Fortification of rice: technologies and nutrients

Apparent amylose content positively influences the quality of extruded fortified rice kernels

The present research studies the impact of apparent amylose content (AAC) on the quality of fortified rice kernels (FRK), a health food designed to combat iron deficiency anemia by fortifying with iron, folic acid, and vitamin B12. Five FRK formulations with varying AAC (0.46-23.89 %) were prepared, and AAC influence on the extruder-system parameter and physicochemical, cooking, and textural properties of FRK was investigated. The torque, die-pressure, length, redness, and cooking time increased with an increase in AAC and were in the range of 12.55-22.81 Nm, 58.31-88.96 bar, 4.58-5.09 mm, 0.35-1.15, and 6.1-11.2 min, respectively. The other parameters, such as the breadth, whiteness index, and cooking loss decreased with an increase in AAC. Except for cohesiveness, all other textural properties of cooked FRK increased with an increase in AAC. These correlations of the FRK properties with AAC were confirmed through multivariate analysis. SEM, XRD, FTIR, and rheology supported the observed AAC trends in FRK properties. SEM showed a reduction in pores and cracks with an increase in AAC. The XRD and FTIR showed an increase in crystallinity with an increase in AAC due to better gelatinization leading to rapid retrogradation. This leads to better physical, cooking, and textural properties of FRK.

Enhancing micronutrient absorption through simultaneous fortification and phytic acid degradation

Phytic acid (PA), an endogenous antinutrient in cereals and legumes, hinders mineral absorption by forming less bioavailable, stable PA-mineral complexes. For individual micronutrients, the PA-to-mineral molar ratio below the critical level ensures better bioavailability and is achieved by adding minerals or removing PA from cereals and pulses. Although several PA reduction and fortification strategies are available, the inability to completely eradicate or degrade PA using available techniques always subdues fortification's impact by hindering fortified micronutrient absorption. The bioavailability of micronutrients could be increased through simultaneous PA degradation and fortification. Following primary PA reduction of the raw material, the fortification step should also incorporate additional essential control stages to further PA inactivation, improving micronutrient absorption. In this review, the chemistry of PA interaction with metal ions, associated controlling parameters, and its impact on PA reduction during fortification is also evaluated, and further suggestions were made for the fortification's success.

Integrated surveillance strategy to support the prevention of neural tube defects through food fortification with folic acid: the experience of Costa Rica

PURPOSE

(1) To describe how Costa Rica implemented an integrated surveillance strategy of folate deficiency, neural tube defects (NTDs) prevalence, NTDs-associated infant mortality rate (NTDs-IMR), and folic acid food fortification (FAFF), to support with evidence NTDs prevention policies; (2) to disseminate updated data from monitoring programs.

METHODS

We performed a cross-sectional analysis, using the databases of national surveillance systems for NTDs outcomes to compare NTDs-prevalence and NTDs-IMR observed in the pre-fortification (1987-1998) and post-fortification (2010-2020) periods. In addition, using data from FAFF monitoring program (2010-2020), means of folic acid concentration (mg/kg) and folic acid daily intake (μg/day) were calculated for each fortified food (corn and wheat flour, rice and milk), as well as its contribution to folic acid estimated average requirement (EAR).

RESULTS

After FAFF Costa Rica showed a decrease of 84% in folic acid deficiency in women of childbearing age, as well as a 53% decrease in the prevalence of NTDs, falling from 11.82/10,000 to 5.52/10,000 livebirths. In addition, there was a 76% reduction in the NTDs-IMR from 77.01/100,000 to 18.66/100,000 livebirths. Between 2010 and 2020, all fortified foods provided an average contribution of 119% of the EAR of folic acid in the population.

CONCLUSION

To reduce NTD risk, an integrated surveillance strategy is essential not only to base prevention strategies on evidence, but also to demonstrate their impact and improve interventions over time. The experience in Costa Rica provides evidence that this type of surveillance is feasible to be implemented in developing countries.

Ferric Pyrophosphate Forms Soluble Iron Coordination Complexes with Zinc Compounds and Solubilizing Agents in Extruded Rice and Predicts Increased Iron Solubility and Bioavailability in Young Women

BACKGROUND

Co-extrusion of ferric pyrophosphate (FePP) with solubilizers, citric acid/trisodium citrate (CA/TSC), or ethylenediaminetetraacetic acid (EDTA) sharply increases iron absorption. Whether this can protect against the inhibition of iron absorption by phytic acid (PA) is unclear. Sodium pyrophosphate (NaPP) may be a new enhancer of iron absorption from FePP.

