antidiabetic properties of phenolic extracts (free and bound) from white Tambun pomelo peels, kaffir lime peels, lime peels and calamansi peels. AC, total phenolic content (TPC) and antidiabetic properties of selected citrus peels extracts were determined pectrophotometrically using 2,2-Diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging, ferric-reducing antioxidant power (FRAP), Folin-Ciocalteu (FC) and α-amylase and α-glucosidase inhibition assay, respectively. This study found that the methanolic extract of kaffir lime showed the best AC with the lowest IC50 value of DPPH radical (7.51 ± 0.50 mg/ml) and highest FRAP value [369.48 ± 20.15 mM Fe (II) E/g DW]. TPC of free phenolic extracts of all citrus peels were significantly (p< 0.05) higher compared to the bound phenolic extracts with extract of calamansi showed the highest TPC. Free- and bound phenolic extract of calamansi also had the highest α-amylase inhibition activity (61.79 ± 4.13%; 45.30 ± 5.35%) respectively. The highest inhibitory effect in α-glucosidase inhibition assay of free- and bound phenolic extracts were white Tambun pomelo (41.06 ± 10.94%) and calamansi (43.99 ± 22.03%) respectively. Hence, the citrus peels could be furthered study for their potential in management and/or prevention of diabetes

In vitro bioaccessibility of β-carotene in pumpkin and butternut squash subjected to different cooking methods

β-carotene, a type of provitamin A, is beneficial to our health. However, the compound needs to be released from its food matrix before being utilised by the body. Thus, understanding the bioaccessibility of β-carotene in the food consumed is a crucial step. The objective of this study was to determine the effect of various cooking methods on bioaccessibility of β-carotene in pumpkin and butternut squash. In vitro digestion was carried out on raw and cooked (steamed, boiled, and deep-fried) pumpkin and butternut squash. β-carotene was identified using RP-HPLC. Generally, butternut squash (4.99±0.02mg/100g) had higher β-carotene content than pumpkin (4.34±0.04mg/100g). Thermal processing resulted in lower β-carotene content in pumpkin samples; however, it increased the β-carotene content in butternut squash samples. In term of bioaccessibility, thermal processes increased the percentage of bioaccessible β-carotene in both pumpkin and butternut squash samples. Raw pumpkin had 10.56±0.44% of bioaccessible β-carotene while raw butternut squash had only 1.65±0.04%. Bioaccessibility of β-carotene in deep-fried pumpkin and butternut squash were significantly higher than their raw sample with 68.86±0.86% (p<0.001) and 22.32±2.12% (p<0.05) of bioaccessible β-carotene respectively. The deep-frying method was found to enhance the bioaccessibility of β-carotene significantly in both of these samples but not boiling and steaming methods

A comparison of the antioxidant properties and total phenolic content in a Diatom, Chaetoceros sp. and a green microalga, Nannochloropsis sp.

The aquaculture industry commonly makes use of microalgae as live feed. Chaetoceros sp., a diatom, and Nannochloropsis sp., a unicellular green microalga, have both been reported to contain a substantial amount of polyunsaturated fatty acids and carotenoids. Their potential as natural sources of antioxidants has gained recent attention. This study focuses on determining the antioxidant properties of the different solvent extracts, namely hexane, dichloromethane, chloroform and methanol, from both microalgae. The evaluation of antioxidant capacities was done by Folin-ciocalteu, 1,1-diphenyl-2-picrylhydrazyl radical-scavenging, metal chelating, nitro-blue tetrazolium reduction and ferric-reducing antioxidant power assay. Results showed that the non-polar solvent extracts from the diatom were highest in antioxidant power, whereas both polar and non-polar solvent extracts of green microalgae showed good antioxidant potential. In general, Chaetoceros sp. had higher antioxidant capacities than Nannochloropsis sp. This study suggests that different solvent extracts contain different potential antioxidant compounds able to scavenge different types of free radicals

Nutritional compositions and antioxidant activities of non-polar and polar extracts of germinated brown rice

The objective of this study was to investigate the nutritional compositions and antioxidant activities (AA) of non-polar and polar extracts of germinated brown rice (GBR). Nutritional compositions such as moisture, ash, carbohydrate, fat, protein and fibre were determined. Energy and minerals content were determined by using bomb calorimetry and Atomic Absorption Spectroscopy (AAS), respectively. Total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were determined by Folin-Ciocalteu method and aluminium chloride colorimetric method. The AA was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and [2,2′-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt (ABTS) radical scavenging capacity assay, ferric reducing antioxidant potential (FRAP) assay, and β-carotene bleaching assay. Total energy content of GBR sample was 390.95±11.31 kcal/100g and carbohydrate (54.30±1.04 g/100 g) was the most abundant nutrient. The predominant minerals in the GBR sample were sodium, potassium and magnesium. The polar extract showed significantly higher (p0.90, p<0.001) existed between antioxidants (TPC and TFC) and AA. Therefore, polar extract was better than non-polar extract. The nutritional composition of GBR also provided an update for food composition database