Bioavailability of iron from novel hydrogen reduced iron powders: Studies in Caco-2 cells and rat model.

The bioavailability of iron from elemental iron powders, including hydrogen reduced iron powder (HRIP), is influenced by particle size and surface area. In the present study, we investigated the solubility, bioaccessibility, and bioavailability of iron from novel HRIPs (particle size ≤25 and 38 µm generated at low [LT] and high [HT] temperature), with porous morphology and high surface area, in intestinal Caco-2 cells and in rat models. The acceptability of fortified wheat flour was tested in human volunteers. The iron solubility and ferritin induction in Caco-2 cells were significantly higher from wheat flour fortified with HRIPs compared to electrolytic iron powder (EIP, ≤45 µm size) either in the absence or presence of ascorbic acid. Nevertheless, ferritin induction in Caco-2 cells was significantly higher with FeSO4 compared to HRIP or EIP. The relative biological value of HRIPs was significantly higher (≤38HT) or similar compared to EIP in rats. However, serum ferritin was significantly higher in rats fed HRIPs than EIP. Further, wheat flour fortified with HRIP was found to be acceptable for consumption. These findings demonstrate higher iron bioavailability from novel HRIPs compared to the reference EIP (≤45 µm) and merits further studies on toxicity and efficacy. PRACTICAL APPLICATION: The use of elemental iron powders for food fortification to alleviate iron deficiency is limited due to its poor bioavailability. The novel hydrogen-reduced elemental iron powders used in this study had higher bioaccessibility and bioavailability compared to reference EIP (≤45 µm) in in vitro and in vivo models, respectively. Further, there were no sensory differences between roti prepared with fortified or unfortified wheat flour. These results suggest that the novel hydrogen reduced elemental iron powders used in the present study are suitable for wheat flour fortification.

Retention, stability, iron bioavailability and sensory evaluation of extruded rice fortified with iron, folic acid and vitamin B12.

Fortification of rice with micronutrients using extrusion technology is considered a sustainable strategy to prevent nutritional deficiencies in general population. The objective of the present study is to assess the retention, stability and iron bioavailability from indigenously developed triple fortified rice (iron, folic acid and vitamin B12 ) during rinsing and different cooking methods. Further, we also assessed the acceptability of fortified rice in adult human volunteers. The retention of iron during rinsing with excess water was ≥90%, whereas folic acid and vitamin B12 levels were reduced by ~25% during rinsing. Watertight cooking of rice (in electric cooker or on flame) had no additional effect on the nutrient levels as compared with rinsed rice, implying their stability during cooking. However, cooking with excess water followed by decanting led to loss of 45% iron and ≥70% folic acid and vitamin B12 . The dialyzable iron and ferritin synthesis in Caco-2 cells was significantly (P < .01) higher from fortified rice compared with unfortified rice. In addition, inclusion of ascorbic acid significantly (P < .01) increased the iron bioavailability from the fortified rice. Triangle tests in adult human subjects revealed that there are no significant sensory differences among fortified and unfortified rice. Further, fortified rice consumption appears to bridge the gaps in dietary iron intake deficits in children and women of reproductive age. These results suggest that the iron-, folic acid- and vitamin B12 -fortified rice has higher retention and stability of fortified nutrients and is acceptable for consumption in adult human volunteers.

High dietary micronutrient inadequacy in peri-urban school children from a district in South India: Potential for staple food fortification and nutrient supplementation.

Multiple micronutrient deficiencies (MNDs) co-exist, often because of poor intakes and adversely impact health. Habitual diets were assessed in 300 school children (6-17 years old) recruited from two government schools by simple random sampling. Probability of adequacy (PA) for 11 micronutrients and mean probability of adequacy (MPA) was calculated. Haemoglobin, plasma ferritin, folic acid, vitamin B12 and C-reactive protein were estimated. Descriptive statistics and regression analysis were used to estimate magnitude and factors associated with MNDs. The contribution of fortified foods and/or supplements in addressing inadequacies and excessive intakes was modelled. The PA ranged from 0.04 for folate to 0.70 for zinc, and the MPA was 0.27. Prevalence of anaemia (53%), iron deficiency (57%; ID), iron deficiency anaemia (38%; IDA), folate deficiency (24%) and B12 deficiency (43%) was high. Dietary inadequacy of iron, zinc and a low MPA was associated with anaemia and IDA. Inclusion of double fortified salt (DFS), fortified rice (FR) or iron folic acid (IFA) supplements individually in habitual diet reduced probability of iron inadequacy significantly from 82% to ≤13%. Inclusion of DFS and FR simultaneously led to disappearance of iron inadequacy, but risk of excessive intake increased to 16%. Inclusion of DFS, FR and IFA together increased risk of excess iron intake to 40%. Nevertheless, intakes of folate and B12 remained inadequate even with FR and/or IFA. These results indicate a high risk of dietary MNDs in children and suggest need for more systematic intake measurements in representative sample and adjustment of iron dosages to avoid excessive intakes.

Dietary fat composition, food matrix and relative polarity modulate the micellarization and intestinal uptake of carotenoids from vegetables and fruits.

Dietary fat increases carotenoid bioavailability by facilitating their transfer to the aqueous micellar fraction during digestion. However, the specific effect of both quantity and type of dietary fat required for optimal carotenoid absorption remained unexplored. In the present study, the effect of amount and type of vegetable oils on carotenoid micellarization from carrot, spinach, drumstick leaves and papaya using in vitro digestion/Caco-2 cell model have been assessed. Although, dietary fat (0.5-10% w/w) significantly increased the micellarization of carotenoids from all the test foods, the extent of increase was determined by the food matrix (papaya > drumstick = spinach > carrot) and polarity of carotenoids (lutein > ß-carotene = α-carotene > lycopene). Among the dietary fats tested the carotenoid micellarization was twofold to threefold higher with dietary fat rich in unsaturated fatty acids (olive oil = soybean oil = sunflower oil) compared to saturated fatty acids (peanut oil = palm oil > coconut oil). Intestinal cell uptake of lutein exceeded that of ß-carotene from micellar fraction of spinach leaves digested with various oils. However, cellular uptake of ß-carotene is depended on the carotenoid content in micellar fraction rather than the type of fat used. Together these results suggest that food matrix, polarity of carotenoids and type of dietary fat determines the extent of carotenoid micellarization from vegetables and fruits.