OBJECTIVES

Our objectives were to 1) investigate the ligand coordination of iron, zinc, and solubilizers in extruded rice and test associations with iron solubility and absorption, 2) assess whether co-extrusion of FePP + CA/TSC rice can protect against inhibition of iron absorption by PA; 3) determine the effect of zinc oxide (ZnO) compared with zinc sulfate (ZnSO4), and 4) quantify iron absorption from FePP + NaPP rice.

METHODS

We produced labeled 57FePP rice cofortified with ZnSO4 and EDTA, CA/TSC or NaPP, and FePP + EDTA rice with ZnO. We used electron paramagnetic resonance (EPR) to characterize iron-ligand complexes. We measured in vitro iron solubility and fractional iron absorption (FIA) in young women (n = 21, age: 22 ± 2 y, BMI: 21.3 ± 1.5 kg/m2 geometric mean plasma ferritin, 28.5 μg/L) compared with ferrous sulfate (58FeSO4). FIA was compared by linear mixed-effect model analysis.

RESULTS

The addition of zinc and solubilizers created new iron coordination complexes of Fe(III) species with a weak ligand field at a high-spin state that correlated with solubility (r2 = 0.50, P = 0.02) and absorption (r2 = 0.72, P = 0.02). Phytic acid reduced FIA from FePP + CA/TSC rice by 50% (P < 0.001), to the same extent as FeSO4. FIA from FePP + EDTA + ZnO and FePP + EDTA + ZnSO4 rice did not significantly differ. Mean FIAs from FePP + EDTA + ZnSO4, FePP + CA/TSC + ZnSO4, and FePP + NaPP + ZnSO4 rice were 9% to 11% and did not significantly differ from each other or from FeSO4.

CONCLUSION

Rice extrusion of FePP with solubilizers resulted in bioavailable iron coordination complexes. In the case of FePP + CA/TSC, PA exerted similar inhibition of FIA as with FeSO4. FePP + NaPP could be a further viable solubilizing agent for rice fortification. This study was registered at clinicaltrials.gov as NCT03703739.

Essential nutrient element profiles in rice types: a risk-benefit assessment including inorganic arsenic

Rice is consumed by nearly half of the global population and a significant source of energy and nutrients. However, rice consumption can also be a significant pathway of inorganic arsenic (iAs) exposure, thus requiring a risk-benefit assessment. This study assessed nutrient element (NE) densities in fifty-five rice types (white, brown and wild rice) marketed in the UK. Densities of essential NE were used to rank rice types in meeting daily NE targets under different consumption scenarios through a newly developed optimisation approach. Using iAs data from these rice types, we assessed the margin of exposure (MOE) for low (the UK) and high (Bangladesh) rice intake scenarios. Our results showed that brown and wild rice are significantly higher in many NE and significantly contribute to dietary reference value (DRV). Our modelling showed that switching to brown or wild rice could increase the intake of several essential nutrients by up to eight times that of white rice. Using rice consumption data for mid-to-high-consumption countries, we estimate that brown rice could provide 100 % adult DRV for Fe, Mg, Cr, P and Mo, and substantial contributions for Zn, Se and K. Our results show that the amount of rice primarily determines risk from iAs consumed rather than the type of rice. Therefore, switching from white to brown or wild rice could be beneficial, provided iAs concentration in rice is within the recommended limits.

Development of rice analogues fortified with iron, folic acid and Vitamin A

Fortified rice analogues were developed utilising the broken-rice fortified with selected micronutrients like iron, folic acid and Vitamin A. The purpose of this study was to investigate the feasibility of fortifying rice analogues with micronutrients and retention after extrusion and cooking. Cold extruder operated at 55 rpm screw speed and 1.5 kg/h feed rate was used for the study. The composite flour prepared using broken-rice flour, sodium alginate (1%), water (30%) and micronutrient mix was extruded through rice shaped die at barrel temperature of 60 °C. The level of fortifying nutrient ready mix (FNRM) was statistically optimised based on retention of nutrients after extrusion and cooking. The retention results for iron was observed to be 73.3 to 91.3 per cent after cooking whereas folic acid and Vitamin A being sensitive to processing and culinary operations were 44.2 to 60.4 and 10.1 to 12.4 per cent, respectively. Statistical optimisation resulted 150 per cent of FNRM could supply nutrient levels nearing the standards with the desirability of 0.835. The production cost was calculated as Rs.53.50 per kg whereas, increase in the cost of raw rice mixed with fortified analogues @ 1:50 ratio was about Rs.1.00 per kg with benefit-cost ratio of 1.22:1.

Development of rice analogues using by-products of rice and dhal mills

Development process of rice analogues by utilising the broken rice (BRF) and broken pigeonpea dhal (BPDF) flours together with water and sodium alginate as binding agent through extrusion was carried out. Two variable viz., BPDF (20, 30 and 40%) and moisture content (25, 30 and 35%) were controlled in the study to produce rice analogue resembling the raw rice. The optimum combination of flour mixture established for 30% BPDF and 30% water content with highest desirability of 0.855. The optimum combination had highest crude protein, carbohydrate and ash contents of 12.70, 71.72 and 0.99%, respectively. The colour values L*, a* and b* were found to be 68.30, 4.62 and 25.91, respectively. The pasting temperature and peak viscosity were 78.68 °C and 23,173.3 cP. The physico-chemical and pasting properties can be modified by altering the different constituents for specific quality requirements.

Rice: a potential vehicle for micronutrient fortification

The choices of consumer towards food have been changed. Consumer prefers to eat food which is not only safe but also nutritious. Now a day, they like to eat the food which promote their health and help in minimizing nutrition related health hazards. Rice is a staple food in many countries, but most emerging issue is that rice is deficit in minerals. Rice ranks second among cereals in dietary uses around the world. Rice is deficit in iron (Fe) zinc (Zn) and these are important micronutrients for infants, men and women. Fortification of rice with iron and zinc would help to minimize nutrient deficient disorders among humans. Present study is aimed to introduce nutrients rich rice for consumers and also to encourage food-fortification organizations for diverting their focus on rice fortification. In south Asian countries, micronutrient deficiency especially Fe and Zn deficiency is very common. The rice because of its use as a staple food can be utilized as a carrier medium for transporting micronutrients from plants sources to human beings. Hence, rice fortification with microminerals can prove as a miracle for the virtual eradication of nutrition related diseases in humans.

Higher Extrusion Temperature Induces Greater Formation of Less Digestible Type V and Retrograded Starch in Iron-Fortified Rice Grains But Does Not Affect Iron Bioavailability: Stable Isotope Studies in Young Women

BACKGROUND

Hot extrusion is widely used to produce iron-fortified rice, but heating may increase resistant starch and thereby decrease iron bioavailability. Cold-extruded iron-fortified rice may have higher bioavailability but has higher iron losses during cooking. Thus, warm extrusion could have nutritional benefits, but this has not been tested. Whether the addition of citric acid (CA) and trisodium citrate (TSC) counteracts any detrimental effect of high-extrusion temperature on iron bioavailability is unclear.

OBJECTIVES

Our aim was to assess the effects of varying processing temperatures on the starch microstructure of extruded iron-fortified rice and resulting iron solubility and iron bioavailability.

METHODS

We produced extruded iron-fortified rice grains at cold, warm, and hot temperatures (40°C, 70°C, and 90°C), with and without CA/TSC at a molar ratio of iron to CA/TSC of 1:0.3:5.5. We characterized starch microstructure using small- and wide-angle X-ray scattering and differential scanning calorimetry, assessed color over 6 mo, and measured in vitro iron solubility. In standardized rice and vegetable test meals consumed by young women (n = 22; mean age: 23 y; geometric mean plasma ferritin: 29.3 μg/L), we measured iron absorption from the fortified rice grains intrinsically labeled with 57ferric pyrophosphate (57FePP), compared with ferrous sulfate (58FeSO4) solution added extrinsically to the meals.

RESULTS

Warm and hot extrusion altered starch morphology from native type A to type V and increased retrograded starch. However, extrusion temperature did not significantly affect iron solubility or iron bioavailability. The geometric mean fractional iron absorption of iron from fortified rice extruded with CA/TSC (8.2%; 95% CI: 7.9%, 11.0%) was more than twice that from extruded rice without CA/TSC (3.0%; 95% CI: 2.7%, 3.4%; P < 0.001).

CONCLUSIONS

Higher extrusion temperatures did not affect iron bioavailability from extruded rice in young women, but co-extrusion of CA/TSC with FePP sharply increased iron absorption independently from extrusion temperature. This trial is registered at www.clinicaltrials.gov as NCT03703726.

Rice as a vehicle for micronutrient fortification: a systematic review of micronutrient retention, organoleptic properties, and consumer acceptability

CONTEXT

Previous reviews have focused on evaluating the efficacy and effectiveness of rice fortification, despite the need to also understand the outcomes of micronutrient retention, organoleptic properties, and acceptability to inform nutrition programs.

OBJECTIVE

This systematic review aims to consolidate existing evidence on micronutrient retention, organoleptic properties, and acceptability of fortified rice.

DATA SOURCES

Eligible articles were identified from 22 electronic databases and personal referrals and reviews.

STUDY SELECTION

Studies on rice fortified via extrusion or coating technologies were included in the review if they reported outcomes in at least 1 of 3 domains: micronutrient retention, organoleptic or physicochemical properties, and acceptability (evaluated by sensory tests and consumer surveys). Any years of publication and study populations were considered for inclusion. A total of 15 391 articles were screened, yielding 49 for inclusion.

DATA EXTRACTION

Study results were summarized descriptively through discussions by intervention conditions, study population, measurement methods, and key findings. The included studies were independently reviewed by 2 of the 3 authors, and all 3 authors reached consensus on the quality and major findings from the included articles.

RESULTS

Extrusion and coating fortification technologies were found to be comparable across studies that assessed retention, organoleptic properties, and acceptability. Cooking fortified rice in excess water increased micronutrient loss for both technologies. Fortified kernels containing ferric pyrophosphate, zinc oxide, or zinc sulfate showed the most positive results for all outcomes reviewed, while retention rates of vitamin A in multiple-micronutrient-fortified rice were variable.

CONCLUSIONS

The current practice of fortifying rice with ferric pyrophosphate provides high micronutrient stability and results in rice with organoleptic properties and consumer acceptance levels comparable to those of unfortified milled rice, although it presents challenges regarding the effect of vitamin A-fortified rice on vitamin A status.

Biological Properties of Vitamins of the B-Complex, Part 1: Vitamins B1, B2, B3, and B5

This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5. These B-complex vitamins must be taken from diet, with the exception of vitamin B3, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B3, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Thiamine fortification strategies in low- and middle-income settings: a review

Thiamine (vitamin B1 ) is an essential micronutrient in energy metabolism and cognitive and neurological health. Thiamine deficiency disorders (TDDs) have a range of clinical presentations that result in various morbidities and can be fatal if not promptly recognized and treated, especially in infants. To intervene, thiamine intakes by breastfeeding mothers and others at risk of thiamine deficiency should be increased to ensure adequate thiamine intake. Although thiamine fortification programs have a long history in high-income countries, there are few mandatory fortification programs to address TDDs in low- and middle-income countries (LMICs), particularly in the regions of greatest concern, South and Southeast Asia. This review highlights essential aspects for consideration in the development of a mandatory fortification program in LMICs, including an overview of the data required to model fortification dosing schemes, available thiamine fortificants, and potential fortification vehicles, as well as identifies current knowledge gaps.

Effect of high pressure impregnation on micronutrient transfer in rice

Rice, consumed by most people across the world, serves as a great mode for carrying nutrients. The processed, starch-rich white rice is mostly devoid of nutrients. High-pressure processing (HPP) is a technology known to produce cold gelatinizing effects in starch. This work shows the application of HPP in fortification of two types of white rice through high pressure gelatinization. The rice grains were impregnated with vitamin B₁, calcium, and zinc. HPP treatment was carried out at the temperatures of 50 °C and 70 °C for up to 20 min. The samples were analysed for thiamine using the fluorometric method and minerals using ICP-MS. Results showed that the transfer of nutrients increases with treatment temperature and time, producing high level of nutrient uptake. HPP-fortified rice also showed stability after storage of two months. The moderate-temperature HPP has a great potential to be used as a method to produce a ready-to-eat variety of rice.

Enhancing health benefits of milled rice: current status and future perspectives

Milled rice is an essential part of the regular diet for approximately half of the world's population. Its remarkable commercial value and consumer acceptance are mostly due to its promising cooking qualities, appealing sensory properties, and longer shelf life. However, the significant loss of the nutrient-rich bran layer during milling makes it less nutritious than the whole grain. Thus, enhancing the nutritive value of milled rice is vital in improving the health and wellbeing of rice consumers, particularly for those residing in the low-economic zones where rice is the primary source of calories and nutrition. This article provides a critical review on multiple frontiers of recent interventions, such as (1) infusing the genetic diversity to enrich amylose and resistant starch to reduce glycaemic index, (2) enhancing the minerals and vitamins through complementary fortification and biofortification as short and long-term interventions, and (3) developing transgenic solutions to improve the nutrient levels of milled rice. Additionally, the review highlights the benefits of functional ingredients of milled rice to human health and the potential of enhancing them in rice to address the triple burden of malnutrition. The potential merit of milled rice concerning food safety is also reviewed in this article.

Improved rice cooking approach to maximise arsenic removal while preserving nutrient elements

Inorganic arsenic (iAs) is a group 1 carcinogen, and consumption of rice can be a significant pathway of iAs exposure in the food chain. Although there are regulations in place to control iAs for marketed rice in some countries, additional measures are explored to remove arsenic from rice. Due to the surface-bound and soluble nature of iAs, previous studies have shown that it can be removed to a significant extent using different cooking methods. Towards this goal we modified and tested the absorption method in combination with four home-friendly cooking treatments (UA = unwashed and absorbed, WA = washed and absorbed, PSA = pre-soaked and absorbed, and PBA = parboiled and absorbed) using both brown and white rice (3 types each). The nutrient elements were measured using ICP-MS and arsenic speciation was carried out using LC-ICP-MS. Overall, our results show that PBA was the optimum approach assessed, removing 54% and 73% of inorganic arsenic (iAs) for brown and white rice respectively, raising the margin of exposure (MOE) by 3.7 for white rice and 2.2 times for brown rice, thus allowing the consumption of rice more safely for infants, children and adults. Other cooking treatments were effective in reducing the iAs concentration from white rice only. Here we also report changes in selected nutrient elements (P, K, Mg, Zn and Mn) which are relatively abundant in rice. In general, the treatments retained more nutrients in brown rice than white rice. No significant loss of Zn was observed from both rice types and the loss of other nutrients was similar or less than in comparison to reported losses from rice cooked in excess water in the literature. We conclude that PBA is a promising technique and further research is needed by including different regional rice types and water quality levels.

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.

The Unfinished Agenda for Food Fortification in Low- and Middle-Income Countries: Quantifying Progress, Gaps and Potential Opportunities

Large-scale food fortification (LSFF) is a cost-effective intervention that is widely implemented, but there is scope to further increase its potential. To identify gaps and opportunities, we first accessed the Global Fortification Data Exchange (GFDx) to identify countries that could benefit from new fortification programs. Second, we aggregated Fortification Assessment Coverage Toolkit (FACT) survey data from 16 countries to ascertain LSFF coverage and gaps therein. Third, we extended our narrative review to assess current innovations. We identified 84 countries as good candidates for new LSFF programs. FACT data revealed that the potential of oil/ghee and salt fortification is not being met due mainly to low coverage of adequately fortified foods (quality). Wheat, rice and maize flour fortification have similar quality issues combined with lower coverage of the fortifiable food at population-level (<50%). A four-pronged strategy is needed to meet the unfinished agenda: first, establish new LSFF programs where warranted; second, systems innovations informed by implementation research to address coverage and quality gaps; third, advocacy to form new partnerships and resources, particularly with the private sector; and finally, exploration of new fortificants and vehicles (e.g. bouillon cubes; salt fortified with multiple nutrients) and other innovations that can address existing challenges.

Micronutrient-fortified rice can be a significant source of dietary bioavailable iron in schoolchildren from rural Ghana

Iron deficiency and anemia are prominent contributors to the preventable disease burden worldwide. A substantial proportion of people with inadequate dietary iron rely on rice as a staple food, but fortification efforts are limited by low iron bioavailability. Furthermore, using high iron fortification dosages may not always be prudent in tropical regions. To identify alternative fortification formulations with enhanced absorption, we screened different iron compounds for their suitability as rice fortificants, measured in vitro gastric solubility, and assessed dietary iron bioavailability using stable isotopic labels in rural Ghanaian children. Isotopic incorporation in red blood cells indicates that in the two age groups of children investigated (4 to 6 and 7 to 10 years), formulations provided 36 and 51% of the median daily requirement in absorbed iron, respectively. We describe approaches to enhancing iron bioavailability from fortified rice, which can substantially contribute to the prevention of iron deficiency in rice-eating populations.

Large-Scale Food Fortification and Biofortification in Low- and Middle-Income Countries: A Review of Programs, Trends, Challenges, and Evidence Gaps

BACKGROUND

Food fortification and biofortification are well-established strategies to address micronutrient deficiencies in vulnerable populations. However, the effectiveness of fortification programs is not only determined by the biological efficacy of the fortified foods but also by effective and sustainable implementation, which requires continual monitoring, quality assurance and control, and corrective measures to ensure high compliance.

OBJECTIVE

To provide an overview of efficacy, effectiveness, economics of food fortification and biofortification, and status of and challenges faced by large-scale food fortification programs in low- and middle-income countries (LMIC).

METHODS

A literature review of PubMed publications in English from 2000 to 2017, as well as gray literature, targeting nongovernmental organizations whose work focuses on this topic, complemented by national reports and a "snowball" process of citation searching. The article describes remaining technical challenges, barriers, and evidence gap and prioritizes recommendations and next steps to further accelerate progress and potential of impact.

RESULTS

The review identifies and highlights essential components of successful programs. It also points out issues that determine poor program performance, including lack of adequate monitoring and enforcement and poor compliance with standards by industry.

CONCLUSIONS

In the last 17 years, large-scale food fortification initiatives have been reaching increasingly larger segments of populations in LMIC. Large-scale food fortification and biofortification should be part of other nutrition-specific and nutrition-sensitive efforts to prevent and control micronutrient deficiencies. There are remaining technical and food system challenges, especially in relation to improving coverage and quality of delivery and measuring progress of national programs.

Pathway Editing Targets for Thiamine Biofortification in Rice Grains

Thiamine deficiency is common in populations consuming polished rice as a major source of carbohydrates. Thiamine is required to synthesize thiamine pyrophosphate (TPP), an essential cofactor of enzymes of central metabolism. Its biosynthesis pathway has been partially elucidated and the effect of overexpression of a few genes such as thi1 and thiC, on thiamine accumulation in rice has been reported. Based on current knowledge, this review focuses on the potential of gene editing in metabolic engineering of thiamine biosynthesis pathway to improve thiamine in rice grains. Candidate genes, suitable for modification of the structural part to evolve more efficient versions of enzymes in the pathway, are discussed. For example, adjacent cysteine residues may be introduced in the catalytic domain of thi4 to improve the turn over activity of thiamine thiazole synthase 2. Motif specific editing to modify promoter regulatory regions of genes is discussed to modulate gene expression. Editing cis acting regulatory elements in promoter region can shift the expression of transporters and thiamine binding proteins to endosperm. This can enhance dietary availability of thiamine from rice grains. Differential transcriptomics on rice varieties with contrasting grain thiamine and functional genomic studies will identify more strategic targets for editing in future. Developing functionally enhanced foods by biofortification is a sustainable approach to make diets wholesome.

Tailoring rice flour structure by rubbery milling for improved gluten-free baked goods

Ever-growing demand for gluten-free products calls for the development of novel food processing techniques to widen the range of existing baked goods.

Cold Extrusion but Not Coating Affects Iron Bioavailability from Fortified Rice in Young Women and Is Associated with Modifications in Starch Microstructure and Mineral Retention during Cooking

Background: Rice can be fortified with the use of hot or cold extrusion or coating, but the nutritional qualities of the resulting rice grains have never been directly compared.Objective: Using fortified rice produced by coating or hot or cold extrusion, we compared 1) iron and zinc absorption with the use of stable isotopes, 2) iron and zinc retention during cooking, and 3) starch microstructure.Methods: We conducted 2 studies in young women: in study 1 [n = 19; mean ± SD age: 26.2 ± 3.4 y; body mass index (BMI; in kg/m²): 21.3 ± 1.6], we compared the fractional iron absorption (FAFe) from rice meals containing isotopically labeled ferric prophosphate (⁵⁷FePP), zinc oxide (ZnO), citric acid, and micronutrients fortified through hot extrusion (HER1) with rice meals fortified through cold extrusion containing ⁵⁷FePP, ZnO, citric acid, and micronutrients (CER); in study 2 (n = 22; age: 24 ± 4 y; BMI: 21.2 ± 1.3), we compared FAFe and fractional zinc absorption (FAZn) from rice meals fortified through hot extrusion (HER2) compared with rice meals fortified through coating containing ⁵⁷FePP, ZnO, a citric acid and trisodium cirate mixture (CA/TSC), and micronutrients (COR) relative to rice meals extrinsically fortified with ferrous sulfate (reference). Rice types HER1 and CER contained citric acid, whereas types HER2 and COR contained CA/TSC. We assessed retention during standardized cooking experiments and characterized the rice starch microstructure.Results: FAFe (95% CI) was greater from CER [2.2% (1.4%, 3.4%)] than from HER1 [1.2% (0.7%, 2.0%)] (P = 0.036). There was no difference in FAFe between HER2 [5.1% (3.7%, 7.1%)] and COR [4.0% (2.9%, 5.4%)] (P = 0.14), but FAFe from COR was lower than that from the reference meal [6.6% (4.9%, 9.0%)] (P = 0.003), and the geometric mean FAZn (95% CI) did not differ between HER2 [9.5% (7.9%, 11.6%)] and COR [9.6% (8.7%, 10.7%)] (P = 0.92). Cooking in a rice-to-water ratio of 1:2 resulted in iron and zinc retentions >80%, and cooking in excess water did not affect iron retention from hot-extruded rice but caused iron losses of 25% from CER and COR. Distinct variations in starch microstructure were found in CER and HER1.Conclusions: Iron absorption was 64% higher from CER than from hot-extruded rice, with no difference between COR compared with hot-extruded rice. Lower extrusion temperatures may generate a more readily digestible starch structure, allowing for greater iron release in vivo but lower mineral retention during cooking. This trial was registered at clinicaltrials.gov as NCT02176759.

Public and Private Sector Dynamics in Scaling Up Rice Fortification: The Colombian Experience and its Lessons

BACKGROUND

Fortification of cereal grains with at least iron or folic acid is legislated in 85 countries worldwide. Relative to wheat and maize flour, rice fortification is relatively new and provides an opportunity to deliver essential micronutrients to populations that consume rice as a dietary staple.

OBJECTIVE

To describe miller and public sector experiences and perspectives on rice fortification with micronutrients in Colombia and offer recommendations for policy makers.

METHODS

Interviews with Colombian rice millers, research and development personnel, and public sector leaders; desk review of key documents.

RESULTS

In Colombia, rice fortified with micronutrients is market driven and a few very large rice millers, currently representing about 35% of the market, have voluntarily fortified rice since 2002. The technology used (spraying) is unique to Colombia and to date there is no independent verification of nutrient retention after washing and cooking rice fortified through this technology. Millers are unwilling to switch to more proven methods, such as extrusion or coating, which will incur higher capital investment and recurring costs. Despite interest from multiple stakeholders between 2002 and 2011, mandatory rice fortification is not part of the Colombian government policy as of July 2015.

CONCLUSION

Rice fortified with micronutrients through spraying technology has achieved moderate coverage in Colombia, but the technology is unproven, its effectiveness unknown, and public health impact likely limited. For rice fortification to be an effective nutrition intervention to improve micronutrient status, policy makers should explore standards to guide industry and improvements to regulatory capacity.

Cofortification of ferric pyrophosphate and citric acid/trisodium citrate into extruded rice grains doubles iron bioavailability through in situ generation of soluble ferric pyrophosphate citrate complexes

BACKGROUND

Iron fortification of rice is a promising strategy for improving iron nutrition. However, it is technically challenging because rice is consumed as intact grains, and ferric pyrophosphate (FePP), which is usually used for rice fortification, has low bioavailability.

OBJECTIVE

We investigated whether the addition of a citric acid/trisodium citrate (CA/TSC) mixture before extrusion increases iron absorption in humans from FePP-fortified extruded rice grains.

DESIGN

We conducted an iron absorption study in iron-sufficient young women (n = 20), in which each participant consumed 4 different meals (4 mg Fe/meal): 1) extruded FePP-fortified rice (No CA/TSC); 2) extruded FePP-fortified rice with CA/TSC added before extrusion (CA/TSC extruded); 3) extruded FePP-fortified rice with CA/TSC solution added after cooking and before consumption (CA/TSC solution); and 4) nonextruded rice fortified with a FeSO4 solution added after cooking and before consumption (reference). Iron absorption was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration. In in vitro experiments, we assessed the soluble and dialyzable iron from rice meals in which CA/TSC was added at different preparation stages and from meals with different iron:CA:TSC ratios.

RESULTS

Fractional iron absorption was significantly higher from CA/TSC-extruded meals (3.2%) than from No CA/TSC (1.7%) and CA/TSC solution (1.7%; all P < 0.05) and was not different from the FeSO4 reference meal (3.4%). In vitro solubility and dialyzability were higher in CA/TSC-extruded rice than in rice with No CA/TSC and CA/TSC solution, and solubility increased with higher amounts of added CA and TSC in extruded rice.

CONCLUSIONS

Iron bioavailability nearly doubled when CA/TSC was extruded with FePP into fortified rice, resulting in iron bioavailability comparable to that of FeSO4 We attribute this effect to an in situ generation of soluble FePP citrate moieties during extrusion and/or cooking because of the close physical proximity of FePP and CA/TSC in the extruded rice matrix. This trial was registered at clinicaltrials.gov as NCT02176759.

Soft matter food physics--the physics of food and cooking

This review discusses the (soft matter) physics of food. Although food is generally not considered as a typical model system for fundamental (soft matter) physics, a number of basic principles can be found in the interplay between the basic components of foods, water, oil/fat, proteins and carbohydrates. The review starts with the introduction and behavior of food-relevant molecules and discusses food-relevant properties and applications from their fundamental (multiscale) behavior. Typical food aspects from 'hard matter systems', such as chocolates or crystalline fats, to 'soft matter' in emulsions, dough, pasta and meat are covered and can be explained on a molecular basis. An important conclusion is the point that the macroscopic properties and the perception are defined by the molecular interplay on all length and time scales.

Considerations for rice fortification in public health: conclusions of a technical consultation

Fortification of staple foods and commonly used condiments with vitamins and minerals has been considered one of the most cost-effective interventions to prevent and control micronutrient deficiencies. Because of its wide local consumption, acceptability, reach, and quantum of consumption, rice (Oryza sativa) far exceeds the requirements of a staple food vehicle that can be considered for fortification purposes at a population-level intervention. The World Health Organization (WHO) has the mandate to develop evidence-informed guidelines for the fortification of staple foods as a public health intervention, including rice fortification with micronutrients. The WHO, in collaboration with the Global Alliance for Improved Nutrition (GAIN), convened a consultation on "Technical Considerations for Rice Fortification in Public Health" in Geneva, Switzerland on October 9-10, 2012 to provide technical inputs to the guideline development process, particularly with reference to feasibility and implementability. The industrial and regulatory technical considerations in rice fortification, as well as the considerations for implementing it as a public health strategy and assuring equitable access and universal coverage, were reviewed in this consultation. This paper summarizes the discussions and priority research areas for the forthcoming years.

An overview of global rice production, supply, trade, and consumption

Rice is the staple food for over half the world's population. Approximately 480 million metric tons of milled rice is produced annually. China and India alone account for ∼50% of the rice grown and consumed. Rice provides up to 50% of the dietary caloric supply for millions living in poverty in Asia and is, therefore, critical for food security. It is becoming an important food staple in both Latin America and Africa. Record increases in rice production have been observed since the start of the Green Revolution. However, rice remains one of the most protected food commodities in world trade. Rice is a poor source of vitamins and minerals, and losses occur during the milling process. Populations that subsist on rice are at high risk of vitamin and mineral deficiency. Improved technologies to fortify rice have the potential to address these deficiencies and their associated adverse health effects. With the rice industry consolidating in many countries, there are opportunities to fortify a significant share of rice for distribution or for use in government safety net programs that target those most in need, especially women and children. Multisectoral approaches are needed for the promotion and implementation of rice fortification in countries.